Montage of images from NASA’s NEAR spacecraft, as it approached the tumbling asteroid Eros from January 22nd through February 12th, 2000. Eros is the second largest near-Earth asteroid, and the first to be discovered, in 1898.

It’s thought that Eros could cross the orbit of our planet within the next two million years. If it did, the asteroid would likely cause more damage to our ecosystem than the impact that wiped out the dinosaurs and most other life on our planet 65 million years ago.

This week, the 21 by 7 by 7 mile wide rock is making its closest approach to Earth since 1975 (and until 2056), appearing bright enough (magnitude 7-8) in the constellation of Hydra to be visible through binoculars or a small telescope (image credit: NASA/NEAR Project/JHU/APL).