The Swedish atmospheric research and astronomy satellite Odin celebrated eight years in orbit (on Friday, February 20th) and the value of its observations continues to increase.

Recently, new insights into couplings between noctilucent clouds in the northern hemisphere and the ozone hole in the southern, and into water vapour abundance and transport processes in the upper atmosphere, have been offered. Before Odin there was no water vapour data from 80 km altitude and above, and no polar coverage in the upper atmosphere. Odin is the benchmark for measurements over the polar winter hemisphere, says Dr. Dan Marsh, atmosphere scientist at the U.S. National Center for Atmospheric Research. Odin can also show a unique set of high-vertical resolution observations of the ozone layer, all obtained since 2001.

Originally a dual discipline satellite, Odin astronomy observations have essentially been ended. Among many interesting achievements, the detection of molecular oxygen in the outer space of our galaxy was a scientific first. The low abundance of the molecule in star forming regions has led to major rethinking regarding chemical models and the large variations in water vapour also observed by Odin. This is also of importance for the oxygen and water observations to be made with the new, large ESA mission Herschel, to be launched in April, where Odin astronomers are now focussing their efforts. The satellite is still in excellent shape and there is presently no known complications that would prevent observations by Odin over the next few years. Atmospheric scientists dream about measuring during an entire solar cycle, about 11 years. "We cannot guarantee that, of course," says Dr. Urban Frisk, Mission Manager at Swedish Space Corporation, "but we will try our best in order to try to make it possible!"