Science news archive

« Back

Cold electrons observed around a comet

Cold electrons observed around a comet

New study shows direct detection of strong electron cooling around a comet. Strong electron cooling on the neutral gas in cometary comae has been predicted for a long time, but now first actual measurements of low electron temperature were detected.

Comets are mainly composed of dusty ices originally from the young solar system. Most comets are located in the outer solar system far from the Sun and Earth, where no processes change their composition over long periods of time. Studying comets gives information about conditions when the planets and the solar system was forming. In this work observations of electrically charged particles from Rosetta's LAP instrument were analyzed. Finnish Meteorological Institute has participated in the LAP instrument as well as several other instruments on the Rosetta orbiter and the Philae lander.

More information::

Researcher Riku Järvinen, tel. +358 50 380 3195,

Eriksson et al. (2017), Cold and warm electrons at comet 67P/Churyumov-Gerasimenko, A&A 605, A15,

Vapaasti saatavilla oleva ennakkojulkaisu artikkelista:



The Finnish Meteorological Institute is a leading expert in meteorology, air quality, climate change, earth observation, marine and arctic research areas. FMI is in a unique position to study various themes of climate change in the Northern context.


High-quality observational data and research is utilized to develop services to benefit our everyday life. Visible examples are improvement of weather forecasts, development of new expert and warning services as well as applications of the newest research results.