Astronomy behind the scenes: great successes and colossal blunders

The most recent gathering of Astronomy on Tap Seattle promised to take us inside the way science is really done, and delivered with tales of unexpected successes and a colossal fail that left a team of cosmologists with cosmic egg on their faces.

Leah Fulmer

Leah Fulmer, a second year graduate student in astronomy at the University of Washington, gave a talk titled “Falling with Style: How Astronomy’s Most Intriguing Discoveries Happen by Accident.” Fulmer noted that astronomers have lots of choices when it comes to their research. They can select which part of the sky to examine, what to look at, how long to look, how often to look, and in which wavelengths of light to look, just to name a few. There’s lots of potential there.

“Every time we look at the universe in a new way we discover new phenomena that we never even expected to see,” she said. Fulmer shared three historical examples of such scientific serendipity.

The first was the detection of the cosmic microwave background (CMB) back in the 1960s. At the time it was theorized that 400,000 years after the Big Bang the CMB would have left its energy throughout the universe as a result of the event. Arno Penzias and Robert Wilson had access to a big radio telescope and were working on doing some radio astronomy. The problem was that they couldn’t tweak out some pervasive and persistent noise from their observations. Meanwhile down the road some theorists at Princeton were trying to figure out how to detect evidence of the CMB. Penzias and Wilson had already done it!

“By accident they took this telescope that NASA had built for satellite communication, they stuck it out there, and they found literally the origins of the universe,” Fulmer said. “This changed our understanding of astronomy and physics as we know it and it was a really, really big deal, just by looking at something in a new wavelength.”

More recently the operators of the Hubble Space Telescope decided to pick out an empty, black part of the sky and have the scope stare at it for 100 hours. Many scientists thought this was a bit daft.

The Hubble Deep Field. Image credit: Robert Williams and
the Hubble Deep Field Team (STScI) and NASA/ESA.

“They found what’s now known as the Hubble Deep Field,” Fulmer said. “They found an incredible plethora of galaxies that they never expected to see.” It revolutionized our understanding of the number of galaxies in the universe and added greatly to the types, shapes, and sizes of galaxies that we know about.

The Kepler Space Telescope found thousands of exoplanets and collected data on so many things that scientists couldn’t possibly look at all of them. They enlisted citizen scientists through Zooniverse to help examine objects.

Participants looked at the data and among their findings is an oddly behaving star for which its light curves defy explanation. We now know of it as “Tabby’s Star,” after astronomer Tabetha Boyajian, who wrote the paper about the discovery.

“To this day we don’t actually know what this star is,” Fulmer said. There have been lots of ideas about the odd light curves, from a random pack of asteroids that might be irregularly blocking light, some sort of cosmic catastrophe that kicked up debris, and even giant space structures built by an unknown civilization.

“It’s very precarious for an astronomer to suggest that this might be aliens,” Fulmer laughed, noting that the media would have a field day with that sort of thing.

The potential for discovering strange new things in the universe is about to increase. The Large Synoptic Survey Telescope is scheduled to go online in a few years, and when it does it will collect petabytes of data, doing a complete sweep of the sky every few nights for a decade.

Fulmer said a big part of her job in the project will be to help “develop an algorithm that is going to be able to systematically identify the things that we’ve never seen before.” That’s a tall order, combing all of that data for things we know about, things that have been theorized, and those that come out of the blue.

“We don’t what surprises we might find,” Fulmer said, “but that’s what makes it so exciting.”

Oops

Samantha Gilbert, a first-year graduate student in astronomy at the UW, told a story about a colossal and embarrassing failure. Her talk was titled, “Leaving the Competition in the Dust: A CMB Case Study.”

“The story I want to tell you tonight has everything: It has science. It has drama. It has egos. It has really esoteric vector math,” Gilbert said to laughter. “It encapsulates some of the things that are really wrong with how some people do science today.”

The story also involves the cosmic microwave background. Cosmologists are trying to figure out what happened between the Big Bang and the formation of the CMB 400,000 years later. A leading theory is that there was a period of inflation in the moments after the Big Bang during which the universe expanded rapidly. If that happened, it would have created gravitational waves, and those waves would have left behind a pattern in the CMB that we could recognize, called “B-mode polarization.”

A map of the cosmic microwave background. Image credit:
NASA/WMAP Science Team

“B-mode polarization is an extraordinarily difficult thing to detect,” Gilbert said, “but proving it exists, proving that inflation really happened by detecting the traces of inflationary gravitational waves” would be Nobel Prize-worthy.

That’s where the intrigue starts. One group striving for this discovery had an experiment called BICEP (Background Imaging of Cosmic Extragalactic Polarization), which was followed by BICEP2, which had more sensitive detectors than the first version and more of them. They found what they were looking for. In fact, the signal of B-mode polarization was even stronger than anticipated. The team declared the discovery during a 2014 news conference at Harvard, issued a video, broke out the bubbly, and in general whipped up lots of hoopla about the discovery.

In the following months some 250 papers were published in response to BICEP2. One of them was from BICEP’s main competitor, the Planck Experiment, and their point was that BICEP’s discovery was bunk and that what they detected was not B-mode polarization, but cosmic dust.

“The fact that BICEP2 had so confidently announced a result that was so quickly disproven had a rippling effect throughout the community,” Gilbert said. “Scientists were horrified because they thought, ‘now the public is going to discredit us, they’re not going to trust us.’ Journalists were also horrified because they felt they had a role in spreading disinformation.”

They were also seeing an ugly side of the scientific community.

The need for speed

How did this happen? BICEP principal investigator Brian Keating wrote a book about their process, titled Losing the Nobel Prize (W.W. Norton & Company, 2018). Gilbert summarized their decision-making.

She said BICEP2 only looked at one wavelength of light so they could get the results as quickly as possible. They knew about the possibility of cosmic dust, but didn’t have the tools to distinguish between dust and B-mode polarization. The Planck folks were thought to have the data, and BICEP asked them to share. They declined.

This led BICEP to jump to the conclusion that Planck also had evidence of B-mode polarization and were aiming to scoop them on the discovery and dash their dreams of a Nobel Prize. So they hurried to make the announcement. This might have worked out OK, if they’d been right, but the BICEP group made one other glaring error.

“They actually hadn’t put their paper through peer review,” Gilbert noted, generating groans among the science-savvy audience at Astronomy on Tap.

“That is a no-no,” she understated. “That is a bad thing to do because peer review is what makes science credible in the first place. It’s a really important check against the dissemination of junk science. You really need other scientists to independently assess your results.”

Gilbert said the bad decisions were all motivated by fear.

“Overly competitive environments are part and parcel of an individualistic conception of science and an individualistic conception of science says that the most important thing is to get a result before your competition,” she said. “When that’s the environment that you’re working in you tend to make decisions based on fear.”

“I would argue that the reason that BICEP2 made these decisions based on fear is that they were operating in such a toxically competitive environment that it became dysfunctional,” Gilbert said. “Whether you think competition is really good for science, really bad, or somewhere in between, I think that this case study shows us that it’s really worth thinking about the ways that we systemically and interpersonally encourage competition, and how that might jeopardize our ways of knowing.”

Gilbert said there’s hope for the future. The hunt for B-mode polarization continues, and BICEP and Planck are teaming up going forward, combining their resources and know-how in the work.

“Competition might be the most efficient way to A result, but collaboration is probably the most efficient way to a RELIABLE result,” she said.

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

More info:

Watch both talks on YouTube

Mapping the Moon

When we went on a road trip to a new place when I was a kid my dad would pick up a map from the nearest gas station. There were no gas stations on the way to the Moon, but the first astronauts to land there had a map anyway, thanks to the work of Harlan “Buzz” Reese and colleagues. His son, Tom Reese, talked about his father’s work at the most recent meeting of the Seattle Astronomical Society.

“What I’m honored to share tonight are images mainly from our dad’s collection, which for more than 50 years was pretty much just stuffed in boxes and cardboard tubes, but we now think of them as artifacts,” Tom Reese said. His father, who passed away in 2013, worked for many years at the Aeronautical Chart and Information Center (ACIC) in St. Louis. It was an office of the Air Force and was considered the premier mapping organization in the country. The elder Reese was a civilian who worked on the project creating charts of the Moon for NASA.

“They worked with the photographs from any source they could get, the best pictures that were available,” Reese said. That included images made by ground-based telescopes and lunar orbiters, and later photos shot by astronauts during Apollo missions. There was no image-editing software in the 1960s, but the folks at ACIC did have a cut-and-paste operation; they literally pieced together many of their charts by making copies of photographs, cutting them out, and building maps of larger areas as mosaics of many images. Some of them were huge, room-sized. They’d sometimes build these maps on the entire floor of a large room and walk around in stocking feet so as not to damage them too much. The charts include handwritten notes and tell-tale identification of the people who made them.

This photo of the Apollo 11 landing site was made by Apollo
10 and includes a handwritten overlay by Harlan Reese.
Photo: Tom Reese.

“My dad’s smeared fingerprints and careful mapping marks are also a down-to-Earth tribute to the other 400,000 human beings whose efforts made the journey possible,” Reese said.

Reese, an independent journalist, photographer, author, artist, and teacher whose work as a newspaper and magazine photojournalist was nominated for Pulitzer Prizes during his career at The Seattle Times, spoke of a sense of awe and wonder when making a photograph of the Moon.

“I think it was with the same sense of wonder that my dad saved all these things that were actually scraps of his work,” Reese said, “but I also think he thought of these as a gift to be shared.”

Part of that wish came true this year, when several of the charts were included in the Destination Moon exhibit that wrapped up earlier this month at the Museum of Flight. Reese said he hopes the entire collection can some day wind up in a place where it can continue to tell a part of the story of the Apollo missions.

Tom Reese spoke about his father's
Moon mapping at the Sept. 18, 2019
meeting of the Seattle Astronomical
Society. Photo: Greg Scheiderer

It’s amazing to think that the lunar orbiters that preceded Apollo were shooting photos using film, processing that film in space and then sending the images to Earth via radio. Today’s digital cameras on spacecraft capture far greater resolution. For the cartographers who mapped the Moon there was a good deal of art to go with the science.

“On the early maps of the Earth you can see where they would come to the limit of the known world and simply mark down ‘terra incognita’ or ‘beyond this point there be dragons,’” Reese said. “In the early mapping of the Moon precision was key, of course. But the audacity to fire three men packed into a rattling tin can to an unexplored world also required calculating on the unforeseen.” The mappers analyzed all of the data they had to give accurate representation of the sizes of and distances between lunar features so that the maps would be useful guides.

You can see many of the images Reese shared during his presentation on his website.

War in space

If there’s a war in space it won’t involve huge fleets of ships in a shoot-‘em-up accompanied by classical music, as battle is often depicted in science fiction movies.

“Our war in space won’t be particularly a Star Wars version,” according to Linda Dawson, senior lecturer emeritus in physics and space sciences at the University of Washington Tacoma and author of the recent War in Space: The Science and Technology Behind Our Next Theater of Conflict (Springer Praxis Books, 2018). Dawson recently gave a talk about the book at the Museum of Flight.

Linda Dawson, author of War in
Space, spoke Sept. 14, 2019 at the
Museum of Flight. Photo: Greg
Scheiderer.

“Spacecraft with weapons in space are still pretty far in the future,” Dawson said. “We’re talking decades.”

Such a conflict would likely destroy every spacecraft in orbit, according to Dawson.

“That kind of a battle would end up disastrous for everyone involved,” she said. “The war would be over in a matter of minutes if that happened just outside of Earth orbit, and it would affect us on Earth for decades.”

That’s not necessarily what is preventing it from happening.

“Space is a very harsh theater of war,” Dawson said, listing the lack of air, extreme temperatures, radiation, and space junk as just the start of the problems such a war would face.

“Access [to space] is expensive and technologically challenging,” Dawson said. “It’s not like we would choose to go to outer space to engage in a war. It’s just that we have spacecraft up there that we all depend on, and so it is an area that is intriguing to countries that don’t agree with each other.”

The likely nature of war in space

War in space would be more subtle than a bunch of big explosions. A variety of weapons, including Earth-to-space, space-to-Earth, and space-to-space varieties are possible. Lasers, missiles, and various “kill vehicles” or “jammers” could be employed to foul up orbiting assets. Space debris itself could be a weapon. Take a look at this video from NASA:

Video Credit: NASA Orbital Debris Program Office at JSC

Earth is at the center of the graphic, and each of the dots represent spacecraft, whether working or not. There’s a lot of junk out there. The Kessler syndrome is a scenario proposed in 70s by NASA scientist Donald Kessler; it posits that if there’s a dense enough amount of debris in space, then one collision or explosion could create a chain reaction of other collisions or explosions.

“Pretty soon all you have is debris out there and you can’t get through it,” Dawson said. That would make it extremely difficult to operate existing satellites or launch new ones.

We sometimes don’t realize how much we depend on space systems. Wrecking all of those satellites would mess up a lot of things, from our GPS navigation systems to television signals, data exchange, air traffic control, communication systems, and weather forecasting. It would be a total pain.

Though a number of different entities are tracking space debris, it continues to get more challenging. Space X plans to launch 12,000 cube sats to create broadband service; these smaller objects are harder to track. There are unanswered questions about who owns space debris and who can or should clean it up.

“Major spacefaring nations have all been increasingly aggressive with military and surveillance operations in space,” Dawson added.

Preventing war in space

Dawson said the notion of preventing war in space is simple on its surface. It’s the same as preventing war on Earth. You use diplomacy, establish rules of conduct, and operate with openness and cooperation. She said we need more detail than is included in the 1967 Outer Space Treaty, a United Nations effort signed by more than 100 nations that set ground rules for peaceful exploration of space, and we need to figure out if and how existing international law applies to space. It’s all easier said than done.

“The international part of it is the difficult part,” Dawson said. The US has recognized its vulnerabilities in space and is working to protect its own assets, but other countries are doing their own thing.

“I try to be hopeful, but I think the international part of it is the biggest challenge,” Dawson said.

###

Also by Linda Dawson:

Hubble's latest pic of Saturn is a pretty good one

The notion of a picture being worth a thousand words can often be an understatement. Witness the newest, just-released photo of Saturn captured by the Hubble Space Telescope.

The NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 observed Saturn on 20 June 2019 as the planet made its closest approach to Earth this year, at approximately 1.36 billion kilometers (845 million miles) away. (Photo: NASA, ESA, A. Simon (Goddard Space Flight Center), and M.H. Wong (University of California, Berkeley))

This image is the second in a yearly series of snapshots taken as part of the Outer Planets Atmospheres Legacy (OPAL) project, according to news releases from the European Space Agency and the Space Telescope Science Institute. OPAL is helping scientists to understand the atmospheric dynamics and evolution of our Solar System’s gas giant planets. In Saturn’s case, astronomers will be able to track shifting weather patterns and other changes to identify trends.

Celestial Pig Pens and new tricks for old scopes

It takes a lot of detective work to figure out the nature of a type Ia supernova. Celestial Pig Pens and new tricks from old telescopes are contributing to the effort. That’s what we learned at the most recent meeting of Astronomy on Tap Seattle.

Messy Siblings: Supernovae in Binary Systems

Dr. Melissa Graham is a project science analyst for the Large Synoptic Survey Telescope, working out of the Astronomy Department at the University of Washington. Her main research focus is supernovae. In particular, she’s doing a lot of work on type Ia supernovae, which occur in binary star systems. One of the stars involved will be a carbon-oxygen white dwarf star.

“It’s a star that wasn’t massive enough to fuse anything else inside the carbon layers,” Graham explained. Outer layers of hydrogen and helium are thrown off in a planetary nebula phase, so the carbon and oxygen are what’s left.

Melissa Graham. UW photo.

“Carbon-oxygen white dwarf stars are very compact, very dense, about the size of the Earth but they can be up to about 1.4 times the mass of the Sun,” Graham said. These stars are pretty stable as stars go, so they don’t blow up under normal circumstances.

“When we do see these kind of supernovae that are clearly the explosion of carbon-oxygen white dwarf stars we have to wonder why,” she said. It turns out there are two possible scenarios. The binary can be a pair of carbon-oxygen white dwarf stars that spiral in on each other, merge, and then explode. Or the binary can include one white dwarf and a more typical hydrogen-rich companion star.

“In this case the companion star can feed material onto this carbon-oxygen white dwarf star, might make it go over 1.4 solar masses, become unstable, and then explode,” Graham said.

Which is which?

The key to figuring out which of these scenarios actually occurred is to take a look at the area around the supernova. If the companion is a more hydrogen-rich companion star, the neighborhood can get a little messy.

“It’s sort of like a celestial Pig Pen star that leaves a lot of material lying around,” Graham said. A blast from a supernova can interact with this material and cause it to brighten. The trouble is that astronomers typically only observe type Ia supernovae for a couple of months; they fade quickly. So if this extra material is far away from the event, they might not see the interaction. The answer is patience, to look at the supernova sites for up to 2-3 years after.

Graham did exactly that, using the Hubble Space Telescope to keep an eye on the locations of 65 type Ia supernovae.

“Out of these 65, I very luckily found one” in which there was brightening much later. They checked the spectrum of the light and found hydrogen, a sure sign that the companion in this particular type Ia supernova was a Pig Pen. Graham suspects that up to five percent of such explosions involve messy sibling stars.

Graham looks forward to having the Large Synoptic Survey Telescope (LSST) come on line. She expects it will find some 10 million supernovae in a decade.

“This marks a massive increase in our ability to both find and characterize supernovae,” she said.

Old scope, new tricks

While we wait for LSST an old workhorse telescope is doing interesting work in a similar vein. Professor Eric Bellm of the UW works with the Zwicky Transient Facility (ZTF), which uses the 48-inch telescope at Palomar observatory in California. The scope is a Schmidt, completed in 1948, and for years it was the largest Schmidt telescope in the world. It’s main function at first was to use its wide-field view of the sky to create maps that helped astronomers point Palomar Mountain’s 200-inch Hale Telescope.

Eric Bellm. UW photo.

The 48-inch was used to do numerous sky surveys over the years. It discovered many asteroids, and Mike Brown used it to find the dwarf planets he used to kill Pluto. The old photographic plates gave way to modern CCDs, and Bellm became the project scientist for the Zwicky Transient Facility—named for astronomer Fritz Zwicky, a prolific discoverer of supernovae—in 2011.

They outfitted the scope with a new camera with 16 CCDs that are four inches per side. They got some big filters for it and put in a robotic arm that could change the filters without getting in the way of the camera. They started surveying in March of last year and can photograph much of the sky on any given night.

“That’s letting us look for things that are rare, things that are changing quickly, things that are unusual,” Bellm said.

Examples of what the ZTF has found include a pair of white dwarfs that are spinning rapidly around each other, with a period of just seven minutes. They can see the orbits decay because of gravitational wave radiation. It has discovered more than 100 young type 1a supernovae. And it found an asteroid with the shortest “year” of any yet discovered; its orbit is entirely within that of Venus.

It’s doing the same sort of work that the LSST will do when it comes online.

“It’s super cool that we’ve got this more than 70 year old telescope that we’re doing cutting-edge science with thanks to the advances of technology,” Bellm said.

Astronomy on Tap Seattle is organized by graduate students in astronomy at the University of Washington, and typically meets on the fourth Wednesday of each month at Peddler Brewing Company in Ballard. The next event is set for September 25.