Mars Express heading for closest flyby of Phobos ESA’s Mars
Express will skim the surface of Mars’ largest moon Phobos on
Wednesday evening. Passing by at an altitude of 67 km, precise
radio tracking will allow researchers to peer inside the
mysterious moon. Mars Express is currently engaged in a series
of 12 flybys of Phobos. At each close pass, different
instruments are trained towards the mysterious space rock,
gaining new information. The closest flyby will take place on 3
March at 21:55 CET (20:55 GMT). From close range, Mars Express
will be pulled ‘off-course’ by the gravitational field of
Phobos. This will amount to no more than a few millimetres every
second and will not affect the mission in any way. However, to
the tracking teams on Earth, it will allow a unique look inside
the moon to see how its mass is distributed throughout. How will
the ground teams make these tremendously sensitive measurements?
Ironically, they will turn off all data signals from the
spacecraft. The only thing that the ground