Hubble Images Capture Universe's Beauty, AweBy Betsy Mason
Entering its 20th year of service, the Hubble Space Telescope has made more than 880,000 observations, taken 570,000 images of 29,000 different celestial objects, and piled up a load of impressive scientific accomplishments.
After a rocky start that included a delay due to the Challenger shuttle disaster and a flaw in the optical mirror that prevented the fine focus the telescope was designed to achieve, Hubble has had a glorious career. The scope helped determine the age of the universe and the rate at which it is expanding, as well as the prevalence of black holes in the universe and the existence of dark matter.
The telescope was designed to allow servicing using the space shuttle, which has visited it four times. The final shuttle service mission is scheduled for May and will involve five spacewalks to refurbish and upgrade the telescope and replace parts that have stopped working. Hubble, with any luck, will have several more years of life after that.
Left: The Antennae Galaxies/NGC 4038-4039
These two spiral galaxies began to collide about 300 million years ago. They are some of the youngest and nearest colliding galaxies, giving astronomers one of their best opportunities to study the phenomenon. It may be a preview of what will happen when our galaxy runs into the Andromeda galaxy in a few billion years.
Billions of stars will form during the course of the collision. The blue regions are where stars are forming, the pink light is hydrogen gas, and the two orange blobs are the galaxy cores. The galaxies were named for the antenna-like arms that grew from the cores when the collision began.