Category Archives: lectures

Comet hunter Machholz to keynote annual Seattle Astronomical Society banquet

Don Machholz

Comet hunter Don Machholz will keynote the Seattle Astronomical Society annual banquet Jan. 24.

The Seattle Astronomical Society always seems to score interesting speakers for its annual banquet, and this year is no exception. Renowned comet hunter Don Machholz will give the keynote talk at the 2015 banquet Saturday, January 24, at the Swedish Club, 1920 Dexter Avenue North in Seattle.

Machholz is a prolific comet finder; he has eleven comet discoveries listed to his credit. The first was Machholz 1978L, discovered in September of that year after more than 1,700 hours of observing. The most recent was comet C 2010 F4 (Machholz). All of his discoveries have been made visually, quite a record in these days of digital cameras, computers, and space telescopes joining in the hunt.

Machholz is also considered to be one of the creators of the Messier marathon, an challenge to astronomers to observe all 110 objects in Charles Messier’s catalog in one night. Machholz has written a guidebook, The Observing Guide to the Messier Marathon: A Handbook and Atlas, published by Cambridge University Press in 2002.

Machholz has written several other books. Decade of Comets chronicles the comets discovered visually between 1975 and 1984. An Observer’s Guide to Comet Hale-Bopp came out in 1996.

It should be a most interesting evening.

Tickets to the banquet have been available for members of the Seattle Astronomical Society for several weeks, and went on sale to the general public today. The cost is $40 for members, and $50 for non-members. But why not sign up? Membership is just $35 annually. The Jan. 24 event will begin with a happy hour at 5 p.m., followed by a buffet dinner at 6 p.m. and the program at 7 p.m.

Further reading:

Don Machholz website


Spotting black holes

Black holes remain among the more mysterious objects in the universe. Though John Michell and Pierre-Simon LaPlace first posited their existence back in the 18th century, nobody has ever actually seen a black hole. Dr. Sean O’Neill, visiting assistant professor in the Department of Physics at Pacific Lutheran University in Tacoma, attempted to shed some light on these objects that don’t emit any during a talk at this month’s meeting of the Seattle Astronomical Society.

Steve O'Neill

Dr. Steve O’Neill of PLU spoke about black holes at the December meeting of the Seattle Astronomical Society. Photo: Greg Scheiderer.

O’Neill’s talk was titled “If We Can’t See Black Holes, How Do We Know They Exist?” His answer to the question boiled down to the notion that scientists have not yet come up with any other plausible explanation for some of the phenomena that they have seen.

The professor noted that traditional methods of observing astronomical objects simply are not practical for viewing black holes.

It would not work to send a spacecraft for a look. O’Neill pointed out that the nearest likely black hole is some 1,300 light years away from Earth. It would take a craft like Voyager about 25 million years to get there, and then, even if it arrived with its power source and transmitter intact, you would still have to wait 1,300 years to receive any messages about its findings.

“Traveling there is a terrible option,” O’Neill understated. “The direct visit option is bad even for things in the outer solar system, let alone things outside of our solar system.”

Imaging is also well nigh impossible, O’Neill said, and not just because a black hole, by definition, does not emit any light. Black holes, though incredibly massive, are also dense and quite small. Today’s telescopes don’t offer adequate resolution for a visual or photographic look; it would take a scope about ten thousand times the size of Hubble to spot the supermassive black hole at the center of the Milky Way.

Other methods offer some hope. O’Neill says we might well be able to spot the gravitational effects of a black hole, especially one circling another or dancing gravitationally with another massive object. In such cases general relativity predicts gravitational waves in space-time, and these might be observed directly. The approach is to use laser interferometry to detect changes in light wavelength. O’Neill says it’s a complicated process from which it is difficult to separate observational noise.

“In practice, there have been no detections of this phenomenon happening yet, even though most people think it probably does happen,” O’Neill said.

O’Neill says gravitational lensing also holds some promise, especially as observing equipment gets better.

“It’s tough to pick out the individual little black holes, though,” he said, noting that the method is used to look at distant, large, massive objects that lens other distant objects.

Though we haven’t yet seen a black hole, there’s plenty of evidence that infers that they exist. O’Neill shared data from observations of stars orbiting the center of our galaxy, seen in the infrared to cut through the dust blocking our direct visual view. Using Newton’s laws on the data from a number of years to reconstruct the orbits of the stars suggests they’re going around something that is about 3.7 million times more massive than our Sun. Whatever it is, we can’t see it because it doesn’t emit any light of its own.

“It’s tough to come up with a good alternative of what this could be,” O’Neill said. “It’s tough to imagine that gravity just goes wrong at this one point, for some reason, at the center of our galaxy.”

“That’s where we get a lot of direct evidence for what we think is the black hole at the center of our own Milky Way,” he concluded.

Looking at other objects leads to similar conclusions. Cygnus X-1 is a huge source of x-rays that is pulling material from a donor star nearby. The material holds a great deal of potential energy because of the high gravity of the system.

“All of that energy has to be converted into some form,” O’Neill explained. “Some of it is certainly kinetic, because stuff will speed up, but some of it is also going to be thermal energy. It will hit other little particles of gas, all of this will heat up to the point that it starts emitting x-rays, and that’s the stuff that we think we can see.”

One of O’Neill’s research interests is computer modeling of the jets of material often spotted shooting out of the centers of galaxies, such as Centaurus A. He shared a number of these simulations, in which material plummets toward a presumed black hole, doesn’t quite fall in, and then shoots away at great velocity. The models can be rotated to simulate views from various angles and compare the results to actual observations. While it’s an active area of research, O’Neill says most scientists are on the same page with their thinking.

“The reigning theoretical model for these jets by far—there’s essentially no viable alternative—is that fundamentally they’re powered by black hole gravity at the source,” he said.

While O’Neill notes that computer simulations like the ones he creates are way cheaper than observing, he expects that actual observations of gravitational waves from merging black holes are not far off. He also thinks that high-resolution x-ray and radio observations will allow us to see the disks of material around black holes within his lifetime.


Asteroid mining: not such a crazy idea

When Bellevue-based Planetary Resources, Inc. first went public in April of 2012 with its plans to mine astroids for water and minerals there were many who reacted with an “Oh, pshaw.” Less than three years later, the successful landing by the ESA Rosetta mission of its probe Philae on the comet 67P/Churyumov–Gerasimenko, out in the far reaches of the solar system, makes it all seem like a more plausible idea.

“I love seeing the success of this mission because it proves that what we are doing is technically feasible today,” said Caitlin O’Keefe, director of marketing for Planetary Resources, on Tuesday during a Science Café talk sponsored by the Pacific Science Center at The Swiss Pub in Tacoma. O’Keefe added that Philae and Rosetta are ten-year-old craft that have spent a decade traversing six billion kilometers of space. Technology has advanced during that time; think about what your cell phone couldn’t do in 2004.

Caitlin O'Keefe

Caitlin O’Keefe, marketing director for Planetary Resources, spoke about asteroid mining at a Science Café event Tuesday in Tacoma. Photo borrowed from Facebook.

O’Keefe and everyone at Planetary Resources understand the skepticism. She quoted company co-founder Peter Diamandis as saying, “The day before something is a breakthrough it is a crazy idea.”

They’re creating the technology today to get themselves to that breakthrough. Advances in spacecraft control, avionics, communication systems, propulsion, and observation will help them identify and then get to resource-rich asteroids.

Unfortunately, one of their first tests of the technology went up in flames. Their Arkyd 3 satellite, which was to try out some of their new systems, blew up with the Antares rocket back in October.

“This was a bummer for our team to watch,” O’Keefe said. “There was a big hooray when it launched, and some not so nice words when it exploded six seconds later.”

But, she added, they’ve been able to shrug it off, in large part because their philosophy is to build a lot of small and relatively inexpensive spacecraft rather than putting all of their space-bound eggs into one billion-dollar basket.

“This is going to be a very important part of the space industry going forward: the ability to accept failure,” she said.

Many of the questions from the patrons of The Swiss during the talk centered around the financial aspects of mining in space. O’Keefe noted that there is a lot of potential. For example, one target astroid is thought to contain some $500 billion worth of platinum, which if mined would be more than has been extracted from Earth to date. While that could be a big payday, their first target is a more common substance: water. Water is good for drinking and protection from radiation, and can be turned into rocket fuel. And O’Keefe pointed out that it’s a lot cheaper to pick up water in space than it is to take it with you. To launch a bottle of water into low-Earth orbit you need about 50 times its mass in rocket fuel, and that pencils out to about $20,000. The savings add up, and it will make long space missions much more fiscally possible; a spacecraft can go all the way from Earth to Pluto on the same amount of fuel it takes just to launch into low-Earth orbit.

Mining may well be easier in the zero gravity of space, too, and the methods for doing it are pretty straightforward.

“Building this technology will be extremely difficult,” O’Keefe admitted. “I’m not downplaying the difficulty of a complicated system, but the theory of how to extract it is pretty well known.”

O’Keefe invited us all to join the asteroid mining effort. You can go to Asteroid Zoo, a venture launched this summer by Planetary Resources and Zooniverse, to help comb through data and identify potentially resource-rich asteroids.


Science jargon and the all-there-is

Sometimes when scientists speak nobody has the foggiest idea what they’re talking about. Even other scientists can have trouble decoding the lingo of colleagues from other specialties.

Roberto Trotta thinks that’s a problem. A theoretical astrophysicist with Imperial College in London, Trotta is also passionate about good communication about science. As science communicators ourselves, Seattle Astronomy was excited to hear his recent talk at Town Hall Seattle.

The Edge of the Sky“I’m very much interested in sharing the mysteries and the outstanding questions that cosmology raises with the public at large,” Trotta said. “It’s only fair that we share our ideas and the reasons why we do what we do with the people who are actually funding the work. To me, talking about science in a way that’s understandable and utterly engaging for the public is a very important concept.”

Trotta’s new book, The Edge of the Sky: All You Need to Know About the All-There-Is, uses just the 1,000 most common English words to explain what he does in his day job. That’s a tall order; Trotta had to write about cosmology without using words like telescope, galaxy, Big Bang, universe, and dark energy, none of which made the list.

“This book came out of a little idea that it should be possible to talk about very hard things in a straightforward way that all people can understand,” Trotta said.

It doesn’t always happen that way. Trottoa told the story of Arno Penzias and Robert Wilson working at Bell Labs in New Jersey in 1964. The two were using a new antenna to detect radio waves, but were having trouble eliminating persistent background noise. Eventually they wrote a short paper titled “A Measurement of Excess Antenna Temperature at 4080 MC/S.”

Roberto Trotta

Roberto Trotta talked about his book “The Edge of the Sky” Sept. 30 at Town Hall Seattle

“What these two gentlemen were trying to say is ‘We picked up the echo from the Big Bang!'” Trotta marveled. They had found the cosmic microwave background and eventually received a Nobel Prize for the work. Trotta gave other examples of scientific papers with language that he called “impenetrable” and “incomprehensible.”

“Jargon is in the way,” he said. “Jargon is one big obstacle in having a dialog with the public.”

Trotta’s first shot at the 1,000-word concept was describing his own job in this simple, straightforward language during a public lecture. It received a positive reaction at that talk, as it did at Town Hall, and so he decided to take the concept further.

“The book began very much as an experiment because I wanted to see how far I could stretch this language,” he explained. “Would it break? Would it become boring? Would it become impossible?” He wondered whether complicated concepts such as dark matter could be explained in such simple terms.

It worked, and early reviews of the book have been positive. Trotta said that writing the book was almost like learning a new language. There were a few hiccups along the way. He first thought of translating “Big Bang” to “Hot Flash.” This turned into “Big Flash” for obvious reasons. Other terms in The Edge of the Sky:

  • Universe: The all-there-is
  • Galaxy: Star crowd
  • Telescope: Big seer
  • Dark energy: Dark push
  • Earth: Home world

Trotta said that since the book began as a thought experiment he really didn’t have a target readership in mind, but that he hopes it will appeal to readers from young adult on up who want to get a better grip on the sometimes challenging but always fascinating topics of cosmology.

The Edge of the Sky is worth a look.

Other reading:

Roberto Trotta’s website
The 1,000 word list



Ride, Sally, ride

Journalist Lynn Sherr was good friends with astronaut Sally Ride for more than thirty years, but when Ride died in 2012 Sherr said she knew neither of Ride’s diagnosis of pancreatic cancer, nor knew for certain of her twenty-seven-year relationship with science writer Tam O’Shaughnessy.

“Sally was very good at keeping secrets,” Sherr said during a recent talk at Town Hall Seattle while promoting her biography of the astronaut, Sally Ride: America’s First Woman in Space.

Sherr met Ride in 1981 when she was on track to fly on the space shuttle and Sherr was newly appointed to the ABC Television News team covering space missions. Sherr laughed at the notion of joining Frank Reynolds, who covered NASA from the beginning of the space program, and Jules Bergman, whom, she said, “practically invented the field of science journalism.”

“Then there was me—who took botany in college to get around my science requirement!” Sherr joked. “I was the color guy.” Ride was among her first interviews, and Sherr said they soon became fast friends.

“We shared a very healthy disregard for the overblown egos and the intransigence of both of our professions, and beneath her very unemotional demeanor, which some found icy, I found a caring and a witty friend,” Sherr said.

Sherr explained that she understands why it took a quarter century of the space program before NASA finally put a woman in space. In the beginning, the need was for military pilots with security clearances, which meant virtually all of the candidates were white men. But when the shuttle program came along, they had bigger crews and needed scientists, so NASA created the position of mission specialist.

“That’s what they started looking for when they reached out to women and minorities starting in 1976,” Sherr said. “All of this, of course, opened the door for people like Sally Ride.”

Ride originally wanted to be a tennis pro but was headed for an academic career when she saw a notice in the Stanford Daily that said NASA was recruiting women. She applied for the gig, and a year later was part of a thirty-five-member astronaut class that included six women, three African American men, and one Asian American man.

“NASA was suddenly looking like the poster child for multiculturalism,” Sherr said, “and all credit to them.”

Ride flew on the shuttle in 1983, and upon her return from being the first American woman in space received a call from President Ronald Reagan, who told Ride she was the best person for the job.

“Millions of other women agreed,” Sherr said. “I think what they did was translate her bold journey into their own tickets for success. Sally became an icon; the can-do symbol of what we can do in the world.”

Photo (9)

Journalist Lynn Sherr spoke about Sally Ride and her new biography of the first American woman in space during an appearance at Town Hall Seattle.

Sherr said she never fully appreciated the “psychic price” her friend Ride—an extreme introvert and naturally shy person—paid for her celebrity, and felt especially sorry that Ride didn’t feel able to go public with her romantic relationship with another woman, O’Shaughnessy.

“I think it’s also part of her story, because hers is a story of a particular time and a particular place and a woman who had the brains and the agility to sieze the moment,” Sherr said. “When Sally was born in 1951 outer space was science fiction and women’s rights were marginal. The social advances and the lucky timing that would enable both to intersect with this life of a very gifted young scientist I think makes hers an inspiring lesson in modern American history. She took full advantage of the ever-widening definition of a woman’s place, and spent much of her life making sure it was everywhere. That she could not or would not openly identify herself as a gay woman reflects not only her intense need for privacy, but the shame and the fear that an intolerant and ignorant society can inflict even on its heroes.”

Sherr said Ride’s life is one for the history books.

“She proved that you don’t need the right plumbing to have the right stuff, in any field or any endeavor.”


Celebrating 10 years at Saturn

The Cassini spacecraft went into orbit around Saturn ten years ago, on July 1, 2004 in universal time. Ron Hobbs, a solar system ambassador of the NASA Jet Propulsion Lab, says some of the mission’s most exciting science has occurred quite recently.

10 years at SaturnHobbs spoke at the most recent meeting of the Seattle Astronomical Society about Cassini’s decade at Saturn, and notes that recent measurements of the gravitational field of the moon Enceladus have yielded some interesting findings.

“We are very confident that there is body of liquid water at the south pole that extends at least to 50 degrees south latitude on Enceladus,” Hobbs says. “There’s a body of water that’s in contact with rock. We know that some of the ice particles that get shot out into the E-ring have salt and organics in them. This has become on a very short list of places in our own solar system where we might find life.”

Mars and Jupiter’s moon Europa are two others on what Hobbs calls the “astrobiological short list.” Many scientists believe that life on Earth may have originated in hydrothermal ocean vents—a safe haven during the heavy bombardment era—and so it’s reasonable to suspect that life might thrive in similar environments elsewhere in the solar system.

Hobbs calls Cassini “the largest, most complex, and capable spacecraft ever built” and notes that we may owe its existence to persistent Europeans. There was some talk in the mid-’90s that Congress would scrap the mission before it got off the ground because of budget concerns. But the Europeans had already built the Huygens probe that hitched a ride on Cassini in order to do a study of the atmosphere of the moon Titan. Hobbs says word is that protests about the proposed cuts made it all the way to the vice president.

“The fact that we have Cassini, as far as I’m concerned, is in large part due to the fact that the Europeans had the guts to talk to the U.S. government and say, ‘You don’t renege on your promises,'” Hobbs says.

Like the Mars rover missions, Cassini has far exceeded the time allotted for its original scientific mission.

“The plan for Cassini when it arrived in July of 2004 was to study Saturn for four years,” Hobbs notes. “Cassini is still one of the healthiest spacecraft we have anywhere in the solar system. All of its instruments are working great, it’s got fuel.” Nonetheless, Hobbs says he occasionally hears talk that Congress again is considering pulling the plug on the mission. He says that would be a bad idea, as we still have a lot to learn.

The NASA video below gives a preview of the work they’re planning for Cassini over the next four years.


Seattle as sundial capital of North America

“I am passionate about sundials,” says Woody Sullivan, professor of astronomy at the University of Washington. “I have a goal to turn Seattle into the sundial capital of North America.”

Most of us don’t think of Seattle as the capital of anything related to the Sun, and we’re especially grumpy about it in the midst of a relentlessly gloppy March. But Sullivan points out that the second half of our year has long, clear days, and he observes that while people in, say, Phoenix often seek to escape from the Sun, we celebrate it.

“In Seattle, when the Sun comes out you go running out to see your sundial!” Sullivan says.

Sullivan gave a talk titled “Sundials Around Seattle and Beyond: Fascinating Mixtures of Astronomy, Art, Design, and History” at a recent meeting of the Eastside Astronomical Society in Bellevue. While the designation of sundial capital is hardly an official one, Sullivan thinks Seattle is on the way because of its large collection of interesting, well-cared-for public sundials.

The sundial on a SW-facing wall of the University of Washington Physics/Astronomy building was the first Sullivan helped build and design, 20 years ago.

The sundial on a SW-facing wall of the University of Washington Physics/Astronomy building was the first Sullivan helped build and design, 20 years ago.

Sullivan’s academic interests include astrobiology, the search for extraterrestrial intelligence, and the history of astronomy. His passion for sundials came about almost by accident. When the UW was constructing a new physics/astronomy building in the early ’90s, he suggested that a sundial should be placed on one of its large, outside walls. The architects went for it, and Sullivan spent a couple of years supervising the design and installation of the sundial.

“This is what got me into sundials, and ever since my life has been changed,” he says.

Inspired by the design of a sundial at the Sorbonne in Paris, the UW dial is on a wall that faces southwest. That means it’s design is asymmetrical, “which I think is more interesting from an aesthetic point of view,” Sullivan says.

Sullivan notes that all good sundials have a motto, and the one for the UW dial is “What you seek is but a shadow.”

“I thought that was good for a university,” he says. “It feels like it’s making progress.”

In a nod to our northwest weather the dial also is inscribed with a little poem:

I thrive on the Sun
Can’t work in the rain
So if I’m beclouded
Please come back again.

There’s a wealth of information about the UW dial on the web, including a webcam.

If you visit a Seattle sundial you will notice that the it doesn’t agree with your watch.

“Sundials do not tell you clock time,” Sullivan explains. “Your watch is off because we keep the same time as the people in Spokane. That ain’t right! Solar noon”—the moment when the Sun is due south and highest in the sky—”happens there 20 minutes before it happens here.”

Mars dials.

Sullivan helped design pancam calibration targets like this one that also serve as sundials on the three rovers on Mars.

Sullivan gave us a look at numerous other sundials in the area, and he’s had a hand in the design and construction of many of them. They’re in parks and at schools and even on picnic tables. He supported the Battle Point Astronomical Association in its successful effort to fund a new sundial on Bainbridge Island which is scheduled to be completed this summer.

In addition to all of those here on Earth, Sullivan also helped design three sundials that are now on Mars. The rovers Spirit, Opportunity, and Curiosity all have targets that are used for color calibration of their cameras in light and in shade. Bill Nye the Science Guy, who is now CEO of the Planetary Society, saw a mockup of the target, a disk with a post in the middle of it, and immediately thought it should be a sundial. Nye got Sullivan involved in the design. Coincidentally, Tyler Nordgren, astronomer who keynoted the Seattle Astronomical Society‘s annual banquet in January, was also part of the team that put it together.

Woody Sullivan

Woody Sullivan brought a variety of small sundial samples to his talk, and the conversation continued well past the end of his formal presentation.

There’s also a bit of baseball on the Red Planet. As Sullivan and Nye share a passion for baseball in addition to their love of sundials, they made weight-saving cutouts in the bases of the Mars dials in the shape of home plate. Seattle’s Museum of Flight has Sullivan’s copy of the Mars dial on display in its space gallery.

Sullivan’s talk was tremendously well received. One EAS member noted that she switched her scheduled night at the opera to be at the talk instead. Staff at the library at which the talk was held booted us out well after closing time, and even at that the discussion continued in the parking lot for a good 45 minutes more.

Check out Sullivan’s sundial trail website for a guide to visiting Seattle sundials.

Other reading: