The above figure shows the temporal evolution of Comet Hale-Bopp over the course of about 1 year, as observed by the Hubble Space Telescope. In the far-left frame we caught the comet about 60 hours after a huge outburst of dust, and the image shows an impressive spiral structure reminescent of a water sprinkler observed from above. The middle frame shows the comet during a more quiescent phase in which hardly any structure is seen in the coma without employing a strong intensity contrast in the display. The image at the far-right shows that the comet has now taken on a "porcupine" appearance as at least five jets can be seen sprouting from the nucleus. The nucleus of the comet is located at the center of each frame, but most of the light observed is due to scattered sunlight from fine dust grains that are emitted from the nucleus and which produce the cometary "coma".
Each frame above is 10 arcsec across. For the far-left frame this corresponds to 47,000 km at the comet, for the middle frame this corresponds to 49,000 km at the comet, and for the far-right frame this correponds to 21,000 km at the comet. (The comet was much closer to the Earth during the September 1996 observations.)
Click here to see the postscript version of the new HST Hale-Bopp image. (The GIF version is given above.)
You can send me e-mail at weaver@pha.jhu.edu .