If all trojans from the Greek camp and all the trojans of the Trojan camp were combined into two bodies respectively, what sizes and masses these bodies would have? Would they qualify as dwarf planets? Would they be greater than Ceres?


1 Answer 1


The mass of the Trojans (both camps as far as I know) is estimated at around 0.0001 Earth masses (reference) (Note that this number is debated). The density of them vary but the highest found is around 2.5 g/cm^3 (reference) Assuming that the composition is mainly rocky/icy with very little gas, the act of combining all of them should make a rocky/icy object with that mass.

The mass of Ceres is estimated to be 0.00015 Earth masses with a density of some 2.1 g/cm^3 (reference).

If we assume that the object made from the Trojans has the same density then they should roughly make an object the same size or slightly smaller than Ceres (about 1 % the mass of the Moon). Make that into two equal bodies and you have half a Ceres per group (so each smaller than Ceres) (assuming that there are the same mass of bodies in each group originally).

Given that there is much uncertainty associated with this, I would bet that the mass and size would be smaller than this. Whether they would qualify as dwarf planets, I'm not sure. But they would have to be captured into the orbit rather than be formed there as I'm pretty sure the gravitational influence of Jupiter would prevent any coalescence and gravitational stability of the Trojans (though I could be wrong on this).

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    $\begingroup$ I think that should be 0.0001 Earth masses or 0.01%. Otherwise, nice answer. $\endgroup$
    – userLTK
    Commented Feb 17, 2017 at 16:38
  • $\begingroup$ Yes you are absolutely right. It is indeed Earth masses that I was meant to write but it seems it got bundled up. I'll change it right away. Thanks :) $\endgroup$ Commented Feb 18, 2017 at 12:11

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