The Hubble Telescope Essay, Research Paper
The Hubble Space Telescope was named after Edwin Hubble, the leading American astronomer of the 20th century. It was built under the supervision of NASA after the U.S. Congress had authorized its construction in 1977. It is capable of performing observations in the visible, near-ultraviolet, and near-infrared. Power to the two on-board computers is generated by two 2.4 by 12.1 meter solar panels. The Hubble s current science instruments include three cameras (Wide-Field Planetary Camera 2, Near Infrared, and Faint Object), two spectrographs (High Resolution and Multi-Object), a high-speed photometer, and three fine guidance sensors. The crew of the Discovery space shuttle placed it about 370 miles above the Earth on April 25, 1990. The telescope is a cooperative program of the European Space Agency and NASA to operate a long-lived space-based observatory. The observatory was first dreamt of in the 40 s, designed and constructed in the 70 s and 80 s, and operational in the 90 s. From the beginning, HST was designed to be a long-term space-based observatory.
Astronomer Mario Livio of the telescope institute says, The thing that is so amazing is that, literally every place HST has looked, it has found something fantastic. The Hubble Telescope has found some amazing things. During the week of October 26th, Francois Schweizer and colleague Brad Whitmore announced that Hubble spied more than 1,000 brilliant clusters of stars exploding into existence. With those images, the telescope showed that galaxies are not the isolated structures they were once thought to be. Instead, they collide and merge, cannibalize each other, fade, flare, and change shape like Flubber. Astrophysicist Alan Dressler, of the Carnegie Observatories in Pasadena California says, We all believed the galaxies looked the same for all time. But they don t. HST, by telling us about how galaxies formed and evolved, is telling us something about we got here. It s really amazing that humans could learn that.
The Hubble Telescope has shown us some spectacular displays–like Comet Shoemaker-Levy hitting Jupiter in 1994, the black hole at the center of galaxy M87, exploding stars, supernovas, and pillars of creation trillions of miles high where stars are being born. It has also answered some of the more perplexing questions in astronomy.
Looking at young stars in the Orion constellation, the telescope has spotted platters of swirling dust called protoplanetary discs. Astronomers believe these disks will eventually break into distinct clumps of matter orbiting the star. They call these clumps of matter planets. That means that our sun is probably not alone in having what scientists call a retinue . The Hubble suggests that it s a rare star that doesn t have planets. That makes the odds that we are alone in the universe even shorter.
The space telescope has shown that galaxies do not evolve in splendid isolation as astronomers believed. Instead, they shape each other. Edwin Hubble discovered in the 1920 s that the universe is expanding. The idea that is believed to be common sense that the universe is expanding into empty space is wrong. By definition, if there were extra space, it would be part of the universe. But the universe is all there is; there is no empty space beyond it to expand into. Out of nothing, the universe expands by actually creating new space between groups of galaxies. Therefore, the universe is getting bigger and the galaxies are growing farther apart. Sometimes, when galaxies get close enough together to feel each other s gravity, they collide. The Milky Way is now swallowing a dwarf galaxy called Sagittarius. This galaxy probably started with an almost spherical shape, says astrophysicist David Weinberg of Ohio State University. But now that the Milky Way is stretching it out, it is five times longer than it is wide. Astronomers say that in another 200 million years, the Milky Way will have captured Sagittarius.
Astrophysicist John Bahcall of the Institute for the Advanced Study in Princeton, New Jersey, says Of all the secrets that the Hubble has unlocked, its images of galaxies that formed when the universe was in its infancy would be at the top of my list of its achievements. HST speaks eloquently to how galaxies got started and got together, something we argue about endlessly. The Hubble Deep Field is an image taken over the course of 10 days in December 1995. It shows how the Hubble Space Telescope is also the Hubble Time Machine . Light falling on the space telescope today left its source at some time in the past because images form when light hits a telescope and light travels at 186,000 miles per second. Light from the sun takes 8.3 minutes to reach the earth, so when we look at the sun, we are seeing it as it was 8.3 minutes ago. Because light from an object billions of miles away began its journey years ago, astronomical distances can be measured in light-years , which is the distance light travels in a year. So the image we see is the object as it appeared in the past. The images in the Hubble Deep Field appear as they were roughly 11.7 billion to 10.4 billion years ago. Only an astronomer living 10 billion years in the future will know what these objects look like today. If the big bang theory is right, then the data from the HST can be used to calculate the age of the universe.
The space telescope s nominal mission , as NASA calls it, runs until 2005. In 2002, space walkers will install a new spectrograph. Astronomers hope that the Hubble can operate until the year 2010. As Robert Williams, director of the Space Telescope Science Institute, paraphrases, The HST has shown us not only that the universe is stranger than we supposed, but that it is stranger than we can suppose.