Overview
- A peer-reviewed study published Thursday in The Astronomical Journal reports that comet 41P reversed its rotation, a first in comet observations.
- Researchers combined March 2017 data from Lowell Observatory’s Discovery Channel Telescope, May 2017 readings from NASA’s Swift, and December 2017 images from Hubble.
- Swift measured a slowdown to a 46–60 hour spin in May, while Hubble found about a 14 hour period in December that fits a near-stop followed by a flip.
- Hubble constrained the nucleus to about 0.6 miles (1 kilometer) across, and scientists say uneven outgassing jets from solar heating likely drove the reversal.
- Activity fell by roughly tenfold between 2001 and 2017, and modeling warns that ongoing torques could destabilize the weak nucleus and lead to breakup, a risk still under study.