The European spacecraft Mars Express is to make a daring flyby of the Martian moon Phobos in the hope of gaining insights into its enigmatic surface, temperature and geological past, the European Space Agency (ESA) said on Wednesday.
On 23 July, the unmanned craft will swoop to within just 97 kilometres of Phobos, using a battery of instruments, including a high-resolution stereo camera, infra-red scanner and atmospheric spectrometer.
A programme of five flybys have been scheduled by Mars Express. The first, on 12 July, took place at an altitude of 563 kilometres.
The second, on Thursday 17 July, entails an altitude of 273 km. The two others, on 28 July and on 3 August, will have a closest approach of 361 and 664 km respectively.
Mars has two small satellites, Phobos and Deimos, named after the horses Fear and Panic that hauled the chariot of Ares, the Greek god of war.
The moons are irregularly shaped, measuring respectively just 26 km and 16 km across at their widest.
They were discovered in 1870, but little is known about them, and some astronomers believe they are wandering asteroids that became ensnared by Mars’ gravity and never left its orbit.
Russia is to send a lander, called Phobos-Grunt, to Phobos in 2009, and the flybys hope to capture an image of the intended landing site for the mission. The “Grunt” refers to samples of soil which the mission hopes to return to Earth for analysis.
Mars Express was launched in 2003.