The dark, dusty disk represents a cold outer region, which moves inward to within a few hundred million miles of the suspected black hole. This disk feeds matter into the black hole, where gravity compresses and heats the material.
Some hot gas squirts out from the black hole's near-vicinity to create the radio jets.
The jets are aligned perpendicular to the disk, like an axle through a wheel. No research mission in NASA history has generated higher scientific expectations than HST, designed to be the most powerful astronomical telescope ever built and far surpassing the capabilities of ground-based optical telescopes for many kinds of research. The key to HST success is its operation in space - above the blurring, obscuring and absorbing effects of the Earth's atmosphere. Actions have been taken to alleviate that flaw and, as a result, scientists have made a number of significant discoveries with the observatory. Designed to be serviced in space and to remain in operation for 15 years, HST is scheduled to undergo its first maintenance in late 1993 or early 1994.