Category Archives: astronomy

Total lunar eclipse visible from Seattle

Seattle astronomy buffs are downright pessimistic about seeing celestial events, even those that happen during our good-weather months. (And we have them.) Thus in the week before the total lunar eclipse of January 20, 2019, I posted this on the Seattle Astronomy Facebook page.

Amazingly enough, at about mid-day on eclipse day the clouds actually did begin to part a little, and a check of the Seattle Clear Sky Chart revealed a prediction that we’d have just 30 percent cloud cover come eclipse hour, and that it would be downright clear late in the evening.

One learns not to trust these things, but when the full Moon actually got up above the trees and into a clear sky out back of Seattle Astronomy headquarters, I decided this was going to happen and hauled the telescope out of the basement and onto the back deck. As the eclipse began I snapped a quick photo in order to express my amazement.

I am not an astrophotographer, as people who evaluate the entries for the Seattle Astronomical Society‘s quarterly photo contest always remind me. This one was shot with my smartphone, though when using it with the telescope I find it devilishly difficult to get the proper aim through the eyepiece (must pick up one of those gadgets from Cloud Break Optics soon.) My other “astro” camera is an old Canon Powershot A530, which is pretty easy to just stick up to the eyepiece and shoot.

I used the phone to get a pretty OK, if somewhat pixellated, pic at totality, too.

Interestingly enough, I found that the color of the “blood Moon” wasn’t quite so pronounced through the telescope and camera is it was in my naked-eye view. I think the magnification diffuses the color a bit, and the camera isn’t really made for that sort of work.

Even my sweetie, who is not normally prone to looking through telescopes at night in January, or any other month, for that matter, went out quite a few times for a magnified look, and we both spent most of the eclipse watching from a warm environment inside behind the glass of the French doors.

I hope you got a chance to see the eclipse wherever you were. The next one visible in Seattle will happen in May of 2021.

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Searching for life with giant telescopes

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

David Charbonneau

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

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

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

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

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

Giant Magellan Telescope

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

James Webb Space Telescope

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

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

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

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

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

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

TESS and MEarth

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

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

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

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

 

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

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

You can watch the entire lecture here:

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Waffles and big data in the universe

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

Leah Fulmer

Fulmer at work. Photo: Astronomy on Tap Seattle

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

Back in the 1990s the Palomar Digital Sky Survey and the Two Micron All-Sky Survey each collected about a terabyte of data. That’s a trillion bytes; 1012 bytes. Enough to fill a thousand one-gigabyte smartphones.

The 2000s brought the Sloan Digital Sky Survey (SDSS) and the Galaxy Evolution Explorer. These collected in the tens of terabytes of data. In the 2010s Pan-STARRS collected a petabyte of data; a quadrillion bytes.

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

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

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

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

A new way to look at data

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

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

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

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

Fulmer finds the era of big data exciting.

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

Astronomy with your breakfast

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

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

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

“That’s what you’re making your stars out of, so there’s going to be a lot in your disk,” Sanchez said.

In fact, her faculty advisors got wind of the waffle model and said it would need A LOT of syrup, which led to the hilarious twitter thread below. Click on it to see the academic discussion.

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

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

Sanchez studies galaxies by using cosmological hydrodynamic simulations.

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

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

Pass the syrup.

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Exploring the solar system with Emily Lakdawalla

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

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

Lakdawalla

Emily Lakdawalla (Isabel Lawrence/Planetary Society)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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Astro Biz: Orion apartments

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

Today’s Astro Biz is Orion apartments in Tacoma. We stumbled across Orion during a quickie stay-cation in Tacoma’s Stadium District. It’s in a pretty peachy location near restaurants, pubs, bookstores, and shopping in the district. They’re just a hop and a skip from Wright Park. It looks like they have great views, too.

It’s interesting how many apartment and condo buildings are Astro Bizzes. So far we’ve found Astro, Jupiter, Luna Court, Nova, and Vega. There may be more in the queue. Stay tuned!

More info:

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Mars is here!

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

We may have buried the lede on that one.

Mars

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

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

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

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

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

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

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

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

InSight

Krumm noted that InSight is something of an interplanetary RN.

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

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

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

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

Dust storm

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

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

Opposition

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

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A cosmic perspective with Jill Tarter of SETI

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

Jill Tarter

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

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

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

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

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

Earthrise

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

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

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

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

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

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

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

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

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

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

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

Tarter encouraged everyone to go home and set their discriptions on their social media profiles to “Earthling,” and to start thinking and acting from that perspective.

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

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