Category Archives: spectroscopy

SpaceFest at MOF tops week’s astro calendar

A three-day space fest, several star parties, some astronomy club meetings, and a chance to meet Viking mission folks are on tab for the next week of astronomy events.

SpaceFest: Ladies who LaunchThe third annual SpaceFest at the Museum of Flight kicks off Thursday for three days of exhibits and presentations. Under the theme of Ladies Who Launch, this year’s SpaceFest celebrates women astronauts, engineers, authors, and others who helped put America into space.

The days are packed with events. Highlights include a talk by South Korean Astronaut Soyeon Yi at 1 p.m. Friday, November 4, and a keynote at 2:15 p.m. Saturday, November 5 by Nathalia Holt, author of Rise of the Rocket Girls: The Women Who Propelled Us, from Missiles to the Moon to Mars (Little, Brown and Company, 2016). The book is a tale of young women who, with only pencil, paper, and mathematical prowess, transformed rocket design, helped bring about the first American satellites, and made the exploration of the solar system possible.

You can order the book by clicking the link above; purchases through the Seattle Astronomy Store help defray our operating costs and enable us to bring you great astronomy stories. Check the full schedule for the weekend on the museum’s online calendar. We plan to attend a number of the sessions, and will report back!

Viking at Portland Science Pub

VMMEPPMeet some of the folks involved with the Viking Mars missions in the mid-1970s at Science Pub Portland at 7 p.m. Thursday, November 3 at McMenamins Mission Theater in Portland. As an 11-year-old girl Rachel Tillman saved the last remaining un-flown Viking spacecraft from the scrap heap. She later became founder and is executive director of the nonprofit organization The Viking Mars Missions Education & Preservation Project. Tillman will speak at Science Pub Portland, along with Al Treder, who worked on Viking guidance and control; Pat DeMartine, Viking lander command sequence and simulation programmer and science team member; and Peggy Newcomb, wife of NASA Viking engineer and author John Newcomb, who passed away in March.

Suggested donation for admission is $5. Science Pub Portland is a program of the Oregon Museum of Science and Industry. If you can’t make this Viking Mars Mission event, it will be repeated at Science Pub Eugene on November 10 and Science Pub Corvallis on the 14th.

Saving the planet

Ed Lu

Ed Lu. Photo: NASA

When the Large Synoptic Survey Telescope comes online, it is expected that the discovery rate of near-Earth asteroids will increase by more than a factor of 20 over the current rate, and that the list of asteroids with a worrisome probability of hitting the Earth will also become much larger. Astronaut Ed Lu, CEO and co-founder of the B612 Foundation, will discuss the scientific as well as public policy challenges related to potential asteroid impact scenarios at this week’s University of Washington astronomy colloquium. The event will be held at 4 p.m. Thursday, November 3 in the Physics/Astronomy Auditorium on the UW campus in Seattle.

Club meetings

The Tacoma Astronomical Society will hold its monthly meeting at 7:30 p.m. Tuesday, November 1 in room 175 of Thompson Hall on the University of Puget Sound campus in Tacoma. Topics will include a review of some of the club’s new gear and a primer on Proxima b, a roughly Earth-sized planet believed to be in orbit around our nearest stellar neighbor.

The Spokane Astronomical Society will hold its monthly meeting at 7:30 p.m. Friday, November 4 at the planetarium at Spokane Falls Community College. Specific topics or guest speakers for the gathering had not been published as of this writing.

Star parties

There are three star parties on the calendar for this week. The Covington Community Park Star Party is planned for 8 p.m. Friday, November 4 at the park. The event is a joint effort of the Seattle Astronomical Society and the Boeing Employees’ Astronomical Society.

The Seattle club also plans its free monthly public star parties for 6 p.m. Saturday, November 5 at two locations: Green Lake in Seattle and Paramount Park in Shoreline. Cloudy weather will mean cancellation of the star parties; watch the club’s website or social media for updates.

Tacoma Astronomical Society will hold one of its free public nights at 7:30 p.m. Saturday, November 5 at the Fort Steilacoom campus of Pierce College. The indoor program will be about spectroscopy. If the weather is clear they’ll break out the telescopes and have a look at what’s up in the night sky.

Futures file

You can scout out future astronomy events on our calendar. New additions to the calendar this week include:

Up in the sky

The Taurid meteor shower peaks this Thursday and Friday. This Week’s Sky at a Glance from Sky & Telescope magazine and The Sky This Week from Astronomy have more observing highlights for the week.

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Radioactivity is good for you

While most of us tend to think that radioactivity is dangerous, experts say that, like beer, it’s actually good for you in moderation. We learned this while drinking radioactive beer at Bad Jimmy’s Brewing Company in Ballard on Wednesday during the “radioactive edition” of Astronomy on Tap Seattle.

Radioactive beer

Barnes

UW prof. Rory Barnes makes a point about radioactive beer during his Astronomy on Tap talk at Bad Jimmy’s Brewing Company on Wednesday, Jan. 20, 2016. Photo: Greg Scheiderer.

University of Washington astrobiology professor Rory Barnes did the math on the beer. Figuring that a pint is about 90 percent water, carbon is about ten percent of the rest. That works out to 4.5 grams, or about 200 billion carbon-14 atoms. Carbon-14 has a half-life of 5,730 years, which Barnes said means that, in your glass, there’s about one atomic decay every second.

“You are all drinking radioactive beer,” he said. Nobody stopped. I was sipping on a red IPA which was delightful and may have been even a bit more radioactive than the others!

Barnes noted that while we think of Chernobyl or Fukushima when we think about radiation, the process of radioactive decay is pretty important.

Radioactivity is good

“If it weren’t for the radioactivity inside our planet we’d all be dead,” he said. Barnes explained that decay of uranium, thorium, and potassium inside the Earth produces about 50 terawatts of energy, or about 0.1 watt per square meter on the surface. That much energy could run our entire civilization if we could capture it. As it is, it drives geologic processes such as plate tectonics, which helps regulate the amount of carbon dioxide in our atmosphere.

“It’s really important that the planet does a good job of keeping it from building up to too high of a level or dropping down to too low of a level because then our Earth would not be habitable,” Barnes explained. “Without (plate tectonics) the carbon dioxide would either build up and our planet would roast or it would get drawn down and our planet would freeze.”

Earth is in a sweet spot as far as this internal energy goes. Mars generates less than half the energy Earth does and is geologically dead. Jupiter’s moon Io generates a whopping two watts per square meter and is wildly active volcanically. For life, conditions have to be just right.

Radioactivity may lead us to ET

Barnes said that this fact could help guide us to other planets that might be likely to harbor life. The trouble is that in order to determine a planet’s internal energy and radioactivity we would have to look inside a rock that is hundreds of light years away.

“It’s not really obvious how you do that, but that’s what we need to do,” he said. “I’m sorry to say that the answer is that we can’t at this point. This is the limit of our scientific research right now.”

The James Webb Space Telescope will be able to determine the elements in the atmospheres of distant planets. Barnes said it would make sense to use JWST to look at planets that are near where supernovae have occurred, because these stellar explosions spread the heavy elements needed for this sort of planetary energy generation.

Radioactivity and the ages of stars

Sakari

UW postdoctoral research associate Charli Sakari explains how the age of a star can be determined by the presence of radioactive elements. Photo: Greg Scheiderer.

UW astronomy post-doc Charli Sakari also uses radioactivity in her work. During her Astronomy on Tap talk she explained how she determines the makeup of stars by looking at spectra of the light they emit. Different elements leave a clear signature in the spectrum, absorption lines created when atoms in a star’s atmosphere absorb certain color wavelengths.

“If we measure how dark those lines are we can figure out how much of those elements is present in the atmospheres,” Sakari said.

It is especially informative to look for uranium and thorium.

“Uranium-238 has a half-life of 4.5 billion years, which is about the age of the Sun, whereas thorium-232 has a half life of 14 billion years,” Sakari explained. “These half-lives are long enough that we can use them to date the ages of the oldest stars in the universe.”

The oldest stars have few elements heavier than helium. Younger stars can contain many heavier elements fused in the cores of the generations of stars that preceded them.

Astronomy on Tap Seattle drew a big crowd to Bad Jimmy’s on a rainy Wednesday night. In fact astronomy and beer lovers were packed in so tightly, and were generating considerable warmth, that the staff popped the garage-type doors open to let in a little fresh air. One wag in the crowd speculated that the robust attendance may have been an indicator of the sorry state of network television. We would say that, in eleven months of events Astronomy on Tap, which is organized by astronomy graduate students at the UW, has delivered plenty of good information and tons of fun. The next gathering is scheduled for Feb. 24.

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Seattle amateur astronomer has spectroscopy article in S&T

Seattle Astronomical Society member Tom Field, creator of RSpec software for spectroscopy, has an article on the topic in the August 2011 issue of Sky & Telescope. Photo: Greg Scheiderer.

Local amateur astronomer Tom Field is rapidly becoming the face of spectroscopy for the backyard stargazer. An article by Field, a member of the Seattle Astronomical Society and creator of RSpec spectroscopy software, has been published in the August 2011 issue of Sky & Telescope magazine. The article, titled “Spectroscopy for Everyone”, begins on page 68 of the print edition. Subscribers can view it online as well.

Field spoke about RSpec at a Seattle Astronomical Society meeting a year ago, and I wrote about that talk in my old Seattle Astronomy Examiner column. When he got interested in spectroscopy, Field found existing software difficult to use, prone to crash, not particularly user-friendly, and often in a foreign language. So, as a professional software developer, he set out to create something that worked better for the backyard astronomer, and RSpec was the result.

“It is a big thrill,” Field said of seeing the article in print. He got involved with S&T back in April, when magazine editor Dennis di Cicco interviewed him for the video below about RSpec and spectroscopy. The piece was shot at the Northeast Astronomy Forum (NEAF) in Suffern, New York, and published by Sky & Telescope in May. The current issue of the magazine also features an article and many photos from NEAF, one of the biggest amateur astronomy events in the country.

The lure of spectroscopy for Field is that you can do solid science and analyze the spectral signatures of celestial objects even from light-polluted back yards, and you can do it at pretty low cost. He says that doing spectroscopy also improves his understanding of astronomy; he finds he now reads the literature much more closely.


A sidebar to Field’s article in S&T recommends Astronomical Spectroscopy for Amateurs by Ken M. Harrison as a recent and informative resource for anyone interested in getting into the subject.

Congratulations, Tom! It’s great to see the attention for you and RSpec from the major astronomy press!

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