Hubble’s Space Telescope is one of the largest and most resourceful telescopes in the field of astronomy, astrophysics and research. Hubble was first deployed on 25th April 1990 and entered into service on 20th May 1990, into the low Earth orbit and remains in operation to date. This spectacular space telescope was named after United States astronomer Edwin Powell Hubble who discovered that the universe is constantly expanding, by finding a constant relationship between galaxies redshift and their distance. Even after thirty years of service Hubble is one of NASA’s Great Observatory along with Chandra X-ray Observatory, Compton Gamma Ray Observatory and the Spitzer Space Telescope.
Hubble is as long as a school bus and weighs around that of two adult elephants. It travels around Earth about five miles per second, which is as fast as driving a car from the East Coast of the United States to the West Coast in about ten minutes. It was built by the United States space agency, NASA, along with contributions from the European Space Agency. While the Space Telescope Science Institute (STScI) selects Hubble’s targets and processes the resulting data, the Goddard Space Flight Center controls the Spacecraft.
Previously, it was estimated by scientists that the age of the Universe was ranging between ten billion to twenty billion years. Among its primary mission targets, one of them was to measure distances to estimate the rate at which the universe is expanding to understand its age. Previously, before the launch of this telescope, estimates of the Hubble constant typically had errors up to fifty percent, but Hubble Telescope measurements of variables in the Virgo Cluster and other distant galaxy cluster provided a measured value with an accuracy of +/- 10%. Consequently, as Hubble’s Telescope had helped researchers to estimate the age of the universe, it has also raised questions about theories of its future. Researchers and Astronomers from the High-z Supernova Search Team and the Supernova Cosmology Project used ground-based telescopes and Hubble’s Telescope to observe distant supernovae and uncovered evidence that, far from decelerating under the influence of gravity, the expansion of the universe may in fact be accelerating. Three members of these two groups have subsequently been awarded Nobel Prizes for their discovery as well. Though the cause of this acceleration remains poorly understood, the most common cause attributed is dark energy. Dark energy is a form of energy postulated to act in opposition to gravity, occupying the entire universe accounting for most of the energy in it and causing its expansion to speed up.
In the 1960’s there was an interesting hypothesis amongst the scientific communities that every galaxy probably had a Black Hole at the center and in the 1980’s astronomers had confirmed a fair number of Black Holes at the center of various galaxies. The high-resolution spectra and images provided by Hubbles have been especially well-suited in establishing the prevalence of black holes in the center of nearby galaxies. There were further studies conducted and concluded that the mass of nuclear black holes and properties of the galaxies are closely related to each other. Hence, Hubble has an immense contribution in demonstrating a deep correlation between galaxies and their central black holes.
Another unique window on the Universe enabled by Hubble are the Hubble Deep Field, Hubble Ultra-Deep Field, and Hubble Extreme Deep Field images, which used Hubble’s unparalleled sensitivity at visible wavelengths to create images of small patches of sky that are the deepest ever obtained at optical wavelengths. These images obtained have revealed galaxies billions of light-years away, and have generated a wealth of scientific papers, providing a new perspective on the early Universe. On 3rd March 2016, researchers using Hubbles data announced the discovery of the farthest known galaxy to date GN-z11. The GN-z11 is a galaxy found in the constellation Ursa Major, which is currently the oldest and most distant known galaxy in the observable universe.
Hubble’s Telescope has also been used to study objects in the outer reaches of the Solar System, including the dwarf planets such as Pluto and Eris. In 1994, the collision of Comet Shoemaker-Levy 9 with Jupiter was perfectly timed for astronomers, coming just a few months after Servicing Mission 1 had restored Hubble’s optical performance. Hubble images of the planet were sharper than any taken since the passage of Voyager 2 in 1979, and were vital in studying the dynamics of the collision of a comet with Jupiter, an event which is believed to occur once every few centuries. In 2012, the United States astronomers using Hubble discovered Styx, which is the fifth moon orbiting Pluto.
Hubble’s had a quite a few accomplishments of late. In March 2015, researchers announced the presence of a subsurface ocean around Ganymede, one of Jupiter’s moons. Using Hubble to study the motion of its aurorae, the scientists determined that a large saltwater ocean was helping to suppress the interaction between Jupiter’s magnetic field and that of Ganymede. This ocean is estimated to be 100 km (60 mi) deep, trapped beneath a 150 km (90 mi) ice crust. Furthermore, on its 20th anniversary in space, NASA, ESA and STScI released a captivating image of a pillar of gas and dust in the Carina Nebula. In addition, to commemorate Hubble’s 25th anniversary in space, STScI released images of the Westerlund 2 cluster which is located about 20,000 light-years away.
For the past thirty years, Hubble’s had helped scientists and researchers learn and understand not only our solar system but also other galaxies. In the year 2009 astronauts flew to Hubble’s on the space shuttle to fix it for the fifth time and also put new parts and cameras in the telescope. NASA is currently focusing on building another space telescope called James Webb Space Telescope, which is supposed to be bigger and better than Hubble’s. Unlike Hubble’s, Webb Telescope won’t orbit around the Earth, but would orbit around the Sun in a spot on the other side of the moon. The Webb Telescope is designed to see a different kind of light than the light Hubble’s observes. Though many space telescopes may come and go, Hubble’s mighty contribution to the world of astrophysics has left a huge irreplaceable mark in the history of cosmic studies.
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