NASA Reveals How It Hunts Monster Asteroids In Pitch-Black Darkness Of Space

An astronomer from NASA explained how the agency uses one of its space telescopes to spot hard-to-see asteroids. This has become one of NASA's leading tools to hunt down asteroids that might pose a threat to Earth.

Currently, the agency has numerous systems in place that were specifically designed to keep track of asteroids that fly near Earth. However, due to the vastness of space and the dark color of asteroids, finding these space rocks against a pitch-black background can be a bit challenging.

This issue was highlighted in earlier in July when an asteroid that was about 60 to 130 kilometers wide almost had a near-collision with Earth. Dubbed as 2019 OK, the asteroid flew past the planet from a distance of only 65,000 kilometers away.

If the asteroid collided with Earth, the energy it would have released would have been equivalent to about at least 30 atomic bombs. Surprisingly, space agencies such as NASA were not aware of the asteroid’s presence until about five hours before its near-Earth approach.

According to NASA, one of the main reasons as to why the asteroid remained undetected was because it moved towards Earth at a straight line. From Earth’s perspective, the asteroid looked like it stayed in place like a faint star. In addition, the brightness of a full moon during that time hid the asteroid.

As a solution to visibility issues, NASA has started turning to its other equipment to hunt down asteroids. One of these is the Wide-field Infrared Survey Explorer (WISE) space telescope. Launched in 2009, it uses its infrared imaging capabilities to spot minor planets and star clusters.

Through infrared wavelengths, WISE is able to detect cosmic objects due to their natural temperature.

“The two longer wavelengths on WISE are really optimized for finding things that are around room temperature,” NASA astronomer Amy Mainzer said during the latest episode of the “On a Mission” podcast.

“We think of space as either being extremely cold or brutally hot, but sometimes there's stuff that's just sort of in the middle, and that's what these wavelengths of light can be good for sensing,” she added.

In the case of asteroids, especially near-Earth ones, their natural orbits bring them relatively close to the Sun, which means they are as warm as some of the planets in the Solar System. This makes them the ideal targets for the WISE telescope.

“If you take an asteroid, which is a chunk of rock, and you park it at the same distance from the Sun as the Earth, it's going to warm up to a similar temperature as the Earth,” Mainzer said. “That means, it's going to radiate really brightly between 10 and 20 microns. So, even though WISE wasn't originally looking for asteroids when it was designed, it turns out it's pretty good at it.”