Spitzer Space Telescope - General Observer Proposal #70049 Towards Earths and Beyond: the GJ1214 Opportunity Principal Investigator: Drake Deming Institution: NASA's Godddard Space Flight Center Technical Contact: Drake Deming, NASA's Godddard Space Flight Center Co-Investigators: Michael Gillon, University of Liege, and Observatoire de Geneve Sara Seager, MIT Brice-Olivier Demory, MIT Amoury Triaud, Obervatoire de Geneve Xavier Bonfils, Universite Joseph Fourier, Grenoble Science Category: extrasolar planets Observing Modes: IRAC Post-Cryo Mapping Hours Approved: 485.0 Abstract: We propose a continuous 20.2-day photometric monitoring of the nearby M-dwarf star GJ1214b, known to host a transiting super-Earth inward of its habitable zone. The ultimate goal of our program is to detect a habitable world in this planetary system, and many other science goals can be accomplished during that search. Our program will observe 12 consecutive transits and eclipses of GJ1214b at 4.5-microns, thereby measuring its thermal emission, and improving our knowledge of the planetary radius and orbit, as well as quantifying the IR variability of the star. Our observations will be sensitive to moons and trojan planets, and to the presence of other transiting planets down to 0.45 Earth-radii (smaller than Mars). Our 20.2-day monitoring will cover orbits to the outer edge of the habitable zone. Some models of planetary formation predict that rocky planets are common orbiting M-dwarf stars. If these models are correct, then multi-planet systems may be the norm for lower main sequence stars. Our program has the significant potential to culminate by discovering a habitable rocky world transiting this nearby M-dwarf. That discovery would be of historic significance, and the major molecular constituents of such a world would be amenable to characterization by JWST.