Image from May 14th from the Hubble Space Telescope Wide Field Planetary Camera 2 showing the Dawn mission's first destination, arriving in 2011 to orbit Main Belt asteroid 4 Vesta (see misson news below). To get a better sense of surface features, the smallest of which here are 60 km. (37 miles) across, see a video with the 5.34-hour rotation, also shown as a montage. Credit: NASA, ESA, L. McFadden, and G. Bacon. Vesta's southern hemisphere, to the lower right, is shaped by an impact crater almost as wide as the asteroid's diameter.
Contents on 27 June '07
- Minor-Object News -- three items
- Minor-Object Science -- one paper
- IAU Minor Planet Center
- Impact Risk Monitoring -- three objects reported
WELCOME to A/CC's prototype daily news publication designed to be the viewing end of a planned autonomous 24-hour news service. The new tools and this publication format are working well enough now to share with readers. It is expected that this approach will require less time to maintain than our previous news and small asteroid pages, which were retired on May 14th. There's still more development ahead and there probably will be some glitches along the way, but this is what's needed to keep up with the increasing pace of minor-object news. The CRT page will be maintained separately for a little while longer, until all of this is working smoothly. And the CRT and small-asteroid ephemerides will be kept going.
Minor-Object News on 27 June '07
- "June 23rd Dawn Journal," NASA Dawn mission 26 June - Quote: "The spacecraft was designed so that it would be balanced, but minor adjustments in individual components during assembly and test can alter the balance. So the spacecraft was placed on a rig that measured how stable it was as it spun at 50 revolutions per minute (rpm). After each spin, engineers calculated how to improve the balance. Small weights then were attached to mounting fixtures on the spacecraft that had been included for just such a possibility. Then the spin was repeated to verify the predicted improvement."
- "How NASA's Dawn Spacecraft Will Explore Solar System's Origin," Space.com 27 June - Quote: "Dawn is scheduled to arrive at [dwarf planet] Ceres by February 2015, a few months before NASA's New Horizon probe reaches the dwarf planet Pluto."
- "UCLA Professor Christopher Russell Leads NASA's Dawn Mission," UCLA 26 June - Quote: "UCLA is in charge of Dawn's science and public outreach. Russell leads the science team, brings together the mission's partners, manages the budget and participates in all major decisions. Russell and his colleagues will make science decisions and develop the operations plans through the science center at UCLA's Institute of Geophysics and Planetary Physics. His science team has the lead role for analyzing and interpreting the data from Dawn. UCLA graduate students and postdoctoral scholars will work on the mission, including helping to analyze the data from Dawn."
Minor-Object Science on 27 June '07
- "Interpretation of the near-IR spectra of the Kuiper Belt Object (136472) 2005 FY9" by Eluszkiewicz, J. with K. Cady-Pereira, M.E. Brown & J.A. Stansberry, PDF from Michael E. Brown 25 June - Quote: "Visible and near-IR observations of the Kuiper Belt Object (136472) 2005 FY9 have indicated the presence of unusually long (1 cm or more) optical path lengths in a layer of methane ice. Using microphysical and radiative transfer modeling, we show that even at the frigid temperatures in the outer reaches of the solar system, a slab of low-porosity methane ice can indeed form by pressureless sintering of micron-sized grains, and it can qualitatively reproduce the salient features of the measured spectra. A good semiquantitative match with the near-IR spectra can be obtained with a realistic slab model, provided the spectra are scaled to a visible albedo of 0.6, at the low end of the values currently estimated from Spitzer thermal measurements. Consistent with previous modeling studies, matching spectra scaled to higher albedos requires the incorporation of strong backscattering effects. The albedo may become better constrained through an iterative application of the slab model to the analyis of the thermal measurements from Spitzer and the visible/near-IR reflectance spectra."
NEOCP Activity on 27 June '07
The MPC's NEO Confirmation Page has 1 listing: 1 new
When last checked at 2033 UTC today, the Minor Planet Center's NEO discovery Confirmation Page (NEOCP) had one new listing. This was a "one nighter." So far Major News has counted a total of six objects listed on the NEOCP at some point today.
New MPECs on 27 June '07
Minor Planet Electronic Circulars
As of last check at 2347 UTC, there have been two MPECs issued today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.
- MPEC 2007-M46 time-stamped "06:06 UT" - Daily Orbit Update - see below
- MPEC 2007-M47 time-stamped "11:55 UT" - 2007 ML24
MPEC 2007-M47 - "11:55 UT" - 2007 ML24
- K07M24L 2007 ML24 (risk-listed, Earth MOID=4.3 LD, H=19.1 ~513m) was discovered at 1053 UT 22 June by the Mt. Lemmon Survey (MLS), which observed it at June 21.43-45p4 and 22.45-46p4. The discovery was confirmed by the Spacewatch 1.8m telescope (June 24.45p3).
- Observations of risk-listed objects
- K07M24B 2007 MB24 (i=47.5°, arc=3 days, H=18.6 ~645m) from LINEAR (June 26.32-37p7), CAST Obs. (June 26.85p1), and Vallemare di Borbona Obs. (June 26.96-97p4)
- Observations of other objects
- K07M20T 2007 MT20 (arc=2 days, H=18.4 ~708m) from LINEAR (June 26.27-31p5)
- K07M06K 2007 MK6 (q=0.196 AU, arc=6 days, H=19.9 ~355m) from Jim Young via Table Mtn. Obs. (June 27.23-24p4)
- K07L32R 2007 LR32 (arc=32 days, H=17.1 ~1.29 km) from the Catalina Sky Survey (CSS) (June 26.37-38p3)
- K07L00F 2007 LF (arc=18 days, H=20.5 ~269m) from El Leoncito Obs. (June 23.10-12p3)
- K07L00D 2007 LD (arc=19 days, H=19.1 ~513m) from Spacewatch 1.8m (June 26.28-31p3)
- K07C19A 2007 CA19 (Q=5.089 AU, arc=66 days, H=17.6 ~1.02 km) from New Millennium Obs. (March 12.89-04p11)
- K06V13D 2006 VD13 (arc=2 opp, H=19.0 ~537m) from New Millennium Obs. (March 12.87-90p3)
- K05N44W 2005 NW44 (arc=2 opp, H=20.4 ~282m) from LINEAR (June 26.24-26p3)
- K00U16V 2000 UV16 (arc=4 opp, H=17.0 ~1.35 km) from El Leoncito Obs. (June 23.07-09p3, 24.05-07p2 & 26.06-07p3)
- F2895 152895 2000 CQ101 from El Leoncito Obs. (June 23.05-07p3 & 24.03-04p3)
- A8519 108519 2001 LF from El Leoncito Obs. (June 23.99-02p5)
- 86878 86878 2000 HD24 from CSS (June 26.36-38p4)
- 53435 53435 1999 VM40 from New Millennium Obs. (March 12.89-05p12)
- 05626 5626 1991 FE from New Millennium Obs. (March 12.89-05p11)
- 04341 4341 Poseidon (1987 KF) from El Leoncito Obs. (June 26.11-13p3)
- 01866 1866 Sisyphus (1972 XA) from New Millennium Obs. (March 12.85-99p11)
- 01627 1627 Ivar (1929 SH) from New Millennium Obs. (March 12.89-01p10)
Observers on 27 June '07
Nine observing facilities appear in today's MPECs.
|235||CAST Obs., 1 in MPEC 2007-M46 -- 2007 MB24|
|703||Catalina Sky Survey in Arizona, 2 in MPEC 2007-M46 -- 2007 LR32, 86878|
|808||El Leoncito Obs. in Argentina, 5 in MPEC 2007-M46 -- 2007 LF, 2000 UV16, 152895, 108519, 4341|
|704||LINEAR in New Mexico, 3 in MPEC 2007-M46 -- 2007 MB24, 2007 MT20, 2005 NW44|
|G96||Mt. Lemmon Survey in Arizona, 1 in MPEC 2007-M47 -- 2007 ML24|
|A24||New Millennium Obs. in Italy, 6 in MPEC 2007-M46 -- 2007 CA19, 2006 VD13, 53435, 5626, 1866, 1627|
|291||Spacewatch 1.8m telescope in Arizona, 2 in MPECs 2007-M46 & 2007-M47 -- 2007 ML24, 2007 LD|
|6735||Jim Young via Table Mtn. Obs. in southern California, 1 in MPEC 2007-M46 -- 2007 MK6|
|A55||Vallemare di Borbona Obs. in Italy, 1 in MPEC 2007-M46 -- 2007 MB24|
Impact Risk Monitoring on 27 June '07
Notes for Today's Latest Risk Assessments
|2007 ML24||JPL||1909||2011-2071||193||2.4e-06||-2.12||-2.44||0||JPL: "Analysis based on 11 observations spanning 3.0256 days (2007-Jun-21.42934 to 2007-Jun-24.4549)." Diameter approximately 0.511 km. from mean, weighted H=19.1.|
|2007 MB24||JPL||1256||2034-2106||35||6.1e-08||-3.59||-4.56||0||JPL: "Analysis based on 55 observations spanning 2.6488 days (2007-Jun-24.32377 to 2007-Jun-26.97253)." Diameter approximately 0.710 km. from mean, weighted H=18.4.|
|NEODyS||1256||2028-2089||45||4.72e-08||-3.63||-4.52||0||NEODyS: "Based on 55 optical observations (of which 0 are rejected as outliers) from 2007/06/24.325 to 2007/06/26.973."|
|2002 TX55||NEODyS||2033||2089||1||1.86e-05||-4.38||-4.38||0||NEODyS: "Based on 75 optical observations (of which 2 are rejected as outliers) from 2002/10/03.396 to 2002/10/29.396."|
For a list of all risk-rated objects recently in view, see our ephemerides page.
An impact solution, also known as a "virtual impactor" (VI), is not a prediction but rather a possibility derived from an orbit calculation that cannot be eliminated yet based on the existing data. Elimination can come quickly with just a little further observation or may take weeks or months, sometimes years. Once superceded or eliminated, a former impact solution has zero relevance to an object's risk. See Jon Giorgini's "Understanding Risk Pages" for more about all this.
Chronology on 27 June '07
Times are UTC for when the items were noted by Major News.
|2033||Noted that NEODyS has updated its 2002 TX55 risk assessment - see above|
|1911||Added link to news story, "June 23rd Dawn Journal"|
Added link to news story, "How NASA's Dawn Spacecraft Will Explore Solar System's Origin"
|1909||Noted that JPL has posted 2007 ML24 as an impact risk - see above|
|1353||Added MOS paper, "Interpretation of the near-IR spectra of the Kuiper Belt Object (136472) 2005 FY9" - see above|
Added link to news story, "UCLA Professor Christopher Russell Leads NASA's Dawn Mission"
|1256||Noted that JPL has updated its 2007 MB24 risk assessment - see above|
Noted that NEODyS has posted 2007 MB24 as an impact risk - see above
Grabbed MPEC 2007-M46 - Daily Orbit Update - see above
Grabbed MPEC 2007-M47 - 2007 ML24 - see above