Searching for life with giant telescopes

The Kepler Space Telescope discovered more than 2,600 exoplanets—planets orbiting stars other than our Sun. Kepler used the transit method, watching for tiny dips in the amount of light coming from a star when a planet passed in front of it. After more than nine years in space, Kepler ran out of fuel last month and NASA officially ended the telescope’s science mission. The torch has been passed to a new generation of planet hunters, and experts in the field of exoplanets say we may be less than a decade away from answering one of humanity’s biggest questions: is there life somewhere besides Earth?

Harvard physics Prof. David Charbonneau
gave a lecture at the UW Oct. 16.
Photo: Greg Scheiderer.

“We are the special generation that for the first time in human history is going to have the technological ability—if we choose—to go and answer this great question,” said David Charbonneau, professor of astronomy at Harvard University and a member of the Kepler mission team. Charbonneau gave a lecture recently at the University of Washington, part of the Frontiers of Physics series. He suggests that when we look for an inhabited planet, we don’t confine ourselves to just finding people.

“There may be other humans out there, but I’m going to advocate that we need to create and cast the broadest net possible when we go and actually make the first search for life outside the solar system,” Charbonneau said. He noted that SETI has been listening for years with no contact so far, and other planets are too far away to visit any time soon. But we are on the verge of being able to analyze the chemical content of exoplanet atmospheres, and that can tell us if there’s life on the ground. A scientist on a distant planet looking at Earth could tell there is life here by the chemicals in our atmosphere.

“Life has radically changed the content of our atmosphere,” he said, by creating oxygen and other elements. “We’re going to try to detect life through the unintentional waste products that are produced as life goes about its business.”

News reports of discoveries often note if an exoplanet is “Earth-like,” but in reality we know little about conditions on these far-away worlds. We can accurately figure an exoplanet’s size, mass, and density, but know little else about them. Two new telescopes—one in space, one on the ground—may be able to give us the data we need to know about actual conditions on these planets.

Giant Magellan Telescope

The Giant Magellan Telescope (GMT) is being built in Chile by an international consortium, and is expected to begin science operations around 2023. The GMT will be the largest optical telescope ever constructed, with seven 8.5-meter mirrors. This huge telescope will be able to gather an enormous amount of light, enough to analyze the atmospheres of exoplanets.

James Webb Space Telescope

The James Webb Space Telescope (JWST) is a NASA project scheduled to launch in 2021. JWST will have a 6.5-meter primary mirror, and the observatory will be able to observe light in the infrared, and that’s important.

“Infrared is where all the molecules we want to study show their fingerprints,” Charbonneau said, listing oxygen, water, and methane among the molecules of interest.

He said the JWST “will revolutionize essentially all major branches of astrophysics.”

Charbonneau said we need both of the new telescopes to nail down whether an exoplanet is inhabited.

“Individually, a large ground-based telescope or the James Webb Space Telescope cannot tell us if there’s life on a planet,” he said. That’s because they’re sensitive to different molecules. The GMT could spot oxygen, which usually means life. It’s not certain, though, because oxygen could be created in other ways. The JWST could find methane, carbon monoxide, and carbon dioxide, which would put that oxygen in context, determining if it’s there because of biological activity.

“The idea is together they can get the data that will allow us to conclude that there really is life,” Charbonneau said.

TESS and MEarth

While we wait for these two observatories to be completed, astronomers are not sitting idly by. NASA’s Transiting Exoplanet Survey Satellite (TESS) is continuing the work of Kepler, using the transit method to search for more exoplanets.

“Our mission is to find hundreds of nearby small planets amenable to detailed characterization,” said Charbonneau, who is a co-investigator on the mission. TESS will survey the entire sky over a period of two years. It was launched in April, began science work in August, and found its first exoplanet in September. Charbonneau said that by December they should have the data to determine if this new exoplanet has an atmosphere.

Charbonneau is the primary investigator for the MEarth Project, which is searching for habitable exoplanets around nearby stars. MEarth consists of two automated observatories, one near Tucson, Arizona and the other in Chile. Each employs eight robotic 16-inch telescopes that constantly watch M-dwarf stars for transiting exoplanets. There are several good reasons to look at these “red dwarf” stars. They’re plentiful—there are about 240 of them within 30 light years of us, compared to just 20 G-stars like the Sun. Since they’re smaller stars and not as bright, they won’t wash out an orbiting planet’s atmosphere, making the observation technically easier.

The following time-lapse video shows the MEarth-North observatory in action.

The point of both TESS and MEarth is to create a good list of things for GMT and JWST to check out once they come on line.

“The search for atmospheric biomarkers such as oxygen will be humanity’s first attempt to really answer this great question about whether or not we are alone,” Charbonneau said.

You can watch the entire lecture here:

Six things you may not know about NASA

NASA turned 60 on October 1, 2018 and last weekend the Museum of Flight hosted a talk by the agency’s chief historian, Bill Barry, as part of the anniversary celebration. Since we all know about the Moon landing, the space shuttle program, explorations of the planets, the Hubble Space Telescope, the International Space Station, and various NASA research and discoveries, Barry focused his talk on six things you may not know about NASA.

#6: NASA science data saved us from disaster

In a day and age when there’s significant distrust of science, it’s interesting to note NASA’s role in solving a difficult environmental problem. Researchers as early as the late 1950s noticed that there was a depletion of ozone in the atmosphere above the South Pole, but it was difficult to document.

NASA chief historian Bill Barry gave a talk at the Museum 

of Flight Oct. 6, 2018 celebrating the 60th anniversary 

of the creation of the agency. Photo: Greg Scheiderer

Barry explained that NASA used the Total Ozone Mapping Spectrometer (TOMS) on the Nimbus 7 weather satellite to confirm and map the hole in the ozone.

“It was pretty clear that the ozone hole was big and getting bigger,” Barry said, and that got people’s attention. Scientists postulated that the ozone depletion was caused by chemical reactions with chlorofluorocarbons (CFCs) such as refrigerants and spray-can propellants, but again it was tough to prove. Observations made from NASA’s ER-2 aircraft and DC-8 Flying Laboratory eventually confirmed that the CFCs were the culprit.

This led to an amazing act of international cooperation on an environmental issue. In the Montreal Protocol in 1987 nations agreed to phase out CFCs and other ozone depleting substances. It’s working; Barry noted that the ozone is gradually recovering.

“Demographers suggest that this action saved us at least two million cases of skin cancer,” since then, he said.

#5: NASA almost didn’t happen

At the dawn of the space age, after Sputnik, the military became keenly interested in spy satellites and possible space weaponry. US Secretary of Defense Neil McElroy created the Advanced Research Projects Agency (ARPA), which later became the Defense Advanced Research Projects Agency, with the aim of collaborating with academic, industry, and government partners on military programs involving space.

In the meantime over at the National Advisory Committee for Aeronautics (NACA) director Hugh Latimer Dryden had pushed the committee’s research agenda toward high-speed flight and space research. In January 1958 he wrote a key report suggesting that space efforts be a collaboration between the DOD, NACA, National Academy of Science, research institutions, universities, and industry. That’s pretty close to the ARPA mission, with a civilian bent.

Barry said that within about a month of the issuance of Dryden’s report, President Dwight Eisenhower went along with it, and sent Congress proposed legislation creating the National Aeronautics and Space Agency. Congress soon approved it.

In the early days of the collaboration there was still arm wrestling over control. A memo from Eisenhower directed that NASA would run all programs “except those peculiar to or primarily associated with military weapons systems or military operations.” The DOD took a broad definition of that—figuring putting people in space was military and so that was within their bailiwick.

Eisenhower intervened to clarify that the legislation made NASA a largely civilian organization.

“This key decision on Eisenhower’s part was really important,” Barry said. “NASA in some ways has become the world’s space agency, one of the most positive aspects of US international relations,” and the civilian nature of the agency is vital to that.

#4: NASA is a serial creator of new industries

There’s a common belief that Tang, Teflon, and Velcro were creations of the space program. Barry said those aren’t correct, but a lot of other stuff has NASA origins. Excimer lasers developed for ozone detection proved useful for laser surgery, for example, and the complementary metal-oxide semiconductor (CMOS) chips in your smartphone camera were originally developed to build a better camera for space probes. Oddly, those never flew, but they’ve taken off here on Earth. NASA’s annual Spinoff magazine highlights stuff that originated in the space program.

Beyond those, NASA has spun off entire industries. Weather satellites and communication satellites (now a $2 billion/year industry) came from NASA. Under COTS (Commercial Orbital Transportation Services) companies such as SpaceX and Boeing are building crewed vehicles and plan to begin testing next year.

“We hope by the end of next year to be launching US astronauts from Florida again up to the International Space Station and paying American companies to do it for us,” Barry said.

#3: NASA revolutionized the understanding of the universe

One’s first response to that is, “Well, duh!” but Barry said it’s easy to take for granted what has happened over the last 60 years.

“We don’t often think about how much things have changed since 1958 when NASA was created,” he said. Sixty years ago otherwise sane people thought there may be civilizations and canals on Mars and dinosaurs on Venus. They figured the outer solar system was just boring ice. There were nine planets; we now know that virtually every star has at least one. We had no idea the Van Allen Belts existed. Now we have a photo of the cosmic microwave background.

#2: Why did we go to the Moon?

President John F. Kennedy wasn’t actually that big on space; in early speeches after he was sworn in he kept proposing that the US and Soviet Union team up on space projects.

The Soviet Union wasn’t too keen on that. They were using the success of their space program to proclaim the superiority of their system and to recruit allies in a world that had been “decolonized” after World War II. The Soviets were winning the propaganda war. JFK wanted a way to beat them without breaking the bank.

Trailing in the game, Kennedy moved the goalposts and declared the race to the Moon.

“The Soviet Union’s success in space was a major strategic strategic problem for the United States,” Barry explained, “so investing money in going to the Moon was a way to prove that the western, capitalist model of government was, in fact, at least as good as if not better than the Soviets.”

#1: The race to the Moon was closer than you think

JFK made his speech to Congress about setting the goal of “landing a man on the Moon and returning him safely to the Earth” in May of 1961, shortly after Yuri Gagarin became the first man in space. It wasn’t until years later, with President Lyndon Johnson pushing the goal as Kennedy’s legacy, that the Soviets took notice.

“It’s really obvious by the summer of 1964 that the US was serious about going to the Moon and had the political will and the money to make it happen,” Barry said.

The Soviet response was the Zond program. They wouldn’t orbit the Moon, but would instead fling their spacecraft around it and then return to Earth.

The Soviets made five Zond launches in 1968 had a few successes. Zond 5 in September took some tortoises and other life forms along and landed back on Earth, though in the Indian Ocean rather than on land as intended. Zond 6 made the trip and landed on target in Kazakstan, but its heat shield failed. Tests weren’t going well on the N-1 rocket, the Soviet counterpart to the Saturn V that would be their way of launching people to the Moon. In December 1968 Apollo 8 and three US astronauts orbited the Moon.

“It was pretty clear they weren’t going to get their guys on the surface of the Moon before we did,” Barry said. But the Soviets didn’t give up. They sent up a Hail Mary.

The Soviets had been launching Luna spacecraft since the late 1950s, and in the space of six months they cobbled together a robotic craft that would land on the Moon, collect a few rocks, and bring them to back Earth.

A first launch attempt failed, but Luna 15 blasted off three days before Apollo 11. The Eagle got to the Moon first. Neil Armstrong and Buzz Aldrin did their Moon walk and were catching a few winks before launching to return to the command module Columbia.

“While they’re sleeping in the lunar module the Soviets fired the retro rockets on Luna 15 and landed on the surface of the Moon. It crashed,” Barry said. But he added that if it had landed successfully, the Soviets may well have been able to get their Moon sample back to Earth first.

“The race to the Moon ends July 20, 1969 after the first Moon walk actually happened,” he marveled. “It was that close.”

Waffles and big data in the universe

Waffles and big data were on the menu at the most recent gathering of Astronomy on Tap Seattle at Peddler Brewing Company in Ballard.

Fulmer at work. Photo: Astronomy on Tap Seattle

Leah Fulmer, who is working at the University of Washington on her Ph.D. in astronomical data science, gave a talk titled, “Data-Driven Astronomy in the 2020s and Beyond.” Fulmer explained that we’re in the midst of a “data tsunami” that’s been growing over the last three decades of astronomical surveys.

Back in the 1990s the Palomar Digital Sky Survey and the Two Micron All-Sky Survey each collected about a terabyte of data. That’s a trillion bytes; 10¹² bytes. Enough to fill a thousand one-gigabyte smartphones.
The 2000s brought the Sloan Digital Sky Survey (SDSS) and the Galaxy Evolution Explorer. These collected in the tens of terabytes of data. In the 2010s Pan-STARRS collected a petabyte of data; a quadrillion bytes.

In the future this astronomical growth in data collection will continue. The Large Synoptic Survey Telescope (LSST) under construction in Chile will survey the entire night sky every few nights for ten years. It will ultimately collect an astounding 500 petabytes of data—that’s 20 terabytes every single night.

“SDSS had a total data collection of 40 terabytes,” Fulmer pointed out. “We’re going to have one SDSS every two nights in the 2020s. This is a big freaking deal.”

On top of the data, Fulmer noted that the LSST will alert its network when it finds something interesting. Given the amount of data, Fulmer said there will be ten million alerts every night, or about 232 every second.

“This is overwhelming; this is a data tsunami,” she said. “With this sort of data collection astronomers cannot do our science in the way we have up until this point.”

A new way to look at data

Up until recently astronomers would apply for telescope time, make their observations, take the data home, and analyze it. That won’t work in the era of big data for a couple of reasons. First, you can’t jam that much data onto your laptop. Second, there just aren’t enough astronomers to sort through data on objects one by one. As you might guess, we need the help of computers.

“Specifically, we need the help of machine learning,” Fulmer said. This can be both “supervised” and “unsupervised” learning. Astronomers can identify objects by their light curves, and the computers can be taught what those are. That’s supervised. In unsupervised learning, the computers can go out on their own and sort various observations into categories with similar characteristics, and we can figure out what’s in each category.

Once you figure that out, a data broker like ANTARES (the Arizona-NOAO Temporal Analysis and Response to Events System, and yes, astronomers still rule at acronyms) can let the right people know about discoveries in a timely manner.

Fulmer said it’s interesting that ANTARES will never look at the sky, just at data, and that many future astronomers may never visit a telescope, just analyze the data. Different fields can learn from each other about how to process all of this information.

Fulmer finds the era of big data exciting.

“It’s not just data-driven astronomy, it’s data-driven everything,” she said.

Astronomy with your breakfast

N. Nicole Sanchez is working on her Ph.D. in astronomy at the UW, and her research interest is in spiral galaxies like our own Milky Way and how they evolve. This, naturally, led her to think of galaxies as waffles. Thus the title of her talk, “Black Holes, Gas, and Waffles.”

Spiral galaxies form into disks, she explained, and a waffle is a disk. The galaxies have a central bulge, represented on the waffle by a big pat of butter. Marshmallows, suspended by toothpicks, represent globular clusters of stars. Red and blue sprinkles represent old red stars and young blue ones. You just have to imagine the supermassive black hole at the center of the waffle. It may be massive, but it’s super small compared to the size of the waffle.

Sanchez came up with the idea for this model while teaching at the UW in the “Protostars” summer science camp for middle school girls the last couple of years. In the waffle model, syrup represents the gas in the galaxy.

“That’s what you’re making your stars out of, so there’s going to be a lot in your disk,” Sanchez said.
In fact, her faculty advisors got wind of the waffle model and said it would need A LOT of syrup, which led to the hilarious twitter thread below. Click on it to see the academic discussion.

Also! For those of you interested in the galaxy waffles: Here’s a nice example from class!
Waffle galaxy disk
Marshmellow globular clusters
Cherry bulge/bar
Red and blue sprinkles for stars
And syrup gas 
Plus a nicely labeled diagram  pic.twitter.com/vw8Pnt7gZO

— Nicole “Hella Metal” Sanchez (@the_n_nicole) August 15, 2018

Sanchez admitted that her waffle galaxy may be “a bit too simplified” as a model. But the syrup is important.

“There’s actually tons of gas around really all galaxies, in what’s called the circumgalactic medium,” Sanchez said. The gas is important to the evolution of a galaxy. It feeds the black hole and helps  form stars.

Sanchez studies galaxies by using cosmological hydrodynamic simulations.

“I put a bunch of particles in a box, turn on gravity, and let time happen,” she laughed. After running a simulation she looks for a galaxy similar to the Milky Way, and examines interactions between the galaxy’s supermassive black hole and the circumgalactic medium.

“The supermassive black hole is actually really vital to the evolution of the CGM because it’s moving all of this metal that’s being created in the hearts of stars in the disk of the galaxy and it’s propagating them out into the CGM,” Sanchez explained. Without a supermassive black hole, the circumgalactic medium would not look like what astronomers have observed.

Pass the syrup.

Exploring the solar system with Emily Lakdawalla

Emily Lakdawalla gushes with enthusiasm about the cool things to see and learn in our solar system, and for her that would be reason enough to explore those places.

“I’m just curious,” she told the Rose City Astronomers at their most recent meeting in Portland. “I like to see the new places, I like to see the planets. I think it’s awfully fun, but that’s not a good reason to make somebody else pay for it.”

Emily Lakdawalla
(Isabel Lawrence/Planetary Society)

Lakdawalla, senior editor and planetary evangelist for the Planetary Society, said the public policy reasons for exploration are to answer the questions of how we got here and whether we’re alone in the universe. We need to find those answers off-planet.

“Earth is a wonderful planet to live on!” she said. “It’s my favorite planet; it’s temperate, it’s a very comfortable place to live. It’s also a terrible place to try to answer these questions from a planetary science point of view.”

That, she says, is because Earth is dynamic. Forces like weather and volcanism and even life and evolution change things and mess up the ancient evidence about how things were before. We need to go to space to find territory in a more undisturbed state.

After the first wave of planetary exploration, with Viking, Mariner, and the like, enthusiasm and political will and funding for planetary exploration waned. Lakdawalla explained that the Planetary Society was founded in 1980 to be an advocate for finding the answers. We’re now enjoying a second wave of exploration.

“Since the end of the second millennium, we’ve had this amazing expansion of robotic space explorers all over the solar system,” Lakdawalla said. She talked about many of them, with a particular emphasis on Mars. This is squarely within her bailiwick, as she is the author of the book The Design and Engineering of Curiosity: How the Mars Rover Performs Its Job (Springer Praxis Books, 2018).

She explained how a series of Mars missions followed the water. Mars Global Surveyor made a map. Mars Odyssey detected evidence of hydrogen by analyzing neutron movement, and hydrogen could mean water. Phoenix went to look for water and found ice. Mars Express found places where there’s clay, evidence of water, in many places. Curiosity went to one of those places.

“Curiosity has found environments on Mars that are unequivocally habitable,” Lakdawalla said. “Curiosity is not capable of looking for fossil evidence of microbial life on Mars. It doesn’t have the instruments.”

While Curiosity continues its mission, Lakdawalla said we’ve pretty well exhausted this particular line of research.

“We have found that, yes, Mars could have originated life in the past, but we can’t tell you if there was life there or not,” she said. That question will be up to the next line of rovers, such as the ESA’s ExoMars and NASA’s Mars 2020.

Lakdawalla spent some time on the outer solar system, particularly the life possibilities on the jovian moons Ganymede and Europa and Saturnian moons Titan and Enceladus. She noted that on Titan the temperature is such that methane could exist on the surface in liquid, gas, or solid forms, much as water can exist on Earth. The Huygens probe found round rocks on Titan, a significant discovery for a geologist.

“We have a river, except it’s a bizarro river,” Lakdawalla said. “Those rocks are made of water ice, and the river they were tumbled in was a methane river. It’s so familiar and so completely bizarre.” She said it’s hard to say if life could exist in that strange environment. Another reason for further exploration!

Lakdawalla said she’d love to see a mission soon to either Uranus or Neptune.

“They don’t get enough respect,” she said. “I think they’re awesome worlds.” But remembering her statement that coolness alone isn’t enough of a reason for the trip, she noted that the ice worlds are at an intermediate size between the gas giants and the terrestrial planets.

“Most of the exoplanets that we have discovered in the last 30 years have been of this size,” Lakdawalla noted. “We’ve never studied up-close the ones in our own solar system except for one Voyager 2 fly-by. We don’t understand these worlds very well at all, so how are we going to understand the rest of the universe and all of these other planets orbiting all of these other stars?”

Lakdawalla concluded that it’s a great time to be in the planetary exploration business.

“We’re doing it for a reason; we’re trying to understand how we got here, whether we’re the only life in the solar system,” she said. “It’s just a wonderful field of study.”

The amazing story of New Horizons

The New Horizons spacecraft is hurtling through deep space toward its New Year’s Day encounter with the Kuiper Belt object “Ultima Thule,” a nickname which is better than the object’s official moniker of 2014 MU69. New Horizons collected amazing photos and data during a 2015 fly-by of Pluto, and I’ve just finished reading the account of that mission, Chasing New Horizons: Inside the Epic First Mission to Pluto (Picador, 2018). Penned by New Horizons principal investigator Alan Stern and astrobiologist and author David Grinspoon, Chasing New Horizons is a fabulous read that tells the tale of the nearly 25 years it took to get the mission from a back-of-the-napkin concept to a real spacecraft that delivered those amazing images of the former ninth planet.

Stern and Grinspoon visited Seattle in May in support of the book. Grinspoon called the tale of New Horizons an unlikely story.

“The effort to send a mission to Pluto,” he said, “was one that had so many twists and turns, seeming dead ends, and inescapable traps that it’s still amazing to me that it happened.”

“I think there’s a lot of genuine suspense and drama, and yet, you know how it ends!” Grinspoon added. “It really is an adventure story as well as a nerd-fest of solving technical problems and ultimately succeeding spectacularly in this amazing exploration.”

The story truly is incredible. The New Horizons team that at its biggest included 2,500 people had to battle from the beginning. The first fight was simply getting approval just to do some preliminary work on a project as audacious as sending a mission to Pluto. They had to compete over whose proposed project would be selected, to get funding, to decide what science would happen, to actually build, launch, and fly the craft, to get it to the right place at the right time, and to deliver the science that was promised. Stern said they euphemistically referred to their challenges with the resident reptiles around the Kennedy Space Center in mind.

“There were so many alligators in the water at one point that we had no idea how we could solve all of the problems that we were having,” Stern said.
Yet—spoiler alert!—they did, and they accomplished it for a fraction of the cost of the Voyager mission, for example, and in a time frame that, by NASA standards, was break-neck.

Grinspoon interviewed Stern and more than two dozen others for the book, so it is really something of an oral history of New Horizons team members’ recollections of what happened along the amazing journey.

All of the jockeying makes for interesting storytelling, but the near loss of the mission just days before it’s Pluto fly-by, and how that was solved, is an incredible tale. Many of the team were taking a quick breather before the fly-by and trying to enjoy the Independence Day holiday when contact with New Horizons was lost. The work the team did to figure out what happened, to fix the problem, and to make sure the craft’s computers were ready for the complicated maneuvers ahead, is simply remarkable. Imagine doing that work around-the-clock with the whole mission hanging in the balance. For Stern, there was the real possibility that 25 years of work could go down the drain. That’s a whole lot of egg aimed right at your face. Cool heads, smart engineers, preparation, and a little luck prevailed. The science we got out of it is amazing.

“Pluto is an exotic, sci-fi world,” Stern said. “This book is a page-turner; it is a techno-thriller.”
You don’t necessarily want the author writing his own dust-jacket blurbs, but in this case we agree! Chasing New Horizons is highly recommended.

Last month New Horizons, about 100 million miles away from Ultima Thule, was able to spot its next destination with its own cameras, something the team announced on Twitter.

Ultima Thule in view! We’ve made our first detection of our next flyby target, more than 100 million miles out from our New Year’s 2019 close-up encounter in the Kuiper Belt. LEARN MORE >> https://t.co/DHNzillUDB pic.twitter.com/Rmz0EW4RWA

— NASA New Horizons (@NASANewHorizons) August 28, 2018

If you read Chasing New Horizons you’ll have an idea of what the team has ahead between now and its fly-by on January 1.

Further reading:

• Astronomy on Tap Seattle takes a look at the first Pluto pics from New Horizons
• New Horizons reveals much, raises questions about Pluto
• Beyond Pluto with New Horizons

You can purchase Chasing New Horizons through the title link or by clicking the book cover image above. A small percentage of the fee comes to Seattle Astronomy and helps us create interesting astronomy stories. We thank you!

Apollo 11 command module amazes in St. Louis

We tend to remember where we were at the time of major historical events, like when we found out that Elvis was dead or when a gimpy Kirk Gibson hit that home run against Dennis Eckersley to win the first game of the 1988 World Series. For space geeks and for anyone over age 56 or so, the ultimate such shared experience has to be when Neil Armstrong and Buzz Aldrin set foot on the Moon. Estimates are that up to 600 million people worldwide and more than 130 million in the US alone watched the Moon landing on live television.

Your correspondent with the Apollo 11 command module Columbia
last month at the St. Louis Science Center. Photo: Greg Scheiderer

Thus, it was a thrill for me to recently stand about a foot away from an amazing piece of space exploration history, the Apollo 11 “Columbia” command module, at the St. Louis Science Center. Columbia hadn’t left the Smithsonian since doing a national tour in the early 1970s, but the historic space capsule is part of a touring exhibit called Destination Moon that will visit four cities before returning to the National Air and Space Museum as part of a new comprehensive Apollo exhibit. The tour started last year in Houston and the St. Louis stop wraps up Sept. 3, 2018. It will be on display in Pittsburgh starting later this month and then—get this!—its final stop on the tour will be the Museum of Flight in Seattle, where it will be on display beginning in March for a stay that will include the 50th anniversary date of the Moon landing. Huzzah!

The Destination Moon exhibit is great, with lots of information about how we got there, who the key players were, and why we did it. But the Columbia capsule was just completely mesmerizing, at least for me. I was a total space nut kid, kept scrapbooks of newspaper clippings of stories about the space flights, and was glued to the TV for launches and landings. Standing next to Columbia took me back to my almost-12 self. I dare say I was giddy in its presence. I spent a couple of hours in the exhibit, mostly just looking at this fabulous artifact.

There were a couple of other cool items in the exhibit. Aldrin’s helmet and gloves used on the Moon were there, as was a sample collection case in which he and Armstrong stowed their Moon rocks. They also have one injector plate from an Apollo engine, of they type around which the Museum of Flight has built its popular Apollo exhibit. Columbia’s escape hatch is on display separately from the capsule. There is a collection of gear such as first-aid items and a survival kit in case the capsule splashed down far away from its target upon return to Earth. And, oh yes, there’s a Moon rock, too.

Interestingly enough, I saw Moon rocks at both the St. Louis Science Center and Adler Planetarium in Chicago during a recent trip to the Midwest, and visitors showed little interest in either. THAT’S A HUNK OF THE MOON FOR CRYING OUT LOUD! OK, rant over. Maybe that’s not a big thing in the age of virtual reality and interactive exhibits. Alas.

Elsewhere in the St. Louis Science Center they have Mercury and Gemini capsules, too, and another current exhibit is Mission: Mars that is a lot of fun. The center is also home to the James S. McDonnell Planetarium, built in 1963 and named for the co-founder of McDonnell-Douglas, who kicked in a good chunk of change for equipment for the facility.

Membership has its privileges; I got $1 off admission to Destination Moon thanks to my membership in the Museum of Flight. Parking would have been free had I driven, but I took public transit to the center.

Destination Moon will be at the Museum of Flight from April 13–Sept. 2, 2019. Check below for a trailer video, and for more of our photos from the exhibit.

Mars is here!

It’s been a big year for Mars. The InSight lander is on the way to the Red Planet, scheduled to land November 26 on a mission to take the vital signs of Mars. There’s a big dust storm on Mars just as it reaches opposition this week, its closest approach to Earth since 2003. Oh, and organics have been found on Mars.

We may have buried the lede on that one.

July 18 image of Mars by the Hubble Space Telescope.
 (Image credit NASA, ESA, and STScI)

Dave Cuomo and Keith Krumm from the Pacific Science Center were guest speakers at the July meeting of the Seattle Astronomical Society, and discussed all things Mars.

The discovery of organics on Mars is evidence that science is not necessarily fast. The work came out of a hole the Curiosity rover drilled in a Mars rock way back in 2015. The papers outlining the discovery just came out earlier this year.

“What it found in a rock that is about three-and-a-half billion years old was organic molecules,” Cuomo said. The substance found was kerogen, which Cuomo called, “a gooey precursor to petroleum.”

Cuomo repeatedly stressed that this does not, not, not mean that there is or ever was life on Mars.

“What we have found is evidence that the building blocks for life on Mars certainly did exist three-and-a-half billion years ago,” he said. “This was the first time that we found clear evidence that this was there.”

Cuomo noted that we know a good bit about the history of the surface of Mars.

“Mars certainly was a warmer and a wetter environment that could have supported life, that life could have evolved on,” he said. “What we don’t know—and this is what InSight is going to help us find out—is how long Mars was more Earth-like.” The longer that warm, wet environment lasted, the greater the potential that life could have arisen.

InSight

Krumm noted that InSight is something of an interplanetary RN.

“It’s going to be taking Mars’ vital signs,” he said. It will use a seismometer to take Mars’s pulse, a heat flow probe to measure its temperature, and the Rotation and Interior Structure Experiment, RISE, will check its reflexes, precisely tracking the location of the lander to determine just how much Mars’ north pole wobbles as it orbits the Sun. Cuomo said a big part of the mission’s purpose is to find out if Mars has a molten core today.

“It has volcanoes, so we know at some point in the past it had a molten interior,” he said. “It had a magnetosphere—the remnants of it are frozen in the rocks—but it does not have an active magnetosphere.”

InSight will help us figure out of the core solidified, or if there’s some other reason for the loss of the magnetosphere. Krumm and Cuomo showed this video about the InSight mission.



The Pacific Science Center plans an event for watching the InSight landing on November 26. Watch this space for details!

Dust storm

The rover Opportunity is powered by solar panels, and the dust storm on Mars has blocked the Sun to an extent that Opportunity has shut down. NASA hasn’t heard from Opportunity since June 10. It’s programmed to switch back on every so often, and shut right back down if it doesn’t find power. Cuomo said that can only go on for so long.

“It’s possible it won’t wake up,” he said. If that happened, it would be a sad end to a tremendous run. Opportunity and its twin, Spirit, landed on Mars in 2004 on missions expected to last 90 days. The last contact with Spirit, stuck in the sand, was in March 2010, while Opportunity, up until last month, at least, has been running for more than 14 years.

Opposition

Mars reached opposition to Earth on the evening of July 26 in Pacific Daylight Time, and will be at its closest approach to Earth for the year on Tuesday, July 31. Those dates are different because of the geometry of the elliptical orbits of the two planets. In any case, we’re closer to Mars than at any time since the great apparition of 2003, which is good news for amateur astronomers. The bad news is that the dust storm could foil our attempts to image and observe surface features of Mars. There was word this week, however, that the storm is fading. Bright red Mars will be a good observing target for the rest of the summer and into early fall.

LSST to the rescue

We hope the Large Synoptic Survey Telescope (LSST), under construction in Chile on a timeline that would have it begin science work in 2022, works. There are a bunch of astronomers banking on it to make their lives a lot easier. A group of them—the LSST Solar System Science Collaboration—met earlier this month in Seattle, and four of them gave talks at a special edition of Astronomy on Tap Seattle at Peddler Brewing Company in Ballard.

David Trilling of Northern Arizona University noted that the LSST will have an 8.4-meter mirror and a camera the size of a small car.

“In terms of telescopes, this is a really, really, really big machine,” he understated. That car-sized camera will boast 3.2 billion pixels.

“You’d need 1,500 HDTV screens to look at a single LSST image,” Trilling said. LSST will scan the entire night sky every three to four nights for ten years.

“That’s about ten terabytes of data every night, which is a huge computational challenge,” he noted.

It’s an asteroid. It’s a comet. It’s complicated…

Michael Mommert of Lowell Observatory studies asteroids and comets. He said that sometimes it’s difficult to tell one from another. An asteroid can look like a comet if the asteroid is “active.” This could be because it collided with something else, or it is spinning rapidly, or it was warmed by its proximity to the Sun.

“If we can understand those active asteroids we can better understand the average asteroid,” Mommert said. “We can learn a lot about the mechanisms that are going on in asteroids from those active asteroids.”

Similarly comets can go dormant, with no tail, and look more like asteroids. As they often share similar properties, Mommert said comets and asteroids are on something of a continuum rather than being two distinct types of objects.

In his research Mommert is tracking about 20 active asteroids and 50 dormant comets. He figures he spends 30 nights per year using a telescope. He’ll be able to cut down that time tremendously with LSST; he’ll be able to find his targets and pull data collected by the telescope.

“LSST will improve our understanding of small body populations,” Mommert said. “Asteroids, comets, active asteroids, everything that is out there.”

Tales from the Outer Solar System

Kat Volk of the University of Arizona focuses her research on objects in the outer solar system. Pluto, Eris, and other far-out objects have been discovered by comparing photos of an area of sky and looking for something that moved. In fact, Pluto was the first object discovered in this way.
There are about 2,000 known objects in the Kuiper Belt. That’s about how many asteroids we knew of a century ago.

“Kuiper Belt science is a hundred years behind Asteroid Belt science because these things are just so much more difficult to find,” Volk said, because they’re far away, faint, and move slowly. “We had to wait until we had digital cameras and computers to process those images.”

Volk said we probably have discovered all of the 10-kilometer asteroids and most of the 1-kilometer ones. They’re easier to spot because they’re brighter, and there’s money for the hunt because of the potential threat asteroids pose to Earth.

“For comparison, the smallest ever observed Kuiper Belt object is 30 kilometers across, very roughly,” Volk said, adding that we only found that one because the Hubble Space Telescope was used to look for another target for the New Horizons mission after it passed Pluto.

“We’re pretty incomplete in terms of our object inventory in the outer solar system,” Volk said. She said LSST will change that.

“They expect 40,000 new Kuiper Belt ojects,” Volk said. “It’s going to be an entirely new era for the Kuiper Belt with a huge playground of new objects to look at.”

“I am realy excited to see what we’re going to find with LSST, and it’s going to completely revamp our idea of the outer solar system.”

A Crash Course in Asteroid Defense

Andy Rivkin of the Johns Hopkins University Applied Physics Laboratory said that even a 20-meter asteroid packs a wallop when it smashes into Earth. That was roughly the size of the Chelyabinsk meteor in 2013.

Doing the math tells us that there should be about 10 million objects of that size zipping around the solar system, but so far we’ve found only around 10 thousand of them. Back in 2005 Congress told NASA to find 90 percent of objects 140 meters or larger.

“LSST is going to be a critical piece in reaching this goal,” Rivkin said, “and we expect that by 2034 about 86 percent of hazardous asteroids will be found.”

So, what do we do when we spot one headed our way? Rivkin said that for really small ones, like Chelyabinsk, and really large ones, the best idea might be duck and cover. There’s not much to be done about something very large, and small ones don’t pose much of a threat. For those in between, a few options are viable. For one, we could try to deflect the asteroid with a nuclear bomb.

“A lot of people are uncomfortable with nuclear explosions in space, for good reason, and so there’s been a lot of interest in having something else that could work,” Rivkin said.

That something else is a kinetic impactor, which is a fancy way of saying we’ll just smash something into the asteroid to change its speed, and therefore its orbit. It’s a fine idea in theory, but we have no idea if it would actually work. Rivkin is involved in a project that will give it a try.

It’s called DART, which is for Double Asteroid Redirection Test. DART is on schedule to launch for the asteroid Didymos in June of 2021, and then crash into its satellite, nicknamed “Didymoon,” in October 2022. Astronomers will watch through ground-based telescopes and see what happens. Rivkin called it a dress rehearsal for the day we might have to do something about an incoming asteroid.

“A dress rehearsal for, needless to say, a performance we hope never to actually stage,” he said, “demonstrating that we could do this, allowing us to pin these computer simulations to something real, allowing us to better understand asteroidal properties, and giving us a lot of science as an ancillary benefit.”



Astronomy on Tap Seattle is organized by graduate students in astronomy at the University of Washington.

I looked through a telescope the other day

The weather gets to amateur astronomers from Seattle sometimes. I had several conversations at the Seattle Astronomical Society’s annual banquet back in January with attendees who, like me, fessed up to not doing much observing these days. It’s so cloudy so often that we tend to forget about the telescope, waiting patiently in the corner down by the door to the wine cellar. So it was fun on a string of clear evenings recently to get out and get some scope time.

I even announced it on Twitter.

Hey, that bright thing near the Moon is Jupiter! Look up! Clear sky in Seattle!! pic.twitter.com/ZfEByjy9t1

— Seattle Astronomy (@SeattleAstro) June 24, 2018

The views of Jupiter on that night were a little murky, though the Great Red Spot occasionally popped into sight as plain as the cyclone on your face. The next evening seeing and transparency were about as good as they get in West Seattle, and I enjoyed some of the best views of Jupiter I’ve ever had.

I also took a look at Saturn, which was at opposition June 27, but on that evening it was still awfully low in the southeast sky and thus looked pretty fuzzy. I’m looking forward to some better views of Saturn as it comes around a little earlier in the evening each day. I took a few peeks at Venus, too.
While Jupiter and Saturn are among my favorite observing targets, the big show of the summer will be put on by Mars. The Red Planet will reach opposition on July 30, and this particular apparition will be an outstanding one. Mars will be the closest it has been to Earth since 2003, which was its closest approach in 60,000 years! It was that event that pushed me to get more involved in observational astronomy. This summer we’ll have great opportunities to see surface details on Mars.

As I write this, at 1 p.m., it’s looking pretty clear outside, though some clouds are in the forecast for the early morning hours. I shouldn’t even think this, lest to jinx clear skies, but I think I’ll get out again today and see how Saturn is looking.

A cosmic perspective with Jill Tarter of SETI

Jill Tarter thinks that Craig Venter and Daniel Cohen may not have been bold enough when they declared in 2004 that the 21st Century would be the century of biology.

The SETI Institute’s Jill Tarter spoke recently at the Rose
City Astronomers in Portland, Oregon.
(Photo: Greg Scheiderer)

“I think the 21st Century is going to be the century of biology on Earth—and beyond,” Tarter declared during a talk at last month’s meeting of the Rose City Astronomers in Portland, Oregon. Tarter, the Bernard M. Oliver Chair for SETI at the SETI Institute and former director of the Center for SETI Research, thinks there are many ways we might find extraterrestrial intelligence. We might discover it through biomarkers or even artifacts in our own solar system. We could assay the atmospheres of exoplanets looking for biosignatures. We could spot alien “work product” such as structures or signs of engineering. We might even export it, traveling to the Moon, Mars, or even other star systems.

“I think life beyond Earth is a good bet in this 21st Century,” Tarter said, “and when you begin to think about that kind of thing, you really have to reorient your point of view, your perspective. You have to start talking about here and now in a different way, a much bigger point of view, a cosmic perspective.”

Tarter feels that our perspective has changed much since the advent of the space age. Photographs like the Apollo 8 Earthrise or “selfies” by Voyager and Cassini have helped make that happen. We’ve also looked far into the past in viewing distant galaxies.

In the time we’ve been involved in SETI, Tarter says there have been two gamechangers: extremeophiles and exoplanets.

Photos from Space, such as Earthrise by astronaut Willam
Anders from Apollo 8, have changed our global perspective.
(Photo: NASA)

“Extremeophiles are life as we did not know it until a just few decades ago,” she said, “thriving in places that we once thought completely hostile to life, and they are now illuminating the amazing possibilities for life on our own planet by suggesting more potentially habitable real estate within our solar system and out into the cosmos.”

Similarly, this discovery of thousands of exoplanets has given us more places to look for life.

“Today we know that there are more planets than stars in the Milky Way, and that’s a fundamental change in our perspective,” Tarter said. “When I was a student we knew of nine planets—then lost one!—and didn’t know whether planets would be plentiful around other stars.”

“There is more potentially habitable real estate out there than we ever imagined,” she added, stressing the potential. “We have no idea whether any of it is, in fact, inhabited, but that’s what this century is going to tell us.”

Tarter noted that a big assumption of SETI is that since our technology is visible from a distance, that alien technology might be as well. So we’re looking for something engineered, not a natural occurrence of astrophysics.

“Whether or not SETI succeeds with its optical, infrared, radio searches for signals is going to depend on the longevity of technologies,” Tarter explained, “because unless technologies, on average, last for a long time, there are never going to be two technologies close enough in space to detect one another and coeval in time—lined up at the same time in this ten billion year history of the Milky Way galaxy.”

Tarter said that, in 50 years of SETI, we’ve searched an amount of the cosmos that compares to a 12-ounce glass of water out of the total of Earth’s oceans, so it’s not so surprising that we haven’t yet caught a fish. She adds we’ve been limited by our technology.

“We are beginning to build tools that are commensurate with the vast size of this search, and we understand that the ocean is vast and we are still very, very motivated to go and find what might be out there,” Tarter said. The Allen Telescope Array is a big part of that; you can follow the search at setiquest. There are dozens of other instruments that may provide data to help with SETI, and more than a half-dozen on the drawing boards for the next decade or so.

“This is a hard job,” Tarter said. “This is a lot of very difficult technology to get this job done.”

“Whether or not SETI succeeds in the near term, it has another job to do,” Tarter concluded.  “Whether or not it ever finds a signal, it has another job to do. And that is holding up a mirror to all of us on this planet and showing us that in that mirror, when compared to something else out there, we are all the same. Talking about SETI, thinking about SETI, listening to talks about SETI, helps to transfer and to encourage this cosmic perspective. It helps to trivialize the differences among us.”
Tarter encouraged everyone to go home and set their descriptions on their social media profiles to “Earthling,” and to start thinking and acting from that perspective.

“SETI is a very good exercise at working globally to solve a problem,” she said, “and there are many problems that we are going to have to solve quickly in the near term, and do so as a global community.”

Celebrating three years of Astronomy on Tap Seattle

Astronomy on Tap Seattle observed its third anniversary last month, and celebrated by breaking format, with updates on talks from the past year and some new tidbits of information.

One of the fun new items was a story by Dr. James Davenport about how he helped convince NASA to use the Kepler space telescope to take a selfie of Earth.

“This is a personal story,” Davenport explained. “This is a story about an image that we asked NASA to take, and they were kind enough to take it.”

It took more than a year of cajoling, using the usual bureaucratic channels and also social media campaigns to get the shot.

Selfie from space: Earth as observed by Kepler in December.
(Image: NASA)

“We guilted them into taking this picture that we wanted for no other value than just to have this amazing image,” Davenport said. He noted that NASA has a long tradition of taking photos of the home planet, starting with the “Earthrise” photo from Apollo 8 and going through the “Pale Blue Dot” image from Voyager and the more recent pic of Earth from Cassini at Saturn.

The Kepler telescope usually points away from Earth, but sometimes NASA moves the aim to look at a different part of the sky, and that’s when Earth can move through the scope’s field of view. This happened on December 10, 2017, and that’s when Kepler got this shot. Now, Kepler usually looks a dim objects that are far away—a typical exposure is about 30 minutes. This isn’t the best setup for taking a photo of Earth from about 94 million miles.

“We expected it to look like a bright mess,” Davenport said. “We were not disappointed.”

It’s a personal story for Davenport because he was doing an entirely different thesis project for his Ph.D. program when Kepler came on line. He was so excited about the hunt for exoplanets that he ditched his other thesis and started working with Kepler.

“It represented a huge turning point in my career,” he said.

Polarimetry

Back in September Kim Bott gave a talk about how she and other astronomers are using polarimetry to try to figure out if exoplanets are habitable or inhabited. Since then she’s done some actual modeling of Venus at various phases to see if polarimetry can tell us what we need to know.
The short answer appears to be no, at least for right now. The instruments simply aren’t sensitive enough to detect the changes in light wiggle that might reveal a variety of indicators.

“It’s just a couple orders of magnitude,” Bott explained, “so something that we might be able to obtain within the next decade” as the technology improves.

Trappist 1

The planets around the star Trappist 1 have attracted a lot of interest since they were discovered beginning in 2015. There are seven planets in all orbiting this red dwarf star; they’re all roughly the size of Earth, and three of them orbit within the star’s habitable zone.

“These are planets that could be a lot like Earth, that could potentially support life,” said Dr. Rodrigo Luger, adding that this is an active area of research. Luger said it’s interesting that all seven planets are in orbital resonance.

“There’s a very distinct pattern linking the orbital periods of all seven planets,” he said. Interestingly enough, this resonance and the gravitational influence the planets have on each other makes the transit times of the planets change from orbit to orbit.

“It’s just like when you’re at the bus stop here in Seattle,” he explained. “Sometimes the bus comes early, sometimes it’s on time, sometimes it’s late. Transits are the same way.”

This gives astronomers a lot of information about the system.

“By studying the transit time variations you can actually get the mass of the planets because you know how strong their gravity is,” Luger said. “Because of the geometry of the system we can get the radius of the planets—the size when it transits the star—and by doing some clever numerology and math we can figure out their mass. If you have the radius and the mass you actually have the density, so you have an idea what these planets are made of.”

It turns out that the Trappist planets mostly appear to be of lower density than Earth and Venus. This could mean that the planets have large amounts of water or large hydrogen atmospheres.

“These planets are going to be studied a ton in the next decade to figure out if in fact they are habitable,” Luger said.

Astronomy on Tap Seattle co-founder Brett Morris noted that much future study of exoplanets was to have been done by the James Webb Space Telescope, but the recent decision to delay the launch of that instrument has been disappointing to many.

“That affected some people a lot,” Morris said. “Some of those people were me!”

When the announcement that the launch would be pushed out to 2020 was made last month, Morris and others were coming up on what was an April 6 deadline to propose observing targets for the Webb.

“We were all working really hard because this telescope is super cool and it’s going to be the one that’s going to tell us if these planets are actually habitable and what’s going on in their atmospheres,” Morris noted. “Then the rug got pulled out from under us.”

R-process is better than your process

Back in July Trevor Dorn-Wallenstein told the AoT crowd how the universe makes beer for us. Last month he explained how heavier elements are made, and how we now know that theory to be true.
Dorn-Wallenstein explained how elements are made within stars. Typically, when neutrons collide with protons, they are captured. Nature stabilizes this through a process known as beta decay; the neutron just turns into a proton. This causes the release of an electron and a neutrino, or maybe an anti-neutrino.

“The jury is still out on whether neutrinos are the same as anti-neutrinos,” Dorn-Wallenstein observed. In any case these particles just go away.

“What we’ve really done here is we’ve converted one of those neutrons into a proton, and in doing so we’ve made a whole new element,” Dorn-Wallenstein said. “We’ve gone from hydrogen to helium, though both are unstable and have oddball numbers of neutrons.”

This happens slowly—that’s why it’s called the s-process. It occurs in low-mass stars, which can make strontium, barium, and lead.

Then there’s the r-process, which is rapid. In this process neutrons get bombarded onto atomic nuclei so quickly that beta decay can’t happen, and you get ridiculously unstable nuclei. Eventually neutron capture either slows, or it becomes so unstable that beta decay happens all at once, and BAM, you’re making silver, gold, platinum, and other heavier elements.

Essentially to do this you need three big explosions. First you need two supernovae to leave behind a pair of neutron stars. Then the neutron stars need to merge. Their collision is called a kilonova.

“There’s a lot of free neutrons around, and maybe those free neutrons are created rapidly enough that the r-process occurs,” Dorn-Wallenstein said. To confirm this you’d need to see evidence of a neutron star collision, a gamma-ray burst from the event, and follow up to make sure r-process elements were actually being formed. That’s exactly what happened when LIGO detected gravitational waves from a neutron star merger back in August.

“We found evidence that r-process elements were being formed and it confirmed that neutron star mergers were the dominant sites of the r-process,” Dorn-Wallenstein concluded.

Exoplanet instruments

Back in August Lupita Tovar did a talk about LUVOIR and SAMURAI and how they will help us map exoplanets. Her latest interest is the Transiting Exoplanet Survey Satellite—TESS—which launched April 18. Its primary mission is to search for Earths and super-Earths. While Kepler looked at a relatively small swath of sky, TESS will scan about 80 percent of the sky and observe some 200,000 stars.

“You can imagine how many more things we’re going to be finding,” Tovar marveled. TESS will look at brighter stars than Kepler was able to observe, and will be a constant source of data. It will send back full-frame images every half hour or so, and about 200,000 smaller “postage stamp” images every two minutes.

“What that translates to is a whole lot of data that’s going to be coming down from this telescope,” Tovar said. “You’re going to get a lot of planets—planets everywhere!”

There could be as many as 20,000 new ones; Tovar said many will likely be gas giants, which are easier to spot.

SPAMS a lot

UW student Aislynn Wallach is involved in a project called The Search for Planets Around post-Main Sequence Stars—SPAMSS.

The question is what becomes of planets like Earth when their host stars become red giants.

“They blow up to a larger size, much like a marshmallow in a microwave,” Wallach said. After that the stars become white dwarfs. The prospects for the close-in planets aren’t good.

“Anything inside (the expanded red giant) will probably be disintegrated,” Wallach noted. “That’s what we’re trying to find—these broken up planets around stars like the Sun.”

The approach is to look at the spectra of white dwarf stars. If we spot heavier elements in those spectra, the elements will have come from ripped-up planets. If those materials were part of the star, they would sink quickly from its surface.

For her search Wallach has been using the ARCSAT (Astrophysical Research Consortium Small Aperture Telescope) at the Apache Point observatory in New Mexico. Results of her search so far: nothing.

“Nothing is still a result!” She laughs. The search continues.

The beautiful music of the universe

An interesting new approach to data is to turn it into sound. Locke Patton is doing this with the brightness of supernovae. Brighter data points are assigned higher musical pitches. The process is called sonification.

“We don’t just look at it, we listen to it,” said Patton of the data.

Sadly, his recording of a supernova sound didn’t play—a rare technical glitch at Astronomy on Tap Seattle. He sang it. Sort of! You can hear a recording here. 

The search for Earth 2.0

Astronomers have to date discovered more than 3,700 exoplanets—planets in orbit around stars other than our Sun. With each discovery, someone wants to know if the newly discovered planet is like Earth.

Elizabeth Tasker at Astronom on Tap
Seattle. Photo: Greg Scheiderer.

Elizabeth Tasker thinks that’s not a very good question. Tasker, associate professor at the Japan Aerospace Exploration Agency, Institute of Space and Aeronautical Science and author of The Planet Factory: Exoplanets and the Search for a Second Earth (Bloomsbury Sigma, 2017) gave a talk at the most recent edition of Astronomy on Tap Seattle. She said that some of the exoplanets confirmed so far have at least a little resemblance to Earth.

“Roughly one third of those are approximately Earth-sized, by which I mean their physical radius is less than twice ours,” Tasker said. News media often wish to leap from that to describing a planet as Earth-LIKE, but Tasker said we don’t have nearly enough information to make that sort of call. Our current methods of detecting an exoplanet can give us either its radius or its minimum mass, and a pretty good read of its distance from its host star.

“The problem is neither of those directly relates to what’s going on on the surface,” Tasker noted. Part of the challenge is what Tasker feels is the somewhat oversimplified notion of the “habitable zone” around a star, a band of distance in which liquid water—a key to life as we know it—could exist on a planet’s surface.

“Like all real-estate contracts, there is small print,” Tasker said. “Just because you’re inside the habitable zone doesn’t mean you’re an Earth-like planet. Indeed, of all the planets we’ve found in the habitable zone around their stars, there are five times as many planets that are very likely to be gas giants like Jupiter than have any kind of solid surface.”

Another misleading metric that has been used is something called the “Earth similarity index.” This method compared exoplanets to Earth on the basis of properties such as density, radius, escape velocity, and surface temperature.

“None of these four conditions actually measure surface conditions at all,” Tasker said, pointing out that the index didn’t take into account such features as plate tectonics, a planet’s seasons, it’s magnetic fields, greenhouse gases, or existence of water. We can’t observe any of those things about exoplanets yet. As an example of the flaws of the index, Venus came out at 0.9, pretty similar to Earth, which is at 1.0 on the zero-to-one scale. While Venus is about the size of Earth and is around the inner edge of the Sun’s habitable zone, its surface temperature could melt lead. Not very Earth-like, or habitable. It’s one of the reasons that the index is seldom used these days. So we don’t have much of a clue about conditions on any of the known exoplanets.

“Our next generation of telescopes is going to change that,” Tasker said. She noted that NASA’s James Webb Space Telescope is scheduled to launch next year, the ESA’s Ariel in 2026, and the UK’s Twinkle in the next year or so.

“All of these are aiming at looking at atmospheres, and these may be able to tell us what is going on on the surface, and may even give us the first sniff of life on another planet,” Tasker said. “Maybe then we’ll be able to talk seriously about Earth 2.0.”

Astronomy's neglected stepchild

Robert Reeves has been an astronomer for nearly 60 years. The Moon was his first love; he shot his first photograph of it in 1959, and laments that it isn’t such a popular target for amateur astronomers any more.

Astrophotographer and author Robert Reeves was the guest
speaker at the annual banquet of the Seattle Astronomical
Society on Jan. 28, 2018. Photo: Greg Scheiderer

“The Moon is not just that big ball of light pollution in the sky,” said Reeves during his keynote talk at the Seattle Astronomical Society’s annual banquet last month. “The Moon used to be a target for American technology. The Moon was a place to be explored; it was a destination.”

Reeves was interested in the Moon even before there was a space program. We were all agog during the race to land on the Moon, but when the race was won many moved on to other things.

“Back then American heroes rode a pillar of fire and dared to set foot on another world,” Reeves said. “The scientific mindset, the desire to explore the solar system was there. That was a time when America was only limited by its imagination; we could do anything we wanted to do.”

Alas, Reeves notes, politics is different now.

“America has lots its will, it’s lost the guts to go into deep space,” he said. “We’ve been rooted in low-Earth orbit for four decades.”

“Space exploration is not the same, but the Moon that we wanted to go to still beckons us,” he added.

Bringing the Moon back

Reeves’s talk was titled Earth’s Moon: Astronomy’s Neglected Stepchild. He aims to turn that around.
“I’m here to bring the Moon back,” he said. “The Moon is still a viable target; we can see it from our own back yard.”

Reeves is a prolific writer about astronomy. His first published article appeared in Astronomy magazine in 1984. Since then he’s written some 250 magazine articles and 175 newspaper columns about the topic. In fact, just days after his talk here the March 2018 issue of Astronomy arrived, including an article and photos by Reeves about hunting for exoplanets. His mug also appears, along with one of his lunar photographs, on a back-cover advertisement for Celestron.

Reeves has written five books in all, including three how-to manuals about astrophotography: Wide-Field Astrophotography: Exposing the Universe Starting With a Common Camera (1999), Introduction to Webcam Astrophotography: Imaging the Universe With the Amazing, Affordable Webcam (2006), and Introduction To Digital Astrophotography: Imaging The Universe With A Digital Camera (2012). All are from Willmann-Bell.

Reeves feels the webcam book helped launch a whole industry and trained a generation of astrophotographers. He points out that back in the 1960s you could count the number of good astrophotographers with the fingers of one hand. Now there are thousands of people turning out great images, and they all get to use superior gear.

“Amateur instruments off the shelf today just blow away what the pros used to do on the Moon, and it’s relatively easy to do this,” Reeves said. I asked Reeves if he laments the passing of film photography. He said he did, a little, noting with a laugh that he has four decades worth of photography that is obsolete! But he said the fact that he can turn out more better-quality images in less time with digital makes up for that.

Check out Reeves’s website for a image-processing tutorial, to buy prints and posters, and find lots of other lunar photography information.

Asteroid 26591 is named Robertreeves and asteroid 26592 is named Maryrenfro after his wife; Renfro is her maiden name. It is believed they are the only husband and wife with sequentially numbered asteroids named after them! Robert noted that his takes about four years to orbit the Sun, while Mary’s goes around in about 4.4 years.

“Every ten years I catch up to her,” he said, “so for eternity I’m going to be chasing Mary around the solar system.”

###

Books by Robert Reeves:

Beyond Pluto with New Horizons

Ron Hobbs has been a NASA JPL Solar System Ambassador almost since that program started just over 20 years ago. What began as an effort to recruit volunteers to help keep people informed about the Galileo mission to Jupiter soon expanded to include most other JPL missions.

“Education and public outreach is very important to NASA,” Hobbs explained. “They’re spending Americans’ money to go out and explore the universe, and they want to make sure that they get the information out to everyone who’s interested in it.”

New Horizons

There’s a lot of interest. Hobbs and I talked recently about New Horizons, which did a historic fly-by of Pluto in 2016 and is now napping while whizzing through space for a New Year’s date with the romantically named 2014 MU69. This object, discovered in 2014 using the Hubble Space Telescope specifically to find a potential place for New Horizons to visit after Pluto, is in a relatively undisturbed part of the Kuiper Belt. Observations made of MU69 suggest that it is either oblong or a binary object, perhaps a contact binary. Recent research has suggested that most early planetesimals were binaries.

“It is very likely that it is one of these primordial planetesimals,” Hobbs said. “So in some senses the exploration of MU69 may be more important than the exploration of Pluto. And that’s saying a lot.”
Hobbs shared a couple of favorite bits of information about New Horizons. For one, the spacecraft is carrying human remains.

“Clyde Tombaugh, the discoverer of Pluto, will become the first human being to have their remains interred in interstellar space,” Hobbs noted.

New Horizons Principal Investigator Alan Stern presents a
plaque to Venetia Burney Phair in December 2006,
commemorating the name “Venetia” for the New Horizons Student
Dust Counter. Phair passed away in 2009. Photo: NASA

One of the instruments aboard New Horizons is the The Venetia Burney Student Dust Counter, named after the English schoolgirl who suggested the name for Pluto way back in 1930. The instrument was built and managed by students at the University of Colorado.

“It is the first student built instrument on a major NASA probe, ever,” Hobbs said. It’s just one example about how the mission is becoming a world-wide effort. Hobbs marvels that we are all space explorers.

Scientists are searching for another possible target for New Horizons after it does its flyby of MU69. Hobbs said the craft has limited fuel, so it’s unclear how much more it can maneuver.

Listen to the podcast to learn more about New Horizons and how ordinary citizens are participating in science.

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Hobbs also recommends a recent NASA “Gravity Assist” podcast featuring New Horizons principal investigator Alan Stern.