MIMOS II

MIMOS II is the miniaturised <a href="/facts/M%25C3%25B6ssbauer_spectrometer/GIhmBXL6">Mössbauer spectrometer</a>, developed by Dr. Göstar Klingelhöfer at the <a href="/facts/University_of_Mainz/oE7eeKPz">Johannes Gutenberg University</a> in <a href="/facts/Mainz/vT0TxGjz">Mainz</a>, <a href="/facts/Germany/paluuWBX">Germany</a>, that is used on the <a href="/facts/Mars_Exploration_Rover/74WxIsHS">Mars Exploration Rovers</a> <a href="/facts/Spirit_rover/qNWFPqzj">Spirit</a> and <a href="/facts/Opportunity_rover/MEC0VIuy">Opportunity</a> for close-up investigations on the Martian surface of the mineralogy of iron-bearing rocks and soils.
MIMOS II uses a <a href="/facts/Cobalt/gqhScEw4">Cobalt</a>-57 gamma ray source of about 300 mCi at launch which gave a 6-12 hr time for acquisition of a standard MB spectrum during the primary mission on Mars, depending on total Fe content and which Fe-bearing phases are present. 
Cobalt-57 has a half-life of only 271.8 days (hence the extended measuring times now on Mars after over a decade).
The MIMOS II sensorheads used on Mars are approx 9 cm x 5 cm x 4 cm and weigh about 400g
The MIMOS II system also includes a circuit board of about 100g.

MIMOS II open-in-new

MIMOS II