Discovered by Carl Gustav Witt
Discovery date August 13, 1898
This 6-scene animated sequence shows the NEAR Shoemaker spacecraft as it probably looked when it descended from orbit above Eros to the surface of the asteroid on Feb. 12, 2001. Hydrazine engine bursts slowed the spacecraft into a gentle descent.
NEAR Shoemaker de-orbited with an engine burn at 10:31 a.m. EST, about 4½ hours before it reached the surface. The final leg of the controlled descent began with the spacecraft about 5 kilometers (3 miles) above the surface; it then executed an unprecedented series of four engine burns that slowed its descent from about 20 mph to under 4 mph. NEAR Shoemaker landed in an area just outside Himeros, the asteroid's distinctive saddle-shaped depression, after providing the highest-resolution images ever taken of Eros' boulder-strewn, cratered terrain. Though it was never designed to land, NEAR Shoemaker survived the touchdown and continued to transmit data from the surface.
433 Eros is an S-type near-Earth asteroid approximately 34.4×11.2×11.2 kilometres (21.4×7.0×7.0 mi) in size, the second-largest near-Earth asteroid after 1036 Ganymed. It was discovered in 1898 and was the first near-Earth asteroid discovered. It was the first asteroid to be orbited by a probe (in 2000). It belongs to the Amor group.
Eros is a Mars-crosser asteroid, the first known to come within the orbit of Mars. Objects in such an orbit can remain there for only a few hundred million years before the orbit is perturbed by gravitational interactions. Dynamical integrations suggest that Eros may evolve into an Earth-crosser within as short an interval as two million years, and has a roughly 50% chance of doing so over a time scale of 108–109 years. It is a potential Earth impactor, comparable in size to the impactor that created Chicxulub crater and led to the extinction of the dinosaurs.
The NEAR Shoemaker probe visited Eros twice, first with a 1998 flyby, and then by orbiting it in 2000 when it extensively photographed its surface. On February 12, 2001, at the end of its mission, it landed on the asteroid's surface using its maneuvering jets.
Dimensions 34.4×11.2×11.2 km 16.84 km (mean)
Mass 6.69×10 to the 15 kg
Mean density 2.67±0.03 g/cm³
Equatorial acceleration due to gravity 0.0059 m/s²
Escape velocity 0.0103 km/s
Rotation period 0.2194 d (5 h 16 min)
Temperature ~227 K
Epoch October 22, 2004 (JD 2453300.5)
Aphelion 1.783 AU (266.762 million km)
Perihelion 1.133 AU (169.548 million km)
Semi-major axis 1.458 AU (218.155 million km)
Orbital period 1.76 Earth years (643.219 d)
Average orbital speed 24.36 km/s
Mean anomaly 320.215°