Using data obtained by the omega spectrometer on board european space agency ' s mars express , the team found the existence of ice clouds which sometimes become so dense that they throw quite dark shadows on the dusty surface of the planet 根据欧洲航天局“火星快车”探测器上装备的omega光谱仪获取的数据，该科学家小组发现，由于火星上空的干冰云有时很密集，所以会在覆盖着很多尘埃的火星表面投下阴影。
