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©NASA

When astronomers peer up at the sky through the lens of a telescope situated on the Earth's surface, they have to deal with the adsorbtion and blurring of light by the Earth's atmosphere. This is one of the reasons space-based telescopes can be so powerful: the light they observe is not affected by the atmosphere. New work presented at this week's meeting of the American Astronomical Society describes how astronauts could build mirrors - capable of powering telescopes or reflecting solar light - with relative ease on the lunar surface using materials found there.

The work was carried out by a team of scientists at NASA's Goddard Space Flight Center. It suggests that building the mirror for a telescope on the moon would not be as difficult as one might imagine. Leveraging his previous work in using carbon-fiber composite materials in the production of high-quality telescope mirrors, Peter Chen and colleagues found a simple substitute material - moondust. They found that when they mixed carbon nanotubes, epoxies, and crushed rocks that are similar in size and consistency to lunar dust, a strong material, similar to concrete was formed. This means that far fewer raw materials would need to be hauled from Earth to the lunar surface if a construction mission was undertaken.

Minimal additional processing steps created a 12 inch wide mirror blank with the correct parabolic shape to be useful in telescopes. According to team member Douglas Rabin, "after that, all we needed to do was coat the mirror blank with a small amount of aluminum, and voilà, we had a highly reflective telescope mirror." If their method was scaled up, the researchers suggest that mirrors on the moon could reach sizes as big as 50m across, almost 5 times the size of the largest optical telescope on Earth. Telescopes on the moon would be capable of carrying out science such as recording the spectra of extrasolar terrestrial planets, detecting atmospheric biomarkers such as ozone and methane.

Chen states that the construction of such a large scale telescope could provide "a strong rationale for doing astronomy from the moon." While the earliest NASA is planning to head back to the moon is over a decade from now, adding the construction of such a device to the mission schedule could make it a profound step for the future of astronomy, at least from an extraterrestrial vantage point