NASA's Stardust spacecraft passes Comet Tempel 1 on February 15th at 06:40. The spacecraft is carrying the Finnish Meteorological Institute's dust analyser.
On 15 February at 06:40 hours Finnish time, NASA’s Stardust spacecraft will pass Comet Tempel 1. The spacecraft is carrying the Finnish Meteorological Institute’s dust analyser, which will collect samples during the flyby. The dust analyser was built together with a German research team. The Finnish Meteorological Institute has been responsible for the development of software for the instrument and for its operation during the flight.
One of the instruments on the Startdust NExT mission is CIDA, a comet and interstellar dust analyser developed in Germany, for which the Finnish Meteorological Institute supplied the measurement software and ground equipment. Much of the software for analysing the results has been developed in Finland. The Finnish Meteorological Institute will also make widespread use of the measurement results in its scientific work.
Tempel 1 is the same comet that was hit by an impactor carried by NASA’s Deep Impact spacecraft in 2005. For that mission, the Finnish Meteorological Institute used the SWAN instrument to study the amount of water released by the impact. The intention during the current flyby is to take images of the crater created by the impact and to investigate the details of the impact, a task prevented by a dust cloud during the Deep Impact mission.
The spacecraft will measure the composition and amount of dust floating around Comet Tempel 1 and will image the comet nucleus. The goal of the research project is to increase understanding of the formation of our solar system and the characteristics of interstellar dust. The chemical and physical processes on the comet surface may have played a vital role in the origin of life, since we already know that one-third of the water in Earth’s oceans originated in comets.
“We hope that, within a couple of minutes during the flyby, we’ll be able to collect as many dust particles as possible so that the composition of the dust surrounding the comet can be studied,” says Research Manager Walter Schmidt of the Finnish Meteorological Institute.
The instrument will be turned off after the flyby
Stardust was launched into space on 7 February 1999. A similar flyby has taken place once before. The spacecraft passed Comet Wild 2 on 2 January 2004. The 72 images and measurement material obtained from the comet during the flyby were sent to Earth. While passing Wild 2, CIDA was hit by 30 particles. The small number of particles is explained by the observation that the mass distribution of the particles was 25 times greater than had been expected.
CIDA is a mass spectrometer that has a silver target with a diameter of 15 cm. When dust particles from the comet hit the target, they disintegrate completely. The molecules created in the process are ionised and an electrostatic grid directs them to a detector. The flight time of the ions is used to calculate their mass. After the Tempel 1 mission, the dust analyser will stop operating and will be turned off.
An instrument of the same type, CIDA-2, was delivered for NASA’s Contour spacecraft, which was meant to have three encounters with comets. Contour was launched in 2002, but it was destroyed six weeks after the launch. A second generation CIDA instrument, COSIMA, is currently on the Rosetta spacecraft of the European Space Agency, heading towards Comet 67P/Churyumov-Gerasimenko, which the spacecraft will reach in 2014.
As a representative of the Finnish Meteorological Institute’s research team, Senior Research Johan Silén is following the flyby in NASA’s laboratory in the United States.
Finnish Meteorological Institute, Research Manager Walter Schmidt, tel. +358 9 1929 4658, firstname.lastname@example.org