Mars Now a Cycle 1 Target for Webb

Mars has been one of the targets for James Webb Space Telescope from the outset (see white paper at But prior to the launch date change, it was only available in Cycle 2. With the revised dates, Mars is now available in Cycle 1. Heidi Hammel, Webb Interdisciplinary Scientist for Solar System Observations, thus requested that 5 hours of her guaranteed time be reprogrammed for Mars observations. Webb will obtain NIRCam images at 2.2 and 4.3 microns, as well as a full NIRSPEC survey (all gratings), employing a mosaic on Mars of 4 x 4 with the 0.2 x 3.3 slit.  Hammel’s Mars team, led by Geronimo Villanueva (NASA GSFC), expects detections of both H2O and HDO. According to the current Exposure Time Calculator, Mars will saturate in some cases, but many regions (both on the disk and in the
spectra) the data should be excellent. This Mars data from Webb will be made available to the planetary community immediately, in order to facilitate planning for Mars observations with Webb.