Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

January 3, 2022

A couple of good astro tools from the NY Times

Perseid meteor shower in 2015 from
Joshua Tree National Park. (NPS/Brad Sutton)
Happy New Year from Seattle Astronomy!

The New York Times has published a useful article and a nifty tool to kick off 2022. The article is a list of the year's meteor showers, with some background on the showers, how they form, and how to watch them. It's out just in time for the Quadrantid shower, peaking right about now.

The tool is a 2022 space and astronomy calendar that covers a variety of celestial shows and scheduled mission launches during the year. It's a simple, one-click process to subscribe and add the calendar to your own. Subscribe here or save the trouble and visit our events calendar from the menu above; we've already incorporated it into our listings.

August 1, 2020

New book The Last Stargazers by Emily Levesque out this week

An interesting new book by University of Washington astronomy professor Emily Levesque is coming out this week. The Last Stargazers: The Enduring Story of Astronomy's Vanishing Explorers (Sourcebooks, 2020) will be published August 4. In The Last Stargazers Levesque shares the tales and experiences of astronomical observing. Weaving together stories from more than 100 astronomers and observatory employees, The Last Stargazers explores how modern observatories are run, shares some of the many incredible stories from the astronomy community about what it’s like to work at a telescope, and reveals the transformative developments in astronomy's immediate future.

Several events mark the release of the book, including a virtual meeting of Astronomy on Tap Seattle at 8 p.m. August 6. Watch live on either Zoom or YouTube. Levesque also will do a launch event August 3 through Elliott Bay Book Company and another through Denver's Tattered Cover bookstore August 13 in conversation with Bad Astronomy's Phil Plait

Levesque's research specialty is the evolution of dying stars. We covered a talk she did for Astronomy on Tap Seattle back in 2016. She's an engaging speaker and writer and we're looking forward to reading the book.

By the way, you can pre-order the book by clicking the image to the left or the title link above. Seattle Astronomy gets a small cut, at no cost to you, when you do that, and it helps support our work. Many thanks!

July 15, 2020

NEOWISE spotted from Alki Beach

Last night, July 14, 2020, was a pleasantly mild one on Alki Beach in West Seattle, and it turned out to be a perfect on during which to catch a glimpse of Comet C/2020 F3, to which we will henceforth refer as NEOWISE.

I wandered down to the beach with my binoculars and my DSLR camera a little past 9pm to stake out a good spot for comet searching. It turned out to be way earlier than was necessary. Scanning often with the binoculars, I didn't finally spot the comet until right around 10:30pm. Once spotted it was still pretty faint, but at the same time easy to find again.

Comet NEOWISE by Greg Scheiderer
Shot of Comet NEOWISE from Alki Beach on July 14, 2020.
Photo: Greg Scheiderer
I'm not often accused of being an astrophotographer, though I sometimes like to get a snapshot just to prove I was there. In this case, as the weather forecast looked favorable for the evening I must have read a dozen articles during the day about how to photograph a comet. This gave me about two dozen techniques from which to choose, but enough ballpark information that I thought I would be able to get a decent shot. The one directly to the left is my favorite from the evening.

An unexpected challenge of getting this shot is that NEOWISE was so faint that I couldn't really frame the photos through the camera viewfinder or with the back screen. I ended up taking images, and if the comet wasn't there, I'd just move the camera a bit, take another one, and another, until I found a composition that I liked.

Comet NEOWISE by Greg Scheiderer
NEOWISE from Alki
Photo: Greg Scheiderer
It worked out pretty OK!

For the photog types out there, I used a Nikon D3100 with the 55-200mm zoom kit lens. I was at ISO 1600. The upper photo was a 10 second exposure at f4.2 with the lens at 66mm. The one to the left was at 55mm, eight seconds at f4.

I found several shots that were zoomed in a little closer to be a tad blurry. It was pretty hard to set focus!

Comet hunting was fun and I was a bit surprised that there were so many folks out who were aware of this event, many of them back for a second evening at Alki. My binoculars gave lots of folks a better look, so that was enjoyable.

NEOWISE was the most impressive comet I've seen. Back in early 2007 Comet McNaught was spectacular, but mostly a Southern Hemisphere event. I caught it briefly one evening as it moved between the clouds right around sunset. Hale Bopp was great in 1996-97, but I don't remember being able to see so much of it's tail, at least when I saw it. I was in college when Comet West was here and still haven't figured out how I missed that entirely.

NEOWISE will be around for a few more weeks. This NASA site has good info for spotting it.

April 19, 2020

Helicopters on Titan

Jason Barnes hesitates to call the upcoming Dragonfly mission to Saturn’s moon Titan a helicopter.

“Dragonfly is a nuclear quadcopter lander,” said Barnes while admitting that it sounds at least a little bit crazy. Barnes, a professor of physics at the University of Idaho and deputy principal investigator for Dragonfly, made a presentation at an online astrobiology colloquium at the University of Washington this week. Dragonfly will search for signs of life, biosignatures, on the distant moon.

Why Titan?

The online colloquium was attended by more than 100
people. This slide compared places with an atmosphere and 
solid surfaces.
Barnes noted there are several good reasons for a mission to Titan. It’s one of just four places in our solar system with both a solid surface and a significant atmosphere—the others being Earth, Venus, and Mars. Titan has important similarities to Earth, especially the pressure and composition of its atmosphere.

“The combination of a thick atmosphere and low gravity make Titan the easiest place to fly in the entire solar system,” Barnes said. He noted that we’ve focused on finding water in the search for life, and there’s lots of water on several of the icy moons of the outer solar system.

“The real reason that Titan among these is the most compelling target, I think, is not the water, it’s the carbon,” Barnes said.

He explained that Titan’s atmosphere is made up of mostly nitrogen, but that it contains about 5 percent methane. Ultraviolet light from the Sun breaks methane molecules down into smaller ones that then recombine into larger complex carbon chains that eventually rain down to the surface of Titan.

“They provide the carbon from which you can potentially build up prebiotic and possibly biotic molecules to start the process of how we think life may have formed on Earth four billion years ago,” Barnes said.

Where to look

Observations from the Cassini mission and its Huygens probe have given us several places to look. There are large dunes of organic material on Titan separated by open areas of the moon’s water-ice crust. The impact crater Selk may have once contained a huge water sea that remained liquid for tens of thousands of years—a great place for life to form. Hopscotching to these various places is how the concept of the mission came about.

“We came upon this solution because we needed mobility to be able to get to both the water ice and organic sediments,” Barnes said. “We call it a rotorcraft relocatable lander because we spend almost all of our time on the ground.”

Indeed, Dragonfly will fly to a new spot only about once every Earth month, using time on the surface of Titan to conduct a battery of experiments. One of the mission’s main goals is finding chemical biosignatures. Barnes figures it will be the first mission with such a specific goal since the Viking landings on Mars. He added that there won’t be a rush to judgement on the question of life.

“There’s no silver bullet when it comes to looking for biology,” Barnes said, adding that no single indicator will make them declare they found it. “This is going to be a long, scientific process by which we put in multiple lines of evidence to try to see if we can figure out what’s going on.”

A big spacecraft

Dragonfly will be about two or three meters tall, about three and a half meters long, and weigh about half a ton. It will carry four instruments: a camera suite with eight cameras in all, a mass spectrometer, a gamma ray/neutron spectrometer, and environmental monitoring systems including a seismometer.

The launch of Dragonfly is set for 2026, and it will take about eight and a half years for the craft to get to Titan.

“Exploration of the outer solar system is a process for the patient,” Barnes said.

###

Watch Barnes’s entire presentation:




April 13, 2020

International Dark Sky Week April 19-26

International Dark Sky Week is coming around at just the right time.

The weeklong (April 19-26) celebration of the night is supported by the International Dark-Sky Association (IDA). It is an opportunity for us all to consider the role of the night and its star-filled sky in each of our lives. This year, IDA is encouraging people around the world to come together online to celebrate the night and engage with authors, creators, scientists, and educators whose works have been vital to the movement to protect the night from light pollution.

“Right now, families around the globe find themselves spending many hours at home together,” notes Ruskin Hartley, IDA’s executive director. “It’s a perfect time to reconnect with the night sky — and International Dark-Sky Week provides a portal for that experience.”



The week includes online presentations by a couple of authors that we have featured in the past on Seattle Astronomy. Paul Bogard wrote one of our favorite books, The End of Night: Searching for Natural Darkness in an Age of Artificial Light (Little, Brown and Company, 2013). Bogard will do a reading from the book Tuesday, April 21. Tyler Nordgren, a professor of physics and an artist, will do a talk about the role of art in conversation on Monday, April 20. Nordgren has created a series of great solar system travel posters and is the author of Sun Moon Earth: The History of Solar Eclipses from Omens of Doom to Einstein and Exoplanets (Basic Books, 2016). Jeffrey Bennett, author of What Is Relativity?: An Intuitive Introduction to Einstein’s Ideas, and Why They Matter (Columbia University Press, 2014), will give a presentation called “I, Humanity” on Sunday, April 19. It is geared toward kids in grades five through seven.

There will be numerous other presentations about various astronomical topics. You can access the full schedule online, but beware that it isn’t particularly user friendly, and specific times for most of the presentations have not yet been set as of this writing.



Further reading:

April 8, 2020

Pink supermoon

I always note that I’m not really an astrophotographer, and this is readily apparent to anyone who sees my shots, but I do occasionally like to take a snap just to prove I was there. Thus, here’s my photo of the full Moon of April 7, 2020.

There are those who call this the pink Moon, even though it isn’t pink, and a supermoon, which may be an exaggeration even though the Moon is excellent. I’ve read a few sources this morning claiming that we “often” call the April full Moon the “Grass Moon” or the “Egg Moon.” This may well depend on just how you define often.

The super bit comes from the fact that this particular Moon does appear to be slightly larger in the sky–about seven percent bigger than the average full Moon. That’s because the moment of fullness came when the Moon was near perigee, its closest point to Earth during its orbit around us.

For those into photo specs, I made this with a simple Canon PowerShot A530 pointed through the eyepiece of my 8-inch Dobsonian at 50x magnification.

The Moon will be pretty close to full this evening and almost as super, so check it out if you can.

April 7, 2020

Open houses on hold at Jacobsen Observatory

Photo: Greg Scheiderer
The first of this year’s semimonthly open houses at the Theodor Jacobsen Observatory on the University of Washington’s Seattle campus was scheduled for today. Like many events, the series has been halted by our “Stay Home, Stay Healthy” response to the coronavirus pandemic.

In normal years the events are held on the first and third Tuesdays of each month from April through September, but the observatory’s website notes that the open houses “are suspended until all classes are being held in their regular classrooms and our undergraduate volunteers are back on campus.” Undergrads give talks about astronomy at the events, and volunteers from the Seattle Astronomical Society staff the observatory’s vintage 1892 telescope, which features a 6-inch Brashear objective lens on a Warner & Swasey equatorial mount.

The website notes that organizers hope to welcome students back and to resume the open house series “soon.”

Watch this space for updates.


April 2, 2020

Summer astronomy from home

Yesterday I did an interview with a writer who is working on an article for a regional travel magazine. Its editors have concluded that most folks aren’t so anxious to go anywhere right now given our situation with coronavirus and stay-at-home orders. They correctly note that astronomy is something that one can enjoy without venturing too far afield.

It’s true! The sky is everywhere. All you have to do is look up! There are lots of interesting things to see that don’t even require a telescope or binoculars. Here’s a quick look at just a few of the things headed our way this spring and summer.

Venus 

Venus is the queen of the evening hours these days and is high in the west at dusk. She’s flirting with the Pleiades, the Seven Sisters, and will be closest to this gorgeous star cluster tomorrow, April 3. The Sun will set around 7:40 p.m. Pacific time. Give it until a little after eight for the Pleiades to appear, then they and Venus will hang out together until they all set a bit after 11 o’clock. If you have binoculars or a telescope take a closer look to spot the phase of Venus. It’s a pretty thin crescent right now. The Pleiades look great through binoculars, too!

Comet ATLAS 

Discovered in December, the comet ATLAS, so-named because it was first spotted by astronomers using the Asteroid Terrestrial-impact Last Alert System in Hawaii, has some folks thinking it may become a highly visible naked-eye object, perhaps the best in 20 years. Comets can be pretty fickle, and such predictions are often the kiss of death. But it doesn’t cost anything to keep an eye out.

This article from EarthSky explains how to find ATLAS. If it’s going to be spectacular, that will happen later this month through most of May. Maybe.

Parade of planets 

Your view of Jupiter from your back yard won’t be
quite as great as the 2016 Hubble Space
Telescope photo. Credits: NASA, ESA, and
J. Nichols (University of Leicester)
Mars, Jupiter, and Saturn are keeping pretty close company in the pre-dawn sky these days. You can spot all three low in the southeast after about 4:15 a.m. when Mars rises, the last of the trio to peek above the horizon. Mars will appear to move east of the others in the coming weeks and months, but Jupiter and Saturn will stay pretty close together all summer. They reach opposition on July 14 and July 20, respectively. Mars reaches opposition on October 13, and this year’s apparition of the Red Planet will be a good one. They aren’t great naked-eye targets, but Neptune will be at opposition on September 11 and Uranus will be opposite the Sun on Halloween.

Meteor showers 

The Perseid is probably the most well-known of the annual meteor showers. Maybe that’s because it’s pretty consistent and happens in the summer when folks don’t mind being outside in the evening. This year’s peak will occur around August 11-12. The last quarter Moon will brighten the sky somewhat at that time, making some of the dimmer meteors difficult or impossible to spot. While you can catch many of the brighter meteors even from light-polluted cities, the darker the sky you have, the better the show. The Lyrid meteor shower peaks around April 22 and the Eta Aquarids May 5. EarthSky has a full rundown of the year’s meteor showers.

Keep looking up!

March 25, 2020

A look at the Perseverance mission to Mars

Astronomy events are few and far between these days as clubs cope with stay-at-home restrictions and institutional closures in response to the coronavirus pandemic. Most meetings and public star parties have been canceled for March and April while a few wait to see how events unfold.

Like some in arts and entertainment, astronomy clubs are looking for ways to take at least some of their activities online. Case in point, the Seattle Astronomical Society last week held its monthly meeting using the Zoom videoconferencing platform. Members enjoyed a presentation by SAS president John McLaren, who also is a NASA Solar System Ambassador, about the upcoming Perseverance mission to Mars.

A history of Mars exploration

McLaren gave a quick history of Mars exploration, from Mariner 4 which sent 21 photos back from Mars after a fly by in 1965 to the present work of Curiosity. He noted that Viking 1 in 1976 sent back the first photo from the surface of Mars. It was no accident that it shot its own foot.

The first Viking 1 photo from Mars. Credit: NASA
“If we can only get one picture back, this is the most important picture, because they want to see how well the landing gear performed,” McLaren explained. “If they can see how the landing gear did, it gives them an idea of how they can improve the next lander.”

Unfortunately, experiments conducted by Viking were thought to rule out the possibility of life on Mars, though McLaren noted that there’s still some discussion about whether those experiments were conducted and interpreted properly. In any event, the zeal for Mars exploration cooled somewhat until the mid-1990s, when a Mars meteor discovered on Earth was found to contain what could be fossilized bacteria. This sparked new scientific interest in the Red Planet.

We returned to the surface of Mars in 1997 with Sojourner and Pathfinder, which proved we could land and drive around a rover on Mars.

“It truly was the Pathfinder that led us to design more sophisticated vehicles,” McLaren said. Spirit and Opportunity followed in 2004 and Curiosity landed in 2012.

Same car, new features

Perseverance, known as Mars 2020 until a recently concluded naming contest, will be something of a souped-up version of Curiosity. It’s based on the same design, but they’ve re-engineered the wheels, as those on Curiosity showed heavy wear unexpectedly early in its mission. Perseverance will also carry different instruments more specialized for astrobiology and geology. It will drill core samples and leave them cached on Mars awaiting a possible future return mission. And its cameras in general are more powerful and versatile than those of Curiosity. It’s mission is different, too. While Spirit and Opportunity were sent to follow the water and Curiosity is trying to figure out if Mars could have supported microbial life, Perseverance will actually be looking for evidence of that life.

A photo by Mars Reconnaissance Orbiter of the
planned landing site for Perseverance. The
target is the smooth, purple-ish area to
 the right of what looks like a river
delta. Credit: NASA/JPL-Caltech/ASU
A big challenge for the engineers will be delivering Perseverance to its landing site, which is in a crater called Jezero on the edge of what appears to have once been a lowland sea. There’s what looks like a former river delta on the edge of Jezero crater.

“The hope is that water was here for a long time, water flowed down here building this silt, that this is the most likely location where they hope to find any signs of life,” McLaren said.

A small target

The challenge is that the landing ellipse, the target they need to hit, is ten times smaller by area than that of Curiosity and some 300 times smaller than Pathfinder’s. They’ll use a technologically enhanced version of the sky crane technique that worked for Curiosity to try to hit that target.

The window for a possible launch opens on July 17 this year and McLaren said NASA expects to land Perseverance on Mars on February 18, 2021.

You can watch a recording of McLaren’s presentation on the Seattle Astronomical Society website.

March 12, 2020

Goldendale Sky Village gives amateur astronomers dedicated observing site

Amateur astronomers in the Seattle area have been dreaming of a clear, dark place from which to observe the heavens since the clouds rolled in and light pollution obliterated much of the night sky. Those dreams are coming true at the Goldendale Sky Village just east of that south central Washington town.

It's dark at Goldendale Sky Village! This image
made at the site was created by Mark Vinup.
The Goldendale Sky Village (GSV) is owned by a limited liability company (LLC) of the same name, made up of members with interest in astronomy. The effort to establish the GSV is the end result of a search several decades in the making.

Most recently, the Seattle Astronomical Society (SAS) took a run at establishing a dark-sky observing site beginning in about 2005. Three years later, the project was tabled because the society couldn’t reconcile two desired criteria for the site: clear, dark skies and convenient proximity to Seattle. (I wrote about the end of the project for the April 2008 issue of the SAS newsletter, The Webfooted Astronomer.)

In 2016 Stephanie Anderson, a co-owner of Seattle’s Cloud Break Optics who was president of the SAS at the time, wanted to re-start the initiative and recruited SAS member Christopher Smythies, who is now the general manager of GSV, to head up the search.

Searching for the spot

“For two years I went out east of the mountains and familiarized myself with the land,” Smythies said. His focus was on two areas: Cle Elum and Goldendale. He found Cle Elum to be prohibitively expensive, and most parcels of land available for sale there were intended for housing and carried restrictions.

“Goldendale had a lot of attractive things about it,” Smythies said. “It was darker, the land was much cheaper, the rules were much looser, but it was further away.”

Smythies figures he must have looked at more than 100 properties over the course of a couple of years. By the time of the annual SAS Spring Star Party in May 2018 at Brooks Memorial State Park near Goldendale, he had a list of five of them for attendees to check out. The last of those that they visited is the one that is now Goldendale Sky Village.

“I immediately knew that was going to be it,” he said. “It was very remote, it was relatively flat, there were low horizons. It was pretty land; it wasn’t scrub land or pasture land, it was very attractive land with nice vegetation on it. And it was relatively cheap.”

“I thought it was perfect,” Smythies added. Unexpected bonuses include a line of sight to a communication tower that gives the site Internet access, and a great view of Mt. Hood to the west. There is federal land and open prairie nearby that will likely remain unoccupied, so future light intrusion isn’t a big concern.

LLC created for site

By this time the Seattle Astronomical Society had cooled to the idea of owning and operating a dark-sky site. Current president John McLaren said cost was a big concern. SAS would have had to do a major, multi-year fundraising effort or raise dues drastically to cover costs. Neither seemed likely to fly given the varying visions SAS members have for such a site. They considered trying to build a coalition with other regional astronomy clubs.

“That looked like it would be a legal headache,” McLaren noted. Running the site also would have created administrative tasks, including IRS reporting, that would have placed a burden on the club. The SAS board opted out.

“At that point, I decided to go another route to form a private group of people, an LLC, and then make it available to the SAS later on,” Smythies said. In June he put out a call for possible investors in the site.

“Within six weeks, two of which I was on vacation, we had 21 people saying ‘I’m in,’” he said. Smythies believes that a turning point for the project was when Anderson and Cloud Break Optics co-owner Matt Dahl signed on.

“She and Matt have such a good reputation for being kind of the hub of the astronomy community because of Cloud Break Optics, that once they said they wanted to be a part of it it was like a stamp of approval and everyone else piled on,” he said.

Astronomy can be hard work! Goldendale Sky Village
members clear rocks from the future telescope field, the
National Dark Sky Portal. Photo: Christopher Smythies.
Original members paid $1,000 per share in the new LLC. That entitled them to the use of their own 2,500 square-foot parcel within the village. They sold more than 100 shares and by the end of July had the cash to buy the land. The purchase became final in September 2018.

Since then they’ve made improvements to the road into the property, created parking space, and moved “a billion” rocks and boulders to create a smooth place for the village’s central telescope field, known as “The National Dark-Sky Portal.” They’re planning for improvements that include a big tent, the Red Light Lounge, for sharing refreshments and for shelter from the elements. Work this summer may include bringing electricity to the site as well.

It takes a village

Smythies says the village aspect of the GSV is vitally important.

“I wanted to put together something where people have lots, sure, but then there’s common areas right in the middle where they put their telescopes out and they observe together,” he said. This differs from some large astronomy communities where people might build a home on a two-acre plot. “Goldenndale sky village is all close together to promote the community atmosphere and the learning.”

While the GSV is a private company they intend to invite guests often. They hope to be ready by this year to host the SAS and its spring and fall star parties, and would like to build a similar relationship with the Rose City Astronomers in Portland, which is actually closer to the site. Smythies dreams of an astrophotography school and other educational efforts at the village.

The SAS hasn’t given up on creating observing sites. McLaren, who is a member of GSV, said SAS members also crave a dedicated site within 30 minutes of the city and one perhaps in the Cle Elum or Ellensburg areas, that might offer better observing conditions and still be relatively convenient. He hopes the Goldendale Sky Village model can be a good template for creating more observing sites.

“That would be awesome if it happened,” McLaren said, “and if some day astronomy clubs were able to negotiate access to all three locations that would be amazing.”

Smythies says there is room for perhaps 60 to 70 members at Goldendale Sky Village. The current price to join is $2,500 per share with a minimum of four shares. You can check out the site at an open house on March 21. Contact Smythies if you’re interested.

January 11, 2020

Seattle Astronomy turns nine; our favorite stories of the year

We’ve been at this for nine years now! The first post on Seattle Astronomy happened January 11, 2011. It’s been a fun ride! On our birthday we’re looking back on our favorite stories of the last 12 months.

Moon landing anniversary


The big story of 2019 was the 50th anniversary of Apollo 11 and the first human landing on the Moon. We had quite a lot of activity around the anniversary. The best had to be the Destination Moon exhibit at the Museum of Flight, which included the command module Columbia that carried Neil Armstrong, Buzz Aldrin, and Michael Collins to the Moon and back. We wrote about the Seattle exhibit, and were fortunate enough to have seen it in St. Louis during the summer of 2018.

We did a series of talks about the Moon landing for Tacoma Public Libraries, reviewed Dr. David Warmflash‘s fine book Moon: An Illustrated History (Sterling, 2019), made a lunar reading list, and heard an interesting talk by UW astronomy professor Toby Smith about an almost accidental discovery from Apollo 11 that gave us new insight about the formation of the Moon.

AAS visits Seattle

Every four years the American Astronomical Society meets in Seattle, and 2019 was one of those years. Our favorite session of the meeting was a talk by Yale astronomy professor Gregory Laughlin about ‘Oumuamua, the strange interstellar visitor that whizzed through our solar system in late 2018. Our article also included information from  Ka’iu Kimura, executive director of the ‘Imiloa Astronomy Center in Hilo, Hawaii, about how objects discovered by instruments on the islands are being given Hawaiian names.

We’d love to cover more such events even when they’re not held in Seattle. Your support with a subscription through Patreon can help bring that about. Please consider contributing; even a dollar a month will bring us closer to being able to support travel to events of interest to the astronomy community.

Meeting David Levy

Seattle Astronomy's Greg Scheiderer (left) visited with
comet hunter David H. Levy at the Seattle Astronomical
Society banquet Jan. 27, 2019. Photo: Greg Scheiderer.
The year started off well with a chance to chat with David Levy, author and comet discoverer who was the keynote speaker at the annual banquet of the Seattle Astronomical Society last January. Levy gave an engaging talk about his life and his love of astronomy and writing.

This year’s SAS banquet is coming up on January 25. The guest speaker will be meteorologist and astrophotographer Kerry-Ann Lecky Hepburn, who has had a number of her shots featured on Astronomy Picture of the Day.

Observing highlights

Our final two favorite stories of the year involve a couple of observing opportunities, one of which was successful, the other maybe only kind of so!

Back on January 20, 2019 there was a total lunar eclipse. Contrary to our usual weather in January, we got a clear evening and the eclipse was visible from Seattle. It was a good show! The next total lunar eclipse possibly visible from Seattle will be in May of 2021.

The semi-successful observation was a try at a rare transit of Mercury across the face of the Sun on November 11, 2019. In our story we describe waiting out a possible look at the transit through insistently cloudy skies that morning. Finally there was a Sun break, just minutes before the transit was to end. I thought I caught a fleeting glimpse of Mercury just before it cleared the Sun’s disk, but then, Mercury being speedy of foot, was gone. I and a group of interested folks to gathered at Seacrest Park had fun anyway. We successfully viewed a Mercury transit from there in 2016. The next visible from Seattle won’t happen until 2049.

That’s our recap of the year. We look forward to our tenth anniversary celebration 12 months hence!

December 20, 2019

Battling clickbait science

I was sorely tempted to headline this post “Alien megastructures discovered in Ballard,” but that would have meant sinking low into the sort of clickbait science that concerns Dr. James Davenport. Davenport, a research scientist at the University of Washington, gave a talk about the topic at the most recent gathering of Astronomy on Tap Seattle.

Dr. James Davenport. UW photo.
Davenport described himself as a big fan of science, and noted that to be such one needs to be OK with failure.

“Being wrong is just nature telling you, no, try again. Come up with a better idea, a better explanation for how the universe is working,” Davenport said. “If you love science, you have to love the struggle and you have to love truth.”

Davenport believes that it’s important to communicate about science, but often that leads to misconceptions or outright lies. Sometimes the misinformation is silly stuff, like trying to pump up the hype about a lunar eclipse by calling it the super blood wolf coyote Moon. Sometimes it’s just wrong. An example is what now seems like the annual return of social media posts announcing that Mars is going to appear as large as a full Moon in the night sky. This particular hoax may date back to 2003, when Mars actually was closer to Earth than it had been in some 60 thousand years. The falsehood was based on a nugget of truth, and Mars was an especially good target for astronomers that summer, but if you looked up it was still just a bright red dot in the sky. When someone doesn’t see that giant Mars they might conclude that science is stupid.

“Little by little we chip away at your interest, your excitement, your enthusiasm, your belief, and your trust in science as an institution,” Davenport lamented.

Outrageous headlines

You’ve probably read many stories for which you found that the headline had little to do with the actual content. The purpose of the headline is to make you look. Davenport noted this phenomenon related to media coverage of Boyajian’s star, which brightens and dims in odd and unexpected ways. Scientists kicked around a lot of possible explanations for this observation. Maybe it’s a weird dust cloud or passing comets or debris from an asteroid collision. Someone even suggested a Dyson sphere or some other sort of “alien megastructure.” This grabbed the attention of the headline writers, and articles in Scientific American, the Washington Post, The Atlantic, Discover magazine, and others featured headlines about the possible discovery of alien megastructures, though the articles essentially said, “probably not.”

“There’s real science here but oh, golly, we need to be careful about reporting it,” Davenport said. “We have an obligation as scientists to be really careful and I worry that we’re not.” The truth about Boyajian’s star has yet to be figured out.

Where’s the rigor?

Another challenge for science communication is that there are some sites out there that are not exactly rigorous. For example, Davenport shared the following tweet from a site called Physics and Astronomy Zone.

You probably know that Pluto has not been reinstated. The tweet links to an old article—from April Fool’s Day. Also attached to that article are a slew of links to “stories” about the gifts men really want, amazing rebates for seniors, alien DNA in marijuana, and lots of other nonsense. It’s pure clickbait.

“This is a machine to get you to click on things, to get your eyeballs on things, to get you to engage with things so they make a few pennies,” Davenport said. “They do that a million times a day.”

There’s a lot of churn there. @zonephysics has more than 900 thousand Twitter followers.

“This is a huge impact for nonsense,” Davenport said. “Where is the celebration of truth?”

Few legitimate scientists have nearly so many Twitter followers. Neil deGrasse Tyson has more than 13 million, and Bad Astronomer Phil Plait has more than 615 thousand. As of this writing Davenport has 2,917. Seattle Astronomy has 2,135.

What to do

Davenport figures there are three things we can do to battle against the spread of pseudo-science and downright rubbish:
  1. Communicate about science; don’t leave it to pseudoscientists spread misinformation
  2. Share and intervene. Point out bunk when you see it.
  3. Get the help of technology and tech companies to figure out how to weed out bad sources and find a way to remove the incentive for clickbait.
“We need other solutions besides just eyeball time equals dollars equals the only thing that matters on the Internet,” Davenport said. “We need tools that help us optimize for things beside just eyeball time. We need tools that help us figure out what’s the most efficient way to get knowledge across. What’s the most efficient way to help us identify bad actors who are spreading misinformation and intervening when people are trying to share that content.”

There’s some heavy lifting ahead.

“We need to do science outreach. We need help from everyone to spread truth and identify falsehoods. And we need the help of technology,” Davenport concluded. See below to watch his entire talk!

Astronomy on Tap Seattle is organized by graduate students in astronomy at the University of Washington. They’re taking a break in December and their next event will be held January 22, 2020.






December 4, 2019

Book review: Moon: An Illustrated History

There have been a slew of books published about the Moon in the last year or so as we observed the 50th anniversary of the first human steps on the lunar surface. Among the more interestingly conceived and handsomely presented of those is Moon: An Illustrated History (Sterling, 2019) by astrobiologist and science communicator Dr. David Warmflash.

Moon: An Illustrated History is more than just the story of lunar exploration. It is essentially a collection of one hundred one-page essays about key moments in the history of the Moon, each accompanied by a marvelous illustration. The book lives up to its subtitle of From Ancient Myths to the Colonies of Tomorrow. It goes back 4.5 billion years to the Moon’s formation, and along the way takes many a look at how the Moon inspired science and scholarship and culture over the years.

Knowledge is power

Knowing a lot about the Moon can be important. It would have helped a group of Chinese court astronomers back in the 22nd century BCE, who were executed by emperor Chung K’ang because they didn’t predict the occurrence of a solar eclipse. Emperors needed to know these things; the mythology of the times gave great predictive power to unusual celestial events.

Warmflash explores a number of advancements in the development of lunar calendars, the first of which appeared some ten thousand years ago during the Mesolithic era. Later the Sumerians developed some incredibly complex calendars while trying to sync up the Moon and the Sun into a year.

It’s fascinating to read about the role the Moon has played in the building of knowledge over the centuries. Warmflash takes us back in history to the time the Greeks figured out why the Moon has phases and why there are eclipses. Other chapters explain how the Moon was key to calculating the size of the solar system and how it helped astronomers make an early confirmation of general relativity.

Fantastic illustrations

Some of Moon: An Illustrated History’s more interesting illustrations look at some of the great thinkers of the past. These include folks we in the west might not have heard about, such as the Arab mathematician Ibn al-Haytham and Indian astronomer Aryabhata. Others depict more familiar names, such as one imagining a chit-chat between Halley and Newton and another depicting a confab between Kepler and Emperor Rudolf II.

Aldrin on the Moon. Photo: NASA
The last forty of the book’s chapters cover the space age, beginning with the launch of Sputnik in 1957. Many of these later chapters come along with some of the most iconic imagery of the space age, including the “Earthrise” photo shot by astronaut Bill Anders from Apollo 8 and Neil Armstrong’s portrait of Buzz Aldrin on the Moon that shows the photographer and the lunar module reflected in the subject’s mask. The articles are loaded with little tidbits about lunar exploration that you probably didn’t know.

The final few chapters turn an eye to the future of exploration and possible settlement of the Moon.

Strongly recommended

Each of the chapters of Moon: An Illustrated History is cross-referenced to others that take on similar topics, so the reader can easily follow a particular thread. It’s a well-done volume that would make a fine gift for any Moon-o-philes on your list. Warmflash says that the book is available in Seattle at Elliott Bay Book Company, the Queen Anne Book Company, Island Books on Mercer Island, Barnes and Noble, and possibly others. If you buy through Amazon by clicking the book cover above or the link in the first paragraph of this article, Seattle Astronomy receives a small fee that helps support our site. We appreciate that!

Finally, Warmflash notes that he, along with Apollo 17 astronaut Harrison Schmitt and others, is featured in a documentary called Oregon’s Moon Country that will air December 16 on Oregon Public Broadcasting. You can stream online as well; details in the link above.

November 11, 2019

Sun streak ends! Whither Mercury?

All good streaks must come to an end, like Joe DiMaggio’s 56-game hitting streak or Cal Ripken, Jr.’s consecutive games-played record of 2,632. This morning Seattle Astronomy‘s personal mark of successful astronomical observations of Sun-related events was snapped at a modest four when we failed to spot Mercury during its transit across the face of the Sun.

Conditions looked semi-hopeful shortly after
sunrise that we'd see the Mercury Transit.
Photo: Greg Scheiderer.
Hope of spotting Mercury remained alive until the bitter end. I arrived at Seattle’s Seacrest Park just before sunrise when the transit had already been under way and below our horizon for a couple of hours. We got a few glimpses of the Sun during the morning, most not enough to register even a glimmer of light through properly filtered optics.

Then came proof that Mother Nature can be cruel and sadistic, especially to those who would practice astronomy in Seattle. With the transit slated to end at about 10:04 a.m. PST, the clouds parted a bit at about 10:02, setting off a mad scramble to point, focus, and look. I thought I caught the barest edge of Mercury leaving the disk of the Sun, but I couldn’t be sure. There were lots of clouds in the view. The Sun was there but Mercury, true to his fleet-of-foot reputation, was gone. I count it as a nice try.

Not everyone who came to our viewing event was skunked. Seattle-based Associated Press photographer Elaine Thompson caught this shot during a brief clearing:

It pays to be prepared! The day was not a total loss. Many folks enjoyed a look at the Mercury-free Sun after the transit, a nice woman named Liz brought some Top Pot donuts to share, and hanging around at the beach waiting to spot Mercury with some new friends was not a bad way to spend a Monday morning.

I’d successfully seen four recent Sun events: the August 2017 total eclipse of the Sun, the Mercury Transit in May 2016, a partial solar eclipse in 2014, and the transit of Venus in June 2012. Off to start a new streak.

There will not, however, be another Mercury transit until 2032, and not one visible from North America until 2049. See you down at Seacrest Park in thirty years!

September 27, 2019

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


September 12, 2019

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.

September 5, 2019

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.

August 24, 2019

A surprise discovery from Apollo 11 lunar samples

As we look back at the 50th anniversary of the Apollo 11 Moon landing, Toby Smith notes that the most interesting science that came out of the mission was a bit of a surprise. Smith, a senior lecturer in astronomy at the University of Washington, gave a talk at the most recent meeting of Astronomy on Tap Seattle.

“There’s only one reason Apollo existed—to beat the Soviet Union to the surface of the Moon,” Smith noted. Few considered the mission to be scientific. “It wasn’t fully embraced by the scientific community even in its day, even among planetary scientists.”

But they figured as long as they were there, they should do some sort of science.

“This little bit of science they did fundamentally changed how we view not only the Moon, but the Earth-Moon system and our solar system,” Smith said.

The Apollo 11 landing site, the Sea of Tranquility on the Moon, is essentially an ancient lava flow, a featureless plain of cooled volcanic rock, Smith said. Think of it like Big Island of Hawaii, except you don’t really see the solidified lava on the Moon. The surface is soft, ground down and rounded off into a soft powder by billions of years of impacts. As Neil Armstrong observed just after his first step, it has the consistency of flour. That consistency almost accidentally led to the mission’s best science.

An Apollo Lunar Sample Return container on display 
at the Destination: Moon exhibit at the St. Louis Science
Center in 2018. (Photo: Greg Scheiderer)
Armstrong spent about 15 minutes of the two-and-a-half hour Moon walk picking up rocks and putting them into a box. At the end he collected nine scoops of lunar regolith and dumped it into the Apollo Lunar Sample Return Container (a fancy NASA term for the case for rocks) as sort of a packing material so the larger rocks wouldn’t clatter around. If they’d taken any styrofoam peanuts he might have used those instead.

Naturally, when this material was brought back to Earth, the scientists looked at it, and Smith said it just might be the most studied geological sample ever.

Smith noted that the regolith is highly angular; lunar dust is sharp.

“This is not material that was broken up by being tumbled,” he said. “This is material that was broken up by being fractured by impacts.”

It’s a diverse sample. It contains basalt, breccia (material created by impacts that shatters and sometimes melts back together), and impact spheres. There was also one unusual, bright white material in the collection. It turned out to be anorthosite, which makes up about four percent of the sample.

“It represents a piece of the original crust of the Moon long since destroyed by four and a half billion years of impacts,” Smith explained. Anorthosite is an igneous rock, like basalt, that comes from the cooling of melted rock. Basalt is created when lava moves across the ground, but Smith noted that anorthosite doesn’t work that way.

“Anorthosite forms in big pools of lava, huge pools of lava, huge chambers of lava,” he said. “As these chambers of lava slowly cool over time, the anorthosite floats to the top.”

“If this was found on the Moon it must mean that at some point early in the Moon’s history it must have been almost completely molten,” Smith added. This information made scientists re-think their notions about the origins of the Moon.

“Before Apollo there was no indication that the whole, entire Moon was almost completely melted,” he said.

The leading theory about the formation of the Moon these days is that something pretty big, about the size of Mars, smacked into the early Earth, and that material flung into space by the impact eventually coalesced into the Moon. The catch is that computer simulations of this event don’t often result in a completely molten Moon. So more study is needed. The lunar samples have been under constant scrutiny for the last 50 years, and Smith says he’s interested to see what new information can be gleaned from those samples as new analytical technology is developed.

Astronomy on Tap Seattle is organized by graduate students in astronomy at the University of Washington. The next gathering is set for Wednesday, August 28, 2019 at Peddler Brewing Company in Ballard.