433 Eros
The
asteroid 433 Eros (
eer'-os) was named after the
Greek god of
love Eros. It is an
S-type asteroid approximately 13 × 13 × 33 km in size, the second-largest
near-Earth asteroid, belonging to the
Amors. It is also a
Mars-crosser asteroid.
Eros was visited by the
NEAR Shoemaker probe, which orbited it, taking extensive photographs of its surface, and then, on
February 12 2001 at the end of its mission, landed on the asteroid's surface using only its maneuvering jets.
Surface gravity depends on the distance from a spot on the surface to the center of a body's mass. The Erotian surface gravity varies a lot, since Eros is not a sphere but an elongated peanut-shaped (or potato- or shoe-shaped) object.The daytime temperature on Eros hovers at about 100 °C and nighttime measurements at âˆ'150 °C.Eros's density is 2,400 kg/m
3, about the same as the density of Earth's crust. It rotates once every 5.27 hours.
NEAR scientists have found that most of the larger rocks strewn across Eros were ejected from a single crater in a meteorite collision perhaps 1 Ga (1
billion years) ago. This impact may also be responsible for the 40 percent of the Erotian surface that is devoid of craters smaller than 0.5 kilometers across. It was originally thought that the debris thrown up by the collision filled in the smaller craters. An analysis of crater densities over the surface indicates that the areas with lower crater density are within 9 kilometers of the impact point. Some of the lower density areas were found on the opposite side of the asteroid but still within 9 kilometers.
It is theorized that
seismic shockwaves propagated through the asteroid, shaking smaller craters into rubble. Since Eros is irregularly shaped, a 9 kilometer straight line through the asteroid can reach locations that would be further away if travelling across the surface, thus leading to the uneven pattern of crater density on the surface. (Thomas & Robinson, 2005)
In an experimental legal case, Eros was claimed as property by
Gregory W. Nemitz of
OrbDev. According to the
Homestead principle, Nemitz argued that he had the right to claim ownership of any celestial body that he made use of; he claimed he had designated Eros a spacecraft parking facility and wished to charge
NASA a parking and storage fee of 20 cents per year for NEAR Shoemaker. Nemitz's case was dismissed and an appeal denied. [
1]
| Opposition distance | Maximum brightness | Stationary, prograde | Conjunction to sun | | 26 February, 2005 ¦¦ 16 April, 2005 | 0.365 96 AU | 10.5 mag | 2 May, 2005 | 3 March, 2006 |
| 23 May, 2007 ¦¦ 9 July, 2007 | 0.747 92 AU | 12 mag | 22 August, 2007 | 11 October, 2008 |
| 14 July, 2009 ¦¦ 1 September, 2009 | 0.689 42 AU | 11.9 mag | 15 October, 2009 | 2 January, 2011 |
| 15 January, 2012 ¦¦ 28 February, 2012 | 0.175 79 AU | 8.5 mag | 15 March, 2012 | 20 February, 2013 |
| 13 May, 2014 ¦¦ 28 June, 2014 | 0.719 76 AU | 12.0 mag | 10 August, 2014 | 16 July, 2015 |
| 3 July, 2016 ¦¦ 21 August, 2016 | 0.727 46 AU | 12.0 mag | 5 October, 2016 | 23 December, 2017 |
| 5 November, 2018 ¦¦ 3 December, 2018 | 0.223 39 AU | 9.3 mag | 22 December, 2018 | 11 February, 2020 |
Eros is also mentioned in
Orson Scott Card's novel
Ender's Game (
1985). It used to be an outpost for the aliens known as
Formics who installed
artificial gravity but was taken over by humans and a
Command School was built there. This is where
Ender was sent after he graduated from
Battle School.
433 Eros also plays an important role in the future evolution of life on Earth in
Stephen Baxter's novel
Evolution (
2003). Millions of years after being perturbed into a new orbit, the asteroid collides with Earth, bringing about another mass extinction. The
micrometeoroid-ravaged shell of
NEAR Shoemaker still stands on the surface of Eros until seconds before the impact.
*
List of geological features on 433 Eros* PMID 16034412
*
NEAR Shoemaker spacecraft*
NEAR image of the day archive*
Movie: NEAR Shoemaker spacecraft landing*
The Eros Project (OrbDev's attempts at litigation over their property claim)
