Tag Archives: Astronomy on Tap Seattle

Meeting the Martians and getting snapshots of far-away planets

It’s possible that some extraterrestrials were at the most recent Astronomy on Tap Seattle gathering, at which we explored the possibility of life on Mars and looked at exciting new techniques for capturing images of exoplanets.

We have met the Martians and they are us—maybe

“Are we all Martian-Americans? We still don’t know,” said Bob Abel, a professor of applied physics at Olympic College and collaborator with the University of Washington’s Large Synoptic Survey Telescope Group. Abel gave a talk titled, “Where Are the Martians?” at Astronomy on Tap Seattle April 26.

Giving a quick geological and topographical history of Mars, Abel said that the Red Planet is just one-half the diameter of Earth, and thus has just one-eighth the volume of Earth, so Mars cooled off pretty quickly.

Mars Mudstones

Curiosity shot this image in Gale Crater on Mars. The mudstones indicate a long history of standing water in that location. Photo: NASA.

“During the early formation of the solar system, it would have cooled to the point where liquid water could exist on its surface before the Earth got to that point,” Abel said, adding that it’s clear that water was once abundant on Mars. The rovers Spirit and Curiosity both landed in craters that used to be lakes, and Opportunity set down on the edge of what scientists think was once a salty sea.

In addition, Abel said that Spirit found opaline silica in Gusev Crater on Mars.

“The place where you find this on Earth is near geysers and hydrothermal vents,” Abel said. You’ll find heat, water, and minerals around these vents. “You’ve got all the stuff for life, and you find the most primitive life clustered around these on Earth.”

Bob Abel

Prof. Bob Abel of Olympic College gave a talk about Mars and Martians at Astronomy on Tap Seattle April 26, 2017. Photo: Greg Scheiderer.

The surface of Mars is awfully barren now, but life could have conceivably existed there in the distant past. Scientists have found meteorites from Mars on Earth, and inside some of those meteorites they’ve found structures that look like nanobacteria. The debate continues over whether these are biological or not.

“It’s still somewhat up in the air, but it’s tantalizing evidence,” Abel said. “The question still remains, did life start earlier on Mars, since it was capable of being inhabited? And by the time Earth was habitable, did meteorites come to Earth and start life on Earth?”

The investigation continues.

As for present-day Mars, while the surface appears devoid of life, we may find something if we dig a little deeper. Abel said that Curiosity detects occasional outbursts of methane on Mars. He pointed out that most methane on Earth is created by biology.

“I’m personally rooting for flatulence, but we don’t know yet what’s causing it,” he laughed. But, through measurements made by many different Mars orbiters, we’ve learned that the planet’s outer core is molten. So beneath the surface there is heat, water, hydrocarbons, and soil: everything life wants. Abel recalled a talk last year by Penelope Boston, head of the NASA Astrobiology Institute.

“She can’t see how life doesn’t exist below the surface of Mars,” Abel said.

Snapshots of exoplanets

Getting photographs of exoplanets—planets orbiting far-away stars—is a relatively new field within astronomy. The first such images were captured just eight years ago or so. Benjamin Gerard said the technology and capabilities within the field are advancing rapidly. Gerard, a doctoral student in physics and astronomy at the University of Victoria in British Columbia, uses the Gemini Planet Imager to trick out pictures of planets near stars that are many light years away. These photos can be useful for figuring out the components of a planet’s atmosphere and whether it has oceans and continents.

Gerard

Doctoral student Benjamin Gerard gave a talk about his work imaging exoplanets at Astronomy on Tap Seattle April 28. Photo: Greg Scheiderer.

Gerard said the main challenges in exoplanet imaging are resolution and contrast. He explained that the key to good resolution is adaptive optics. If you’ve looked through a telescope you have likely had nights when the objects you observe appear to be wiggling around because of atmospheric turbulence. Gemini corrects for this with adaptive optics.

Light from the object hits a deformable mirror as well as a component called a wave-front sensor. The sensor measures the amount of turbulence, sends the information to the mirror’s actuators, which can correct for the aberration.

“The mirror deforms once every millisecond,” Gerard said. “This aberration gets corrected and is constantly re-focused onto the camera. Once it reaches that point this image that is very turbulent suddenly becomes much more stable and we can get much better resolution.”

Gerard said this is a plus for ground-based telescopes.

“With this technique, we can basically take a ten-meter telescope and make it like we were in space,” he said. “With adaptive optics we actually do better than any space telescope in resolution.”

The problem of contrast is apparent to anyone who has visited social media, which is full of bad-contrast photos. Especially common are pics of people posed in front of windows. Often the people appear as silhouettes because the light from the window is way brighter. While exoplanets don’t pose in front of cosmic windows, contrast is a huge problem when it comes to getting the images.

“A planet like Earth is about ten billion times dimmer than it’s host star,” Gerard pointed out. Using a coronagraph helps block out the light of the star and remove its glare from the image. They also use a technique called angular differential imaging to overcome aberrations within the instruments. This is a little bit counter-intuitive to the amateur astrophotographer who typically uses an instrument rotator during long exposures to compensate for the apparent motion of objects caused by the rotation of the Earth.

“For exoplanet imaging this is actually helpful, so we turn off the instrument rotator and the planet appears to rotate with respect to the view of the fixed telescope instrumental aberrations,” Gerard said. “We can distinguish one from the other.” Computer algorithms can later put images made in this way back together to create even greater contrast.

Gerard hopes they’ll be able to do even better in the near future. The Wide Field Infrared Survey Telescope (WFIRST) is scheduled to launch in the mid-2020s. It will have a deformable mirror that should have the capability to image smaller planets like Earth.

“This is many orders of magnitude better than we can do on ground-based telescopes, because on a space telescope you’re much more stable,” Gerard said. “On the Hubble Space Telescope now we can’t reach this sort of contrast because there is no deformable mirror.”

Since Gerard gave the talk NASA announced an independent review of WFIRST that could change its timeline and instrumentation.


The next Astronomy on Tap Seattle gathering is set for May 24 at Peddler Brewing Company.

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Start saving: flying to space with Blue Origin

If there’s any anti-science sentiment around these parts it wasn’t evident last Friday at Peddler Brewing Company in Ballard, where some 500 space enthusiasts packed the brewer’s beer garden—yes, we were sitting outside, in Seattle, in January—to hear from employees of Kent-based Blue Origin about the company’s latest testing and the prospects for an affordable ride to space any time soon. The event was the latest installment of Astronomy on Tap Seattle, organized by graduate students in astronomy at the University of Washington.

Blue Origin Folks

L-R Nicholas Patrick, Dan Kuchan, and Sarah Knights of Blue Origin after their presentation at Peddler Brewing Company. Astronomy on Tap photo: Brett Morris and Nicole Sanchez.

“Our ultimate mission is to have millions of people living and working in space,” said Sarah Knights, outreach coordinator at Blue Origin. “The way that we’re focused on that is to lower the cost of human spaceflight, and one of the ways to do that is to make vehicles reusable, so that’s our primary focus right now.”

Blue Origin’s current test vehicle is the New Shepard, a capsule and vertical takeoff/vertical landing rocket. It’s powered by the BE-3, for Blue Engine 3, which is fueled by liquid oxygen and liquid hydrogen and can deliver 110,000 pounds at full thrust. As suggested, the rocket blasts off, and then lands softly back on Earth.

“As it’s coming back down we can throttle it back to about twenty percent of its full throttle, so that means that as the propulsion module is coming down we can have an equal thrust-to-weight ratio, find the landing pad, and very gently set it down,” Knights explained.

Blue Origin safety test

Dan Kuchan, Product Development Team lead engineer on the New Glenn program at Blue Origin, said the most recent test of New Shepard, conducted in October, was of the vehicle’s full-envelope crew escape system.

“That means that if the rocket at some point decides that we can’t go to space today, the crew capsule can jettison itself and get out of Dodge,” Kuchan explained. It was the first such in-flight escape test for a space vehicle since 1965, during the Apollo program. Kuchan showed this video of the flight test during the presentation.

“That was an awesome test and it capped off the fifth flight and landing for that booster,” Kuchan said. “The system worked flawlessly.”

Astronauts soon

So far New Shepard has only flown without a crew, but they hope to have astronauts on board soon. That’s where Nicholas Patrick comes in. Patrick, a former NASA astronaut who flew on space shuttle missions for construction of the International Space Station, is now Blue Origin’s human integration architect.

“I’m responsible for worrying constantly about every aspect of flying on our spacecraft,” Patrick said. That includes everything from meeting rules and regulations, testing to make everything right, and every imaginable human factor.

They chose a capsule rather than a winged vehicle like the space shuttle partly for safety. The smaller capsule can get away from the booster quickly, as demonstrated in the video above. Patrick said it’s also a better way to travel.

“For those who are paying to ride aboard a New Shepard in the coming years this is a more authentic rocket flight experience than most other ways you could get to space,” he said.

The New Shepard capsule has big windows, the largest ever flown in space, and all passengers will have one of their own; there are no middle seats on New Shepard. Suborbital flights will last about eleven minutes, and passengers will be weightless for several minutes.

“We want to give them the best imaginable experience,” Patrick said. He showed this video animation of what a New Shepard flight will be like.

“That’s a New Shepard flight that we hope will be available to anybody who can get in and out of the capsule, who can tolerate the three Gs on ascent, and a little higher on descent,” Patrick said. “So start saving.”

At what cost?

How much to save is a question that Patrick said hasn’t yet been answered.

“Obviously everybody’s goal is to get this price down a long way,” he said. “We’re not going to get millions of people living and working in space by charging a quarter of a million or a hundred thousand dollars just for a suborbital flight.”

The question of when people will fly on New Shepard also hasn’t been answered.

“We’re not driven by that kind of schedule,” Patrick said. “We’re driven by our flight test program and the success or challenges we face in each of those tests.”

“What I can tell you is that I expect we’ll be flying people in the next year or two,” he added.

Kuchan noted that, in a way, New Shepard astronauts will be human guinea pigs.

“New Shepard and everything we’re doing, sending tourists into space, is all a way for us to practice and master landing a reusable rocket, and using it in a commercially viable way, so that over the next 50, 100, 200 years we can move civilization deeper into space,” Kuchan said.

Next steps: a bigger rocket

Blue Origin’s motto is gradatim ferociter—step by step, ferociously. The next step for the company is on the drawing board now: the New Glenn, which will get payloads into Earth orbit. The New Glenn will dwarf the New Shepard. While the latter is powered by one BE-3 engine that delivers 110,000 pounds of thrust, the New Glenn will have seven BE-4 engines that deliver 550,000 pounds of thrust each. That’s a lot of oomph. Again, there’s no totally firm timeline, but Kuchan said they’ve been asked to deliver the rocket by the end of the decade, and added that they plan to do so. It’s another step on the way to having millions of people living and working in space.

“Every single decision that gets made at Blue Origin is weighed against that ultimate goal,” Knights said.

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Dava Sobel talk highlights week’s calendar

A talk by author Dava Sobel is the highlight of this week’s astronomy calendar. Sobel, whose new book is The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars (Viking, 2016) will speak at 7:30 p.m. Thursday, December 15 at Town Hall Seattle.

The book is the story of the contributions of women at the observatory who made major advancements in the science, often without getting proper credit or recognition. From Williamina Fleming, originally hired as a maid, who identified ten novae and more than three hundred variable stars to Dr. Cecilia Helena Payne-Gaposchkin, appointed as the first woman professor of astronomy at Harvard in 1956, this group of remarkable women disproved the notion that “the gentler sex” had little to contribute to human knowledge.

Tickets to Sobel’s talk are $5 and are available online.

Astronomy on Tap Seattle

December’s edition of Astronomoy on Tap Seattle will consist of three shows at the University of Washington Planetarium on Wednesday, December 14. The program will be a guided tour of the universe. Unfortunately, all of the seats for the three shows were snapped up quickly, but you might watch the AoT Facebook event page to see if any openings occur.

Public night in Pierce County

The Tacoma Astronomical Society plans one of its public nights for 7:30 p.m. Saturday, December 17 at the Fort Steilacoom campus of Pierce College. The indoor program will be a viewing of a movie about the Christmas star. If the weather is clear they’ll break out the telescopes for some observing, too.

Futures file

You can scout out future astronomy events on our calendar. The page also features a full schedule of planetarium and stage science shows at Pacific Science Center. Recently added events include:

Up in the sky

The Geminid meteor shower peaks this week, but will have to compete with the full Moon. The Sky This Week from Astronomy magazine and This Week’s Sky at a Glance from Sky & Telescope offer more observing highlights for the week.

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