In April of 1990, the Hubble Space Telescope (HST) was carried into orbit aboard the Space Shuttle Discovery. A fitting destination for a telescope named after one of the most revered astronomers of our time, Edwin Hubble. Created through international cooperation, the Hubble telescope remains one of the most advanced telescopes of modern times. And, it was destined to give scientists a new eye in space.
In nearly twenty years of observations, the Hubble telescope had provided scientists with numerous incredible pictures of space and offered a wealth of new information about the universe in which we live. The following are this observer's view of the top ten discoveries made by the Hubble telescope.
1. Dark Matter
Through Hubble, scientists have been able to detect the unseen. While analyzing images of the Bullet Cluster, scientists discovered proof of dark matter, cosmic matter which emits little to no radiation, but has gravitational effects on other matter. The existence of dark matter and its diametrically opposite twin, dark energy, offer insight into galaxy formation and universe expansion.
2. Universe Expansion and Galaxy Formation
Based on Edwin's Hubble's theories of universe expansion, scientists have constantly been seeking evidence about the formation and changes in the universe. The Hubble telescope has helped in this pursuit. The powerful telescope has offered images that support that the universe is expanding and that in the outer reaches that our universe is expanding more rapidly. Also, Hubble has offered visuals of nebulae, which are believed to be the site of new planetary formation. Through Hubble's aid, scientists have been able to study interstellar dust which could represent the early stages of planetary system formation, as well.
3. Age of the Universe
After almost a decade in space, the Hubble telescope was sending images of white drafts back to Earth. Through analysis of these images, scientists estimate that our universe may be between 12 to 14 billion years old..
4. Black Holes
Since the 1960s, scientists have theorized about black holes. With Hubble's help, astronomers were able to locate and photograph the phemonenon. Through their study of Hubble data, scientists also theorize that gamma ray bursts detected in space may be the result of stars going supernova and then collapsing into black holes. This cosmic example may actually explain the creation of our galaxy and provide support for the Big Bang Theory.
A quasar, short for quasi-stellar radio source, is a distant galaxy that has an active nucleus, which emits electromagnetic energy in the form of light waves and radio waves. They appear like point like sources verses expanded images like other galaxies. Based on what scientists know from extra-galactic distance calculations, quasars are very distant. Quasars are thought to have massive black holes at their core. Hubble has offered scientists images and data on this cosmic mysteries.
6. Pluto and the Planet Debate
Is it a planet or an asteroid? Hubble's images of the distance celestial body have created more controversy for scientists. Hubble revealed that the former planet Pluto had moons and that it had larger cosmic neighbors.
7. Cepheid Variable Stars
Another important discovery of the Hubble telescope relates to one of its primary purposes. The giant telescope was designed to evaluate Cepheid variable stars which are pulsating stars, whose accuracy aid scientists determine extra-galactic distance, which was a expertise of the telescope's namesake, astronomer Edwin Hubble. HST has catalogued thousands of these variable stars and helped offer an accurate value for Hubble's constant.
8. Extra-solar Planets
With the help of the HST, scientists now realize that the Earth is not alone. They have been able to locate and photograph images of extra-solar planets (planets beyond our own solar system.) An entire new class or worlds have been discovered that rotate around other stars. Earth like and Jupiter sized worlds have been catalogued.
9. Cosmic Comet Collision
In July 1994, who could forget the buzz that Hubble was giving the world a chance to see a cosmic collision in the Earth's backyard. The telescope provided the world images of P/Shoemaker-Levy 9, a massive comet, as it crashed into Jupiter. Scientist learned more about Jupiter and the need to consider ways to prevent intergalactic collisions with Mother Earth.
10. Elliptical Galaxies
In science class, we learned that galaxies were spiral and disk shaped and moved like spirals (hence the name). However, Edwin Hubble had theorized that there were three categories of galaxies, one being elliptical. Through the Hubble telescope, images of elliptical galaxies revealed and scientist now study these older galaxies.
In the almost two decades that the Hubble Space Telescope has orbited our Earth, scientists have made hundreds of discoveries which now define how we view our world. In years to come, Hubble will continue to help us see our world in a new way.
For more information about the Hubble Telescope, check out the following websites: