Astronomers using NASA’s Hubble Space Telescope have discovered that comet 41P reversed its spin direction after slowing down due to gas jets. The findings, based on observations from 2017 and published in 2026, reveal how comet activity can rapidly change the motion and structure of small space bodies.

Bullets

• Scientists observed comet 41P slowing its rotation and then reversing its spin direction for the first time.
• The comet belongs to the Jupiter-family and completes an orbit around the Sun every 5.4 years.
• Initial data showed the comet’s rotation slowed significantly between March and May 2017.
• Later Hubble observations revealed the comet spinning faster again, indicating a reversal in direction.
• Gas jets released from the comet’s surface acted like thrusters, altering its spin over time.
• Uneven outgassing caused torque that first slowed and then reversed the comet’s rotation.
• The comet is very small, about one kilometer wide, making it more sensitive to such changes.
• Scientists noted a decline in the comet’s activity compared to earlier observations.
• Rapid rotational changes suggest the comet may become unstable and could break apart in the future.
• The discovery highlights how small celestial bodies can evolve quickly, even within a human timescale.