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Bug-eyed telescopes could search for threatening near-Earth objects

Elizabeth Howell, News Writer
Sep 14, 2014, 14:50 UTC

Sen—The sky is a big place to scan for threatening comets or asteroids, which often don't pop up in automated finders until almost the last minute. In the case of smaller impactors such as the one that hit Chelyabinsk, Russia in 2013, sometimes no warning comes at all.

The impact—which was large enough to shatter glass and cause thousands of injuries—served as a wake-up call to space agencies worldwide that better monitoring systems need to be in place to watch these asteroids coming in. How to look in several directions at the same time, however?

One European proposal would see a network of "fly-eye" telescopes, each one capable of taking an image and making it into 16 smaller ones to make the field of view larger. The telescope is so called because it would behave similarly to the compound eye of a fly.

Compound eyes, according to online course materials from North Carolina State University, vary considerably between insect species—some worker ants have less than six, while some dragonflies exceed 25,000.

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Model of a new European telescope nicknamed "fly-eye", which is planned to scan for threatening asteroids. Image credit: ESA/Compagnia Generale dello Spazio CGS

Whatever number of smaller eyes are present, their function is to squeeze several similar structures into one area that create a "mosaic" of the environment rather than a single view. The disadvantage is insects can't focus as vertebrates can, causing a lack of image sharpness.

The capabilities of the new telescope aren't known yet, because the contract to build it has just been awarded. The European Space Agency (ESA) hopes that the fly-eye will be able to spot objects that are 40 metres or more in diameter at least three weeks before impact. Its launch date wasn't disclosed in a press release.

Each fly-eye is supposed to be similar to a 1-metre telescope. As is common with asteroid surveyors, they will focus on a wider field of view to look at as much of the sky as possible. This particular design calls for a field of view of 6.7° x 6.7°, each dimension equivalent to about 13 times the Moon's diameter as seen from Earth.

The agency has a €1 million contract signed under a consortium led by CGS S.p.A (Italy) to figure out more details about the design. Should this be successful, the agency plans several more contracts with European firms that would collectively be valued up to €10 million. This money would go towards constructing and putting in place a prototype telescope, to see if the network idea would work.

This is not the only action ESA is taking against threatening asteroids. In 2013, about three months after the February Cheylabinsk event, it started an "NEO Coordination Centre" that will integrate data sources and providers that participate in ESA's Space Situational Awareness Program.

The United States has several near-Earth object program surveys itself, with some telescopes deployed on the ground and others in space. Examples include the Catalina Sky Survey, Pan-STARRS, LINEAR, Spacewatch and NEOWISE.