August 13, 2010

Cluster reaches 10th year studying Sun-Earth connections

It is now a decade since the U.S.-European Cluster quartet of satellites began their mission in space - a good time to review the results of a programme dedicated to the sometimes turbulent Sun-Earth relationship.

7 September 2010

A thousand publications and convincing results

The Cluster mission has certainly lived up to expectations,” says Jean-Yves Prado, Cluster Programme Manager at CNES. Besides the many scientific publications relying on its data, Cluster has given us a first glimpse of the spatial and temporal variations of the solar wind and its interactions with Earth.

Cluster is in fact a constellation of 4 satellites.

Flying in pyramid formation, Samba, Tango, Rumba and Salsa are thus able to track in 3D and in real time the flow of charged particles continuously streaming from the Sun that buffets Earth’s protective magnetic sheath.

These interaction phenomena are extremely complex,” explains Jean-Yves Prado. With the Sun rotating about itself and constantly discharging particles, the Earth finds itself in what can be compared to a spray of water from a rotating sprinkler system. To understand the underlying processes, we therefore need to glean as much data as we can to refine our models.

Since 2000, Cluster has mapped different regions of Earth’s magnetosphere and shed new light on a range of scientific questions.

Better space weather forecasting

For example, Cluster’s discoveries have brought fresh insight into “surface waves generated by the solar wind inside Earth’s magnetic field, and into the phenomenon of “magnetic reconnection that occurs when solar flares hurl huge discharges of energy toward Earth.

Indeed, the Sun’s sometimes violent moods produce geomagnetic storms in the vicinity of our planet.

These result in the magnificent displays of aurora borealis, but can also damage or disrupt telecommunications satellites and terrestrial power grids.

The Cluster satellites have concentrated on the regions of the magnetosphere where these geomagnetic storms form,” explains Jean-Yves Prado, “with a view to forecasting when they are going to occur.”

Using the data amassed by Cluster, scientists hope to refine their models of space weather and be able to forecast solar storms a few days ahead.

The Cluster mission is set to continue to 2012, possibly 2014. In that time, it can be expected to tell scientists still more about the Sun and Earth’s sometimes turbulent relationship.


CNES solar programmes