3200 Phaethon

From Wikipedia, the free encyclopedia
Jump to: navigation, search
3200 Phaethon
Asteroid Phaethon 25dec2010 stack.jpg
Asteroid (3200) Phaethon imaged on 25 Dec 2010 with the 37 cm F14 Cassegrain telescope of Winer Observatory, Sonoita (MPC 857) by Marco Langbroek.
Discovered by Simon Green and
John K. Davies/IRAS
Discovery time October 11, 1983
Named for Phaëton
Other names 1983 TB
Group Apollo asteroid,
Mercury-crosser asteroid,
Venus-crosser asteroid,
Mars-crosser asteroid
Reference date July 14, 2004 (JD 2453200.5)
Longest distance from the Sun 2.403 AU (359.456 Gm)
Shortest distance from the Sun 0.140 AU (20.922 Gm)
Longest distance from the center of its orbital path
("semi-major axis")
1.271 AU (190.189 Gm)
How egg-shaped its orbit is
How long it takes to complete an orbit 1.43 a (523.586 d)
Average speed 19.98 km/s
Mean anomaly 200.798°
Angle above the reference plane
Longitude of where it comes up through the reference plane 265.427°
Angle between its shortest distance from what it orbits around and where it comes up through the reference plane
("argument of periapsis")
Size and Other Qualities
Measures 5.1 km[1]
Mass 1.4×1014 kg
Average density 2 ? g/cm³
Gravity at its surface 0.0014 m/s²
Slowest speed able to escape into space
("escape velocity")
0.0027 km/s
How long it takes to turn around one time 3.604 hr[1]
How much light it reflects 0.11[1]
Avg. surface temp. ~247 K
Light-band group
("spectral type")
B-type asteroid
True brightness
("absolute magnitude")

3200 Phaethon (/ˈf.əθɒn/ FAY-ə-thon, sometimes incorrectly spelled Phaeton is an Apollo asteroid and a dead comet.

Simon F. Green and John K. Davies, while searching Infrared Astronomical Satellite (IRAS) data for moving objects, found 3200 Phaethon (1983 TB) in pictures from October 11, 1983. It was announced on October 14 in IAUC 3878 along with optical confirmation by Charles T. Kowal, who reported that it looks like an asteroid. It was the first asteroid to be found by a spacecraft. It measures 5.10 km in diameter.

Phaethon approaches the Sun closer than any other numbered asteroid. Its perihelion (closest approach to the Sun) is only 0.140 AU – less than half Mercury's perihelion distance. It is a Mercury-, Venus-, Earth- and Mars-crosser. The surface temperature at perihelion could reach ~1025 K, or 1400 F. For this reason, it was named after the Greek myth of Phaëton, son of the sun god Helios.

Phaethon approached to 18.1 Gm on December 10,2007. It will draw nearer in 2017, 2050, 2060, and closer still on December 14, 2093, passing within 0.0198 AU (3.0  Gm).

Sources[change | edit source]

  1. 1.0 1.1 1.2 1.3 "JPL Small-Body Database Browser: 3200 Phaethon (1983 TB)". Jet Propulsion Laboratory. 2012-02-25 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3200. Retrieved 2012-06-19.