Sunlight Splits Asteroids into Pairs

[scottb50]

<h1><br /> </h1> <div id="ynmain"> <div id="storybody"> <div class="storyhdr"> <p> <span> Clara Moskowitz<br />Staff Writer<br />SPACE.com </span> <em class="timedate">Wed Jul 9, 1:15 PM ET</em> </p> </div> <p> Asteroids often come in pairs, with the two objects spinning around each other. Now scientists say sunlight could be the cause of these binary boulders.</p><p>A new study suggests energy from the sun can spin up a single asteroid until it ejects material that becomes a separate satellite.</p> <div class="lrec"><table border="0" cellspacing="0" cellpadding="0" class="ad_slug_table"><tbody><tr><td align="center">&nbsp;

 

[CalliArcale]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> Clara MoskowitzStaff WriterSPACE.com Wed Jul 9, 1:15 PM ET Asteroids often come in pairs, with the two objects spinning around each other. Now scientists say sunlight could be the cause of these binary boulders.A new study suggests energy from the sun can spin up a single asteroid until it ejects material that becomes a separate satellite. &nbsp;Astronomers first discovered these strange asteroid pairs 15 years ago, and have been puzzled about what causes them. Now scientists have created a computer model that matches what they see. "So far our results match the properties of binary asteroids quite well," said astronomer Kevin Walsh of the Observatoire de la&nbsp;Cote D'Azur in&nbsp;Nice,&nbsp;France. Walsh led the study when he was a graduate student at the University of Maryland, working with his advisor Derek Richardson and Patrick Michel of the Cassiope�e, University of Nice-Sophia Antipolis, in Nice.http://news.yahoo.com/s/space/20080709/sc_space/sunlightsplitsasteroidsintopairs Could this also better explain the similar composition of the moon and Earth then the collision theories? <br /> Posted by scottb50</DIV></p><p>Oh, that is sweet.&nbsp; Very cool, and it does make sense.</p><p>However, I don't think it would work for an object as dense and massive as the Earth.&nbsp; The thing about asteroids is that they are very small and many seem to be quite porous.&nbsp; Itokawa, for instance, appeared to be little more than a rubble pile loosely held together by gravity.&nbsp; It wouldn't take all that much energy to break it apart.&nbsp; Breaking the Earth apart, and with enough force to eject a large amount of material into orbit, would take a huge amount of energy -- more than I think sun-induced rotation could possibly account for. </p> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[scottb50]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Oh, that is sweet.&nbsp; Very cool, and it does make sense.However, I don't think it would work for an object as dense and massive as the Earth.&nbsp; The thing about asteroids is that they are very small and many seem to be quite porous.&nbsp; Itokawa, for instance, appeared to be little more than a rubble pile loosely held together by gravity.&nbsp; It wouldn't take all that much energy to break it apart.&nbsp; Breaking the Earth apart, and with enough force to eject a large amount of material into orbit, would take a huge amount of energy -- more than I think sun-induced rotation could possibly account for. <br /> Posted by CalliArcale</DIV></p><p>&nbsp;</p><p>I was thinking more in an earlier sense before the Earth compacted and the Sun was much more active.&nbsp; </p> <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> Could this also better explain the similar composition of the moon and Earth then the collision theories? <br />Posted by scottb50</DIV><br /><br />No, the YORP effect operates only on small masses as it's force is pretty weak.</p><p>It's funny, I was just discussing the YORP effect yesterday.</p><p>Another joke from the cosmic muffin </p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;I was thinking more in an earlier sense before the Earth compacted and the Sun was much more active.&nbsp; <br />Posted by scottb50</DIV><br /><br />Still a nogo. The forces are just too weak.</p><p>The Wiki article in this case is pretty good.</p><p>http://en.wikipedia.org/wiki/YORP_effect</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> Clara MoskowitzStaff WriterSPACE.com Wed Jul 9, 1:15 PM ET Asteroids often come in pairs, with the two objects spinning around each other. Now scientists say sunlight could be the cause of these binary boulders.A new study suggests energy from the sun can spin up a single asteroid until it ejects material that becomes a separate satellite. &nbsp;Astronomers first discovered these strange asteroid pairs 15 years ago, and have been puzzled about what causes them. Now scientists have created a computer model that matches what they see. "So far our results match the properties of binary asteroids quite well," said astronomer Kevin Walsh of the Observatoire de la&nbsp;Cote D'Azur in&nbsp;Nice,&nbsp;France. Walsh led the study when he was a graduate student at the University of Maryland, working with his advisor Derek Richardson and Patrick Michel of the Cassiope�e, University of Nice-Sophia Antipolis, in Nice.http://news.yahoo.com/s/space/20080709/sc_space/sunlightsplitsasteroidsintopairs Could this also better explain the similar composition of the moon and Earth then the collision theories? <br />Posted by scottb50</DIV><br /><br />This is confirmation of last years suggestion by D. P. Rubincam and S. J. Paddack, <em>Science</em> <strong>316</strong> 211 (2007) <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>