4581 Asclepius , provisional designation , is a sub-kilometer-sized

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

, classified as

near-Earth object A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...

and

potentially hazardous asteroid A potentially hazardous object (PHO) is a near-Earth object – either an asteroid or a comet – with an orbit that can make close approaches to the Earth and is large enough to cause significant regional damage in the event of impact. They are ...

of the

Apollo group Apollo Education Group, Inc. is an American corporation based in the South Phoenix area of Phoenix, Arizona, with an additional corporate office in Chicago, Illinois. The company owns and operates several higher-learning institutions, including ...

that makes close orbital passes with Earth. Discovered on 31 March 1989 by American astronomers Henry Holt and

Norman Thomas Norman Mattoon Thomas (November 20, 1884 – December 19, 1968) was an American Presbyterian minister who achieved fame as a socialist, pacifist, and six-time presidential candidate for the Socialist Party of America. Early years Thomas was the ...

Palomar Observatory Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...

, Asclepius is named after the Greek demigod of medicine and healing. Asclepius passed by Earth on 22 March 1989 at a distance of . Although this exceeds the Moon's orbital radius, the close pass received attention at that time. "On the cosmic scale of things, that was a close call", said Dr. Henry Holt. Geophysicists estimate that

collision In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great fo ...

with Asclepius would release energy comparable to the explosion of a 600

megaton Megaton may refer to: * A million tons * Megaton TNT equivalent, explosive energy equal to 4.184 petajoules * megatonne, a million tonnes, SI unit of mass Other uses * Olivier Megaton (born 1965), French film director, writer and editor * ''Me ...

atomic bomb. The asteroid was discovered 31 March 1989, nine days after its closest approach to the Earth. Subsequent discoveries revealed that a whole class of such objects exists. Close approaches by objects the size of Asclepius pass by every two or three years, undetected until the start of computerized near-Earth object searches. On 24 March 2051, the asteroid will pass from the Earth. It will be the eighth pass of less than 30 Gm in this century. JPL shows that the uncertainty region of the asteroid will cause it to most likely pass from 0.02 AU to 0.17 AU from the Earth in 2135.

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

Minor Planet Center * * {{DEFAULTSORT:Asclepius 004581 Discoveries by Henry E. Holt Discoveries by Norman G. Thomas Named minor planets 004581 19890331