Re: [meteorite-list] Alamo Impact Crater Recognized
On Monday Febraury 2, 2015, Count Deiro wrote, Sunday, the Las Vegas Review Journal newspaper carried a second page headline that mentions the recent paper published in the current issue of Geosphere, the online mag for the Geological Society of America, arguing the legitimacy of the 382 million year old Alamo Impact and doubling it's diameter to between 69 and 93 miles. Some articles are: Alamo impact crater: New study could double its size Geological Society of America, January 23, 2015 http://www.sciencedaily.com/releases/2015/01/150123102541.htm http://www.eurekalert.org/pub_releases/2015-01/gsoa-aic012215.php New study ranks Nevada crater among world's largest Las Vegas Review-Journal, January 31, 2015 http://www.reviewjournal.com/news/science/new-study-ranks-nevada-crater-among-world-s-largest 150 Kilometer Diameter Crater In Nevada Result Of Bolide Impact On Ancient Seafloor, January 25, 2015 21:09 http://www.ineffableisland.com/2015/01/150-kilometer-diamerter-crater-in.html The papers are: Retzler, A. J., L. Tapanila, J. R. Steenberg, C. J. Johnson, and R. A. Myers. Post-impact depositional environments as a proxy for crater morphology, Late Devonian Alamo impact, Nevada. Geosphere, 2015; DOI: 10.1130/GES00964.1 http://geosphere.gsapubs.org/content/early/2015/01/14/GES00964.1.abstract Retzler, A. J., 2013, Post-impact depositional environments as a proxy for crater morphology, Late Devonian Alamo impact, Nevada. Uynpublished MS thesis, Department of Geosciences, Idaho State University, Pocatello, Idaho. http://geology.isu.edu/thesis/Retzler.Andrew.2013.pdf Yours, Paul H. __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] room mate
Good day to all met fans. If anyone is coming to Tucson this weekend only, I am looking for a roommate. I have 2 queen sized beds. If you cannot find a room I will have availability. Your price will be $200. It is $200 a nite. I'll pay the extra tax. Let me know if interested. Call me 1-847-804-8810. I get in feb. 6th and I leave feb. 8th. Thanks so much and see all soon. __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] room mate
That is so freaking scary, it rivals Jurasic Earth's SuperBowl commercial. -Original Message- From: steve arnold via Meteorite-list Sent: Monday, February 02, 2015 8:29 AM To: meteorite-list@meteoritecentral.com Subject: [meteorite-list] room mate Good day to all met fans. If anyone is coming to Tucson this weekend only, I am looking for a roommate. I have 2 queen sized beds. If you cannot find a room I will have availability. Your price will be $200. It is $200 a nite. I'll pay the extra tax. Let me know if interested. Call me 1-847-804-8810. I get in feb. 6th and I leave feb. 8th. Thanks so much and see all soon. __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] room mate
What's that supposed to mean Rick? Sent from my iPhone On Feb 2, 2015, at 16:28, Rick Montgomery via Meteorite-list meteorite-list@meteoritecentral.com wrote: That is so freaking scary, it rivals Jurasic Earth's SuperBowl commercial. -Original Message- From: steve arnold via Meteorite-list Sent: Monday, February 02, 2015 8:29 AM To: meteorite-list@meteoritecentral.com Subject: [meteorite-list] room mate Good day to all met fans. If anyone is coming to Tucson this weekend only, I am looking for a roommate. I have 2 queen sized beds. If you cannot find a room I will have availability. Your price will be $200. It is $200 a nite. I'll pay the extra tax. Let me know if interested. Call me 1-847-804-8810. I get in feb. 6th and I leave feb. 8th. Thanks so much and see all soon. __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Met Bulletin Update - 17 NWA Meteorites, R, CK, CV, Ure, Euc, Type 3
Hi Bulletin Watchers, There are 17 new approvals from the NWA DCA. Most are OC's, but there are also some achondrites. Link : http://www.lpi.usra.edu/meteor/metbull.php?sea=sfor=namesants=falls=valids=stype=containslrec=50map=gebrowse=country=Allsrt=namecateg=Allmblist=Allrect=phot=snew=2pnt=Normal%20tabledr=page=0 Best regards and Happy Huntings, MikeG -- - Web - http://www.galactic-stone.com Facebook - http://www.facebook.com/galacticstone Twitter - http://twitter.com/galacticstone Pinterest - http://pinterest.com/galacticstone - __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] room mate
All in good fun Steve! please don't take it wrongI wish I could be there this year. Good fortune chasing your dreams and those pieces you are fortunate enough to get. -Original Message- From: steve arnold via Meteorite-list Sent: Monday, February 02, 2015 8:29 AM To: meteorite-list@meteoritecentral.com Subject: [meteorite-list] room mate Good day to all met fans. If anyone is coming to Tucson this weekend only, I am looking for a roommate. I have 2 queen sized beds. If you cannot find a room I will have availability. Your price will be $200. It is $200 a nite. I'll pay the extra tax. Let me know if interested. Call me 1-847-804-8810. I get in feb. 6th and I leave feb. 8th. Thanks so much and see all soon. __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] India Meteor 2000 Local Time 31JAN2015
List, India Meteor 2000 Local Time 31JAN2015 http://lunarmeteoritehunters.blogspot.jp/2015/02/india-meteor-31jan2015.html Dirk Ross...Tokyo __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Australian Monash University Meteorite Recovery Program is under threat
Hi all, Some of you may have seen me post this on Facebook already but for those of you who haven't, unfortunately the Australian Monash University Meteorite Recovery program is under threat of being cancelled this year due to lack of funding. This is the same one that I assisted with in 2012 2013 so I have seen firsthand the contributions this team makes and what they are doing to further Australian meteoritical science. In fact, over the past several years, this program has been responsible for discovering around 20% of all of Australia's meteorite finds. So this year, with funding having run out, the team is turning to the public and meteorite community for help. For those of you who would like to consider helping or would even just like to learn a bit more about the program, please see the link below. There is plenty of information there about the program and also how this crowd funding would contribute to another successful year. http://www.pozible.com/project/189365 Thanks, Jeff Kuyken Meteorites Australia www.meteorites.com.au __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Tucson Fun Friends
I hope *everyone* attending has as much fun as you are, Greg! Wish I could be there again, but I'll have to be content to work on improving my collection inventory/catalog. Best wishes to all, Linton -Original Message- From: Greg Hupe via Meteorite-list Sent: Monday, February 02, 2015 11:44 AM To: meteorite list Subject: [meteorite-list] Tucson Fun Friends Hello All, Saturday morning we landed in Phoenix on delayed flights due to the storm and didn't make it to Tucson until 3:30 AM. After sleeping in we eventually made our way to the Inn Suites around 2:00 PM enjoying the pouring rain and flooding. Being an experienced show attendee, I was able to 'talk' my way through the blocked hotel parking area and found a spot 10 feet from the covered walkway. We spent the next three hours visiting with old friends, meeting new ones and finally meeting a few 'Facebook' friends I have never met in person. That night we met with close friends from out of state for dinner and enjoyed great seafood and Margaritas... Awesome first day of the show! Yesterday, after a relaxed morning of sleeping in again, we went to a couple show rooms and I bought two nice diogenites, a CM2 and a gorgeous howardite... We later met with friends for fantastic southwest grilled seafood and delicious pizza while watching the Super Bowl, fun times were had by all. Today is another relaxed start of the day and more meteorite 'Fun Friends'... Looking forward to meeting up more peeps! Greg Hupe Sent from my iPhone __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Tucson Fun Friends
Will miss seeing you Linton. Hopefully next year. Michael Farmer On Feb 2, 2015, at 9:05 PM, Linton Rohr via Meteorite-list meteorite-list@meteoritecentral.com wrote: I hope *everyone* attending has as much fun as you are, Greg! Wish I could be there again, but I'll have to be content to work on improving my collection inventory/catalog. Best wishes to all, Linton -Original Message- From: Greg Hupe via Meteorite-list Sent: Monday, February 02, 2015 11:44 AM To: meteorite list Subject: [meteorite-list] Tucson Fun Friends Hello All, Saturday morning we landed in Phoenix on delayed flights due to the storm and didn't make it to Tucson until 3:30 AM. After sleeping in we eventually made our way to the Inn Suites around 2:00 PM enjoying the pouring rain and flooding. Being an experienced show attendee, I was able to 'talk' my way through the blocked hotel parking area and found a spot 10 feet from the covered walkway. We spent the next three hours visiting with old friends, meeting new ones and finally meeting a few 'Facebook' friends I have never met in person. That night we met with close friends from out of state for dinner and enjoyed great seafood and Margaritas... Awesome first day of the show! Yesterday, after a relaxed morning of sleeping in again, we went to a couple show rooms and I bought two nice diogenites, a CM2 and a gorgeous howardite... We later met with friends for fantastic southwest grilled seafood and delicious pizza while watching the Super Bowl, fun times were had by all. Today is another relaxed start of the day and more meteorite 'Fun Friends'... Looking forward to meeting up more peeps! Greg Hupe Sent from my iPhone __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Australian Monash University Meteorite Recovery Program is under threat
Hi Jeff, A worthy program for sure. But, one has to wonder - if Australia's laws were not so restrictive, private hunters would be recovering and classifying more Australian meteorites than the scientists would have time to examine. Take the private hunters out of the equation, and all that's left are scarcely-funded and undermanned official programs. Science suffers. Best regards and Happy Huntings, MikeG -- - Web - http://www.galactic-stone.com Facebook - http://www.facebook.com/galacticstone Twitter - http://twitter.com/galacticstone Pinterest - http://pinterest.com/galacticstone - On 2/2/15, Jeff Kuyken via Meteorite-list meteorite-list@meteoritecentral.com wrote: Hi all, Some of you may have seen me post this on Facebook already but for those of you who haven't, unfortunately the Australian Monash University Meteorite Recovery program is under threat of being cancelled this year due to lack of funding. This is the same one that I assisted with in 2012 2013 so I have seen firsthand the contributions this team makes and what they are doing to further Australian meteoritical science. In fact, over the past several years, this program has been responsible for discovering around 20% of all of Australia's meteorite finds. So this year, with funding having run out, the team is turning to the public and meteorite community for help. For those of you who would like to consider helping or would even just like to learn a bit more about the program, please see the link below. There is plenty of information there about the program and also how this crowd funding would contribute to another successful year. http://www.pozible.com/project/189365 Thanks, Jeff Kuyken Meteorites Australia www.meteorites.com.au __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Meteorite Picture of the Day
Today's Meteorite Picture of the Day: Tektite Contributed by: Michael Hofmann http://www.tucsonmeteorites.com/mpodmain.asp?DD=02/03/2015 __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Alamo Impact Crater Recognized
Hi, Sunday, the Las Vegas Review Journal newspaper carried a second page headline that mentions the recent paper published in the current issue of Geosphere, the online mag for the Geological Society of America, arguing the legitimacy of the 382 million year old Alamo Impact and doubling it's diameter to between 69 and 93 miles. Those of us who have visited the physical area and collected impact breccia sometimes in the face of criticism of the size and even the legitimacy of the event are vindicated by the published findings of some several authors including Retzler, Warme and others. The RJ story can be accessed on the newspaper's online site.Geosphere has the scientific paper online. Regards to all and thanks to the Hupes and Dirk Ross for putting me on the physical material of which I have a small truck load recovered from near what may be the more eastern edge of the remaining displacement. Count Deiro IMCA 3536 MetSoc __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Bill Mason's coming to Tucson!
Wanted to let folks know that Bill Mason will be coming to Tucson this year. He'll be at the PaleoBOND booth at the 22nd Street Show from Wednesday, February 4th through Wednesday, February 12th. Be sure to stop by and say hi! Tracie Bennitt Owner 743 Gold Hill Place #191 Woodland Park, CO 80863 651-227-7000 www.paleobond.com www.facebook.com/paleobond __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Tucson Fun Friends
Hello All, Saturday morning we landed in Phoenix on delayed flights due to the storm and didn't make it to Tucson until 3:30 AM. After sleeping in we eventually made our way to the Inn Suites around 2:00 PM enjoying the pouring rain and flooding. Being an experienced show attendee, I was able to 'talk' my way through the blocked hotel parking area and found a spot 10 feet from the covered walkway. We spent the next three hours visiting with old friends, meeting new ones and finally meeting a few 'Facebook' friends I have never met in person. That night we met with close friends from out of state for dinner and enjoyed great seafood and Margaritas... Awesome first day of the show! Yesterday, after a relaxed morning of sleeping in again, we went to a couple show rooms and I bought two nice diogenites, a CM2 and a gorgeous howardite... We later met with friends for fantastic southwest grilled seafood and delicious pizza while watching the Super Bowl, fun times were had by all. Today is another relaxed start of the day and more meteorite 'Fun Friends'... Looking forward to meeting up more peeps! Greg Hupe Sent from my iPhone __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Rover Opportunity Update: January 22-27, 2015
http://mars.nasa.gov/mer/mission/status.html#opportunity OPPORTUNITY UPDATE: Several Drives This Week Put Opportunity Near Marathon Distance - sols 3909-3914, January 22, 2015-January 27, 2015: Opportunity is on the west rim of Endeavour Crater heading towards Marathon Valley, a putative location for abundant clay minerals now about 984 feet (300 meters) away. The project is operating the rover without using the Flash storage system to avoid reset problems and is using instead random access memory (RAM) for temporary storage of telemetry. The project is preparing to mask off the troubled sector of Flash and resume using the remainder of the Flash file system in normal operations. Opportunity drove on Sols 3909, 3911 and 3914 (Jan. 22, Jan. 24 and Jan. 27, 2015), totaling almost 279 feet (85 meters). On the evening of Sol 3912 (Jan. 25, 2015), an atmospheric argon measurement was collected with the Alpha Particle X-ray Spectrometer. Targeted color imagery is being collected as the rover makes progress towards the Spirit of St. Louis crater and Marathon Valley. As of Sol 3914 (Jan. 27, 2015), the estimated solar array energy production was 534 watt-hours with an atmospheric opacity (Tau) of 0.891 and an inferred solar array dust factor of 0.636. Total odometry is 26.02 miles (41.88 kilometers). __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Odyssey THEMIS Images: January 26-30, 2015
MARS ODYSSEY THEMIS IMAGES January 26-30, 2015 o Schaeberle Crater - False Color (26 January 2015) http://themis.asu.edu/zoom-20150126a o Ganges Chasma - False Color (27 January 2015) http://themis.asu.edu/zoom-20150127a o North Polar Cap - False Color (28 January 2015) http://themis.asu.edu/zoom-20150128a o Makhambet Crater - False Color (29 January 2015) http://themis.asu.edu/zoom-20150129a o Windstreaks - False Color (30 January 2015) http://themis.asu.edu/zoom-20150130a All of the THEMIS images are archive here: http://themis.asu.edu/latest.html NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Scientists say meteorite found in Morocco is 4.4 billion years old from Mars
Hello Listers Enjoy Shawn Alan IMCA 1633 ebay store http://www.ebay.com/sch/imca1633ny/m.html Website http://meteoritefalls.com Scientists say meteorite “Black Beauty” found in Morocco is 4.4 billion years old from Mars by Ben Kochmanon February 2, 2015 Scientists have concluded that the piece of meteorite found in the desert of Morocco is 4.4 billion years old, and definitely came from Mars. And dubbed NWA 7034 – you know, NorthWest Africa – or Black Beauty – because it is predominantly black and not red like normal space rocks from Mars. Mars, usually called the Red Planet because of its characteristic red features will reveal some unusual aspect of itself through Black Beauty. Almost all meteors that fell from Mars were designated as SNC – shergottites, nakhlites, or chassignites – meteors, because they largely consist of igneous rocks made up of cooled volcanic materials. However, researchers at Brown University in Rhode Island and the University of New Mexico who’ve conducted new spectroscopic examinations of the rock say Black Beauty is breccias – a conglomeration of different types of rock that have been fused together in a basaltic matrix. The components of the meteorite chemically match rocks analyzed by NASA rovers on Mars, and this suggests that the stone must have come from the dark crust that underlies Mar’s dusty reddish surface. And if this happens to be the case, then it might be the answer scientists have been looking for in trying to explain why spectrographic examination of SNC meteorites has never quite matched up with spectral data of the Martian surface gathered from space. Reporting their finding in the journal Icarus, “Most samples from Mars are somewhat similar to spacecraft measurements,” said Brown researcher Jack Mustard, “but annoyingly different.” Using an imaging system developed by Massachusetts-based Headwall Photonics to obtain detailed spectral imaging of the entire sample, lead author Kevin Cannon said “Other techniques give us measurements of a dime-sized spot. What we wanted to do was get an average for the entire sample. That overall measurement was what ended up matching the orbital data.” This actually means Black Beauty might belong to the Martian dark plains where the red dust coating is thin and the rocks beneath it exposed. Black Beauty might be a sample of the “bulk background” rocks believed to be hidden underneath the red dust of much of the Martian surface. “Mars is punctured by over 400,000 impact craters greater than 1 km in diameter,” the researchers write. “Because brecciation is a natural consequence of impacts, it is expected that material similar to NWA 7034 has accumulated on Mars over time.” That’s what you’d expect on a planetary surface that has been broken apart and then reassembled by constant bombardment and cosmic impacts, the scientists affirm. “This is showing that if you went to Mars and picked up a chunk of crust, you’d expect it to be heavily beat up, battered, broken apart and put back together,” Cannon said. __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Dawn Journal - January 29, 2015
http://dawnblog.jpl.nasa.gov/2015/01/29/dawn-journal-january-29/ Dawn Journal by Marc Rayman January 29, 2015 Dear Abundawnt Readers, The dwarf planet Ceres is a giant mystery. Drawn on by the irresistible lure of exploring this exotic, alien world, Dawn is closing in on it. The probe is much closer to Ceres than the moon is to Earth. And now it is even closer... And now it is closer still! What has been glimpsed as little more than a faint smudge of light amidst the stars for more than two centuries is finally coming into focus. The first dwarf planet discovered (129 years before Pluto), the largest body between the sun and Pluto that a spacecraft has not yet visited, is starting to reveal its secrets. Dawn is seeing sights never before beheld, and all of humankind is along for the extraordinary experience. We have had a preview of Dawn's approach phase, and in November we looked at the acrobatics the spacecraft performs as it glides gracefully into orbit. Now the adventurer is executing those intricate plans, and it is flying beautifully, just the way a seasoned space traveler should. Dawn's unique method of patiently, gradually reshaping its orbit around the sun with its ion propulsion system is nearly at its end. Just as two cars may drive together at high speed and thus travel at low speed relative to each other, Dawn is now close to matching Ceres' heliocentric orbital motion. Together, they are traveling around the sun at nearly 39,000 mph (almost 64,000 kilometers per hour), or 10.8 miles per second (17.4 kilometers per second). But the spaceship is closing in on the world ahead at the quite modest relative speed of about 250 mph (400 kilometers per hour), much less than is typical for interplanetary spaceflight. [Image] Dawn observed Ceres for an hour on Jan. 13, from a distance of 238,000 miles (383,000 kilometers). A little more than half of the surface was revealed as Ceres rotated. This imaging session is known as OpNav 1. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI Dawn has begun its approach imaging campaign, and the pictures are wonderfully exciting. This month, we will take a more careful look at the plans for photographing Ceres. Eager readers may jump directly to the summary table, but others may want to emulate the spacecraft by taking a more leisurely approach to it, which may aid in understanding some details. While our faithful Dawn is the star of this bold deep-space adventure (along with protoplanet Vesta and dwarf planet Ceres), the real talent is behind the scenes, as is often the case with celebrities. The success of the mission depends on the dedication and expertise of the members of the Dawn flight team, no farther from Earth than the eighth floor of JPLs building 264 (although occasionally your correspondent goes on the roof to enjoy the sights of the evening sky). They are carefully guiding the distant spacecraft on its approach trajectory and ensuring it accomplishes all of its tasks. To keep Dawn on course to Ceres, navigators need a good fix on where the probe and its target are. Both are far, far from Earth, so the job is not easy. In addition to the extraordinarily sophisticated but standard methods of navigating a remote interplanetary spacecraft, using the radio signal to measure its distance and speed, Dawn's controllers use another technique now that it is in the vicinity of its destination. From the vantage point of Earth, astronomers can determine distant Ceres' location remarkably well, and Dawn's navigators achieve impressive accuracy in establishing the craft's position. But to enter orbit, still greater accuracy is required. Therefore, Dawn photographs Ceres against the background of known stars, and the pictures are analyzed to pin down the location of the ship relative to the celestial harbor it is approaching. To distinguish this method from the one by which Dawn is usually navigated, this supplementary technique is generally known as 'optical navigation. Unable to suppress their geekiness (or, at least, unmotivated to do so), Dawn team members refer to this as OpNav. There are seven dedicated OpNav imaging sessions during the four-month approach phase, along with two other imaging sessions. (There will also be two more OpNavs in the spiral descent from RC3 to survey orbit.) The positions of the spacecraft and dwarf planet are already determined well enough with the conventional navigation methods that controllers know which particular stars are near Ceres from Dawn's perspective. It is the analysis of precisely where Ceres appears relative to those stars that will yield the necessary navigational refinement. Later, when Dawn is so close that the colossus occupies most of the camera's view, stars will no longer be visible in the pictures. Then the optical navigation will be based on determining the location of the spacecraft with respect to specific surface features that have
