INCOMING!, Detection and observation of Earth-approaching asteroids. |
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INCOMING!, Detection and observation of Earth-approaching asteroids. |
 Feb 19 2013, 08:42 PM
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#286
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 Senior Member  Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004  |
and a video: Early Radar Observations of Asteroid 2012 DA14
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Feb 19 2013, 08:56 PM
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#287
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 Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
At least over the period observed, I only see rotation along a single axis. That would be somewhat rare, wouldn't it?
-the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Feb 19 2013, 09:16 PM
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#288
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Solar System Cartographer Group: Members Posts: 10146 Joined: 5-April 05 From: Canada Member No.: 227 |
No, it's what we would expect from a fairly rapid rotator like this. But radar images are notoriously difficult to interpret so I would want to see more results of shape and rotation modelling before drawing any conclusions.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Feb 24 2013, 04:32 PM
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#289
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
the Canadian NEOSSat, the first satellite dedicated to the detection of near Earth asteroids is due for launch tomorrow in India
http://www.asc-csa.gc.ca/eng/satellites/neossat/ |
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Feb 25 2013, 02:25 PM
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#290
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 Senior Member Group: Members Posts: 1417 Joined: 26-July 08 Member No.: 4270 |
Launch was successful.
-------------------- -- Hungry4info (Sirius_Alpha)
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Feb 26 2013, 12:51 AM
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#291
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Member Group: Members Posts: 910 Joined: 4-September 06 From: Boston Member No.: 1102 |
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May 30 2013, 10:41 PM
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#292
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Senior Member Group: Members Posts: 1582 Joined: 14-October 05 From: Vermont Member No.: 530 |
Goldstone finds a satellite for 1998 QE2, "Ocean Liner" size comparison results:
http://cosmiclog.nbcnews.com/_news/2013/05...oon-radar-shows |
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May 31 2013, 10:53 AM
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#293
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 Member Group: Members Posts: 495 Joined: 12-February 12 Member No.: 6336 |
QUOTE (stevesliva @ May 31 2013, 12:41 AM)  Goldstone finds a satellite for 1998 QE2, "Ocean Liner" size comparison results: With the satellite about 1/4 the size of the main body, it might qualify 1998 QE2 as a binary asteroid. |
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May 31 2013, 11:04 AM
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#294
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 Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Hopefully not too OT, but I'm wondering just exactly how asteroids even have moons.
The only mechanism I can think of to create them is a very low relative speed impact, which would seem to be a rare event. However, asteroid moons seem to be fairly common, esp. for low-mass objects. (Note that Vesta apparently has none; jury's still out for Ceres. Gravitational capture would be a more likely mechanism for moons around a high-mass body, but thus far we haven't seen much of that.) Might be something else happening here. Calving, perhaps, off of the main body over time due to heating/cooling cycles? -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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May 31 2013, 02:21 PM
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#295
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 Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
From "FORMING THE OBSERVED BINARY ASTEROID POPULATION. S. A. Jacobson1 and D. J. Scheeres2, 1Dept. Astrophysical and Planetary Sciences, Univ. of Colorado, Boulder, USA (seth.jacobson@colorado.edu), 2Dept. Aerospace Engineering Sciences, Univ. of Colorado, Boulder."
QUOTE Rotational fission results in the formation of all classes of observed near-Earth asteroid (NEA) binaries. The NEA population is constantly evolving due to the incredible influence of electromagnetic radiation. The YORP effect, torque from the incident solar irradiation and thermal radiation of an asymmetric body, can rotationally accelerate individual asteroids until centrifugal accelerations match gravitational accelerations, releasing part of the body into orbit and creating a binary asteroid system–i.e. rotational fission. This process has been theoretically predicted and modeled in detail [1, 2], as well as observationally confirmed [3]. The figure below shows the evolutionary pathways from rotational fission to each of the observed binary classes indicated by an underline. q is the mass ratio of the binary (secondary / primary mass). Primary defined to be more massive. Read more here. Or google for binary asteroid formation. -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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May 31 2013, 03:27 PM
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#296
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Solar System Cartographer Group: Members Posts: 10146 Joined: 5-April 05 From: Canada Member No.: 227 |
Another explanation - forget where it came from - a large asteroid is blown apart in a big impact. Two chunks are ejected on almost parallel trajectories, and as they move outwards they stay together and become a binary. I think this dated from about the time Dactyl was discovered orbiting Ida.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Oct 12 2013, 04:01 PM
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#297
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
I was looking for updates on the Canadian NEOSSat, but I could not find any. anybody knows whether the satellite is alive and producing data?
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Oct 19 2013, 05:30 PM
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#298
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 Senior Member Group: Members Posts: 2492 Joined: 15-January 05 From: center Italy Member No.: 150 |
2013 TV135, discovered one week ago, is now rated level #1 in the "Torino scale", with an impact probability 1:48000 for August 2032 approach:
http://neo.jpl.nasa.gov/risk/ Curiously, probability slightly increased from yesterday's value (1:63000). -------------------- I always think before posting! - Marco -
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Oct 20 2013, 09:02 AM
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#299
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Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Doubtless the odds will drop to zero after further observations, as usual. Still, it is extremely prudent to maintain the watch for these things.
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Oct 20 2013, 09:37 PM
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#300
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Senior Member Group: Members Posts: 2492 Joined: 15-January 05 From: center Italy Member No.: 150 |
QUOTE (nprev @ Oct 20 2013, 10:02 AM) Doubtless the odds will drop to zero after further observations, as usual. Well, curiously impact probability keep increasing! For NASA/JPL odds rised to 1:14000, while NEODys gives even higher value of 1:7500... For sure, it will be very close to us in 2032! -------------------- I always think before posting! - Marco -
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