Page 80 - Handbook of Gold Exploration and Evaluation

Nature and history of gold 61

completed by the year 2002. Each time a scientific instrument is replaced the
Hubble scientific power is increased by at least 10%. Hubble achieves 3 to 5
gigabytes of data daily, and delivers between 10 and 15 gigabytes to
astronomers worldwide. As of March 2000, Hubble has:
· taken more than 330,000 separate observations
· observed more than 25,000 astronomical targets
· created a data archive of over 7.3 terabytes
· provided more than 2,663 scientific papers
· travelled about 1.489 billion miles in circling around the Earth about every 97
minutes
· received more than 93 hours of on-orbit improvements in three successful
servicing missions.

The beginning of a new era of planetary science has since been marked by
NASA's `Spitzer Space Telescope', which can directly measure and compare
`extrasolar' planets. It was previously thought that the universe was a reasonably
uncomplicated place containing relatively small star-forming galaxies. But
researchers now think that this is far from true, even the early universe was
extremely complex. A wide variety of galaxies are being found with properties
that were not foreseen. The telescope's infra-red spectrograph captured the
observation of nearby spiral galaxy M83 on February 16th 2005. Using the
Infra-red Array Camera (IRAC) aboard the Spitzer Space Telescope, very
distant old red galaxies post 2.5 billion years `Big Bang' in the Hubble Deep
Field South have also been found. The IRAC images have also displayed about a
dozen very red galaxies at distances of 10±12 billion light years. These galaxies
existed when the universe was only about one-fifth of its present age of 14
billion years. A feature of these images is that the young galaxies exhibit clouds
of dust that are absent from the old galaxies. Some of the old galaxies had
stopped forming new stars, raising the question of why they had died so soon,
i.e., were red and dead.