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NASA's new way to defend Earth from asteroids

Press Trust of India  |  Washington 

NASA scientists have found a simple yet ingenious way to spot tiny near-objects (NEOs) early as they hurtle towards the planet, an advance that may aid the efforts to prevent dangerous impacts.

The Chelyabinsk meteor, which was a mere 17-20 metres across, caused extensive ground damage and numerous injuries when it exploded on impact with Earth's atmosphere in February 2013.

"If we find an object only a few days from impact, it greatly limits our choices, so in our we have focused on finding when they are away from Earth, providing the maximum amount of time and opening up a wider range of mitigation possibilities," said from (JPL).

However, it is a difficult task -- like spotting a lump of coal in the night's sky, Mainzer said.

"are intrinsically faint because they are mostly really small and far away from us in space," she said in a statement.

"Add to this the fact that some of them are as dark as printer toner, and trying to spot them against the black of space is very hard," Mainzer said.

Instead of using visible light to spot incoming objects, Mainzer's team at JPL/Caltech has leveraged a characteristic signature of -- their heat.

Asteroids and comets are warmed by the sun and so glow brightly at thermal wavelengths (infrared), making them easier to spot with the Object Wide-field Infrared Survey Explorer (NEOWISE) telescope.

"With the we can spot objects regardless of their surface colour, and use it to measure their sizes and other surface properties," Mainzer said.

Discovering NEO surface properties provides an insight into how big the objects are and what they are made of, both critical details in mounting a defensive strategy against an Earth-threatening NEO, researchers said.

For instance, one defensive strategy is to physically "nudge" an NEO away from an impact trajectory, they said.

However, to calculate the required for that nudge, details of NEO mass, and therefore size and composition, are necessary.

Astronomers also think that examining the composition of asteroids will help to understand how the solar system was formed.

"These objects are intrinsically interesting because some are thought to be as old as the original material that made up the solar system," Mainzer said.

She is now keen to leverage advances in to aid in the search for NEOs.

"We are proposing to NASA a new telescope, the Camera (NEOCam), to do a much more comprehensive job of mapping asteroid locations and measuring their sizes," Mainzer said.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)

First Published: Wed, April 17 2019. 17:45 IST
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