Mars Express Orbiter Radio Science Mars
Mars Express Orbiter Radio Science MaRS
PI: Martin Pätzold
Institut für Geophysik und Meteorologie, Universität zu Köln
Study how normal radio signals exchanged between Mars Express and
ground station on Earth are altered by and tell us about:
1. The gravity of Mars
2. The charged particles in the atmosphere and ionosphere of Mars
Observations are recorded at the ESA ground station New Norcia
(Australia) and the Deep Space Network (DSN) of NASA
Mars Express Orbiter Radio Science MaRS
radio sounding of the atmosphere / ionosphere (occultation experiment)
measure how density, pressure and temperature change with altitude
understand how density of electrons changes with altitude in the
ionosphere
gravity experiments
study how the gravity changes in certain areas due to crustal features
understand how seasonal mass exchange (polar caps) affects gravity
field and rotation
determine mass and density of the moon Phobos
surface characteristics by a bistatic radar experiment
roughness, composition of the surface
Mars Express Orbiter Radio Science MaRS
Observations are done in different Earth/Mars/MEX configurations
occultation experiments from April to August 2004; December 2004
Tell us about atmospheric conditions in early morning, late afternoon
and during polar night
gravity observations from mid October 2004 to early January 2005
Still under processing and analysis
Mars Express Orbiter Radio Science MaRS
Formation and evolution
of early morning ionosphere
In the morning, when the sun is
about to rise, the ionosphere of
Mars is refilled by an
avalanche of electrons and
other charged particles caused
by solar radiation
Mars Express Orbiter Radio Science MaRS
Formation and evolution
of early morning ionosphere
of Mars (km)
c
enter
t
he
altitude of layer formation
distance to
Mars surface
number of electrons (1010 m-3)
Mars Express Orbiter Radio Science
Results
formation and evolution of early morning ionosphere during sunrise
observations at high latitude southern winter atmosphere
weather report of the southern polar night
very low surface pressure (4 millibar)
very cold atmosphere over the first few kilometres (-143°C to -130°C)
carbon dioxide snow fall
