Universe Amazing Facts
The Large Zenith Telescope (LZT), located near Vancouver, has a mirror made out of mercury. The telescope features 28 litres of mercury in a pan which spins, causing the mercury to assume a parabolic shape. The telescope only cost $500,000, about 1/100th as much as a similarly-sized telescope with a glass mirror would cost. Its main disadvantage is that it can only look straight up - otherwise the poisonous mercury would spill.A massive star has a shorter lifetime than a less massive star. The more massive a star, the more tightly its gravity pulls it together, the hotter it must be to keep it from collapsing, and the more rapidly it uses up its hydrogen fuel. The reason there are so few really massive stars is that they do not live very long, as little as a million years. For comparison, our sun has an expected lifetime of about 11,000 million years.
There are an estimated 50 thousand million galaxies in the universe, with the typical galaxy containing 50 thousand million to 100 thousand million stars. It is estimated that there are 1022 stars in total in the universe.
