Happy Birthday to an Earth’s eye - The Hubble Space Telescope that gave us shining images of galaxies
Source :News Bharati English   Date :24-Apr-2017

The Hubble Space Telescope turned 27 on Thursday, marking another milestone for earth’s eye on space that has brought immense amounts of new knowledge down to the home planet during its lifetime. It’s the great silverback of astronomy, grizzled from wear and tear and yet still powerful and utterly dominant in its field.Astronomers use the legendary Hubble telescope to take a portrait of a stunning pair of spiral galaxies. This starry pair offers a glimpse of what our Milky Way galaxy would look like to an outside observer.

European Space Agency ESA and NASA celebrate Hubble's birthday each year with a spectacular image. This year's anniversary image features a pair of spiral galaxies known as NGC 4302 seen edge-on and NGC 4298, both located 55 million light-years away in the northern constellation of Coma Berenices (Berenice's Hair). These galaxies look quite different because we see them angled at different positions on the sky. They are actually very similar in terms of their structure and contents.

Both were discovered in 1784 by astronomer William Herschel. Such objects were first simply called "spiral nebulas," because it wasn't known how far away they were. In the early 20th century, Edwin Hubble discovered that galaxies are other island cities of stars far outside our Milky Way. The Hubble Space Telescope was launched aboard the Space Shuttle Discovery on April 24, 1990, and deployed into low-Earth orbit the next day. From its perch high above the distorting effects of Earth's atmosphere, Hubble observes the universe in near-ultraviolet, visible, and near-infrared light. Over the past 27 years, the space telescope's breakthrough discoveries have revolutionized the fields of astronomy and astrophysics.

The Hubble changed our understanding of the age of the universe, the evolution of galaxies and the expansion of space itself. Five times, astronauts on the space shuttle paid a visit to swap out old batteries and install new instruments, including, in 2009, the best camera the telescope has ever had.

“It’s fantastic. It’s better than ever. That’s not just hype, it’s the truth,” said Jennifer Wiseman, the senior project scientist for the Hubble at NASA’s Goddard Space Flight Center.“This is 1970s technology, and it is still, after 25 years, the most powerful scientific instrument in the world,” said astrophysicist Patrick McCarthy of the Giant Magellan Telescope under construction in Chile. Hubble’s fate, however, is cloudy. The great telescope is essentially stranded in space.

The Hubble also helped nail down the age of the universe. Before the Hubble, astronomers said the universe was 10 billion to 20 billion years old. Now they say its 13.8 billion years old. The deep gaze of the Hubble offers a view into the remote past; all telescopes are time machines of sorts, gathering light emitted long ago. The Hubble, thanks to new instruments, can see deeper into space than anyone had anticipated when the telescope was first designed, said astronomer John Grunsfeld, NASA’s top official for science, who as an astronaut visited and repaired the Hubble three times. “Before Hubble, we didn’t know how many galaxies there are in the universe,” Grunsfeld said.

Following are some of the interesting images captured by Hubble Telescope: