Here’s what to know about our new, temporary celestial neighbor. Earth has a large gravitational pull. So it’s not uncommon for objects flying through space to be attracted to it or get caught up in an orbit — at which point they earn status as miniature moons. The same happens with objects purposefully placed in space, such as satellites.

When approaching Earth, asteroids tend to do one of two things: Most of the time, they miss. Sometimes, they hit, leaving a bright streak in our planet’s sky or a gruesome new wound in its crust. But very rarely, asteroids are captured by Earth’s gravity and pirouette around the planet, becoming, in effect, a moon — albeit an ephemeral one.