Free Astronomy Magazine November-December 2018

43 NOVEMBER-DECEMBER 2018 ASTROBIOLOGY T he three tran- sits from Ke- pler (top) and the October 2017 transit observed with the HST (bot- tom) for the three trend model solu- tions. The three colored lines show the corre- sponding trend model solutions for model M, the authors’ favored transit model. The shape of the HST transit differs from that of the Kepler transits due to limb dark- ening differences between the bandpasses. [Ad- vances Science] Right, a render of the Kepler Space Telescope. This instrument has spotted many exoplanets, and now maybe an exomoon. [NASA] size of the Earth, could be habitable. When Kipping and Teachey analyzed the light curves of the three previously recorded Ke- pler-1625b transits, they noticed the exis- tence of some anomalies, small photo- metric deviations and oscillations that could not be generated by the transit above the star disc of a lonely planet. The resolution of Kepler’s observations were, however, in- sufficient to understand if these anomalies were real (astrophysical) and, if so, what produced them. The researchers then re- quested telescope time on Hubble (obtain- ing 40 hours) to observe the expected Kepler-1625b transit on 28-29 October 2017 with a resolution four times greater than with Kepler. Knowing that the phenome- non would last about 19 hours, Kipping and Teachey began to monitor the star many hours in advance in order to not risk losing