e2v Image Sensors Search For Earth-Like Planets

With imaging sensors designed and manufactured by e2v, the COROT space telescope launched on December 27 to examine star seismology and to search for extra-solar Earth-like planets. The e2v sensors will capture detailed, telescopic images from COROT as it travels its polar orbit around the Earth.

COROT (Convection Rotation and planetary Transits) is part of the PROTEUS small satellites program. A pioneering mission led by CNES, the French National Space Agency, COROT is a space telescope with a 30 centimetres aperture, which will be put into circular polar orbit around the Earth at an 827km altitude for two and a half years.

Four back-thinned, frame transfer charge coupled imaging devices (CCDs) from e2v - CCD42-80s - have been integrated into COROT's focal plane, which will capture images of stars, with two main objectives:

Firstly, a scientific study of the stars' seismic activity will be carried out. The 2,048 square pixel e2v devices will help COROT to examine ‘star-quakes' or vibrations that change the brightness of stars. This will enable scientists to compute a star's age, size, and chemical makeup.

Secondly, COROT will search for indications of extra-solar habitable planets. The e2v imaging devices will detect the planets as they cross the discs of their parent stars, causing a dip in the brightness of the parent star, just as an eclipse of the sun darkens the Earth. However, COROT will be looking for events millions of times weaker than our familiar solar eclipse.

To achieve the degree of sensitivity required, the e2v sensors will operate in very cold temperatures in the depths of space, sensing light in the visible waveband.

The e2v sensors were selected for their very high and stable quantum efficiency (sensitivity), low dark signal and low readout noise, characteristics crucial to the success of the programme. They were delivered in highly flat, geometrically stable packaging suited to the harsh space environment.

Dr. Ralph Holtom, e2v Aerospace Imaging Business Manager, commented: "COROT is an exciting program as it is the first mission to hunt for rocky planets like Earth around other stars. Whilst many giant, gaseous, Jupiter-like planets have been found around other stars before, these have been at least ten times the size of Earth and whilst scientifically of enormous interest, they are unlikely to be of much interest in terms of extra terrestrial life in a form as we would know it. The excitement of COROT is that it searches for the much smaller, rocky planets, which might support life more like our own. Other missions like NASA's Kepler and ESA's Gaia will follow using e2v's CCDs, which will add more and more to our knowledge of other planets. This really is the start of a new phase of our exploration of space."

COROT launched from Kazakhstan on December 27. Astronomers hope that between ten and forty rocky planets may be found.

SOURCE: e2v technologies