Kbos are not big

[alokmohan]

Latest findings on spitzer tells KBOs are much smaller than thought and no fear of poor pluto to lose its job.

 

[odysseus145]

LINK<br /><br />So what does this mean for Sedna and Quaoar? <div class="Discussion_UserSignature"> </div>

 

[nexium]

Is much smaller 1999 kilometers instead of 2000 kilometers. Please give numbers instead of generalities. Neil

 

[centsworth_II]

The numbers are in the link provided by odysseus145: <br /><br /><font color="orange">"Stansberry and colleagues found that a distant KBO designated 2002 AW197 reflects 18 percent of its incident light and is about 700 kilometers (435 miles) in diameter. 'That's considerably smaller and more reflective than expected, Stansberry said.' " <br /><br />" '2002 AW197 is believed to be one of the largest KBOs thus far discovered,' he said. 'These results indicate that this object is larger than all but one main-belt asteroid (Ceres), about half the size of Pluto's moon, Charon, and about 30 percent as large and a tenth as massive as Pluto.' " <br /><br />" '...[A]stronomers operating under the assumption that 2002 AW197 reflects four percent of its incident light would calculate that it is 1500 kilometers (932 miles) in diameter, or two-thirds as large as Pluto,' Stansberry said."</font><br /><br />The current study shows 2002 AW197, one of the largest KBOs known, to be about one third as large (in diameter) as Pluto. Using previous reflectivity assumptions, the estimate was for 2002 AW197 being two thirds as large (diameter) as Pluto. So the gap between Pluto's size and the size of the next largest KBOs has been widened quite a bit, if this study proves correct.<br /><br /><br /> <div class="Discussion_UserSignature"> </div>

 

[silylene old]

Maybe<br /><br />But they only measured <i>one</i> KBO. I think it is a bit of a reach to generalize about the reflectivity of all 20,000 or so KBO's based upon a single measurement.<br /><br />Thus I consider this report to be nothing more than a <i>hint</i> of what might hold true for the other ca. 19,999 KBO's. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[centsworth_II]

<font color="yellow">"...they only measured one KBO."</font><br /><br />But one of the largest. Even if the smaller KBOs remain their current estimated sizes, the size gap between Pluto and the KBOs as a group widens.<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

I wonder about the possibility that Pluto is related to Phoebe. It's been proposed that the objects forming the Oort Cloud were formed in the area of the outer planets. And subsiquently cast to their current location by interactions with the large planets. Phoebe could be one of those objects that was captured by Saturn rather than being flung to the Oort cloud. <br /><br />Could Pluto have had a similar origin as Phoebe, but rather than being thrown to the Oort cloud, or captured, it was perturbed into its current excentric orbit around the sun? <div class="Discussion_UserSignature"> </div>