Rosetta spacecraft and asteriod Steins

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Jim</i>
<br />The mass of Earth's crust is about equal to the mass of the moon and the asteroid mass is 4% the mass of the moon. Does that indicate the planet assumed to have produced the asteroids was 4% the mass of Earth 3 times the mass of the moon?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">You have the right general idea, but the inferred mass is not a simple proportion. For masses smaller than Erath, the internal pressures remain less, so a much bigger percentage would become asteroids in any explosion. And conversely, for masses somewhat bigger than Earth's, the percentage of exploded debris in the form of asteroids will normally be zero. So the mass surviving in asteroids is maximal for something around Mars size, and drops off quickly for both larger and smaller masses.

We must also allow for asteroids ejected from the solar system, and asteroids on Jupiter-crossing orbits that will soon be absorbed by Jupiter. These lower the percentages of surviving asteroids. -|Tom|-

Do you know who posted the wiki articles about asteroids? The info looks good to me not knowing any better so I wonder why if other ideas are of interest and as you said anyone can post there who is in fact posting and if references are good or bad. Thet say asteroids are being reclassified and some are now minor planets which own 70% of the total mass. Only ten or so asteroids are put in the minor planet class which seems to be based of their large size makes them spheres rather irregular in form. It seems at some mass the force of gravity favors the spherical structure. The remaining mass is divided into 10 or more types and the whole system of classifying is in flux at this time.

Tom,

Are the mass of comets taken into account for the possible size of this planet (possible large oceans/ice covering)? And if they are, what kind of mass would they contribute? Do they account for lost mass due to vaporization/disintegration in the cometary tail?

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by toothdust</i>
<br />Are the mass of comets taken into account for the possible size of this planet (possible large oceans/ice covering)? And if they are, what kind of mass would they contribute?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Comets come from the explosion of Bellona ("Body C") at 3.2 million years ago. We discover less than one in every 10,000 comets, and they have been returning for a few million years. The original mass estimates are consistent with a Mars-sized parent body.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Do they account for lost mass due to vaporization/disintegration in the cometary tail?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">That mass loss is normally negligible. But the latest comet model is used in the estimates. -|Tom|-