英语听力：自然百科 探索世界奥秘之Supermassive Black Holes(超大质量黑洞) Unit08（在线收听）

探索世界奥秘之Supermassive Black Holes(超大质量黑洞) Unit08

In every galaxy scientists looked at, they found evidence for a supermassive black hole.

NGC 3115

NGC 3377

NGC 3379

In M31 and M32

In total there is probably 20-30 or so black holes that have been found.

Supermassive black holes were supposed to be rare, but Hubble was finding them everywhere, both feeding in active galaxies and lurking quietly in ordinary galaxies.

Pretty soon we got used to the idea that everything we would look at would have a black hole in it. You know, after the first three or four cases, we are beginning to wonder: does every one have a black hole?

One by one we were seeing this picture sort of emerge out of the fog that, that every galaxy, almost every galaxy had a supermassive black hole in it. It was really quite astonishing.

Far from being rare freaks of nature, the Nukers began to suspect that all galaxies could have giant black holes at their hearts. If this was true, it would revolutionize ideas of what a galaxy actually is. More disturbingly, it meant there could be a supermassive black hole lurking at the heart of our very own galaxy, the Milky Way.

Andrea Ghez has been coming to Hawaii for the last five years, trying to find out if there is a supermassive black hole in the middle of the Milky Way.

When I first started thinking about astronomy, it never occurred to me that there might be a supermassive black hole at the center of our galaxy. The idea was that galaxies rotated just around the mass of the center, which was just stars and gas and dust, nothing particularly exotic.

Andrea Ghez has been using a telescope even more powerful than Hubble, the Keck Telescope, perched 14,000 feet up on the sacred mountain of Mauna Kea. The Keck Telescope is the biggest optical telescope in the world. It has a vast mirror, ten meters across, made up of 36 segments of highly polished aluminized glass.

freak: a person, animal, or plant with a physical abnormality

perch: be situated above or on the edge of something