SMOS forms three-pointed star in the sky   The SMOS mission makes global observations of soil moisture over Earth’s landmasses and salinity over the oceans. Variations in soil moisture and ocean salinity are a consequence of the continuous exchange of water between the oceans, the atmosphere and the land – Earth’s water cycle.   Carried on the SMOS satellite, the MIRAS instrument consists of a central structure and three deployable arms, each of which has three segments. During launch, these arms are folded-up. Just over 36 hours after SMOS has been injected into orbit, the arms are gently deployed.   Mission Control at the French space agency CNES, in Toulouse, France, received confirmation that the MIRAS antennas had deployed on 3 November 2009.   To measure the moisture in soil and salt in the oceans, SMOS has borrowed techniques used in radio astronomy. The 69 small antennas carried on the instrument's Y-shaped arms and central hub use 'aperture synthesis' or 'interferometry' to mimic a much larger antenna - similar to the way the Very Large Array works in Socorro, New Mexico, US. Release date: 28 April 2010