Reverse-Spinning Comet 41P Faces Potential Self-Destruction

• Astronomers have identified the first-ever comet, 41P/Tuttle-Giacobini-Kresák (41P), exhibiting a reverse spin.
• The comet's rotation is likely being driven by uneven outgassing jets acting as thrusters.
• Due to the forces of its current rotation, researchers predict the comet may self-destruct within decades.

The Discovery and Mechanism

• Data from NASA’s Hubble Space Telescope revealed that 41P reversed its spin direction during its 2017 perihelion.
• Dr. David Jewitt of UCLA, the study's author, suggests that gas jets streaming off the surface behave like thrusters on a merry-go-round, capable of slowing, stopping, and reversing the comet's rotation.
• Observations noted that 41P's surface was significantly less active in 2017 compared to its 2001 perihelion, a rapid change given that such physical shifts typically span centuries.

Future Implications

• Computer models indicate that at its current spin rate, 41P faces structural instability.
• The comet's nucleus, approximately 1 kilometer (0.6 miles) in diameter, is estimated to last only a few more decades, significantly shorter than the average 1,000-year lifetime of a comet.
• Researchers hypothesize that 41P might be emitting unusually high levels of gas or could be a fragment that broke off from a much larger parent comet long ago.

Background on 41P

• 41P is a short-period comet originating from the Kuiper Belt, completing an orbit around the Sun every 5.4 years.
• It belongs to a cataloged group of 4,000 to 5,000 comets traveling between the outer solar system and the inner region near planetary orbits.