Kerberos (moon)
Kerberos | |
---|---|
Kerberos as captured by New Horizons at a distance of 396,100 km | |
Provisional or systematic name | S / 2011 (134340) 1 Pluto IV |
Central body | Pluto |
Properties of the orbit | |
Major semi-axis | (59,000 ± 2,000) km |
Periapsis | ≈ 57,800 km |
Apoapsis | ≈ 57,800 km |
eccentricity | 0.0033 |
Orbit inclination | ≈ 0 ° |
Orbital time | (32.1 ± 0.3) d |
Physical Properties | |
Albedo | ≈ 0.50 |
Apparent brightness | (26.1 ± 0.3) mag |
Medium diameter | Two components, 8 and 5 km respectively |
Acceleration of gravity on the surface | ≈ 0 m / s 2 |
Escape speed | ≈ 0 m / s |
discovery | |
Explorer |
Mark R. Showalter et al. |
Date of discovery | June 28, 2011 |
Remarks | Swell: |
Kerberos is the fourth closest and fourth largest of the five known moons of the dwarf planet Pluto . The moon has a visual brightness of only 10 percent of the moon Nix . Images from the New Horizons probe show that Kerberos consists of two roughly spherical parts that are approximately 8 and 5 km in diameter.
Discovery and naming
On July 20, 2011, NASA announced the discovery of a fourth Pluto moon. The Trabant, with the provisional name S / 2011 (134340) 1, was discovered with the help of the Hubble space telescope while searching for possibly existing planetary rings. The discovery was made by a team of astronomers led by Mark R. Showalter . With an estimated size of 13 to 34 km, it was the smallest known moon of Pluto at the time of its discovery. The moon was discovered in a photo taken on June 28, 2011 with the Hubble Wide Field Camera 3 , and was confirmed in additional photos taken on July 3 and 18. The exposure time for these recordings was eight minutes. The moon could also be identified on archived Hubble recordings of the Pluto system, which were recorded on February 15, 2006 with the ACS / HRC instrument. However, the celestial body was not visible on most of the earlier images, as these were taken with a shorter exposure time.
S / 2011 (134340) 1 was initially the provisional name given by the International Astronomical Union (IAU); sometimes it was wrongly given as S / 2011 P 1 . NASA calls it in its discovery report with the unofficial project name P4 . On July 2, 2013, the IAU announced that the moon was officially recognized as the fourth moon of Pluto and confirmed the name Cerberus - after the hellhound in Greek mythology - proposed by Frank G. Gerigk on the basis of an Internet vote and then officially submitted by Showalter who guards the entrance to the underworld - but in the Greek spelling Kerberos to avoid confusion with the asteroid (1865) Cerberus .
Track properties
The mean distance to Pluto is 57,780 km ± 20 km, so that the orbit lies between the already known moons Nix and Hydra . The orbit has an almost circular and equatorial characteristic.
exploration
No surface shapes can be seen in the images taken with the Hubble Space Telescope. In early May 2015, Kerberos was also captured by the New Horizons spacecraft . The probe passed Pluto on July 14, 2015, but since the mission's focus was on Pluto and Charon, there were only a few images of the small moons from a greater distance.
Web links
- CBET 2769: New Satellite of (134340) Pluto: S / 2011 (134340) 1 July 20, 2011 (discovery)
- IAUC 9221: New Satellite of (134340) Pluto: S / 2011 (134340) 1 (currently still subject to registration) September 10, 2011 (discovery)
- NASA: NASA'S Hubble Discovers Another Moon Around Pluto
- Stefan Deiters: PLUTO Hubble discovers moon number 4 , in Astronews.com, date July 20, 2011. Retrieved: July 20, 2011
Individual evidence
- ↑ a b c Last of Pluto's Moons - Mysterious Kerberos - Revealed by New Horizons. October 22, 2015, accessed October 24, 2015 .
- ^ A b NASA: NASA'S Hubble Discovers Another Moon Around Pluto
- ↑ a b IAU Electronic Telegram No. 2769: NEW SATELLITE OF (134340) PLUTO: S / 2011 (134340) 1
- ↑ Fourth Moon Adds to Pluto's Appeal ( Memento of the original from November 13, 2014 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. - Article on New Horizons website July 20, 2011 (accessed July 24, 2012)
- ↑ Changing Planet. National Geographic Blog
- ↑ IAU1303 News Release: Names for New Pluto Moon Accepted by the IAU After Public Vote , from July 2, 2013
- ^ MR Showalter , DP Hamilton: Resonant interactions and chaotic rotation of Pluto's small moons . In: Nature . 522, No. 7554, June 3, 2015, pp. 45-49. doi : 10.1038 / nature14469 .