Nov 1, 2022 - Science

Huge "planet killer" asteroid found in the glare of the Sun

Artist's illustration of an asteroid in the glare of the Sun.

Artist's illustration of an asteroid in the glare of the Sun. Image: DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA/J. da Silva/Spaceengine

Scientists have discovered a "planet killer" asteroid nearly a mile long within the orbits of Earth and Venus.

Why it matters: The space rock — named 2022 AP7 — poses no immediate threat to Earth, but its orbit crosses the planet's, making it an important object for scientists to keep an eye on in the future.

What they found: 2022 AP7 is thought to be about 0.9 miles long — wide enough that if it hit Earth, a wide swath of the planet would feel the effects.

  • Details of the newfound asteroid and two others were published in the Astronomical Journal in September and announced in a news release Monday.
  • Scott Sheppard of the Carnegie Institution for Science, and an author of the study, stresses there is no evidence to suggest the asteroid will ever impact Earth, and even if it were to threaten the planet, that would happen thousands, if not millions of years in the future.

How it works: Researchers using the Dark Energy Camera in Chile discovered the space rock by observing during twilight — a crucial time for ground-based telescopes to find possibly dangerous asteroids usually lost in the glare of the Sun.

  • The part of the sky where 2022 AP7 was found is particularly challenging to search for asteroids within because astronomers only have two 10-minute windows each night for the survey of the area.
  • "Our twilight survey is scouring the area within the orbits of Earth and Venus for asteroids," Sheppard said in the press release. "So far we have found two large near-Earth asteroids that are about 1 kilometer across, a size that we call planet killers."

The big picture: NASA and other space agencies have been focusing on searching for and characterizing possibly hazardous asteroids for years.

  • Scientists think they've found most of the asteroids near Earth in the size range of 2022 AP7, but other, smaller yet still potentially devastating space rocks have gone undiscovered.
  • "Less than half of the estimated 25,000 NEOs that are 140 meters and larger in size have been found to date," according to NASA.

What to watch: NASA recently conducted the successful DART mission that slammed a spacecraft into an asteroid and threw it off its course around another, larger asteroid.

  • The proof of concept mission shows that one day scientists may be able to do the same for an asteroid found on a collision-course with Earth.
  • NASA is also planning to launch its NEO Surveyor telescope — designed to find dangerous asteroids using infrared light — in 2028. The space-based asteroid-hunting mission is thought to be the major piece of technology needed to find these possibly harmful space rocks.
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