Kiruna, 2014-10-15


Swedish instrument will make measurements when a comet passes Mars

Comet Siding Spring and Mars (Artist's impression: NASA)
Comet Siding Spring and Mars (Artist's impression: NASA)

On Sunday 19 October at 20:29 CEST a comet will pass close to the planet Mars. At the same time the Swedish instrument ASPERA-3 is on board the European satellite Mars Express orbiting Mars and ready to make measurements.

"Noone has before made measurements when a comet passes so close by a planet", says Associate Professor Mats Holmström at the Swedish Institute of Space Physics in Kiruna, Sweden.

The comet Siding Spring will pass by Mars at a distance of only 140 000 km, about a third of the distance from the Earth to the Moon, by way of comparison. The outer parts of the comet's thin atmosphere will collide at high speed (56 km/sec) with the atmosphere of Mars.

"We expect that gas and dust from the comet will impact on the Martian atmosphere, which will be temporarily heated and will expand", says Mats Holmström. "We should be able to see that with our instrument".

The Swedish Institute of Space Physics (IRF) has Principal Investigator responsibility for the satellite instrument ASPERA-3 which is an international collaboration with participants from some 15 research groups from about 10 countries. ASPERA-3 on board the measures how charged particles from the sun, the so-called solar wind, influences the atmosphere of Mars. Mars Express was lauched by the European Space Agency (ESA) and has been orbiting Mars since 2003.

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Updated 2014-10-17, webmaster*

The Swedish Institute of Space Physics (IRF) is a governmental research institute which conducts research and postgraduate education in atmospheric physics, space physics and space technology. Measurements are made in the atmosphere, ionosphere, magnetosphere and around other planets with the help of ground-based equipment (including radar), stratospheric balloons and satellites. IRF was established (as Kiruna Geophysical Observatory) in 1957 and its first satellite instrument was launched in 1968. The head office is in Kiruna (geographic coordinates 67.84° N, 20.41° E) and IRF also has offices in Umeå, Uppsala and Lund.

Institutet för rymdfysik, IRF, är ett statligt forskningsinstitut under Utbildningsdepartementet. IRF bedriver grundforskning och forskarutbildning i rymdfysik, atmosfärsfysik och rymdteknik. Mätningar görs i atmosfären, jonosfären, magnetosfären och runt andra planeter med hjälp av ballonger, markbaserad utrustning (bl a radar) och satelliter. För närvarande har IRF instrument ombord på satelliter i bana runt tre planeter, jorden, Mars och Saturnus. IRF har ca 100 anställda och bedriver verksamhet i Kiruna (huvudkontoret), Umeå, Uppsala och Lund.