 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
| . |  |
. |
Another Candidate For "Planet X" Spotted
Tucson - Dec. 4, 2000 The Spacewatch Project at the University of Arizona has discovered a minor planet in the outer reaches of the solar system which appears to be the brightest known such object other than Pluto. During routine scanning with the Spacewatch 36-inch telescope on 2000 November 28, observer R. S. McMillan was manually blinking the displayed scans in real time and noticed this relatively slow-moving object. Its rate of motion is too slow for the real-time software to detect; normally the slower objects such as this one are found with another computer program that processes the data off-line.
As of 2000 December 1, the MPC's orbit suggests that this object is 43 times farther from the Sun than the Earth is, and is presently 42 times farther from Earth than the Earth is from the Sun. With an apparent magnitude of 20 at those distances, the object would be the brightest of all 346 known Trans-Neptunian Objects other than Pluto. Further observations of the object's position will be made in the coming weeks and months to improve knowledge of the orbital parameters and thereby the object's absolute magnitude, a parameter describing the object's brightness at a standard distance. Since solar system objects shine by reflected sunlight, this brightness depends on the object's size as well as its reflectivity. Therefore it is not possible to give a definitive diameter for 2000 WR106. However, if it has a reflectivity comparable to other minor planets, its diameter would be between 330 and 750 miles. This can be compared to the diameters of the largest known asteroid (1) Ceres of 570 miles or (4) Vesta of 320 miles. Pluto is at a distance comparable to that of 2000 WR106, and is 1,470 miles in diameter. Brightness equates with ease of measuring the object's reflection spectrum, so 2000 WR106 will no doubt be the target of spectroscopy and measurements of its thermal infrared flux (heat output). That additional information will allow a determination of its diameter. The Spacewatch Project is a survey of the whole solar system, from the vicinity of the Earth's orbit all the way out to beyond the orbit of Neptune. Related Links Spacewatch SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express
Lunar Meteorite Ages Strongly Support Lunar Cataclysm
Tucson - Nov 30, 2000Lunar meteorite ages present new, strong evidence for the "lunar cataclysm," a 20-to-200 million-year episode of intense bombardment of the moon and the Earth at 3.9 billion years ago -- when the first evidence of life appeared on Earth, planetary scientists report in the Dec. 1 issue of Science. |
|
|
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement |
The target was subsequently reobserved by J. A. Larsen, whose observing shift followed McMillan's. With their 12 observations spanning three days, The International Astronomical Union's Minor Planet Center at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts determined a preliminary orbit by assuming the orbit is circular.