Figure 15-27: R I V U X G
Comet Nuclei and Jets When sunlight reaches exposed ice on the surface of the nuclei, evaporation produces jets. (a) This image from the European Space Agency spacecraft Giotto shows the dark, potato-shaped nucleus of Comet Halley in March 1986. Sunlight from the left illuminates half of the nucleus, which is about 15 km long and 8 km wide. Two bright jets of dust extend from the nucleus toward the Sun. (b) Comet Hartley 2 imaged by NASA’s EPOXI spacecraft. This small comet is only about 1.2 miles wide from end to end. A spectrum of the jets indicates that they emit about 200 kg/sec of water, and even more carbon dioxide.
Comet Nuclei and Jets When sunlight reaches exposed ice on the surface of the nuclei, evaporation produces jets. (a) This image from the European Space Agency spacecraft Giotto shows the dark, potato-shaped nucleus of Comet Halley in March 1986. Sunlight from the left illuminates half of the nucleus, which is about 15 km long and 8 km wide. Two bright jets of dust extend from the nucleus toward the Sun. (b) Comet Hartley 2 imaged by NASA’s EPOXI spacecraft. This small comet is only about 1.2 miles wide from end to end. A spectrum of the jets indicates that they emit about 200 kg/sec of water, and even more carbon dioxide.
(a: Max Planck Institute for Solar System Research; b: NASA/JPL-Caltech/UMD)