Lunar X-Ray Telescope Passes First Hurdle

The telescope is called MagEX, which stands for “Magnetosheath Explorer in X-rays” and is an international collaboration between scientists from the United States, the Czech Republic, and the University of Leicester.

MagEX will study the magnetosheath, the magnetic “shield” that protects the Earth from the solar wind – the high energy particles that continuously flow out from the Sun. Without this shield, life on Earth as we know it could not exist.

MagEX was submitted to NASA for consideration in their Lunar Sortie Science Opportunites (LSSO) programme and has cleared the first selection hurdle; it will now receive NASA funding for a technical feasibility study.

The LSSO program is part of NASA's New Vision for Space Exploration Program announced by President Bush in 2004. The President committed NASA to return men to the Moon for the purpose of scientfic exploration. This new generation of NASA astronauts will set-up scientific experiments on the lunar surface, just like their Apollo colleagues did over four decades before them. MagEX could be one of those experiments.

The MagEX telescope will be quite compact, being less than one metre tall.
It is designed to be placed on the lunar surface, facing back towards the Earth. The Moon is the ideal location for measuring the X-ray emission of the magnetosheath.

Looking from the Moon, the Earth's magnetosheath covers an area about 30 degrees across on the sky. The magnetosheath glows as solar wind particles strike gas trapped within the region, however, the glow is not in visible light but in X-rays. Invisible to the human eye, X-rays require specialised instruments to detect them. X-rays are produced by many astrophysical phenomenona such as black holes, quasars, stars and galaxies.

The lead Leicester scientist on MagEX, Dr Steven Sembay, said : “MagEX will be unique in that it will be able to view our Earth's entire magnetosheath for the first time. The magnetosheath is not static, but contracts and expands quite dramatically as the solar wind pressure changes during solar storms. The view from the moon should be quite spectacular”

NASA's manned return to the Moon is still some way-off. It will probably be the end of the next decade at least before an astronaut steps foot on the lunar surface again. Dr Steven Sembay said, “Like all space projects, we are in for the long haul. But every long journey starts with a first step.”

The Department of Physics at the University of Leicester has a 40 year history of designing X-ray detectors for space science exploration. These currently include instruments onboard ESA's XMM-Newton observatory, NASA's gamma-ray burst mission, Swift, and in the future, on ESA's BepiColombo mission to explore Mercury.