On December 3, 1995, astronomers using the Hubble Space Telescope identified a black hole in the galaxy .
            
NGC 4621, located 100 million light-years from Earth in the direction of the constellation Virgo. .
            
This is the second super-massive black hole that astronomers using the Hubble Space Telescope .
            
have found. Astronomers believe that the mass of this black hole is about 1.2 billion times the mass of our .
            
sun, but it is concentrated in a space that is not any bigger than our solar system .
            
There are two puzzling questions that astronomers are trying to answer. The black hole is fueled by the .
            
galaxy and its 800 light-year-wide spiral disk of dust. Before the discovery of this black hole, astronomers .
            
did not think that there was any dust in elliptical galaxies like NGC 4261. Currently they believe that the .
            
disk of dust is the remnant of a smaller galaxy that fell into the core of NGC 4261. The black hole will .
            
swallow up the gas from the smaller galaxy over the next 100 million years. Researchers believe that while .
            
the gas is being swallowed by the black hole, the process will produce some amazing fireworks. .
            
The second puzzling question that astronomers are trying to answer is why isn't the black hole at the center .
            
of the galaxy? According to images from the Hubble Space Telescope, the black hole is 20 light-years .
            
from the center of the galaxy, but since the black hole is so massive it is hard to explain how it could have .
            
been moved. One idea is that the black hole is moving itself. Some astronomers think that the disk of dust .
            
serves as a "fuel tank." The black hole sucks in the material which is absorbed by gravity, compressed, and .
            
heated to tens of millions of degrees. This theory would explain why radio telescopes have observed radio .
            
jets, or hot gas exhausts from the black hole's area. The exhaust may be pushing the black hole across .
            
space, as a jet engine gives thrust to a plane. .
            
According to Ted Bunn, an astronomer at Berkley University, "A black hole is a region of space that has so .