Tuesday, May 31, 2022

Secret Science Club Zoom Lecture Recap: The Last Stargazers

Tonight, my great and good friends of the Secret Science Club are presenting a Zoom lecture with astronomer and astrophysicist Dr Emily Levesque of the University of Washington.  Dr Levesque's new book is The Last Stargazers: The Enduring Story of Astronomy's Vanishing Explorers.  Dr Levesque has used some of the most sophisticated telescopes, including using NASA's SOFIA flying observatory.

Dr Levesque has studied the birth and death of the most massive stars.  The Last Stargazers is her first popular science book.  She noted that 2020 was a difficult year for releasing books, and noted that, at a library association meeting, the topic of the importance of first lines in books are extremely important.  She joked that the first line of her book is: "Have you tried turning it off and on again?"  It was uttered to her while she was a 24 year old grad student working at the Mauna Kea observatory on her PhD thesis on the topic of the environments where stars were dying.  There was an unsettling 'bloonk' noise, and the technician noted that she thought it was okay, because she didn't hear the crash of the mirror falling off its supports.  In a worst-case scenario, the secondary mirror would crash into the huge primary mirror (about nine meters in diameter).

She was the astronomer in charge and she'd heard horror stories about the destruction of telescopes, such as the Green Bank radio telescope in West Virginia.  She knew that leaving the telescope would mean giving up research time if it were a false alarm, but if there was a worse case scenario, she would have presided over the breaking of the world's largest piece of glass.

Dr Levesque noted that images of space are beautiful and fire the public imagination.  She briefly touched on the image of the astronomer as a man in a white lab coat, an image she wants to supplant.  She wanted to be a scientist ever since she was a six year-old.  The summer after her second year as a physics student in MIT, she worked at the Kitt Peak observatory.  She was advised by her professors' colleagues to make sure to drink coffee, but not too much, to remember to order a nighttime lunch, and was warned that there were scorpions that matched the color of the carpets.  She listened to stories of lightning strikes and raccoon run-ins, and was itching to make stories of her own.  These stories of behind the scenes adventures make up her book.

Dr Levesque had adventures of her own while writing the book, visiting telescopes and labs she'd worked in before, interviewing fellow astronomers.  She's not an investigative reporter, but she figured out how to glean stories from researchers, and piece together a common thread

What is your most memorable observing story, whether firsthand or tenth-hand?  She wanted not only anecdotes, but legends of the field, such as the Green Bank collapse.  One major topic of interest was a 2007 discovery by the Parkes Observatory in Australia of weird radio bursts, a strange signal to encounter.  The data was filed away to be researched later.  A lot of things give off latent radio signals, such as cell phones, spark plugs, all sorts of electronics.  A grad student, Emily Petrov, decided to research these mysterious signals, dubbed Perytons.  A lot of these Perytons occurred around lunchtime, so the microwave was considered suspect.  The scientists acted like astronomers, not hungry people opening the microwave a bit early, which was detected by the radio telescope as a Peryton... except for the initial burst, which was determined to come from Elsewhere.  These fast radio bursts occasionally occur, and might emanate from dying stars.

In the case of the LIGO gravitational-wave observatory, which uses miniscule (1/1000th of the diameter of a proton) 'squishing' of the arms of the observatory to detect gravitational waves.  The sensors are good at filtering out signals from trucks or footsteps, but one hot summer, suspicious readings were apparent- due to iced over pipes of liquid nitrogen.  Local ravens were pecking the ice condensed on the pipes as a source of water in the eastern Washington desert.  The raven was caught in the act, and measures were taken to prevent these peckings from occurring in the future.

What would surprise people the most about our jobs?  One major thing is that the telescopes now in use typically don't have eyepieces.  Also, the job is more exciting than most people would realize.  Dr Levesque mentioned the SOFIA flying observatory, a plant-mounted infrared telescope.  Infrared light often doesn't reach the Earth's surface, it bounces off of atmospheric water vapor.  SOFIA is above that layer, and Dr Levesque used the telescope to research dying stars.  She noted how excited six year old her would have been about the prospect of flying in an experimental plane over Antarctica and seeing the Southern Lights.  She talked with astronomers who did research at the South Pole and up in Svallbard.  She talked about astronomers using weather balloon mounted telescopes.  She mentioned George Carruthers, inventor of ultraviolet cameras, including one transported on Apollo 16 to the moon.   She also mentioned Doug Geisler, who on May 18, 1980 at the U of Washington's Manastash Ridge observatory, having a lovely clear night... the next day, he woke in the midst of an ash cloud resulting from the Mt St Helens eruption, which resulted in a lost night of observation.

How has astronomy changed since you began observing?  The biggest answer was improving technology.  Up until the 1980s, images were made using thin glass plates covered in silver nitrate.  Kodak would send many plates, but they had to be cut to size and tweaked to improve image quality before being inserted into telescope cameras one-by-one.  Amazing research was conducted using these plates.  Astronomers using these glass plates figured out the shape of the universe.  Now, digital images are created, the difference is incomparable, with dust being visible, and the shape of a galaxy's arms being detailed beautifully.  The work of astronomers has differed- astronomers used to have to apply for observation time, and travel to observatories.  Now, telescopes such as the Vera C. Rubin Observatory under construction in Chile, will be taking continual images of the night sky through an automated process.  Dr Levesque and her colleagues don't have to apply to use the data, they can just log in and download data.  The adventure and experience will be differed, involving fewer scorpions and raccoon encounters

Dr Levesque brought up the topic of Thorne-Zytkow objects, binary stars orbiting each other, in the process of dying.  One star will collapse into a neutron star and get swallowed by the companion, which transforms into a red giant with a core replaced by the neutron star.  Dr Levesque's team discovered a potential Thorne–┼╗ytkow object using the Las Campanas observatory in Chile.

This wouldn't have been discovered using the pre-programmed Rubin observatory, but the Rubin observatory can provide data which can prove to be Thorne-Zytkow objects.  Giant observators such as Rubin are needed, as are smll mountaintop observatories, SOFIA type creative telescopes, and radio telescopes.  Curious stargazers are needed as well as computational processes.  We must combine these approaches to continue the process of discovery.

The lecture was followed by a Q&A session.  The first question involved the depiction of celestial phenomena in art, such as a 1054 supernova depicted on a cave painting, the supernova that resulted in the Crab Nebula.  Are any of these telescopes open to the public?  Kitt Peak observatory in Arizona and Mauna Kea were open to the public during the day, but nighttime visits are off-limits because of light polution from headlights.  Another question involved Vera Rubin's discovery of dark matter through observational methods- at the time, women couldn't be lead researchers, though they had made many astronomical discoveries at the time- Vera Rubin noted gravitational anomalies that proved dark matter existed.  Regarding the imaging of a black hole, the discovery was made by 'a telescope the size of the entire planet', an array of radio telescopes worldwide that obtained that fuzzy donut picture that everybody loves.

Some Bastard in the audience asked about the James Webb Space Telescope, infrared telescope in space, in a cold, dark place far from Earth.  This telescope will be invaluable for studying dying stars.  Recently, Betelgeuse dimmed because it puffed off a cloud of dust that is bright in infrared.  This is going to fill an important niche in studying dying stars, it's the telescope that might find evidence of extrasolar life, it will look further and further back in time than other telescopes.  All astronomers are excited about the 'first light' from this telescope.

Another question involved the collapse of the Arecibo radio telescope in Puerto Rico.  She had never visited Arecibo, though it was on her list.  She received a lot of anecdotes about Arecibo, but it collapsed the year after she released the book.  It was an unparalleled tragedy in the astronomical world... Arecibo detected the first evidence of planets around other stars.  It's the dream of many astronomers to rebuild the observatory.

Another question involved the role of time as well as distance- the universe is about 13.8 billion years old... the naked eye can see objects 400 light years away, from 400 years ago.  As telescopes become more powerful, they reveal the universe at older time periods.

How about extraterrestrials?  Every astronomer dreams of discovering it.  Even Dr Levesque had a moment when she encountered a weird signal at an observatory in the Netherlands, but then realized  that the signal was stronger closer to the admin building, so it was probably someone heating up a stroopwaffel or sending a fax.  She joked that the best phrase in science is not "Eureka!", but "That's weird!"  There are people working on the alien issue, and if they ever discover evidence of aliens, they won't be able to keep it secret.

What pending discoveries is Dr Levesque excited about?  The possibility of detecting life, even intelligent life...  Observing black holes...  Gravitational wave detction... The ability to go from 'we found this one weird thing' to a data driven approach.

How about multi-telescope arrays, interferometry (the use of interference to make multiple telescopes act as one) has to involve closely tracking multiple telescopes such as the Event Horizon Telescope under difficult conditions (such as shifting ice near an Antarctic telescope).  Astronomers dream of setting up an observatory on the Moon and syncing it up with a terrestrial telescope.

How about crowdsourcing science with programs such as Zooniverse, in which citizen scientists can identify different galaxies, such as spiral or elliptical galaxies.  A new form of galaxy was distinguished by citizen scientists.

Where in the universe would Dr Levesque want to go?  She can't pick one place, she wants to discover all sorts of weird stars, but she would love to visit Betelgeuse and that Thorne-Zytkow object she discovered.

Another question involved light pollution, which is an unfortunate occurrence.  There was also the topic of Starlink satellites interfering with observations of the night sky.  These passing satellites rob astronomers of data, producing radio light as well as reflecting visible light.  Astronomers have no say in the regulation of satellite launches, and want to fix the problem of running out of space in space, fundamentally changing the appearance of the night sky.

Another question involved the observed expansion of the universe- distant galaxies appear to be speeding away from us, with more distant galaxies moving at a faster rate.  This discovery was made by Edwin Hubble, using those glass plates.  The best way to determine the possible fate of the universe is through using the Hubble Space Telescope to measure the expansion.  This conundrum has been extremely contentious among astrophysicists, and some evidence (numbers not agreeing) suggests that the expansion might have changed over time.

Regarding getting involved in science, Dr Levesque suggested taking all of the math and computer science you can.  For astronomical observations, a simple pair of binoculars and astronomy apps on your phone are a good start- no need for expensive telescopes.

Who is regulating what goes up into space, if not scientists.  The FCC regulates it, though Dr Levesque notes that there is a conflict of interests.  Scientists and people driven by profits should both be involved.  The American Astronomical Society should get involved to sort out this chaotic situation (a rich enough person can launch a car into space).

Once again, the Secret Science Club has dished out a fantastic lecture.  Dr Levesque's enthusiasm for the topic was infectious, and she hit what I call the 'Secret Science Sweet Spot', that blend of hard science, adventure narrative, and advocacy.  Kudos to Dr Levesque, and Dorian and Margaret for a fun, informative program.  For a taste of the Secret Science Club experience, here is a video of Dr Levesque lecturing on this topic:

Pour yourself a nice beverage and soak in that SCIENCE!!!

3 comments:

Wahld Bill said...

Enjoyed your article very much. As a retired NASA earth scientist it resonated with me.

Big Bad Bald Bastard said...

Thanks. I always enjoy writing these recaps, they force me to bring my A game to blogging. I also like going down various rabbit holes (by which I mean black holes) as I chase down links.

S M McBean said...

Just want to say that I always enjoy these reports. I appreciate your efforts and I always feel like I've learned something, and have long meant to say "Thank You".