It turns out that Earth has another neighbor besides the moon: a so-called Trojan asteroid that has been traveling with us around the sun for thousands of years, reports the Los Angeles Times. Plenty of other planets have their own asteroids—there are at least 4,000 in Jupiter's orbit alone—but scientists were never able to find any around the Earth, in part because the sweet spot where asteroids could exist was hidden by the brightness of the sun.
But an astronomer from Alberta thought to use NASA's Wide-Field Infrared Survey Explorer, a space-based telescope that can point its lens at a 90 degree angle to the sun—and it did indeed find such an asteroid. Should scientists be able to find others, NASA may have itself a candidate for a visit by astronauts, a feat it's looking to attain in as little as 15 years. A scientist who wasn't part of tracking down this Trojan explains that the newly discovered asteroid isn't suitable for a visit because it's too tilted in relation to the solar system. (Read more NASA stories.)