(298) Baptistina

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Asteroid
(298) Baptistina
Properties of the orbit ( animation )
Orbit type Inner main belt
Asteroid family Baptistina family
Major semi-axis 2.264  AU
eccentricity 0.096
Perihelion - aphelion 2.048 AU - 2.48 AU
Inclination of the orbit plane 6.3 °
Length of the ascending node 8.3 °
Argument of the periapsis 135.4 °
Time of passage of the perihelion March 12, 2011
Sidereal period 3 a 148 d
Mean orbital velocity 19.8 km / s
Physical Properties
Medium diameter ≈ 21 km
Albedo 0.131
Rotation period 16 h 14 min
Absolute brightness 11.2 mag
history
Explorer A. Charlois
Date of discovery September 9, 1890
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items.

(298) Baptistina is an asteroid of the main asteroid belt that was discovered by Auguste Charlois at the Observatory of Nice on September 9, 1890 .

Baptistina moves from 2.0474 ( perihelion ) to 2.481 ( aphelion ) astronomical units around the sun in 3.4065 years . The orbit is 6.2847 ° inclined to the ecliptic , the orbital eccentricity is 0.0957.

Baptistina has a mean diameter of about 21 km and is likely to belong to the carbonaceous chondrites .

Collision theory

A number of small objects with similar properties are circling along similar paths. This led to the theory that Baptistina once collided with another asteroid. Baptistina - at that time still about 170 kilometers tall - collided with an asteroid about 60 kilometers in size. Around 100,000 fragments with a diameter of more than one kilometer and around 300 with a diameter of more than 10 kilometers were created. About two percent of these fragments were diverted into the inner solar system by gravity from Mars and Jupiter .

A computer simulation to recalculate the orbits from 2007 showed a high probability that this collision took place around 160 million years ago. According to the simulation, one of the objects created by the collision would have been responsible for the asteroid impact that could have triggered the extinction of the dinosaurs 65 million years ago (the so-called KT impact). The striking Tycho crater in the southern hemisphere of the moon would also have been formed by the impact of one of these objects with a 70% probability.

Recent measurements by NASA's Wide-Field Infrared Survey Explorer space telescope in 2011 disproved this theory. The collision of the two large asteroids took place 80 million years ago, which is why the fragments formed cannot be responsible for the KT impact.

See also

literature

  • William F. Bottke et al .: An asteroid breakup 160 Myr ago as the probable source of the K / T impactor . In: Nature Vol. 449, Vol. 2007, pp. 48-53. doi : 10.1038 / nature06070

Individual evidence

  1. ↑ a b Dino death by cosmic ricochet , Süddeutsche Zeitung , September 6, 2007.
  2. ↑ Origin of Dinosaur-Killing Asteroid Remains a Mystery , Jet Propulsion Laboratory , September 19, 2011.

Web links