Three views of a computer model of asteroid 1998 KY26.
|Discovered by||Spacewatch, Tom Gehrels|
|Minor planet category||Apollo|
± 7.2381e-07 AU
± 1.6462e-07 AU
± 6.0241e-07 AU
|Orbital period||1.37 ± 1.003e-06 yr
(499.5453 ± 0.00036636 d)
|Longitude of ascending node||84.44936
|Argument of perihelion||209.22902
|Dimensions||30 metres (98 ft)|
|Sidereal rotation period||10.704 min|
|Absolute magnitude (H)||25.456|
1998 KY26 (also written 1998 KY26) is a small near-Earth asteroid. It was discovered on June 2, 1998, by Spacewatch and observed until June 8, when it passed 800,000 kilometers (half a million miles) away from Earth (a little more than twice the Earth–Moon distance). It is roughly spherical and is only about 30 metres (98 ft) in diameter. Although it is nearly small enough be classified a meteoroid, the most common definition uses a diameter of 10 m as the demarcation, which makes 1998 KY26 an asteroid.
With a rotation period of 10.7 minutes it has one of the shortest sidereal days of any known object in the Solar System, and cannot possibly be a rubble pile. It is also one of the most easily accessible objects in the Solar System, and its orbit frequently brings it on a path very similar to the optimum Earth–Mars transfer orbit. This, coupled with the fact that it is water rich, makes it an attractive target for further study and a potential source of water for future missions to Mars.
The discovery is attributed to an international team of astronomers led by Dr. Steven J. Ostro of the Jet Propulsion Laboratory. The team used a radar telescope in California and optical telescopes in the Czech Republic, Hawaii, Arizona and California.
Asteroid 1998 KY26 is the smallest solar system object ever studied in detail and, with a rotational period of 10.7 minutes, was the fastest-spinning object observed at the time of its discovery: most asteroids with established rotational rates have periods measured in hours. It was the first recognized minor object that spins so fast that it must be a monolithic object rather than a rubble pile, as many asteroids are thought to be. Since 1998 KY26 was found to be a fast rotator, several other small asteroids have been found to also have short rotation periods, some even faster than 1998 KY26.
Optical and radar observations indicate that 1998 KY26 is a water-rich object.
- Ostro, Steven J.; et al. (July 1999). "Radar and Optical Observations of Asteroid 1998 KY26". Science 285 (5427): 557–559. Bibcode:1999Sci...285..557O. doi:10.1126/science.285.5427.557. PMID 10417379.
- Tholen, D. J. (September 2003). "Recovery of 1998 KY26: Implications for Detecting the Yarkovsky Effect (abstract only)". Bulletin of the American Astronomical Society 35 (4). Retrieved 25 April 2009.
- "Spacewatch discovery of 1998 KY26". SPACEWATCH Project. Retrieved 25 April 2009.
- 1998 KY26 at the JPL Small-Body Database
- "1998 KY26". Retrieved 25 April 2009.
- "Astronomy Picture of the Day: Asteroid 1998 KY26". Nasa. 2002-09-19. Archived from the original on 24 April 2009. Retrieved 25 April 2009.
- MPEC 1998-L02
- Scott Hudson's Homepage: The Earth-Crossing Asteroid 1998 KY26
- Steven Ostro's Homepage: 1998 KY26
- Lipanović, Željko. "1998 KY26 Images". Archived from the original on 2009-10-22.
- Media Relations Office. Sun never sets, for long, on fast-spinning, water-rich asteroid (press release). Pasadena, California: Jet Propulsion Laboratory. July 22, 1999.