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NASA’s Near-Earth Object (NEO) Surveyor space telescope is currently under construction at the Jet Propulsion Laboratory in Pasadena, California. Once launched and operational, it will identify potentially hazardous asteroids and comets that come within 48 million kilometres of Earth’s orbit.
“We know from the geological record that asteroid and comet impacts really do happen,” says Amy Mainzer, principal investigator of NEO Surveyor. “To really advance what we know and find a lot more objects, we need to be able to detect them when they’re further away from us.”
The new telescope builds on the capabilities of its predecessor, NEOWISE, alongside a network of ground-based telescopes. Its 50-centimetre-diameter telescope can operate in two heat-sensing infrared wavelengths, identifying objects that might be very dark on their surfaces from their thermal emissions. “We know that some of the asteroids have very dark, carbon-rich surfaces. They’re just really, really dark, like printer toner,” says Mainzer.
Although the risks seem vanishingly rare, the consequences from even a relatively small object could be catastrophic. NASA and others are already developing ways to distort an asteroid’s trajectory and NEO Surveyor forms an important part of this defence. “The more time we have, the more options we have to actually do something about it,” says Mainzer.