(2) Pallada ( Latin Pallas ) - the second open asteroid .
(2) Pallas  | |
|---|---|
| Asteroid | |
 Image of Pallas taken by the VLT telescope in 2017 Image of Pallas taken by the Hubble telescope in 2007 | |
| Opening | |
| Discoverer | Heinrich Olbers |
| Detection point | |
| Date of discovery | March 28, 1802 |
| Category | Main ring |
| Orbital characteristics [1] | |
| The era of November 30, 2008 JD 2454800.5 | |
| Eccentricity ( e ) | 0,231 |
| Semi-axis ( a ) | 414.835 million km (2.773 a. E.) |
| Perihelion ( q ) | 319.008 million km (2.132 a. E.) |
| Afhelia ( Q ) | 510.662 million km (3.414 a. E.) |
| Period of circulation ( P ) | 1686.643 days (4.618 g ) |
| Average orbital speed | 17.645 km / s |
| Inclination ( i ) | 34.838 ° |
| Ascending node longitude (Ω) | 173.132 ° |
| Perihelion Argument (ω) | 310,257 550 ± 8 × 516 ± 6 × 476 ± 6 |
| Mean Anomaly ( M ) | 327.974 ° |
| physical characteristics | |
| Diameter | 512 ± 6 km (550 ± 8 × 516 ± 6 × 476 ± 6 km) [2] |
| Weight | (2.11 ± 0.26) ⋅10 20 kg [3] |
| Density | 3.0 ± 0.5 g / cm³ |
| Acceleration of gravity on the surface | 0.194 m / s² |
| 2nd cosmic speed | 0.32158 km / s |
| Rotation period | 7.81 h |
| Spectral class | B |
| Absolute magnitude | 4.13 m |
| Albedo | 0.1587 |
| Average surface temperature | 164 K (−109 ° C ) |
| Current distance from the Sun | 2,811 a. e. |
It was opened on March 28, 1802 by Heinrich Wilhelm Olbers and named after Pallas - the daughters of Triton and Athena from ancient Greek mythology (although the Greeks could have had both the male name and the epithet of Athena itself, but it is believed that the first asteroids received only female names) [5] .
Pallas was discovered in the 1779 drawings in the Messier Catalog as a star, marked next to the path of comet Bode [6] . It has a large orbital inclination - 34.8 °.
Refers to the main asteroid belt . For a long time, Pallas was considered the second largest body of the main asteroid belt — at first its diameter was estimated at 608 km, then at 582 × 556 × 500 km (it was thought to be superior to Vesta ). In August 2006, Ceres was transferred to the status of a dwarf planet , and Pallas began to occupy the first place in size and second place in mass (25% lighter than Vesta [3] ) among the main ring asteroids. However, the refined size of Pallas (512 ± 6 km [2] ) turned out to be slightly less than the diameter of Vesta (525.4 ± 0.2 km [7] ), and Pallas again became the second largest body of the main asteroid belt .
The Japanese infrared satellite Akari revealed the presence of hydrated minerals in Pallada [8] .
By the name of the asteroid (2) Pallas is the chemical element palladium , discovered in 1803 by the English chemist William Wollaston .
It is assumed that in 2022 the spacecraft [9] [10] will go to explore the asteroid (2) Pallas.
See also
- List of asteroids ( 1—100 )
- Small Planet Classifications
Notes
- ↑ JPL Small-Body Database Browser: 2 Pallas . The date of circulation is October 11, 2008. Archived August 26, 2011.
- ↑ 1 2 Carry, B. et al. Physical properties of (2) Pallas (English) // Icarus . - Elsevier , 2009. - Vol. 205 . - P. 460-472 . - DOI : 10.1016 / j.icarus.2009.08.007 . - . - arXiv : 0912.3626 .
- ↑ 1 2 Baer, James; Steven R. Chesley. Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris (Eng.) // Celestial Mechanics and Dynamic Astronomy : journal. - Springer Nature , 2008. - Vol. 100 , no. 2008 - P. 27—42 . - DOI : 10.1007 / s10569-007-9103-8 . - .
- ↑ VLT's SPHERE spies rocky worlds . www.eso.org . The appeal date is December 4, 2017.
- ↑ Dictionary of minor planet names. Lutz D. Schmadel, International Astronomical Union.
- ↑ Charles Messier, premier observerur de l'astéroïde Pallas .
- ↑ Russell, CT et al. Dawn at Vesta: Testing the Protoplanetary Paradigm (Eng.) // Science. - 2012. - Vol. 336 , no. 6082 . - P. 684-686 . - DOI : 10.1126 / science.1219381 . - .
- ↑ Fumihiko Usui et al. AKARI / IRC near-infrared asteroid spectroscopic survey: AcuA-spec , December 17, 2018
- ↑ Dorminey, Bruce . Proposed NASA, Our Third Largest Asteroid , Forbes (10 March 2019). The appeal date is March 10, 2019.
- ↑ Athena: the first-ever encounter of (2) Pallas with a Smallsat. JG O'Rourke, J. Castillo-Rogez, LT Elkins-Tanton, RR Fu, TN Harrison, S. Marchi, R. Park, BE Schmidt, DA Williams, CC Seybold, RN Schindhelm, JD Weinberg. 50th Lunar and Planetary Science Conference 2019 (LPI Contrib. No. 2132).