Aug. 1, 2019
Research Highlight
Binaries Help Make Heads or Tails of Planet Formation
Scientists used Hubble Space Telescope images of Kuiper belt binaries to determine that 80% orbit in the same direction as the planets. This research helps scientists improve planet formation models. Kuiper Belt object 2006 CH69 imaged on Jan. 26, 2017, is shown here.Image credit: HST/StSci/SwRI/Simon Porter.
From the Southwest Research Institute (SwRI):
A Southwest Research Institute-led team studied the orientation of distant solar system bodies to bolster the “streaming instability” theory of planet formation.
“One of the least understood steps in planet growth is the formation of planetesimals, bodies more than a kilometer across, which are just large enough to be held together by gravity,” said SwRI scientist Dr. David Nesvorny, the lead author of the paper.
During the initial stages of planet growth, dust grains gently collide and chemically stick to produce larger particles. However, as grains grow larger, collisions likely become more violent and destructive. Scientists have struggled to understand how planetary growth passes the ‘meter-size barrier.’
The streaming instability theory posits that as large dust grains interact with the gas that orbits young stars, streaming mechanisms cause grains to clump into dense regions and collapse under their own gravity to form planetesimals.
Click here to read the full press release from SwRI.
Simulations of the streaming instability model of planet formation, where particle clumping triggers gravitational collapse into planetesimals. This snapshot shows the vertically integrated density of solids, projected on the protoplanetary disk plane.Image credit: Steward Observatory/University of Arizona/Li/Youdin.
The study, “Trans-Neptunian binaries as evidence for planetesimal formation by the streaming instability,” was published in the journal Nature Astronomy. This work was supported by the Emerging Worlds Program. The NASA Astrobiology Program provides resources for Emerging Worlds and other Research and Analysis programs within the NASA Science Mission Directorate (SMD) that solicit proposals relevant to astrobiology research.