Category Archives: astronomy

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 communicaiton, 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.

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More info:

Watch both talks on YouTube

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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.

Saturn by Hubble
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.

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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
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
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.

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.

Moon rock box
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.

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Seattle is just like Mars, and other lessons from a 3-D trip

Attendees at the most recent gathering of the Seattle Astronomical Society went on an entertaining and informative 3-D trip to Mars, and learned that Seattle is just like the Red Planet.

Antonio Paris

Antonio Paris

Our tour guide was Dr. Antonio Paris, chief scientist at the Center for Planetary Science, assistant professor of astronomy and astrophysics at St. Petersburg College in Florida, and author of Mars: Your Personal 3D Journey to the Red Planet (Center for Planetary Science, 2018).

Paris said he loves Mars and expects that humans will be going there sooner than later.

“I suspect that, the way things are going, probably in about 10 to 15 years we’re going to be on Mars,” he said, adding that he doesn’t think anyone is going to go it alone.

“Mars, in my personal opinion, is going to be an international effort, both with corporations as well as the government,” Paris said.

The book was something of a spinoff of an exhibit about Mars that Paris helped put together at the Museum of Science and Industry in Tampa. The exhibit proved pretty popular, and the book seemed the next natural step. Proceeds from book sales support the work of the Center for Planetary Science.

Paris featured fantastic 3-D images of a great many Martian geological features in his presentation. While his Ph.D. is in astronomy, he’s really morphed into something of a rock hound.

“We are primarily geologists that are studying all of the geological features here on Earth,” he said, “and we’re trying to compare and contrast them with what we see on the lunar surface, what we see on Mercury, Venus, and all of the terrestrial planets.”

Paris called the process comparative planetology.

Ripples

Ripple marks such as those shown in this photo from the rover Opportunity were deposited by water moving back and forth. Image: NASA/JPL

“If I look at something here on Earth and I can determine how that thing happened,” he said, “and I see the same thing on Mars, I can deduce that the same processes have occurred, most likely.”

That caveat was included on most of his deductions, but the comparisons are pretty compelling. For example, Paris passed around a flat piece of rock with ripple marks on it that he collected in the Canyonlands in Utah. Such ripple marks are created by water moving back and forth over the rock, and the Canyonlands piece looks exactly like stuff the rovers have seen on Mars.

Paris also showed photos of rock formations made when moving or freezing water breaks up bedrock, and wears it down into small pebbles. At least, that’s how it happens on Earth.

Potholes on Mars

This set of images compares the Link outcrop of rocks on Mars with similar rocks seen on Earth. Image: NASA/JPL-Caltech/MSSS and PSI

“We call that either fragmented sidewalk or conglomerate terrain,” he said. Here in Seattle, especially after our recent cold and snowy weather, we just call it a pothole, and that’s how the Emerald City is like the Red Planet! Potholes all over the place!

Paris does a lot of rock hunting in the American southwest, which has a lot of Mars analog sites that scientists and NASA use in their Mars work. These include Moenkopi in Arizona, Canyonlands, the Mojave Desert, Death Valley, and the Flagstaff area.

The website for the Center for Planetary Science notes that Paris will make a presentation in Portland in September at a time and place not yet published. Dollars to Voodoo Doughnuts it will be with Rose City Astronomers. Stay tuned.

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Astro Biz: Moon’s Kitchen

Moon's KitchenMany businesses, products, and places have names rooted in space and astronomy. We’re featuring one periodically on Seattle Astronomy.

Today’s Astro Biz is Moon’s Kitchen Japanese restaurant. Moon’s Kitchen is on Fourth Avenue in Seattle’s Belltown Neighborhood.

Moon’s Kitchen has no official online presence that we could discover. That’s a little odd in this day and age; if there’s no website, does a place really exist? Probably so, as there’s a robust discussion of the joint on Yelp and the like, and it receives generally good reviews, though one grump called it a “glorified teriyaki place.” You can order Moon’s Kitchen dishes for delivery through Grub Hub, Uber Eats, and possibly others.

More info:

Wow! Check out The Planets Online

There’s a great new website about our solar system that will blow your socks off! The Planets Online introduces viewers to a broad range of subjects in a unique, innovative, and entertaining way. The site naturally interweaves information on science, engineering, music, visual design, and technology—it could be a showcase for STEAM education (Science, Technology, Engineering, Arts, and Math).

Adrian Wyard

Adrian Wyard

The site is the creation of visual artist Adrian Wyard. Followers of Seattle Astronomy may recall that we wrote about Wyard’s show The Planets Live about three years ago (story here). The concept is that Wyard uses images of celestial objects to accompany and enhance classical music. He’s done it with Gustav Holst’s The Planets, Mussorgsky’s Pictures at an Exhibition, and Dvorák’s 9th Symphony.

The core of The Planets Online is a video of a performance of The Planets by the Auburn Symphony Orchestra directed by Anthony Spain and featuring the Seattle Pacific University Women’s Choir and Wyard’s visuals. This is no ordinary video, however. If you remember when we used to get our video on plastic disks, think of The Planets Online as a video loaded with special features. As the video plays, a sidebar describes the images and who created them, offers facts about the music, pulls up Wikipedia pages and other sources about the science, throws in tidbits of trivia, and more. You can switch any of these info streams on or off depending on your interests.

Here’s a little preview video of The Planets Online.

We expect you might spend a good deal of time with the site.

There are live performances of Wyard’s work coming up this spring in Florida, Virginia, and Texas. The last northwest live performances were back in April, May, and October last year. If you missed those, you can have a little fun—and learn a few things—with The Planets Online.

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