28 May 1998
28 May 1998
Minor planet category
Spacewatch, Tom Gehrels
1.4816757 AU (221.65553 Gm)
0.98408102 AU (147.216425 Gm)
1.23287838 AU (184.435980 Gm)
Solar System, 6489 Golevka, 4769 Castalia, 4660 Nereus, (53319) 1999 JM8
Asteroide 1998 ky26
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.
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.
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.
These physical properties were measured by 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.