3

How much mass was deposited on a terrestrial planet during the Late Heavy Bombardment (LHB)?

Is it possible to estimate a reasonable interval, specifically, for Mars?

Could the mass addition to Mars have been as large as, say, 1 % of its original value?

Michael_1812
  • 1,361
  • 6
  • 22
  • 1
    If you understand that there is no concensus... maybe you can edit your question and share the disagreeing sources with us from which you draw your conclusion. And that might at that very same time answer your question. – planetmaker Nov 26 '23 at 22:52
  • 1
    10%? That's a lot of stuff! Roughly 25 times the current mass of the main asteroid belt. – PM 2Ring Nov 27 '23 at 01:04
  • @PM2Ring Playing the Devil's advocate, may I propose that the mass of stuff flying around during the LHB exceeded that left in the Belt. Could that be true, at least in principle? – Michael_1812 Nov 27 '23 at 01:15
  • 1
    I suppose so, but I'm definitely not an expert on this topic. But if Mars picked up that much extra mass then we should also expect that the other inner planets received a big contribution as well. And who knows how much Jupiter gobbled up... We do know from Juno data that Jupiter has a weird diffuse core, though, as I mentioned here: https://astronomy.stackexchange.com/a/35069/16685 – PM 2Ring Nov 27 '23 at 01:38
  • 1
    FWIW, we know that Mercury experienced a late major impact: https://en.wikipedia.org/wiki/Caloris_Planitia – PM 2Ring Nov 27 '23 at 01:43
  • 1
    @PM2Ring Speaking of Jupiter. Its large diffuse core must be helpful in explaining its unexpectedly high value of $k_2/Q$, the Love number to tidal quality factor ratio. – Michael_1812 Nov 27 '23 at 03:13
  • mmm, ... how long is a piece of string & what modeling scenario(s) would one use? – Fred Nov 27 '23 at 05:56
  • @Fred As it turns out, a likely scenario is described in this work. – Michael_1812 Nov 27 '23 at 13:40

1 Answers1

6

Alessandro Morbidelli has kindly consulted me on this topic. He said:

"The late veneer on Mars is approximately equivalent to that of the Earth, from the abundance of highly siderophile elements in its mantle-derived rocks. So it is about 0.5% of Mars mass. The late veneer is carried mostly by the planetesimals left-over from the terrestrial planet formation period."

His words are illustrated by Figure 17 from this recent work by his team:

Nesvorný, David; Roig, Fernando V.; Vokrouhlický, David; Bottke, William F.; Marchi, Simone; Morbidelli, Alessandro; Deienno, Rogerio. (2023)
"Early bombardment of the moon: Connecting the lunar crater record to the terrestrial planet formation"
Icarus, Vol. 399, article id. 115545.

AtmosphericPrisonEscape
  • 9,840
  • 1
  • 31
  • 42
Michael_1812
  • 1,361
  • 6
  • 22