Category Archives: lectures

Seattle Astronomy calendar, week of May 18

There are a lot of great events requiring some difficult choices on this week’s calendar.

Prof. Jim Peebles speaks Tuesday at the University of Washington. Photo: Princeton.

Prof. Jim Peebles speaks Tuesday at the University of Washington. Photo: Princeton.

On Tuesday, May 19, Professor P.J.E. Peebles, Albert Einstein Professor of Science at Princeton University, will give a guest lecture at the University of Washington sponsored by the departments of physics and astronomy. Titled “50 Years of the Cosmic Microwave Background: What We Have Learned, and What Questions Remain,” Peebles’ lecture will explore the science behind the Big Bang and new searches for dark matter and dark energy. The lecture, at 7 p.m. in room A102 of the Physics/Astronomy Building on the UW campus in Seattle, is free, but reservations are required.

Jennifer Wu photography

Light Painting by Jennifer Wu.

Light Painting by Jennifer Wu.

At the same hour astrophotographers may be interested in a presentation by Jennifer Wu at the Mountaineers Seattle Program Center. Wu, the co-author of Photography Night Sky: A Field Guide for Shooting After Dark, is a nature and landscape photographer specializing in creating stunning images of the night sky and stars. Since 2009, she has served as a Canon Explorer Of Light, one of just 36 photographers worldwide to be recognized with that honor.

Tickets are free for students, $14 for Mountaineers members, $16 for non-members. The event starts at 7 p.m. Tuesday, May 19 at the Mountaineers’ Center, 7700 Sand Point Way NE in Seattle.

Astronomy on Tap returns

aot3Enjoy beer and astronomy at the third event of the spring with Astronomy on Tap Seattle on Wednesday, May 20 at 7 p.m. at Bad Jimmy’s Brewing Company in Ballard. UW astronomy grad student John Lurie will give a short talk about our understanding of the evolution of the Milky Way, titled, “Our Galaxy is a Cannibal.” Dr. Matt Beasley of Planetary Resources will discuss asteroid mining. In addition to the brew and lectures, there will be astronomy trivia contests and yummy prizes from Trophy Cupcakes.

Catch our recaps of the first and second Astronomy on Tap Seattle events, and we’ll see you at number three on Wednesday. It’s free; make a reservation here.

Seattle Astronomical Society

The Seattle Astronomical Society will hold its monthly meeting Wednesday, May 20 at 7:30 p.m. in room A102 of the Physics/Astronomy Building on the University of Washington campus in Seattle. Developer Jonathan Fay will talk about Microsoft WorldWide Telescope, free software you can use to plan observations, control a telescope, explore astronomical data sets, or create custom tours for educational outreach.

Back to TJO

Theodor Jacobsen Observatory

May 20 is the third Wednesday of the month, which means it’s time for another open house at the Theodor Jacobsen Observatory on the UW campus. The event gets under way at 9 p.m. Undergrad Boren Li will give a talk titled, “Comparative Planetology: Where Will We Go?” Li will compare conditions on other planets to those on Earth and summarize our best prospects for colonization.

The talks are free but reservations are strongly recommended. Volunteers from the Seattle Astronomical Society will give tours of the observatory and, weather permitting, share a look through its vintage telescope.

Northern lights flick at PacSci

Acclaimed Norwegian solar physicist Pål Brekke will be at the Pacific Science Center Thursday, May 21, for a discussion of the fascinating phenomena of the aurora borealis. They’ll show Brekke’s new 25-minute documentary The Northern Lights: A Magic Experience at 7:30 p.m. in the center’s PACCAR Theater. The film tells the full story of the aurora and includes tips on how to take your own exquisite northern lights photos.

After the screening Brekke will talk about his experience as a longtime observer of the northern lights and about his work on the documentary. Admission is $5. View the trailer for the film below.

Weekend star parties

The Seattle Astronomical Society will hold its free public star parties Saturday, May 23 at two locations: Green Lake in Seattle and Paramount Park in Shoreline. Both events will start at 9 p.m. if the weather is suitable for stargazing.

Saturn at opposition

Saturn will be at opposition Friday, meaning we’ve arrived at the best time this year for observing the ringed planet. Jupiter and Venus are still great targets in the early evening as well. This Week’s Sky at a Glance from Sky & Telescope magazine has more observing highlights for the week.

Keep on top of area astronomy events with the Seattle Astronomy calendar.

 

FacebookTwitterGoogle+EvernoteShare

Game of Thrones and black holes at latest Astronomy on Tap

The extreme seasons on the popular HBO series Game of Thrones and supermassive black holes were the subjects of talks at the most recent Astronomy on Tap event held at Bad Jimmy’s Brewing Company in Ballard.

AoT vs. GoT: Reasons for the (Extreme) Seasons

Russell Deitrick

Russell Deitrick makes a point during his talk at Astronomy on Tap II at Bad Jimmy’s Brewing Company. Photo: Greg Scheiderer.

Russell Deitrick is an graduate student in astronomy at the University of Washington, studying models of the dynamics of exoplanets in multi-planet systems. He is particularly interested in how interactions between planets with high eccentricity and high mutual-inclination might affect habitability of those planets. That, it would seem, makes him the perfect one to figure out what could cause the sort of long, severe, and unpredictable seasons the characters on Game of Thrones experience.

Deitrick started with a quick primer on what causes seasons. The main cause is the axial tilt, or obliquity, of the planet. Earth, for example, has an axial tilt of about 23 1/2 degrees, and when a pole is inclined toward the Sun its hemisphere enjoys summer.

There are several ways to mess with the seasons, Deitrick explained. Our Moon stabilizes precession—the wobble of the orbital axis like a top—so if a planet doesn’t have a large moon, precession would be greater and there would be more variance. You could alter the orbit itself, making it highly eccentric.

Other factors that can change climate include volcanism, solar variability, or having a planet in a binary star system.

Deitrick ran computer models in which all of these varied wildly. The simulations didn’t match the show.

“Eccentricity can’t really explain the duration of the seasons on Game of Thrones,” Deitrick said. “If you’re at high eccentricity, you may have a very long winter, but you’re going to have a correspondingly short summer, and the seasons are going to be the same length.”

He noted that changing the obliquity of the axis can explain everything except the long duration of the seasons. Volcanos can create long seasons, but Deitrick said that doesn’t fit in with the show.

“The problem with the volcanic winter is that it’s possibly too random,” he said. “The fact that the seasons are quasi-predictable suggests that it probably isn’t related to volcanos.”

He said solar variability takes to long to create climate change on the short time scale of a season, and a binary star system doesn’t appear to be part of the story in Game of Thrones.

“You’d think they’d mention somewhere in the series that there were two suns,” he said.

“None of these can explain that long night, that generation of darkness,” Deitrick added.

“The seasons on Game of Thrones probably can’t be explained by a single theory,” Deitrick concluded. “So they’re probably magic.”

Supermassive black holes: size matters

Michael Tremmel

Michael Tremmel is working on figuring out how supermassive black holes came to be. Photo: Greg Scheiderer.

Michael Tremmel, another UW astronomy grad student, took on an equally mysterious if less fictional topic in his Astronomy on Tap talk: supermassive black holes.

Tremmel explained that an ordinary black hole—one of between one and 10 solar masses—is the result of simple stellar evolution.

“When a massive star runs out of fuel and explodes in a supernova, the core of the star continues collapsing and forms a black hole,” he said.

The problem is that supermassive black holes can be of billions of solar masses and could not have formed in the same way.

“It’s still an open question where these black holes came from,” Tremmel said, “but we think that they must have formed very, very early on in the universe when the first stars that exist were beginning to form. Before there were galaxies, before there were stars, there were supermassive black holes.”

We’ve never seen a black hole because they don’t emit light. Their gravity is such that even light can’t break free. But the evidence that they exist is plain. Tremmel explained that we have observed stars orbiting rapidly around the center of our own galaxy. By gauging the trajectories of these stars we reach one conclusion about what they are orbiting.

“This object must be really, massive, and really, really small,” he said. “The only thing this thing could be is a black hole that is a billion solar masses.”

Astronomy and beer go together at Bad Jimmy's.

Astronomy and beer go together at Bad Jimmy’s.

We’ve seen the evidence of black holes in other galaxies by catching the glow of gas as it is consumed by supermassive black holes.

“This gas is flowing in, spiraling around, and becoming very, very hot,” Tremmel noted. “As that gas gets really hot it emits a lot of light.”

Tremmel said it’s an exciting time for his field of study, trying to figure out more about the formation of supermassive black holes.

“These relatively tiny objects within a galaxy are a true mystery still for astronomers,” he said.

The next Astronomy on Tap Seattle is scheduled for Wednesday, May 20 at 7 p.m. at Bad Jimmy’s. It’s free, and you can RSVP here.

More reading

FacebookTwitterGoogle+EvernoteShare

White spots on Ceres may be salt

The first big surprise as the Dawn spacecraft was approaching the dwarf planet Ceres earlier this year were bright white spots on its surface. Now that Dawn has been orbiting Ceres for six weeks, a theory has emerged about what the spots are: salt.

Dr. Tom McCord, a planetary physicist who is co-investigator on the Dawn mission, spoke about the exploration of Ceres Saturday during an astronomy day event at the Pacific Science Center in Seattle. Photo: Greg Scheiderer.

Dr. Tom McCord, a planetary physicist who is co-investigator on the Dawn mission, spoke about the exploration of Ceres Saturday during an Astronomy Day event at the Pacific Science Center in Seattle. Photo: Greg Scheiderer.

Dr. Tom McCord, a co-investigator on the Dawn mission and director of the Bear Fight Institute, a research organization based in Winthrop, Wash., spoke at an Astronomy Day event Saturday at the Pacific Science Center in Seattle. Here’s why he thinks the spots could be salt.

McCord explained that Ceres is differentiated: it has a rocky core, a water-ice mantle layer, and a dirty crust. He noted that they’ve learned a lot from the early photographs.

“There’s a lot of evidence of activity; many craters, an older surface, but not as old as the object, so something obliterated the craters from early on,” McCord said. “Distorted features, so the surface had to have been warped.”

“There are domes, things pushing out from the inside,” he continued, “and bright spots that suggest that material from inside has come to the surface in some sort of volcanism.”

In addition, McCord explained that ground-based telescopes have detected water vapor that comes and goes in the area of Ceres. Liquid water from the interior of Ceres may be being ejected to the surface, where it wouldn’t last long.

Ceres

This image was taken by NASA’s Dawn spacecraft of dwarf planet Ceres on Feb. 19 from a distance of nearly 29,000 miles (46,000 kilometers). It shows that the brightest spot on Ceres has a dimmer companion, which apparently lies in the same basin. Photo: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

“What that would do is leave a residual salt deposit, so these bright spots could be salt deposits that accumulated around vents—volcanos—where the water is coming through,” McCord speculated.

He stresses that the work on data from Ceres is still in its early phases, joking that, “We scientists don’t know entirely what we are seeing.”

McCord said the evidence of geological activity has been the most interesting finding so far at Ceres.

“It has been active and may well still be active today,” he said. “That’s exciting to a physicist because you really want to know whether these processes that you conjure up in your models really have happened and, we hope to learn, to what extent and over what time scale.”

Ceres is a great target for study because it may hold clues to how planets form. It is the only dwarf planet in the inner solar system and is the largest object in the asteroid belt. With a diameter of 590 miles, it’s about as big as Texas.

“This is a very large small planet,” McCord said. Ceres comprises about a third of the mass of all objects in the asteroid belt.

The Dawn spacecraft is unique, according to McCord.

“It is the only interplanetary spacecraft that uses ion propulsion, and that is the only reason we are able to orbit two different objects in the outer solar system and still have enough fuel to go on,” he said. Dawn launched in 2007 and studied the asteroid Vesta for 14 months in 2011 and 2012 before heading to Ceres.

“Dawn is really a pathfinder for this kind of multiple-object extended exploration,” McCord said.

Dawn will be collecting data at Ceres for another year to 18 months. McCord said the spacecraft has four momentum wheels and needs three of them to hold itself in stable position. However two of the wheels have failed, so mission scientists are using the craft’s thrusters as a substitute. The hydrazine fuel will eventually run out, and Dawn will tumble about in a stable orbit around Ceres for a long, long time.

FacebookTwitterGoogle+EvernoteShare

Space policy dean, Curiosity engineer to speak in June at Museum of Flight

Our copy of Aloft, the member magazine of the Museum of Flight, arrived in the mail today bearing news of two interesting space talks planned for the museum in June.

John M. Logsdon, founder of the Space Policy Institute and considered by many to be the dean of U.S. space policy, will discuss his new book, After Apollo?: Richard Nixon and the American Space Program. The book is part of the series of Palgrave Studies in the History of Science and Technology. In it, Logsdon takes a look at how President Nixon and his administration impacted post-Apollo space policy. Logsdon gave something of a preview of his presentation here in Seattle at the meeting of the American Astronomical Society in January. You can read our coverage of that talk to learn that Logsdon doesn’t think very highly of Nixon’s approach. Logsdon is scheduled to speak at 2 p.m. Saturday, June 13, 2015 in the William M. Allen Theater at the museum.

The following weekend Rob Manning will be in town to tout his aptly titled book, Mars Rover Curiosity: An Inside Account from Curiosity’s Chief Engineer (Smithsonian Books, 2014). Manning, who is indeed the chief engineer for the mission, will discuss the challenges of getting such a large and complicated robot safely to Mars to conduct science. Manning’s talk, also in the Allen Theater, will be at 2 p.m. Saturday, June 20.

You can pick up copies of the books by clicking the links or cover photos above, or by visiting the Seattle Astronomy Store. Keep track of any schedule changes by watching the Museum of Flight website. These events are so new that, as of this writing, they weren’t yet listed on the museum’s online calendar. We’re planning to cover both talks.

FacebookTwitterGoogle+EvernoteShare

The Lyrids are here! Seattle Astronomy calendar, week of April 20

Astronomy Day is this Saturday and several local astronomy groups are observing the event. Check out the Lyrid meteor shower and celebrate the 25th birthday of the Hubble Space Telescope, too.

adlogoAstronomy Day began in 1973 as an effort to bring astronomy to the people. Doug Berger, then president of the Astronomical Association of Northern California, decided that rather than try to entice people to travel long distances to visit observatory open houses, they would set up telescopes closer to where the people were, busy urban locations like street corners, shopping malls, and parks. Now a program of the Astronomical League and 13 other organizations, Astronomy Day features hundreds of events around the United States and the world.

Locally there are several events planned. The Everett Astronomical Society will celebrate Astronomy Day from 10 a.m. until 5:30 p.m. Saturday, April 25 at the main downtown branch of the Everett Public Library. They’ll have solar telescopes for views of the Sun, plus displays of meteors, telescopes, and other information. In addition, EAS will hold public star parties both Friday and Saturday evenings from dusk until around midnight at Harborview Park between Everett and Mukilteo.

Seattle Astronomical Society will hold public star parties Saturday evening at Green Lake in Seattle and at Paramount Park in Shoreline. Both get under way at about 8 p.m. The Tacoma Astronomical Society will hold its public night at the Fort Steilacoom campus of Pierce College, with a presentation about space exploration at 7 p.m. and 9 p.m.

Happy birthday to Hubble

Hubble25th-1024x663The Hubble Space Telescope was deployed April 25, 1990. This weekend we celebrate a quarter century of Hubble’s amazing photos and innumerable scientific discoveries.

The Pierce College Science Dome will host a birthday party from 5 p.m. until 8 p.m. Friday, April 24. The event will include a live stream of the National Air and Space Museum celebration, hands-on science projects, and a planetarium show about Hubble.

Watch for our own Hubble article later in the week.

Lyrid meteor shower

Watch on all clear nights this week for Lyrid meteors. The annual shower will peak on the evening of Wednesday, April 22 to the wee hours of the morning on the 23rd. Look toward the radiant in the northeast sky. This EarthSky page tells all you need to know about the Lyrids.

Talk, talk, talk

There are three promising astronomy talks scheduled for Wednesday evening, and the more dedicated listener might be able to catch at least parts of all three.

AOT2 posterThe Museum of Flight celebrates Earth Day all day April 22, capped by a talk at 4 p.m. by former astronaut Ed Lu. Dr. Lu, now CEO of the B612 Foundation, will give a talk titled “Defending Earth From Asteroids” about the foundation’s proposed Sentinel mission to watch for potential killers. Check our coverage from a news conference with Lu last year to learn more about Sentinel.

Solar System Ambassador Ron Hobbs will give a talk at 6:30 p.m. at Explorer West Middle School in West Seattle. Hobbs will discuss discuss comets, dwarf planets and the Mars Rover and how missions to these new frontiers will impact life on earth, now and far into the future.

The second Seattle iteration of Astronomy on Tap will be held Wednesday evening beginning at 7 p.m. at Bad Jimmy’s Brewing Company in Ballard. Topics of talks by University of Washington astronomy graduate students will include supermassive black holes, and the extreme seasons on the recently classified Game of Thrones planet. And there will be beer.

FacebookTwitterGoogle+EvernoteShare

Seattle Astronomy Calendar, week of April 13

A visiting author is the highlight of the week’s astronomy events, and the Moon will be involved in two interesting observing opportunities in the next seven days.

Does general relativity baffle you? Dr. Jeffrey Bennett says you’ll come away with a grasp of the concept if you attend his talk at Wednesday’s meeting of the Seattle Astronomical Society. Bennett is the author of What Is Relativity?: An Intuitive Introduction to Einstein’s Ideas, and Why They Matter (Columbia University Press, 2014.) The meeting begins at 7:30 p.m. April 15 in room A102 of the Physics/Astronomy Building on the University of Washington campus in Seattle. Check our preview article from last week for more about Bennett and the talk.

More talks

Theodor Jacobsen ObservatoryAlso on Wednesday the UW hosts one of its bimonthly open houses at the Theodor Jacobsen Observatory. Tom Esser, a senior in the Aeronautics and Astronautics Program at the university, will give a talk titled, “The Solar System: Planets, Spacecraft, and Rockets!” It will be a jaunt through the solar system, covering the spacecraft we have sent to the planets and some of their moons, and the rockets we used to get them there. Weather permitting, visitors will be able to get a look through the observatory’s vintage telescope, operated by volunteers from the Seattle Astronomical Society. Reservations for the talk are highly recommended, as the classroom where they’re held is relatively small. The events get under way at 8 p.m. April 15 at the observatory.

Another UW student will give a talk Thursday at Town Hall Seattle. Paige Northway, a student in UW’s Earth and Space Sciences Department, looks at magnetic field measurements in space, and the critical work played by magnetometers on small satellites. Her talk begins at 6 p.m. April 16 at Town Hall. It’s part of the UW Science Now lecture series.

Observing

The Moon will be part of some interesting celestial sights this week. On Wednesday evening Neptune will be easy to find, just four degrees south of the Moon. You’ll need a telescope to spot the most distant planet. At dusk Sunday a super-thin crescent Moon bunches up with Mars and Mercury low in the western sky. Mars and Mercury are drawing closer together; they’ll be just 1.3 degrees apart by April 22.

Check This Week’s Sky at a Glance, from Sky & Telescope magazine, for other observing highlights for the week.

Yuri’s Night

LogoYurisNight_WHITEring_TRANSPARENTbackground250x250Yuri’s Night, marking the 54th anniversary of Yuri Gagarin becoming the first human in space, was last Sunday, but the celebration rolls on at Pearson Air Museum in Vancouver, Washington, which will hold a Yuri’s Night World Space Party Saturday, April 18, beginning at 5 p.m.

FacebookTwitterGoogle+EvernoteShare

Bennett talk Wednesday at SAS: general relativity made easy

Dr. Jeffrey Bennett says you don’t have to have the brain of an Einstein to understand general relativity.

“If you want to deal with all the mathematics of it then it is pretty complex,” Bennett says, “but if you want to just understand it on a conceptual level, it’s not that difficult to get a general grasp of it.”

Bennett, the author of of What Is Relativity?: An Intuitive Introduction to Einstein’s Ideas, and Why They Matter (Columbia University Press, 2014), will talk about the book, and relativity, at next week’s meeting of the Seattle Astronomical Society. The meeting, which is free and open to the public, begins at 7:30 p.m. Wednesday, April 15, in room A102 of the Physics/Astronomy Building on the campus of the University of Washington in Seattle. There’s still time to pick up the book, by clicking the link above or the cover to the left, before the talk.

Seattle Astronomy spoke earlier this week with Bennett, an adjunct research associate with the Center for Astrophysics and Space Astronomy at the University of Colorado. He says his Relativity Tour is a bit of an accident of timing. He’d been thinking about writing a book about relativity for several years. When the book came out last year it was just in time for the centennial of Einstein’s breakthrough, and Bennett decided to do his part for the International Year of Light and help the general public understand general relativity and how it makes so many everyday things possible.

Einstein was right

While Einstein proposed general relativity one hundred years ago, Bennett notes that many people still think of it as new physics, and others still strive to prove Einstein was wrong, but Bennett says that’s not going to happen.

“You can’t do that because it has checked out so much; you can’t make the evidence where it does check out go away,” Bennett explains. “In the same way, Einstein didn’t show Newton to be wrong. What you’re really looking for is to see if we can find a place where Einstein’s theory is not yet complete, and we need something else to take us to that next level.”

A good example of such a place is trying to find agreement between general relativity and quantum physics.

“That’s the known hole in our current understanding,” Bennett says. “Even though both work extremely well in the regimes in which they’ve been tested, they don’t quite meet up, and therefore there must be something else that we have not yet figured out that brings them together.”

Relativity for all audiences

Dr. Jeffrey Bennett

Dr. Jeffrey Bennett

Bennett, a recipient of the American Institute of Physics Science Communication Award in 2013, speaks to a wide variety of audiences, from adults down to elementary school kids, and has written children’s books as well as college texts.

“The commonality across all of the work that I do is that it’s all aimed at people who are not really very familiar with science and math, and in some cases, with the older audiences, maybe thinking they’re sort of afraid of these topics,” he says. “I’m always dealing on that introductory level—what science is and why you should care about it. When you’re dealing with it at that level, it’s not really that different to deal with children or with grownups, because either way you’re dealing with the same lack of knowledge and lack of understanding.”

Bennett recommends the talk he will do Wednesday for people from middle school on up, though he says younger kids often understand it as well.

“Come with an open mind,” he urges. “Even if you think this is something that you can’t understand, I think you’ll find you actually can, so I hope people will come in that spirit.”

More reading

FacebookTwitterGoogle+EvernoteShare