Asteroids
The asteroids are not of great interest in small telescopes, appearing only as dim points of light. If you want to pursue them, then Starry Night is a must !
Pallas through a small telescope on 7 January 2000.
Ceres through a large telescope:
Vesta (HST):
This is a NASA Hubble Space Telescope animation composed of a series of 24 images showing the full 5.34-hour rotation of the 525-kilometer (326-mile) diameter asteroid Vesta. Hubble resolved features as small as 56 kilometers (35 miles) across, allowing astronomers to map Vesta's geologically diverse terrain. This sequence was taken with Hubble's Wide Field Planetary Camera 2 between November 28 and December 1, 1994, when Vesta was at a distance of 251 million kilometers (156 million miles) from Earth.
Castalia (HST):
Gaspra
Click on the image for a full screen view
This picture of asteroid 951 Gaspra is a mosaic of two images taken by the Galileo spacecraft from a range of 5,300 kilometers (3,300 miles), some 10 minutes before closest approach on October 29, 1991. The Sun is shining from the right; phase angle is 50 degrees. Gaspra's very irregular shape suggests that the asteroid was derived from a larger body by nearly catastrophic collisions. Consistent with such a history is the prominence of groove-like linear features, believed to be related to fractures. These linear depressions, 100-300 meters wide and tens of meters deep, are in two crossing groups with slightly different morphology, one group wider and more pitted than the other. Grooves had previously been seen only on Mars's moon Phobos, but were predicted for asteroids as well. Gaspra also shows a variety of enigmatic curved depressions and ridges in the terminator region at left. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory.
Ida and (its "moon") Dactyl
This color picture is made from images taken by the imaging system on the Galileo spacecraft about 14 minutes before its closest approach to asteroid 243 Ida on August 28, 1993. The range from the spacecraft was about 10,500 kilometers (6,500 miles). The images used are from the sequence in which Ida's moon was originally discovered; the moon is visible to the right of the asteroid. This picture is made from images through the 4100-angstrom (violet), 7560 A (infrared) and 9680 A (infrared) filters. The color is 'enhanced' in the sense that the CCD camera is sensitive to near infrared wavelengths of light beyond human vision; a 'natural' color picture of this asteroid would appear mostly gray. Shadings in the image indicate changes in illumination angle on the many steep slopes of this irregular body as well as subtle color variations due to differences in the physical state and composition of the soil (regolith). There are brighter areas, appearing bluish in the picture, around craters on the upper left end of Ida, around the small bright crater near the center of the asteroid, and near the upper right- hand edge (the limb). This is a combination of more reflected blue light and greater absorption of near infrared light, suggesting a difference in the abundance or composition of iron- bearing minerals in these areas. Ida's moon also has a deeper near-infrared absorption and a different color in the violet than any area on this side of Ida. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science by the Jet Propulsion Laboratory.
This animation shows the shape and surface of Ida. North is located at the top and the camera view is situated at the equatorial plane of Ida. The animation starts at -90 degrees longitude. This animation is Copyrighted © 1997 by A. Tayfun Oner. Permission is granted to use this image at home for personal enjoyment. Educators may use this image in their class rooms. Any commercial/for-profit use of this image needs to be addressed to Calvin J. Hamilton.
Photos and video: NEAR Rendevous with asteroid Eros: 12 February 2001
Space.com's asteroid image gallery -- click
here, and then on asteroids.
Written by Stephen R. Kessell
Updated 14 February, 2001
