The Newsletter of the Astronomical Society of Greenbelt
I invite you to become an officer of the Astronomical Society of Greenbelt. Like any other organization, the ASG can always use new people at the helm with fresh ideas. If you’re interested, please feel free to talk to me or to any of the other officers. Think of this as a chance to make your mark on Prince George’s County & astronomy outreach. We support a public observatory, act as the PTA for the Owens Science Center, which has the largest planetarium dome in the state, & work with other astronomy clubs to promote a greater understanding of the amazing universe which we inhabit.
Right now, the need for outreach to our neighbors is great. Development without something in place to cut light pollution, which, as we saw in “The City Dark”, threatens not just our dark skies, but also our healths & our ecosystem. The amount of money that goes to professional science outreach, astronomy, & space exploration from public & private sources is small, & pressures on the federal budget may drive that figure lower still. For a lot of people, we may be the only astronomers-perhaps the only scientists-whom they will meet, & a strong society helps us to bring our message to them. Thank you!
Elected officers for 2011-2012
martylou.gay AT gmail.com
stvns.jacht AT yahoo.com
Cleton.Henry AT gmail.com
wb3enm AT amsat.org
Astronomical Events Around Greenbelt in Sept. 2012
Labor Day Info Table @
Roosevelt Center, 9:30-4:30
Star Party @ Northway Observatory
Planetarium show @
General Meeting @ the Owens
Star Party @ Northway Observatory
Sidewalk Astronomy @ Roosevelt Center
For other astronomical events in the DC area, see: Astronomy in DC
Star Party & Business Meeting Reports
8/4: Officers’ meeting:
Labor Day Festival-Information table: The theme: Our Star, The Sun. We’ve got buckets of handouts, & more will be obtained from Goddard. Sat. 9/1: Setup @ 9, runs from 9:30 until 4:30. Food Factory-MG will contact, but things should be in order. No idea where we’ll be that day.
New astronomy club from FHES-a proposal from the new principal. Can we have occasional visits from us to FHES? Family astronomy night in the winter or early spring? Thought: We start informal & wait & see what develops. CL proposed: When the kids think of themselves as astronomers & as a club, *then* we start talking about sponsoring them at the AL. The other officers agreed.
Observatory issues-The telescope warmer’s cables need to be run through the porthole, & the insurance bill was paid. Still needs painting & some yardwork, & a replacement bollard. Some dog waste issues.
8/11: Star Party:
Elizabeth Levin, Elizabeth Suckow, & Craig Levin were at Northway from about 2230 to 2300. They saw a handful of Perseid meteors through a rapidly closing sucker hole in an otherwise cloudy sky. There were also some people-including at least one family-who were also hoping for a glimpse of the Perseids.
8/12: Perseids Viewing at Northway (Doug): We had about 8 visitors to watch Perseids and look through the scope last night. I found Alberio and ? Lyrae, but not the Dumbbell. Brochi's Cluster was there, but too faint to share.
And the clouds kept coming. One group of 4 from Takoma Park, connected with the Maria Mitchell Inst. in Nantucket saw a total of 10 different meteors in 30 min. I finally saw a 4th mag. blue one going southwest through Pegasus at 12:06, and quit for the night.
8/25 & 8/26: Star Party & Sidewalk Astronomy: Rained Out.
8/29: Family Science Night at Goddard Visitors’ Center: Elizabeth Levin, Elizabeth Suckow, Russ, Craig, & Jeff from the GAC talked about different kinds of telescopes, led Moon views through telescopes & binoculars, & talked about getting started in astronomy to a large number of happy families who came to the Goddard Visitors’ Center to learn more about Curiosity. Unfortunately, most people went home before the planets really became visible.
8/30: General Meeting: Speaker: Dr. Tim Livengood, “Heavy Air on Mars”
Dr. Livengood’s work is on isotopes in the atmosphere on Mars. Most of this work is from Mauna Kea, where NASA has an infrared telescope, the IRTF. His team built a highly accurate spectroscope, capable of detecting very subtle changes in wavelength: λ/δλ is 25 million, way better than most telescopes. This enables Dr. Livengood’s team to use the Doppler shift of Mars’ motion to separate components of the Earth’s atmosphere here from the components of the Martian atmosphere. They also check the telescope for its own infrared radiation by nodding the secondary to & fro.
Phoenix, MSL, & Viking landers went to Mars with mass spectrometers, but they’re kind of stuck, while the telescope can scan whole lines of longitude at once. Mars Surveyor & this spectroscope saw Mars lasing in its upper atmosphere in reaction to the Sun’s radiation-no ozone layer to absorb the ultraviolet & higher radiation. The laser peak enables you to see temperature of the upper atmosphere of Mars; the width of the spike is determined by the speed of the particles in the upper atmosphere, & since the kinetic energy of a gas is related to its temperature, again, having a highly accurate spectroscope is very useful. The “scruff” of the spectrum shows isotopic differences in the atmosphere & some higher energy emissions from the gases.
This lets you answer the question of why Mars has an atmosphere: The planet is small & constantly bombarded by solar radiation of all wavelengths & the gusts of the solar wind, since Mars has neither an ozone layer nor a magnetic field. How could Mars hold on to the atmosphere that it has? Some of it’s due to water conserving the CO2, through reactions that exchange the hydrogen for carbon, first as CO, but then as CO2, but lots of it is gone. More massive isotopes & compounds formed from those isotopes will be less likely to escape, however. Since the team can detect differences in isotopic concentration in Mars as compared to the Earth or the solar wind, it has gained insights into how the Martian atmosphere works. For the most part, the landers sent back results saying that the isotopic concentrations in the air on Mars were a lot like those on Earth, & both were different from the composition of the solar wind, so both planets have lost atmospheric components as time has passed. What Dr. Livengood’s team discovered is that the Martian soil seems to “breathe”, “inhaling” heavier isotopes as the atmosphere cools & turns into frost overnight, & “exhaling” as the Sun warms the soil. The landers sent back averages of a day’s mass spectroscopy, so people looking at the landers’ results alone could not see this process.
9/1: Greenbelt Labor Day Fair: Martha, Carol, Ray, George, Craig, & Elizabeth all contributed to bolstering the good image of the ASG to our neighbors. We gave away a lot of our brochures & material from NASA & the IDA.
Good Perseid Meteor Shower Seen in West Virginia
by G.W. Gliba
Lynne and I observed the Perseid Meteor from South Branch Mountain at Mountain Meadows, in Mathias,West Virginia. We had partly cloudy to mostly cloudy conditions all night August 11/12. However, I was lucky to catch an all clear sky during the last hour of full darkness for the Perseid maximum. With a LM=6.5, and 20% obstruction, facing NNW, away from the moon, from 7:55 to 8:55 UT I saw 73 Perseids! There were several bright ones, including a beautiful -4 Perseid fireball seen at 8:41 UT with a 33 second train, a -3 Peresid seen at 8:45 UT, a -2 Perseid also seen at 8:45 UT, and another -3 Peresid seen at 8:47 UT, all with nice trains! This was my best Perseids in 12 years. Earlier, Lynne and I saw several nice long trailed Perseid grazers despite the broken clouds. We also observed M4 near Antares, and M31 with the 25x100 Celestron binoculars on a new tripod we just got. Later, we looked at the planets Jupiter and Venus near the moon, each individually, later with those binoculars during the morning twilight. They were in a line on the ecliptic and only a few degrees apart. A beautiful sight in the twilight sky. I also saw a few extra Perseids as a bonus that were -2 and -3 magnitude in the deep blue twilight sky.
The next night had considerably lower Perseid rates, but the sky was clear most of the night. I was able to get two more hours of formal meteor observing in on Monday morning, but the rates were about half as much for the Perseids, but still a respectable 34 and 35 per hour respectively, from 6:45 to 8:45 UT. There were no Perseids seen that were brighter than -1 that morning. The average Perseid brightness was 1.7 on the 12th and 2.4 on the 13th, with similar observing conditions. Lynne and I both saw a few Perseid grazers, but noticeably fewer of then compared to the previous night. We also both heard Barred Owls and Screech Owls on both nights, along with many field crickets and tree frogs chirping. It was also very clear in the early evening, with a LM=6.8 for a while, allowing much detail to be seen in the Milky Way star clouds with the naked-eye. Later we looked at M8, the Lagoon Nebula, and the large Sagittarius star cloud, with the 25x100 Celestron binoculars. Later, I looked at the planets Jupiter and Venus near the moon, each individually, with the 25x100 binoculars during the morning twilight. It was a great late summer night for observing the starry skies, both nights, and lots of nice meteors and bright planets in the twilight. I saw about 175 meteors total for both nights, most of which were Perseids.
Our Endangered National Observatories
On 8/16, the National Science Foundation released a report on its plans for publicly funded ground-based astronomy, Advancing Astronomy in the Coming Decade: Opportunities and Challenges. This report, a reaction to the concern over the government’s debt, recommends that the NSF defund several observatories which are nearly household names to astronomers, including Green Bank & Kitt Peak, over the next five years, but continuing to fund observatories which only exist on paper or are still being built. In my opinion, this is a mistake. The history of public works is choked with might-have-beens with splendid blueprints, like the Superconducting Supercollider, now just a hole in Texas.
The telescopes at Kitt Peak & Green Bank produce scientific results on a regular basis, & are used by astronomers at all levels of professional development, from graduate students to emeriti. Also, Green Bank & the other observatories are sources of jobs for their neighbors. I’ve been to Green Bank, as have others in ASG. Do you think that Green Bank would have its businesses if the observatory wasn’t there? Please write to your representatives & senators &, if you can, electronically sign this petition.
Godspeed Neil Armstrong
(This is an early photo of Neil Armstrong, when he was an X-15 pilot. Image courtesy of NASA)