simonbp on Nostr: nprofile1q…ksa3n Nope! One of the most fascinating things about Arrokoth is it ...
nprofile1qy2hwumn8ghj7un9d3shjtnddaehgu3wwp6kyqpqdgzsgsvdqg6r9h2pj6x24s2qu9eydcmuukmdpsswvfvwr4ecu6mspksa3n (nprofile…sa3n) Nope!
One of the most fascinating things about Arrokoth is it shows absolutely no tectonic signatures of a violent collision. Given the low assumed material strength, the lobes of Arrokoth had to have come in contact very slowly, ~a few m/s. That's not possible unless they are already gravitationally bound to each other in a close, slowly decaying orbit. McKinnon et al (2020) suggested gas drag in the solar nebula to trigger that decay.
That's possible for Arrokoth because it's small enough to have been born a binary directly out of the disk. Pluto is a vastly larger product of many collisions. Adeene's work is a great constraint on the last of those collisions, producing not only Charon, but the four small satellites. Pluto is a wacky system with a complicated history.
One of the most fascinating things about Arrokoth is it shows absolutely no tectonic signatures of a violent collision. Given the low assumed material strength, the lobes of Arrokoth had to have come in contact very slowly, ~a few m/s. That's not possible unless they are already gravitationally bound to each other in a close, slowly decaying orbit. McKinnon et al (2020) suggested gas drag in the solar nebula to trigger that decay.
That's possible for Arrokoth because it's small enough to have been born a binary directly out of the disk. Pluto is a vastly larger product of many collisions. Adeene's work is a great constraint on the last of those collisions, producing not only Charon, but the four small satellites. Pluto is a wacky system with a complicated history.