You already know the moon is the largest orbiting object floating through space around Earth, but it’s not alone. Fact is, there are hundreds of fast moving rocky structures living in our inner solar system that occasionally fly by earth.
Duncan Forgan, a researcher from the University of St. Andrews, recently documented a rocky structure known as 3753 Cruithne (pronounced krooy-nyuh) on The Conversation, where he declares it as a “second moon”
Here are the best pictures we have of this small, rocky “second moon” that measures a mere 3 miles across. Because of its tiny size, scientists need powerful telescopes to see Cruithne from afar. The instrument at Powell Observatory took the image you see below, where it is seen as a small speck of light.
The astronomy instrument known as NEOWISE captured five images of Cruithne that are compiled into a single image below. NEOWISE searches our sky for structures like asteroid and comets that are in close proximity to the earth.
The reason the structure appears red in this picture is because it is beaming light at lower frequencies than the stars in the the background. James Bauer, a astronomer who specializes in comets at NASA’s Jet Propulsion Laboratory, gave insight to Business Insider in an email.
Cruithne is a type of structure named an Aten asteroid, which is a group of asteroids that reside within the inner parts of the solar system between Earth and the sun. It has a peculiar path through space where it orbits both the sun and the Earth together in a kidney shaped orbit.
Aten asteroids are generally small, which is why researches only recently found them. As a matter of fact, the first Aten asteroid was found in 1976 and Cruithne was not found until 1986.
How to see it
Paul Wiegert, who studies Cruithne from the University of Western Ontario, gave insight to Business Insider in an email that “it’s very hard to see Cruithne in even a very large telescope except as a small star like dot.”
However, it is possible to see.