Category Archives: astronomy

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.

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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.

Waiting for Mercury
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!

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Mercury transit tomorrow!

The weather forecast is decidedly iffy for folks in Western Washington to view the transit of Mercury across the Sun on Monday morning, November 11. But a number of groups, including Seattle Astronomy, are planning to be out and waiting for breaks in the clouds in order to catch a glimpse of this relatively rare astronomical event.

Transit of Mercury
Our photo of the 2016 Mercury transit from Seattle. If you click on this photo to see the larger version you can see Mercury just to the left of the center of the disk of the Sun, and a sunspot cluster to the right. Taken with a Canon PowerShot A530 through an 8-inch Dob at 48 power. Photo by Greg Scheiderer.

Typically there are 13 Mercury transits visible in any given century, and there will be 14 of them during the 21st Century. We last had one visible from Seattle just over three years ago, in May of 2016. Tomorrow’s will be the last until 2032, but that one and the next won’t be visible from North America. Our next chance to see a Mercury Transit from Seattle will be in May of 2049.

Thus we’ll be down at Seacrest Park in West Seattle near the Water Taxi dock in hopes that we won’t have to wait 30 years or travel halfway around the globe to see Mercury in transit. We’re aware of a handful of other viewing opportunities tomorrow in the Northwest:

Watch our calendar page for others; we’ll add them if we hear about them for the rest of the day.

There are a couple of things to consider when viewing the transit. First, the requisite warning not to look at the Sun without eclipse glasses or a properly filtered telescope. Second, you’ll not likely see Mercury without some magnification; it’s pretty small. Third, don’t try to use eclipse glasses with a telescope or binoculars; the equipment itself must be properly filtered or severe eye damage will result.

Alan Boyle of Geekwire has a good article about the 2019 transit that includes some links for viewing the event online should our weather fail to cooperate.

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Astro Biz: 7 Moons wine

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

7 Moons Red Blend

Today’s Astro Biz is 7 Moons Red Blend wine from the 7 Moons Wine Company of Oakville, California. The red blend is a mixture of wine from seven different grape varietals: Syrah, Merlot, Petite Sirah, Zinfandel, Cabernet, Malbec , and Grenache. The company also makes a “dark side” red blend, though its website does not point out how it differs from the standard, and sticklers will quibble with the use of dark side, as the far side of the Moon is often illuminated.

There’s a bit of fun involved as the company uses seven different corks, each depicting one of the Moon’s phases. They urge imbibers to collect all seven, though there’s no indication of any sort of prize for successfully doing so.

More info:

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.