January Meeting
Oklahoma Space Alliance will meet at 3:00 p.m. on Saturday, January 19 at the Koszorus' house in Norman. Prospective members are also welcome. Their house is at 514 Fenwick Court in Norman.
To get the meeting either: (1) Take the Robinson Street west exit off I-35. Proceed west to 36th Street where you will turn left, and go south until you turn left on Rambling Oaks (about half a mile north of Main Street). Fenwick Court is the third street on the left. Tom's house is the last on the left side, or (2) Take the Main Street west exit off I-35, proceed west past the Sooner Fashion Mall, and turn right at 36th Street, and go north until you turn right on Rambling Oaks (about half a mile north of Main Street). Fenwick Court is the third street on the left. Tom's house is the last on the left side
Agenda:
1) Introductions (if necessary)
2)
Read and approve agenda
3)
Read a0nd approve minutes and reports of activities
4) Read and discuss mail
5) Old Business
a) Yuri’s Night
b) Petitions for NSS Board
c) Pictures for web
d) Oklahoma City Astronomy Club Parties
e) Programming at SoonerCon
f) Possible activity with rocket club.
g) Upcoming conferences
6) New Business
7) Create New Agenda
Minutes of December Meeting
The December meeting was our annual Christmas party, when we also had elections. Our officers for 2008 are: Tom Koszoru, President; Claire McMurray, Vice-President; Syd Henderson, Secretary; Tim Scott, Treasurer.
After dinner, we watched two episodes of the television series Firefly.
Sky Viewing
On the night of Wednesday, February 20, the Moon will be totally eclipsed for the third time in 12 months, and this time the entire eclipse will be visible from all of North America except Alaska and extreme western Canada. Here is the schedule for the Central Time Zone (our correspondent in Wyoming should subtract an hour). The partial phase will begin at 7:43 p.m., with the total eclipse lasting from 9:00 until 9:52 p.m. The partial phase will end at 11:09 p.m. The penumbra will become noticeable around 7:05 p.m. and leave around at 11:45 p.m.
At the height of the eclipse, Saturn will be about three degrees to the left of the Moon, and the first magnitude star Regulus about three degrees above the Moon. This puts the Moon just below the base of the Sickle of Leo, which should be easily visible. The Moon will not be going into the center of the Earth’s shadow, so it will stay coppery-colored rather than going very dark as it would if it went through the center of the umbra.
This will be the last total eclipse of the Moon anywhere on Earth until the one of December 20, 2010. That one will again be visible from North America.
Comet Holmes has dimmed quite a bit, but is still visible with binoculars. It is located close to the famous eclipsing binary Algol (Beta Persei), and will, in fact, pass right over it on January 21-22. It will remain in Perseus through mid-March, growing progressively dimmer unless it undergoes another eruption like it did in November.
Comet Tuttle is in the southern regions of the constellation Cetus, the Whale. It’s currently about magnitude 6.0 and is gradually dimming.
Mercury is currently magnitude -0.8 and is visible low in the western sky just after sunset. It will reach greatest elongation on January 20. You should be able to see it 30 – 60 minutes after sundown. After greatest elongation, it will fade rapidly as it approaches inferior conjunction with the Sun on February 6. Beginning on February 23, Mercury and Venus will be within three degrees of each other for five consecutive weeks. Indeed, on February 27, Mercury will be 1.1 degrees above Venus and both should be visible about 45 minutes before sunrise.
Venus is magnitude -3.9 and is visible low in the eastern sky before sunrise and will remain there through the month of February. Venus is gradually approaching superior conjunction with the Sun, which it will not reach until June. Late in the year it will become a bright evening star, but will not reach its greatest eastern elongation until January 2009.
On February 1, Venus and Jupiter will be separated by only 0.6°. This will be the closest conjunction of the two planets until 2014. The constellation where they are meeting is Sagittarius.
Mars reached opposition in December and will remain bright for months. Currently it is magnitude -1.1, but will fade from magnitude -0.6 to 0.2 during February. It is currently in the constellation Taurus and is visible all evening.
Jupiter is magnitude -1.8 and is visible low in the eastern sky at sunrise. It passes Venus on February 1 and will get higher all month until by February 29, it will rise three hours before the Sun.
Saturn is currently magnitude 0.5 in the constellation Leo and getting brighter. It will reach opposition on the night of February 23-24, when it will peak at magnitude 0.2. This is dimmer than usual because the rings are tilted only 8° to us. (The opposition in 2009 will be even worse since the rings will be nearly edge-on.) Saturn will be visible nearly all night for the next couple of months. As a bonus, when the moon is totally eclipsed on February 20, Saturn will be only three degrees away.
Uranus is visible (probably with binoculars) in the constellation Aquarius shortly after sunset. It will be getting ever less visible during the next month because it will be in conjunction with the Sun in March. It is in the constellation Aquarius.
Neptune is too close in the sky to the Sun to be visible even with binoculars this month. It will be in conjunction with the Sun on February 10.
Viewing Opportunities for Satellites (January 17 – February 16)
NASA has dropped the International Space Station from the list of satellites covered by J-Pass, although they are still covered on the Orbital Tracking page via spaceflight1.nasa.gov/realdata/sightings/. This only seems to give you data for a couple of weeks. J-Pass still covers unmanned satellites at science.nasa.gov/Realtime/JPass/.
You can get sighting information at http://www.heavens-above.com/. Heavens Above allows you to get Station data for 10 day periods, and gives you a constellation map showing the trajectory of the satellite. If you go to the bottom of the map page, it will give you a really detailed map with the location at 10 or 15-second intervals, depending on detail. In fact, the detailed charts will even show you the tracks against maps of the constellations, which should help you if you are familiar with the night sky.
Sky Online (the Sky & Telescope web site) carries station observation times for the next few nights at skyandtelescope.com/observing/almanac. Note that with the addition of the solar panels, the magnitude of the Space Station is now -1.0, making it brighter than all the stars other than the Sun and Sirius, and the planet Saturn as well. The Hubble Space Telescope can get up to magnitude 1.5, which is brighter than the stars in the Big Dipper, although, since it is lower in the sky, it is a bit more difficult to see.
Missions to the Space Station or Hubble Space Telescope may change its orbit. At this writing, the target date for the Atlantis launch to the Space Station is February 7. The next repair mission to the Space Telescope is planned for August 7. This will be the final mission unless NASA decides that it will require a crew to de-orbit the Space Telescope.
Station January 18, 2008
Time Position Elevation
6:48 a.m. 333° 16°
6:49 353 29
6:50 42 39
6:51 87 27
Station January 19, 2008
Time Position Elevation
7:10 a.m. 296° 17°
7:11 280 32
7:12 220 48
7:13 168 29
7:14 154 16
Station January 21, 2008
Time Position Elevation
Leaves Earth’s shadow at 263° 47°
6:20 a.m. 218° 53°
6:21 162 31
6:22 151 17
Station January 29, 2008
Time Position Elevation
7:12 p.m. 235° 18°
7:13 243 39
7:14 346 71
Enters Earth’s shadow at 29° 47°
HST January 30, 2008
Time Position Elevation
6:43 a.m. 217° 19°
6:44 198 26
6:45 173 29
6:46 148 26
6:47 130 20
HST January 31, 2008
Time Position Elevation
6:41 a.m. 222° 21°
6:42 203 27
6:43 176 31*
6:44 149 27
6:45 131 21
*Passes 1° above full Moon
HST February 1, 2008
Time Position Elevation
6:40 a.m. 226° 21°
6:41 208 28
6:42 180 32
6:43 152 28
6:44 134 21
HST February 2, 2008
Time Position Elevation
6:38 a.m. 230° 20°
6:39 211 27
6:40 184 31
6:41 157 28
6:42 138 21
Station February 16, 2008
Time Position Elevation
7:12 p.m. 310° 17°
7:13 307 36
7:14 223 82
7:15 139 35
7:16 136 17
Vanishes into Earth’s shadow
Pass times are from Heavens Above.
Key: Position is measured in degrees clockwise from north. That is, 0° is due north, 90° is due east, 180° is due south, and 270° is due west. Your fist held at arm's length is about ten degrees wide. "Elevation" is elevation above the horizon in degrees. Thus to find the Hubble Space Telescope at 6:38 a.m. on February 2, measure five fist-widths west from south, the two fist-widths above the horizon.
In addition to the J-Pass program which I use to provide this satellite viewing data, J-Pass provides a service called J-Pass Generator, which will e‑mail you sighting information for the next three days for up to ten satellites. For more information, go to science.nasa.gov/Realtime/JPass/PassGenerator/.
Calendar of Events
January 14: MESSENGER's first flyby of Mercury. For information on the MESSENGER mission, visit http://messenger.jhuapl.edu/ or http://en.wikipedia.org/wiki/MESSENGER. MESSENGER is an acronym for Mercury Surface, Space Environment, Geochemistry and Ranging, which shows how far you have to go sometimes to get a cool acronym.
January 19: Oklahoma Space Alliance meeting at 3:00 p.m. at the Koszoru house.
January 22: Mercury is at greatest eastern elongation, 19° east of the Sun (hence can be seen after sunset).
February 1: Venus and Jupiter are separated by 0.6° in the morning sky.
February 7: Launch of Atlantis with the Columbus European Laboratory Module. (Postponed from December)
February 13: [Tentative] Oklahoma Space Industry Development Authority Meeting in the Commission Room at the Oklahoma Department of Transportation Building, 200 NE. 21st. Street; Oklahoma City
February 16: [Tentative] Oklahoma Space Alliance meeting at 3:00 p.m. Location to be announced.
February 20: Total lunar eclipse visible from North America.
February 24: Saturn is at opposition.
February 27: Venus and Mercury are separated by 1.1°.
March 3: Mercury is at greatest western elongation, 27° west of the Sun (hence can be seen before sunrise).
Mid-March. Launch of Endeavour with the pressurized section of the Kibo Japanese Experiment Logistics Module to the Space Station. (Moved from February)
March 12: [Tentative] Oklahoma Space Industry Development Authority Meeting in the Commission Room at the Oklahoma Department of Transportation Building, 200 NE. 21st. Street; Oklahoma City
March 15: [Tentative] Oklahoma Space Alliance meeting at 3:00 p.m. Location to be announced.
April: India launches its lunar probe Chandrayaan 1. [Postponed from September.] The craft will orbit the Moon at an altitude of 60 miles for two years. For information, visit en.wikipedia.org/wiki/Chandrayaan or
www.isro.org/chandrayaan/htmls/home.htm.
April 9: [Tentative] Oklahoma Space Industry Development Authority Meeting in the Commission Room at the Oklahoma Department of Transportation Building, 200 NE. 21st. Street; Oklahoma City
April 12: Yuri’s Night. 47th Anniversary of manned spaceflight.
April 19: [Tentative] Oklahoma Space Alliance meeting at 3:00 p.m. Location to be announced.
April 24: Launch of Discovery with the rest of Kibo module to the Space Station.
May 14: [Tentative] Oklahoma Space Industry Development Authority Meeting in the Commission Room at the Oklahoma Department of Transportation Building, 200 NE. 21st. Street; Oklahoma City
May 14: Mercury is at greatest eastern elongation, 22° east of the Sun (hence can be seen after sunset).
May 16: Launch of the Gamma-Ray Large Area Space Telescope (GLAST). (Moved from February 5.)
May 17: [Tentative] Oklahoma Space Alliance meeting at 3:00 p.m. Location to be announced.
May 18: The Phoenix Mars Mission arrives at Mars. For details, see http://phoenix.lpl.arizona.edu/.
May 23 – 26: 27th International Space Development Conference in Washington, DC. Web site is http://isdc.nss.org/2008/.
June 8: Venus is in superior conjunction with respect to the Sun.
June 11: [Tentative] Oklahoma Space Industry Development Authority Meeting in the Commission Room at the Oklahoma Department of Transportation Building, 200 NE. 21st. Street; Oklahoma City
June 21: [Tentative] Oklahoma Space Alliance meeting at 3:00 p.m. Location to be announced.
July 1: Mercury is at greatest western elongation, 22° west of the Sun (hence can be seen before sunrise).
July 9: Jupiter is at opposition.
July 9: [Tentative] Oklahoma Space Industry Development Authority Meeting in the Commission Room at the Oklahoma Department of Transportation Building, 200 NE. 21st. Street; Oklahoma City
July 19: [Tentative] Oklahoma Space Alliance meeting at 3:00 p.m. Location to be announced.
July 31: Launch of the Planck Surveyor and Herschel Space Observatory from Kourou, French Guiana aboard an Ariane 5. For more information, visit www.rssd.esa.int/index.php?project=Planck, en.wikipedia.org/wiki/Planck_Surveyor, http://herschel.esac.esa.int/ and en.wikipedia.org/wiki/Herschel_Space_Observatory. [The spaces in the Wikipedia URLs are underlines.]
August 7: Launch of Atlantis on the fifth and final servicing mission to Hubble Space Telescope. [Updated January 13.]
August 13: [Tentative] Oklahoma Space Industry Development Authority Meeting in the Commission Room at the Oklahoma Department of Transportation Building, 200 NE. 21st. Street; Oklahoma City
August 14-17: Mars Society Conference in Denver, Colorado. For more information, visit http://www.marssociety.org/portal.
August 16: [Tentative] Oklahoma Space Alliance meeting at 3:00 p.m. Location to be announced.
September 5: The ESA's Rosetta asteroid & comet probe passes by asteroid 2867 Steins. Web page is www.esa.int/SPECIALS/Rosetta or visit en.wikipedia.org/wiki/Rosetta_%28spacecraft%29.
September 10: [Tentative] Oklahoma Space Industry Development Authority Meeting in the Commission Room at the Oklahoma Department of Transportation Building, 200 NE. 21st. Street; Oklahoma City.
September 11: Mercury is at greatest eastern elongation, 27° east of the Sun (hence can be seen after sunset).
September 18: Launch of Endeavour to the Space Station.
September 20: [Tentative] Oklahoma Space Alliance meeting at 3:00 p.m. Location to be announced.
October 6: MESSENGER's second flyby of Mercury.
October 8: [Tentative] Oklahoma Space Industry Development Authority Meeting in the Commission Room at the Oklahoma Department of Transportation Building, 200 NE. 21st. Street; Oklahoma City
October 18: [Tentative] Oklahoma Space Alliance meeting at 3:00 p.m. Location to be announced.
March 3: Mercury is at greatest western elongation, 18° west of the Sun (hence can be seen before sunrise).
October 28: The Lunar Reconnaissance Orbiter is launched. It will assume a polar orbit. The mission will last at least a year. For more information, visit http://lunar.gsfc.nasa.gov/ or en.wikipedia.org/wiki/Lunar_Reconnaissance_Orbiter.
November 12: [Tentative] Oklahoma Space Industry Development Authority Meeting in the Commission Room at the Oklahoma Department of Transportation Building, 200 NE. 21st. Street; Oklahoma City
November 15: [Tentative] Oklahoma Space Alliance meeting at 3:00 p.m. Location to be announced.
December 20: [Tentative] Oklahoma Space Alliance Christmas Party at 3:00 p.m. Location to be announced.
January 4, 2009: Mercury is at greatest eastern elongation, 19° east of the Sun (hence can be seen after sunset).
January 14, 2009: Venus is at maximum eastern elongation, 47.1° east of the Sun.
February 13: Mercury is at greatest western elongation, 26° west of the Sun (hence can be seen before sunrise).
February 16, 2009: Launch of the Kepler Mission, which will look for Earth-sized and smaller planets around other stars. For more information, see http://kepler.nasa.gov/.
March 2009: Dawn asteroid probe flies by Mars.
March 8, 2009: Saturn is at opposition.
April 26, 2009: Mercury is at greatest eastern elongation, 20° east of the Sun (hence can be seen after sunset).
August 10, 2009: Saturn’s rings are edge-on with respect to the Sun.
August 14, 2009: Jupiter is at opposition.
September 4, 2009: Saturn’s rings appear edge-on.
September 30, 2009: MESSENGER's third flyby of Mercury.
October 2009: Russia launches Phobos-Grunt, a sample return mission to Martian moon Phobos. For more information, visit http://en.wikipedia.org/wiki/Phobos-Grunt.
December 2009: The Mars Science Laboratory is launched. See http://marsprogram.jpl.nasa.gov/msl/ for details.
January 29, 2010: Mars is at opposition with magnitude -1.3.
June 2010: Hayabusa returns to Earth with a sample of asteroid Itokawa. This will be the first asteroid sample returned to Earth. Web site is www.isas.jaxa.jp/e/enterp/missions/hayabusa/index.shtml.
June 2010: Japan launches the Venus Climate Orbiter (aka Planet‑C) to Venus. Web page is http://www.jaxa.jp/projects/sat/planet_c/index_e.html.
July 10, 2010: The Rosetta comet probe passes asteroid 21 Lutetia.
September 21, 2010: Jupiter is at opposition. This is the closest Jupiter will come to Earth in the next 20 years, about 370 million miles.
October 2010: The Mars Science Laboratory rover lands on Mars. See http://marsprogram.jpl.nasa.gov/msl/ for details.
December 2010: Japan’s Venus Climate Orbiter arrives at Venus.
October 2011: Dawn probe orbits Vesta. See http://dawn.jpl.nasa.gov/ or http://en.wikipedia.org/wiki/Dawn_Mission for details.
March 18, 2011: MESSENGER goes into orbit around Mercury.
October 2011 – April 2012: Dawn probe orbits Vesta.
Sometime in 2012: Russia launches the “Luna-Glob” mission which will deploy 13 mini-probes upon the lunar surface.
March 3, 2012: Mars is at opposition at magnitude -1.2. This is the worst opposition for the next twenty years.
April 2012: Dawn probe leaves orbit around Vesta for Ceres.
June 6, 2012: Venus transits the Sun's disk. The early part of this will be visible from the United States, but the full transit will only be visible from the western Pacific Ocean, eastern Asia, eastern Australia, and eastern Indonesia including New Guinea.
Sometime in 2013: ESA launches the ExoMars Mars Rover. For more information, visit http://en.wikipedia.org/wiki/Exomars.
June 2013: Earliest date for the launch of the James Webb Space Telescope.
August 2013 (approximate): The European Space Agency/JAXA BepiColombo Mercury Orbiter is launched. Home page is sci.esa.int/science-e/www/area/index.cfm?fareaid=30.
August 2014 - December 2015: The Rosetta space probe orbits comet Churyumov-Gerasimenko. In November, 2014, it will release the Philae lander. See September 5, 2008 for website information.
Sometime in 2015 or 2016: Launch of SIM PlanetQuest (aka the Space Interferometry Mission). This mission was originally supposed to have been launched in 2005 and has been delayed at least five times. It was recently moved from 2012. For more information, visit en.wikipedia.org/wiki/Space_Interferometry_Mission.
February 2015: Dawn space probe arrives at Ceres. Operations are scheduled to continue through July. Dawn may continue on to other asteroids if it is still operational.
July 14. 2015: The New Horizons probe passes through the Pluto-Charon system. The New Horizons web site is http://pluto.jhuapl.edu/.
July 2016-2020: The New Horizons probe visits the Kuiper Belt.
August 21, 2017: The next total solar eclipse visible in the United States, on a pretty straight path from Portland, Oregon to Charleston, South Carolina. St. Louis is the biggest city in-between.
August 2019 (approximate) BepiColombo arrives at Mercury orbit.
April 8, 2024: A total solar eclipse crosses the US from the middle of the Mexico-Texas border, crosses Arkansas, southern Missouri, Louisville, Cleveland, Buffalo and northern New England.
August 12, 2045: The next total solar eclipse visible in Oklahoma. This one is also visible in Salt Lake City, Denver, Little Rock (again), Tampa Bay and New Orleans.
Space Probes: Mercury
As I’m writing this, the MESSENGER space probe is flying by Mercury, marking the first time since 1975 and the second time ever that a space probe has visited that planet. On that visit, Mariner 10 flew by Mercury three times, but since it flew by the same hemisphere each time, it only mapped 44% of the surface. MESSENGER will map the rest as it will eventually go into orbit around Mercury.
Mercury presents many mysteries, such as a magnetic field which should not exist since its core should have frozen long ago. This core makes up 40% of the planet’s volume, more than twice the relative size of Earth’s core. Why? Nobody knows. Mercury’s poles are very reflective to radar, which has led to speculations that there may be ice on the pole, or sulfur, which would indicate past volcanic activity.
The precession of Mercury’s orbit was one of the phenomena explained by Einstein’s General Theory of Relativity. A few years after MESSENGER, the BepiColombo spacecraft to Mercury will try to find holes in the theory.
“Ready Mercury?” by Stuart Clark, New Scientist, 9 January 2008, pp 24 – 27.
Space Probes: Venus
The November 29 issue of Nature has more than 30 pages of results from the Venus Express mission.
Venus is of special interest to astronomers because in some ways it is so similar to Earth but took such a different path. It’s not that much closer to the Sun, has 0.95 times the diameter of Earth, 0 86 times the volume, and 0.815 times the mass. The surface gravity is 90% that of Earth. Venus has about the same amount of carbon dioxide as the Earth, the catch, of course, being that on Venus the carbon dioxide is almost all in the atmosphere, and on Earth it is mostly bound into carbonate rocks, which some in the ocean and a much smaller amount in the air. The remainder of Venus’s atmosphere, about 3.5%, is almost all nitrogen, with sulfur dioxide in the clouds. Without all that carbon dioxide, Venus’s atmosphere would only be about three times as dense as Earth’s. Venus contains very little water, enough to cover the planet to an estimated depth of three millimeters. So what accounts for the differences, and which planet is more “normal?”
I think a lot of the differences between Earth and Venus started with Venus’s slow rate of rotation, 243 days, retrograde, which is longer than Venus’s orbital period around the Sun. The length of a solar day on Venus is about half of that, 117 days. Curiously, this means that five Venusian solar days are about equal to the time between close approaches of Venus and Earth. Despite the length of the day, the surface temperature of Venus stays the same because the thick atmosphere retains heat.
Venus has pretty much no magnetic field. This may be partly due to the slow rate of rotation (although some field would still be expected), but more due to lack of convection currents in its core. Because of the lack of a magnetic field, water can be dissociated into hydrogen and oxygen, with the hydrogen escaping into space. Since deuterium is twice as massive as hydrogen, Venus’s atmosphere is enriched by a factor of over a hundred. This means Venus started off with more than a hundred times as much water as has now.
This presents a mystery, because Venus does have magnetic fields produced in its atmosphere, and Venus Express indicates the solar wind doesn’t enter the atmosphere to dissociate the water. However, it did detect hydrogen and oxygen ions escaping from Venus, so further study is needed. Venus does have lightning in its atmosphere; about half as much as Earth.
Because of the lack of water, plate tectonics are different on Venus. Venus’s plates tend to stay put for hundreds of millions of years, until enough pressure builds up that the whole planet has a paroxysm of crustal activity that resurfaces the entire planet. For this reason, impact craters on Venus are less than 500 million years old. The atmosphere is too still at the surface and there is too little water to erode craters, so what craters there are tend to remain in good condition until the resurfacing. (Venus does, however, appear to have volcanoes.)
The thick atmosphere and ridiculous temperatures present a challenge to anyone designing Venusian rovers, and none have lasted more than a few hours. I’ve seen a design for a rover with a device that can refrigerate its electronics, so perhaps we will one day have a rover that lasts a respectable length of time.
Space Probes: Saturn
One of the tasks of the Cassini space probe was to map the small moons of Saturn, including the small moons that act as shepherds for Saturn’s rings. Some of these moons present problems as to how they formed, because they are within Roche’s limit, where tidal forces should disrupt them before they grow to the 20 mile diameters of moons such as Pan and Atlas. It is supposed that they are remnants of a larger body, which may be the same as the one that produced the rings. There is still a limit to the size of the moons, but tidal forces across a small moon shouldn’t disrupt a solid body.
In a paper in the December 7 issue of Science, C. C. Porto, P. C. Thomas, J. W. Wilson and D. C. Richardson discuss the inner satellites of Saturn. In particular, they conclude that they all have densities less than half that of water ice. Two of them, Pan and Atlas have equatorial ridges that make them look like flying saucers. (Pan looks to me like two sombreros glued together at the brims.) Their theory is that the small moons started off as denser pieces a third to a half the size that they are currently, and have been accumulating small particles from the rings, so they are pretty much piles of fluff around a denser core. For Pan and Atlas, the particles accumulated around the equator. The reason for this is easier to see for Pan: its L1 and L2 Lagrangian points with respect to Saturn are very close to its surface, so any material that passes through them almost immediately hits its surface. (It can lose particles through the same two points.) Atlas has a more elliptical orbit and tends to accumulate matter on its forward hemisphere in the inner part of its orbit and on the trailing hemisphere on the outer part if its orbit,
This “fluff” helps moons survive collisions and explains why the moons survive.
Space-Related Articles
“The Armageddon Factor,” by Michael Reilly, New Scientist, 8 December 2007, pp. 42-45.
It is generally (but not universally) accepted that the mass extinction at the end of the Cretaceous Period that killed off the dinosaurs was caused by the asteroid impact that created the Chicxulub crater. The Permian mass extinction, the greatest in the history of the Earth, was apparently cause by enormous a gigantic eruption that covered an estimated 700,000 square miles of Siberia in up to 3.5 miles of basalt. (A similar eruption produced the Deccan Traps in India at about the time of the Chicxulub impact, which is one of the reasons the impact theory isn’t universally accepted. However, another hypothesis is that the impact and mass eruption are related.)
However, other massive impacts and super-eruptions didn’t seem to faze life much at all. For example, the Manicougan impact (the one that produced the 60-mile wide ring-shaped crater known as the “Eye of Quebec”) about 214 million years ago produced a minor extinction, and the Ontong Java Plateau eruption, which covered an area the size of Alaska in up to 18 miles of basalt (!) about 120 million years ago, seems only to have produced a minor marine extinction.
So what’s the difference? Part of it may be location. Large areas of the continental shelves are buried in methane hydrate ice, and if large amounts of this were released at once, it would put huge amounts of methane in the atmosphere. Since methane is a potent greenhouse gas, this would suddenly spike the Earth’s temperature several degrees, which would affect the oxygen content of sea water and interfere with oceanic circulation. (For a fictional treatment of a methane hydrate release, see John Barnes’ novel, Mother of Storms.)
One temperature spike 55 million years ago raised temperatures by up to eight degrees in a few thousand years and produced a minor extinction. This was apparently caused when a mass eruption in the Norwegian Sea encountered deposits of methane clathrate. This would have 20,000 times as much carbon into the atmosphere as humans do in a year (although the methane release would take place over thousands of years).
Similarly, at the Triassic-Jurassic boundary, another mass extinction location, carbon dioxide content of the atmosphere is estimated to have more than tripled the carbon dioxide content of the Earth’s atmosphere. This has been linked to a basalt eruption in Gondwana. Finally, the Siberian eruption mentioned above would have released not only large amounts of methane from the permafrost, but some of the rocks are rich in chlorine, and methyl chloride destroys ozone. Add a possible release of hydrogen sulfide from anoxic bacteria thriving in the ocean depths due to disruption of ocean currents, you have a recipe for a mass extinction.
As for the Chicxulub impact, the Yucatan Platform into which it crashed is mostly limestone, i.e. calcium carbonate.
“A Younger Moon,” by Alan Brandon, Nature, 27 December 2007, pp. 1169-1170. A synopsis of the longer article by Touboul et al. starting on page 1206 of the same issue. Analysis of radioactive decay of hafnium-182 to tungsten indicates that the Moon formed no earlier than 16 million years after the Earth’s core. This supports the impact theory of the Moon’s creation.
Notices:
My father Ralph Henderson died on November 14. He was always interested in space and I’d been sending him copies of Outreach for many years. I remember watching the Apollo 11 Moon Landing with him, and we both regretted that he never got to see a mission to Mars. My nephew Bobby is also interested in space and will inherit the subscription.
Wanda Capps died on December 20. She was the wife for nearly 58 years of former State Senator Gilmer Capps, who now sits on the OSIDA board, and I talked with her many times in the audience there. Pay respects at www.beckerfuneral.com/sitemaker/sites/becker0/obit.cgi?user=wanda-capps. .
Oklahoma Space Alliance Officers, 2008 (Area Code 405)
Tom Koszoru, President 366-1797 (H)
Claire McMurray, Vice-President/Update Editor 329-4326 (H) 863-6173 (C)
Syd Henderson, Secretary & Outreach Editor 321-4027 (H)
Tim Scott, Treasurer 740-7549 (H)
OSA E-mail Addresses and Web Site:
claire.mcmurray at sbcglobal.net(Claire McMurray, new address)
T_Koszoru at cox.net (Heidi and Tom Koszoru)
sydh at ou.edu(Syd Henderson)
ctscott at mac.com (Tim Scott)
john.d.northcutt at tds.net (John Northcutt)
lensman13 at aol.com (Steve Galpin)
dmcraig at earthlink.net (Nancy and David Craig).
E-mail for OSA should be sent to [email protected]. Members who wish their e-mail addresses printed in Outreach, and people wishing space-related materials e-mailed to them should contact Syd. Oklahoma Space Alliance website is osa.nss.org/index.html. Webmaster is Syd Henderson.
Other Information
Air and Space Museum: Omniplex, Oklahoma City, 602‑6664 or 1-800-532-7652.
Oklahoma Space Industrial Development Authority (OSIDA), 401 Sooner Drive/PO Box 689, Burns Flat, OK 73624, 580-562-3500. Web site www.state.ok.us/~okspaceport.
Tulsa Air and Space Museum, 7130 E. Apache, Tulsa, OK 74115.
Web Site is www.tulsaairandspacemuseum.com. Phone (918)834-9900.
The Mars Society address is Mars Society, Box 273, Indian Hills CO 80454. Their web address is www.marsociety.org.
The National Space Society's Headquarters phone is 202-429-1600. The Chapters Coordinator is Bennett Rutledge 720-529-8024. The address is: National Space Society, 1620 I (Eye) Street NW Ste. 615, Washington, DC 20006. Web page is space.nss.org.
NASA Spacelink BBS 205-895-0028. Or try www.nasa.gov. .
Congressional Switchboard 202/224-3121.
Write to any U. S. Senator or Representative at [name]/ Washington DC, 20510 (Senate) or 20515 [House].
OKLAHOMA SPACE ALLIANCE
A Chapter of the National Space Society
MEMBERSHIP ORDER FORM
Please enroll me as a member of Oklahoma Space Alliance. Enclosed is:
___ $10.00 for Membership. (This allows full voting privileges, but covers only your own newsletter expense.)
___________________ $15.00 for family membership
____ TOTAL amount enclosed
National Space Society has a special $20 introductory rate for new members ($35 for new international members). Regular membership rates are $45, international $60. Student memberships are $20. Part of the cost is for the magazine, Ad Astra. Mail to: National Space Society, 1620 I (Eye) Street NW, Washington DC 20006, or join at space.nss.org/membership. (Brochures are at the bottom with the special rate.) Be sure to ask them to credit your membership to Oklahoma Space Alliance.
To join the Mars Society, visit. One-year memberships are $50.00; student and senior memberships are $25, and Family memberships are $100.00. Their address is Mars Society, Box 273, Indian Hills CO 80454.
Do you want to be on the Political Action Network?
____ Yes No. [See brochure for information.]
Name ________
Address __
City State ZIP
Phone (optional or if on phone tree) ___
E-mail address (optional) _____
OSA Memberships are for 1 year, and include a subscription to our monthly newsletters, Outreach and Update. Send check & form to Oklahoma Space Alliance, 102 W. Linn, #1, Norman, OK 73071.
To contact Oklahoma Space Alliance, e-mail Syd Henderson.
102 W. Linn St. #1
Norman OK 73069
Copyright ©2007 Oklahoma Space Alliance.