| • Science | • People | • Locations | • Timeline |
| Discovery | |
|---|---|
| Discoverer | Heinrich Wilhelm Olbers |
| Discovery Date | March 29, 1807 |
| Alternate Designations | |
| Category | Main belt ( Vesta family ) |
| Orbital Elements Epoch July 14, 2004 ( JD 2453200.5) | |
| Eccentricity (e) | 0.089 |
| Semi-Major Axis (a) | 353.323 G m (2.362 AU) |
| Perihelion (q) | 321.956 Gm (2.152 AU) |
| Aphelion (Q) | 384.689 Gm (2.571 AU) |
| Orbital Period (P) | 1325.768 d (3.63 a) |
| Mean Orbital Speed | 19.38 km/ s |
| Inclination (i) | 7.133 ° |
| Longitude of the Ascending Node (Ω) | 103.936° |
| Argument of Perihelion (ω) | 150.271° |
| Mean Anomaly (M) | 69.905° |
| Physical Characteristics | |
| Dimensions | 468.3 km |
| Mass | 2.701×1020 kgThe kilogram (symbol: kg is the SI base unit of mass. A gram is defined as one thousandth of a kilogram. Conversion of units describes equivalent units of mass in other systems. Multiples SI prefixes are used to name multiples and subdivisions of the kilo |
| Density | 5.0 g/ cm³A cubic centimetre cm is an SI derived unit of volume, equal to the volume of a cube with side length of 1 centi metre. It was the basic unit of volume of the CGS system of units. In SI units: 1 cm³ 10−6 cubic metres 1 milli litre (mL) The abbreviat |
| Surface Gravity | 0.30 m/s² |
| Escape Velocity | 0.39 km/s |
| Rotation Period | 0.2226 d |
| Spectral Class | V-type asteroidThe V-type asteroids or Vestoids are moderately bright, and very similar to the more common S-type, which are also made up of stony irons and ordinary chondrites. The only significant difference between this rarer form of asteroid is that it contains more |
| Absolute Magnitude | 3.20 |
| Albedo | 0.423 |
| Mean Surface Temperature | ~223 KThe kelvin (symbol: K is the SI unit of temperature, and is one of the seven SI base units. It is defined by two facts: zero kelvin is absolute zero (when molecular motion stops), and one kelvin is the fraction 1/273. 16 of the thermodynamic temperature o |
Vesta was discovered by the German astronomer Heinrich Wilhelm Olbers on March 29, 1807. He allowed the prominent mathematician Carl Friedrich Gauss to name the asteroid after the Roman virgin goddess of home and hearth, Vesta.
After the discovery of Vesta in 1807, no other asteroids were discovered for 38 years; the next was 5 Astraea.
In the earliest times of the Solar system, Vesta was hot enough for its interior to melt. This resulted in differentiation of the asteroid. It is likely to have a layered structure: a metallic iron- nickel core and an overlying olivine mantle. The surface is basaltic rock from ancient lava flows, obviously some kind of short-lived volcanic activity was present. This makes Vesta unlike any other asteroid and in a sense it is more like the terrestrial planets, which underwent similar geological processes.
However, it was not the only one of its kind; originally, there may have been dozens of similar large planetesimals, but all the other bodies were shattered into families of smaller asteroids during the chaotic early times. Metallic iron-nickel asteroids are thought to originate from the cores of such bodies, with stony asteroids deriving from their crusts and mantles.
Not even Vesta has survived intact. In 1996 the Hubble Space Telescope (see image below) detected a huge crater on Vesta, 430 kilometres across and perhaps a billion years old. It is thought that this crater may be the source of the small V-type asteroids (or Vestoids) observed today.
4 Vesta seen by the Hubble Space Telescope in May 1996 from 177 Gm
In 2001 one such asteroid, 1929 Kollaa , was not only determined to be a piece from Vesta, but also the exact location of its formation was traced to deep in the crust.
The Yarkovsky effect, along with perturbing planets and asteroids, causes scattering among the Vesta family . Some family members, such as 9969 Braille, have become Near-Earth asteroids. Smaller fragments have even rained down as meteorites; Vesta is thought to be the source of the HED meteorite s.
Our knowledge about Vesta is expected to increase tremendously when the Dawn probe enters orbit around the asteroid in 2010.