The asteroid follows a slightly elliptical trajectory, circling the Sun in 1.76 years at an inclination of 10.8 degrees to the ecliptic. Because of its repeated close encounters with Earth, Eros has been an important object historically for refining the mass of the Earth-moon system and the value of the astronomical unit. Eros is no threat to actually hit the Earth, however. Astronomers assign the asteroid a rotation period of 5.27 hours. Geometric albedo is 0.16.
Thermal studies indicate a regolith, and radar suggests a rough surface.
There is no air and no evidence of water on Eros. Daytime temperature is about 100 deg. Gravity on Eros is very weak but sufficient to hold a spacecraft in orbit. This is a major goal of the NEAR mission to Eros.