Tag Archives: Gregory Laughlin

Seattle Astronomy turns nine; our favorite stories of the year

We’ve been at this for nine years now! The first post on Seattle Astronomy happened January 11, 2011. It’s been a fun ride! On our birthday we’re looking back on our favorite stories of the last 12 months.

Moon landing anniversary

Apollo 11 Command Module Columbia

The big story of 2019 was the 50th anniversary of Apollo 11 and the first human landing on the Moon. We had quite a lot of activity around the anniversary. The best had to be the Destination Moon exhibit at the Museum of Flight, which included the command module Columbia that carried Neil Armstrong, Buzz Aldrin, and Michael Collins to the Moon and back. We wrote about the Seattle exhibit, and were fortunate enough to have seen it in St. Louis during the summer of 2018.

We did a series of talks about the Moon landing for Tacoma Public Libraries, reviewed Dr. David Warmflash‘s fine book Moon: An Illustrated History (Sterling, 2019), made a lunar reading list, and heard an interesting talk by UW astronomy professor Toby Smith about an almost accidental discovery from Apollo 11 that gave us new insight about the formation of the Moon.

AAS visits Seattle

Gregory Laughlin
Gregory Laughlin, astronomy professor at Yale, gave a talk about ‘Oumuamua Jan. 7, 2019 at the 233rd meeting of the American Astronomical Association, held in Seattle. Photo: Drew Dettweiler.

Every four years the American Astronomical Society meets in Seattle, and 2019 was one of those years. Our favorite session of the meeting was a talk by Yale astronomy professor Gregory Laughlin about ‘Oumuamua, the strange interstellar visitor that whizzed through our solar system in late 2018. Our article also included information from  Ka’iu Kimura, executive director of the ‘Imiloa Astronomy Center in Hilo, Hawaii, about how objects discovered by instruments on the islands are being given Hawaiian names.

We’d love to cover more such events even when they’re not held in Seattle. Your support with a subscription through Patreon can help bring that about. Please consider contributing; even a dollar a month will bring us closer to being able to support travel to events of interest to the astronomy community.

Meeting David Levy

David Levy
Seattle Astronomy’s Greg Scheiderer (left) visited with comet hunter and author David H. Levy at the Seattle Astronomical Society banquet Jan. 27, 2019.

The year started off well with a chance to chat with David Levy, author and comet discoverer who was the keynote speaker at the annual banquet of the Seattle Astronomical Society last January. Levy gave an engaging talk about his life and his love of astronomy and writing.

This year’s SAS banquet is coming up on January 25. The guest speaker will be meteorologist and astrophotographer Kerry-Ann Lecky Hepburn, who has had a number of her shots featured on Astronomy Picture of the Day.

Observing highlights

Lunar eclipse
Lunar eclipse of January 2019. Photo: Greg Scheiderer.

Our final two favorite stories of the year involve a couple of observing opportunities, one of which was successful, the other maybe only kind of so!

Back on January 20, 2019 there was a total lunar eclipse. Contrary to our usual weather in January, we got a clear evening and the eclipse was visible from Seattle. It was a good show!

The next total lunar eclipse possibly visible from Seattle will be in May of 2021.

The semi-successful observation was a try at a rare transit of Mercury across the face of the Sun on November 11, 2019. In our story we describe waiting out a possible look at the transit through insistently cloudy skies that morning. Finally there was a Sun break, just minutes before the transit was to end. I thought I caught a fleeting glimpse of Mercury just before it cleared the Sun’s disk, but then, Mercury being speedy of foot, was gone. I and a group of interested folks to gathered at Seacrest Park had fun anyway. We successfully viewed a Mercury transit from there in 2016. The next visible from Seattle won’t happen until 2049.

That’s our recap of the year. We look forward to our tenth anniversary celebration 12 months hence!

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A quick visit from ‘Oumuamua

The first known interstellar object to visit our solar system came and went in a hurry, and didn’t give astronomers much time for observations. The strange ’Oumuamua was first discovered when it zipped past Earth in October, and by December it was already way too faint to see. Gregory Laughlin, astronomy professor from Yale, gave a plenary talk about ‘Oumuamua at the recent meeting of the American Astronomical Society held in Seattle.

Gregory Laughlin

Gregory Laughlin, astronomy professor at Yale, gave a talk about ‘Oumuamua Jan. 7 at the 233rd meeting of the American Astronomical Association, held in Seattle. Photo: Drew Dettweiler.

About a half dozen observatories collected data about ‘Oumuamua as it sped through the inner solar system at 26 km/sec. Laughlin said they computed a highly eccentric path that indicated that the object came from beyond our solar system. Spectra of ‘Oumuamua found it to be red and featureless. Much of the other stuff in the outer solar system, such as trojan asteroids, Kuiper Belt objects, and moons of other planets also are reddish.

“The immediate inference is that ‘Oumuamua is some kind of reddish, icy, volatile-rich body from another planetary system,” Laughlin said, “something that’s been ejected and which has traveled through space for a long time, and which has happened to encounter the solar system.”

Laughlin noted that there are a number of strange attributes of ‘Oumuamua. Even though it passed close to the Sun, there was no sign of coma, so there was no or very little fine dust on ‘Oumuamua. It has an odd period light curve that varies in magnitude by three in the space of hours, and that’s a lot. It suggests that ‘Oumuamua is monolithic. It was accelerating as it headed out of the solar system, a fact discerned because its path wasn’t a good match for a Keplerian orbit. The acceleration indicates there must be some sort of outgassing, but ‘Oumuamua didn’t exhibit the chaotic sort of tumbling usually associated with that. Instead, the object’s jet may swing it back and forth like a pendulum.

“We think that the acceleration, the rotation, and the chaotic light curve are all reasonably in match,” Laughlin noted. “There’s lots of mysteries with ‘Oumuamua, but it doesn’t appear that there’s anything completely crazy.”

Laughlin looks forward to a time when our observing tools are more sensitive and we can hunt down other such objects in interstellar space.

“‘Oumuamua’s presence is signaling a vast population of unseen planets,” Laughlin said. He figures there may be about 1026 such objects in the galaxy. For ‘Oumuamua, he said the likelihood of getting close to another star is about once every 1014 to 1015 years.

“Those brief, exciting moments in September and October were wonderful for us, but they were really the time of ‘Oumuamua’s life,” he said.

Hawaiian names for astronomical objects

The relationship between astronomy and Hawaii has not always been a happy one. Witness the legal squabble about the construction of the Thirty Meter Telescope at Mauna Kea, which was just settled in court last fall. But there’s been a thaw in this cold war according to Ka’iu Kimura, executive director of the ‘Imiloa Astronomy Center in Hilo, Hawaii.

“I participated in ‘Imiloa from its very inception in an attempt to bring about collaboration between the indigenous and scientific communities,” Kimura said before Laughlin’s lecture. She recalled that the effort was hardly a collaboration at first, but sharing a space helped, and now they’ve arrived at an agreement that respects both sides.

“Major astronomical discoveries from both Haleakala and Mauna Kea are being given Hawaiian names, honoring Hawaii as a place of discovery and of profound knowledge,” Kimura said, adding that a name isn’t just what something or someone is called.

“A name represents the identity and gives insight to that someone or something’s origins and connections to others, and for Hawaiians this ancient practice affirms Hawaii’s ongoing contribution to global astronomical advancement.”

The name of our recent visitor was largely created by Larry Kimura, Ka’iu’s uncle and a professor of Hawaiian language and Hawaiian studies at the University of Hawaii, Hilo.

“We loosely translate ‘Oumuamua to mean a scout or messenger from the deep, distant past,” Ka’iu said. Future objects will be named by a working group that includes astronomers, indigenous Hawaiians, educators, and community leaders. Kimura believes that the collaboration builds deeper appreciation and creates a shared sense of ownership in the outcomes.

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Further reading: Our article about ‘Imiloa (PDF) in the December 2007 issue of the Seattle Astronomical Society newsletter.

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