spacetoday.net: space news from around the webin association with SpaceNews


Sunlight affects asteroid spin
Posted: Mon, Mar 12, 2007, 8:25 AM ET (1225 GMT)
Radar image of asteroid 2000 PH5 (Cornell Univ.) Astronomers have found that the weak but constant force of sunlight is causing the spin of a small asteroid to accelerate. In a paper published online by Science last week, a group of astronomers said than the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is causing the spin of asteroid 2000 PH5 to speed up at the rate of about one millisecond per year. The YORP effect is created when an asteroid or other body absorbs sunlight and reradiates it as heat. While normally a feeble force, the YORP effect can cause measurable changes in small, irregularly-shaped bodies like this asteroid. Researchers ruled out all other known potential causes for the change in the asteroid's spin, including tidal forces created when the asteroid passes the vicinity of the Earth. The YORP effect may explain why very small asteroids spin either very quickly or very slowly.
<<previous article   next article>>
news in brief
Shenzhou-20 launches to Tiangong space station
Posted: Sun, Apr 27 10:25 AM ET (1425 GMT)

Falcon 9 launches Starlink satellites
Posted: Sun, Apr 27 10:20 AM ET (1420 GMT)

Northwood Space raises $30 million
Posted: Sun, Apr 27 10:16 AM ET (1416 GMT)

news links
Wednesday, April 30
Lockheed Demo Satellite Lost During Firefly Launch Mishap
Aviation Week — 6:54 am ET (1054 GMT)


about spacetoday.net   ·   info@spacetoday.net   ·   mailing list