Hubble records comet’s spin flip as jets reverse its rotation
NASA’s Hubble Space Telescope tracked comet 41P/Tuttle–Giacobini–Kresák and observed its rotation reverse due to jets of gas and dust, with the spin slowing between 2017 observations and then flipping to a much faster rate (about 14 hours) by December 2017. Scientist David Jewitt explains that uneven jets act like tiny thrusters, reversing the comet’s spin, an unprecedented finding that may signal structural changes or breakup; the results were published in The Astronomical Journal.