An American physicist claimed through a new study that aliens might be using asteroids that fly near Earth to spy on the planet. The scientist then called for new missions to visit the near-Earth objects (NEO) to find the alien observers.

In a new study published in The Astronomical Journal, physicist James Benford theorized that extraterrestrial beings might be using space probes or “lurkers” to study civilizations on other planets, such as Earth.

He noted that these probes may have been following the progression of Earth’s technology for decades or even centuries.

“A probe located nearby could bide its time while our civilization developed technology that could find it, and, once contacted, could undertake a conversation in real time,” Benford wrote in his paper.

“Meanwhile, it could have been routinely reporting back on our biosphere and civilization for long years,” he added.

According to Benford, one possible way aliens could spy on Earth without being detected is by using the NEOs, or the asteroids that fly close to Earth on a regular basis. These asteroids visit Earth’s neighborhood so frequently that the planet gets at least one flyby from a NEO every day.

As Benford explained, these kinds of asteroids serve as the ideal platforms for alien space probes.

“A recently discovered group of nearby co-orbital objects is an attractive location for extraterrestrial intelligence (ETI) to locate a probe to observe Earth while not being easily seen,” Benford wrote.

“These near-Earth objects provide an ideal way to watch our world from a secure natural object,” he added. “That provides resources an ET might need: materials, a firm anchor and concealment.”

Due to the possible presence of alien probes on asteroids, Benford called on space agencies as well as alien-focused organizations to take on a more proactive approach in finding extraterrestrial life. The physicist suggested using a combination of satellite data and asteroid missions to check on the alleged probes aboard the NEOs.

“We should move forthrightly toward observing them, both by observing them in the electromagnetic spectrum and planetary radar, as well as visiting them with probes,” he said.

Two Very Different Asteroids Image of two different asteroids captured by NASA. Photo: NASA/JPL/JHUAPL