DigitalSpace visualizations of approaching an asteroid with an "NEO Surface Access Module" attached to the NASA Orion Crew Exploration Vehicle and then, firmly anchored, sampling the surface. See news yesterday and more technology links below. Images courtesy of Digital Space, some rights reserved.
Contents on 31 July '07
- Minor-Object News -- six items
- Minor-Object Science -- three papers
- IAU Minor Planet Center
- Impact Risk Monitoring -- nothing to report
- Consolidated Risk Tables - CRT page
- Ephemerides for risk-rated objects
- Ephemerides for small asteroids
Navigation tips: Use the << and >> arrows on the menus for each regular section (Observers, Risks, etc.) to move to the previous and next day's news for that section. Use the Index menu item to access specific days this year through a calendar interface. And use the all-up news archive to access news from any time since A/CC began in early 2002. To keep track of what's new each day, watch the Chronology section.
Minor-Object News on 31 July '07
- "Researchers Discover Origin of Mysterious Glass Found in King Tut's Tomb," Cray, Inc. 31 July - Quote: "[Researchers] running simulations on the Cray supercomputer at Sandia National Laboratories have re-created what could have happened 29 million years ago when an asteroid explosion turned Saharan sand into glass... [Mark] Boslough and his colleagues at Sandia performed high-resolution hydrocode simulations on [the supercomputer] Red Storm using the CTH shock-physics code. They postulated a 120-meter diameter stony asteroid hitting the atmosphere at 20 kilometers per second and breaking up, touching off a blast equivalent to a 110 megaton bomb and producing intense heat and high-velocity winds. According to the simulations, this explosion would have been more than sufficient to melt rocky material on the surface and then cool it quickly, the conditions necessary to form natural glass." - Note: See also Sandia Lab's Libyan Desert Glass study.
- "Circumstellar space: Where chemistry happens for the very first time," Washington Univ. in St. Louis 31 July - Quote: "[Katharina] Lodders said that nucleosynthesis -- the creation of atoms -- takes place in a star's interior, made of a plasma far too hot for any molecular chemistry to take place. The event that enables chemistry is the death of a star, when elements are spewed out of the core, creating a shell around the star. As this circumstellar shell cools, the elements react to form gas molecules and solid compounds... [Just] one percent of all known presolar grains come from supernovas [out of the] several thousand individual presolar grains [that] have now been analyzed." - Note: This item notes that this year is the 20th anniversary of the first discovery of stardust, of presolar diamonds found in a meteorite in 1987.
- Exploration technology: Yesterday's big news was about visualization of a crewed mission to a near-Earth asteroid based on thinking by some people within NASA (see images above). Some other thinking about asteroid missions also got aired yesterday, as scientific papers posted on arXiv.org. Back on May 15th we published a link to a paper entitled, "Landing screw-rockets array on asteroids, digging soil and fueling engines in phase, to overcome the spin and to fly in space" by Danielle Fargion. That was replaced yesterday with a rewrite that is noted as accepted for publication and now bearing the title, "Asteroid Deflection: How, where and when?" And a paper on biospheres by Alexander Bolonkin has been accepted for presentation that proposes, among other ideas, surrounding a whole asteroid with an inflated structure to allow working in shirt sleeves rather than spacesuits: "[It is] possible for current technology to construct and heat large enclosed volumes inexpensively."
There were two gatherings somewhat related to asteroid exploration held last month in Sudbury, Canada -- Planetary & Terrestrial Mining Sciences Symposium on 10-13 June, followed on the 14th to 17th by a Comparative Planetology Workshop, "From Field to Lab to Payload."
Galileo Avionica has a news release (57Kb PDF) about the use of its star trackers on missions including Rosetta and New Horizons.
- "Fasting for Pluto," Cape Cod Today 31 July - Quote: "After much discussion, we decided to go on a hunger strike until Pluto's status as a full-fledged planet was reinstated. Here's how it turned out."
- "Super bolide," SpaceWeather.com 31 July - Quote: "On Wednesday, July 25th at approximately 10:00 UT, 'a major daylight fireball tore across the skies of Slovenia, Croatia and Italy,' reports veteran meteor observer Jure Atanackov of Maribor, Slovenia. 'It produced two bright flashes that reached an estimated magnitude of -20 and also loud sonic booms.'"
- "Tyden: Czech basin might have arisen through mighty cosmic impact," Prague Daily Monitor 31 July - Quote: "Some experts are starting to support the theory that the fall of a giant meteorite some 2 billion years ago may have created the Czech basin, surrounded by mountain ranges, reminding of a crater."
Minor-Object Science on 31 July '07
- "Orbit Determination with Topocentric Correction: Algorithms for the Next Generation Surveys" by Milani, Andrea with Giovanni F. Gronchi, Davide Farnocchia & 4 others, abstract & PDF at arXiv.org 31 July - Quote: "Given a set of astrometric observations of the same object, the problem of orbit determination is to compute the orbit and to assess its uncertainty and reliability. For the next generation surveys, with much larger number density of observed objects, new algorithms or substantial revisions of the classical ones are needed. The problem has three main steps, preliminary orbit, least squares orbit, and quality control. The classical theory of preliminary orbits was incomplete: the consequences of the topocentric correction had not been fully studied. We show that it is possible to account for this correction, possibly with an increase in the number of preliminary solutions, without impairing the overall orbit determination performance. We have developed modified least squares orbit determination algorithms that can be used to improve the reliability of the procedure. We have tested the complete procedure on two simulations with number densities comparable to that expected from the next generation surveys such as Pan-STARRS and LSST. To control the problem of false identifications we have introduced a quality control on the fit residuals based on an array of metrics and a procedure to remove duplications and contradictions in the output. The results confirm that large sets of discoveries can be obtained with good quality orbits and very high success rate losing only 0.6 to 1.3% of objects and a false identification rate in the range 0.02 to 0.06%."
- "Resonance sticking in the scattered disk" by Lykawka, Patryk Sofia with Tadashi Mukai, abstract & PDF at arXiv.org 31 July - Quote: "We investigate the dynamical evolution of trans-Neptunian objects (TNOs) in typical scattered disk orbits (scattered TNOs) by performing simulations using several thousand particles lying initially on Neptune-encountering orbits. We explore the role of resonance sticking in the scattered disk, a phenomenon characterized by multiple temporary resonance captures ('resonances' refers to external mean motion resonances with Neptune, which can be described in the form r:s, where the arguments r and s are integers). First, all scattered TNOs evolve through intermittent temporary resonance capture events and gravitational scattering by Neptune. Each scattered TNO experiences tens to hundreds of resonance captures over a period of 4 Gyr, which represents about 38% of the object's lifetime (mean value). Second, resonance sticking plays an important role at semimajor axes a<250 AU, where the great majority of such captures occurred... In sum, resonance sticking has an important impact on the evolution of scattered TNOs, contributing significantly to the longevity of these objects."
- "OVRO N2H+ Observations of Class 0 Protostars: Constraints on the Formation of Binary Stars" by Chen, Xuepeng with Ralf Launhardt & Thomas Henning, abstract & PDF at arXiv.org 31 July - Quote: "We present the results of an interferometric study of the N2H+(1-0) emission from nine nearby, isolated, low-mass protostellar cores, using the OVRO millimeter array. The main goal of this study is the kinematic characterization of the cores in terms of rotation, turbulence, and fragmentation [into stellar binary systems]. Eight of the nine objects have compact N2H+ cores with FWHM radii of 1200-3500 AU... Estimated virial masses range from 0.3 to 1.2 M_sun."
NEOCP Activity on 31 July '07
The MPC's NEO Confirmation Page has 2 listings: 1 new, 1 updated
When last checked at 2035 UTC today, the Minor Planet Center's NEO discovery Confirmation Page (NEOCP) had one new and one updated listing. Of these, one was a "one nighter."
To learn how observers use the NEOCP, see Suno Observatory's Practical guide on how to observe NEOCP object.
New MPECs on 31 July '07
Minor Planet Electronic Circulars
As of last check at 2035 UTC, there have been eight MPECs issued today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.
- MPEC 2007-O56 time-stamped "06:06 UT" - Daily Orbit Update - see below
- MPEC 2007-O57 time-stamped "16:33 UT" - Observable Comets - see below
- MPEC 2007-O58 time-stamped "17:15 UT" - Distant Minor Planets - see below
- MPEC 2007-O59 time-stamped "17:21 UT" - Critical-List Minor Planets - see below
- MPEC 2007-O60 time-stamped "17:29 UT" - Atens and Apollos - see below
- MPEC 2007-O61 time-stamped "17:29 UT" - Amors - see below
- MPEC 2007-O62 time-stamped "17:29 UT" - Unusual Minor Planets - see below
- MPEC 2007-O63 time-stamped "17:29 UT" - PHAs
MPEC 2007-O63 - "17:29 UT" - PHAs
MPEC 2007-O62 - "17:29 UT" - Unusual Minor Planets
MPEC 2007-O61 - "17:29 UT" - Amors
MPEC 2007-O60 - "17:29 UT" - Atens and Apollos
MPEC 2007-O59 - "17:21 UT" - Critical-List Minor Planets
MPEC 2007-O58 - "17:15 UT" - Distant Minor Planets
MPEC 2007-O57 - "16:33 UT" - Observable Comets
- K07N05C 2007 NC5 (q=0.278 AU, Q=4.602 AU, arc=27 days, H=17.9 ~891m) from Great Shefford Obs. (July 31.13-14p3)
- K07M13L 2007 ML13 (arc=39 days, H=20.2 ~309m) from Jim Young via Table Mtn. Obs. (July 31.17-20p4)
- K07L32R 2007 LR32 (arc=65 days, H=17.2 ~1.23 km) from New Millennium Obs. (July 28.05-07p6)
- K07DA3T 2007 DT103 (arc=155 days, H=18.7 ~616m) from Stammersdorf Obs. (July 30.92-97p6) and Great Shefford Obs. (July 31.12p3)
- K04S09T 2004 ST9 (arc=2 opp, H=18.0 ~851m) from New Millennium Obs. (July 27.95-00p5)
- 87309 87309 2000 QP from Gualba Obs. (July 28.08p3)
- 85275 85275 1994 LY from New Millennium Obs. (July 27.91-97p9)
- 21277 21277 1996 TO5 from Gualba Obs. (July 28.08-09p4)
- 05143 5143 Heracles (1991 VL) from New Millennium Obs. (July 28.01-07p9)
Observers on 31 July '07
Five observing facilities appear in today's MPECs.
|J95||Great Shefford Obs. in England, 2 in MPEC 2007-O56 -- 2007 NC5, 2007 DT103|
|442||Gualba Obs. in Spain, 2 in MPEC 2007-O56 -- 87309, 21277|
|A24||New Millennium Obs. in Italy, 4 in MPEC 2007-O56 -- 2007 LR32, 2004 ST9, 85275, 5143|
|A97||Stammersdorf Obs. in Austria, 1 in MPEC 2007-O56 -- 2007 DT103|
|6735||Jim Young via Table Mtn. Obs. in southern California, 1 in MPEC 2007-O56 -- 2007 ML13|
Impact Risk Monitoring on 31 July '07
At last check (NEODyS and JPL at 2035 UTC) there was no risk monitoring news to report yet today. See the CRT for activity in the last month.
Chronology on 31 July '07
Times are UTC for when the items were noted or added by Major News.
|2030||Added news report, "Exploration technology"|
Added link to news story, "Researchers Discover Origin of Mysterious Glass Found in King Tut's Tomb"
Added link to news story, "Circumstellar space: Where chemistry happens for the very first time"
Added link to news story, "Fasting for Pluto"
|1851||Grabbed MPEC 2007-O59 - Critical-List Minor Planets - see above|
Grabbed MPEC 2007-O60 - Atens and Apollos - see above
Grabbed MPEC 2007-O61 - Amors - see above
Grabbed MPEC 2007-O62 - Unusual Minor Planets - see above
Grabbed MPEC 2007-O63 - PHAs - see above
|1725||Grabbed MPEC 2007-O57 - Observable Comets - see above|
Grabbed MPEC 2007-O58 - Distant Minor Planets - see above
|1540||Added link to news story, "Tyden: Czech basin might have arisen through mighty cosmic impact"|
Added link to news story, "Super bolide"
|1428||Grabbed MPEC 2007-O56 - Daily Orbit Update - see above|
|0515||Added MOS paper, "OVRO N2H+ Observations of Class 0 Protostars: Constraints on the Formation of Binary Stars" - see above|
Added MOS paper, "Orbit Determination with Topocentric Correction: Algorithms for the Next Generation Surveys" - see above
Added MOS paper, "Resonance sticking in the scattered disk" - see above