NASA to launch James Webb Space Telescope in 2018 with the help of 17 countries
Prof. Dr.M Hafiz Rafique
We cannot see far-off places and objects with our unaided eye because of its less angular resolution. This resolution can be increased by using an optical instrument. To see distant objects, we can use instruments such as a telescope. The exact name of the inventor of the telescope is unknown. Anyhow, it is believed that the first telescope was invented by a Dutch eyeglass maker named Hans Lippershey in 1608. It is also reported somewhere that
Galileo Galilei was the first man who invented telescope. This telescope is based on glass lenses and is called an optical telescope. The optical telescope was initially used in astronomical and terrestrial applications. We usually use a ground-based optical telescope to sight a new phase of the moon.
Nowadays, the word telescope covers a wide range of instruments that are used to see and capture various objects in the upper atmosphere and remote heavenly bodies such as stars, black holes, galaxies: their formation and evolution. Their structure and working principle are different from the optical telescope. Moreover, an optical telescope has limited angular resolution and cannot see very distant objects. So telescopes with much higher angular resolution are need to study faraway objects.
The Hubble Space Telescope (HST) is one of the biggest electronics-based space telescopes that was launched in space on April 24, 1990 with Space Shuttle Discovery. The very next day, it was deployed into a low earth orbit and it started functioning of taking extremely high-resolution images of the nearby and distant celestial bodies. Hubble Telescope revolves around the Earth at about 17,000 mph and does not travel to planets, stars and galaxies but only takes their pictures. The HST was named after NASA’s one of the great astronomers Edwin Hubble. It takes images and sends to the ground station where different scientists process these images to infer information about the celestial objects, going-on processes and various entities of space.
Until now, the HST’s main achievements include:
1) The comet Shoemaker–Levy 9 as it collides with the planet Jupiter, 2) Conclusive evidence for the existence of Supermassive Black Holes in the centres of galaxies, 3) Better understanding of galaxies in the early Universe, 4) Measurement of the elements on the atmosphere, 5) Discovery of previously unknown moons orbiting Pluto, 6) Confirmation of the fact that planet Eris is bigger than Pluto 7) Evidence of the distribution of dark matter in the Universe, 8) Identification of primitive galaxies formed more than 13 billion years ago, 9) Exploration of water vapours floating off the surface of Jupiter’s moon Europa, 10) Observing the disintegration of an asteroid
Last but not least, the Hubble is one of the excellent and the most productive devices ever made to uncover many mysteries of the universe. Scientists have published more than 12,800 scientific research papers so far using the Hubble data.
The life of the HST is going to expire after some years but the launch of its scientific successor, the James Webb Space Telescope (JWST), is planned in 2018 by NASA with the international collaboration of about 17 countries.
The JWST is an improved scientific version of the Hubble telescope and it takes its name from NASA’s second administrator James E. Webb (1906-1992), who played a vital role in the Apollo mission. The aims of this scientific mission are: to investigate the emission of light from the first star formed after the Big Bang occurred, to study the formation and evolution of stars and galaxies, to comprehend planetary systems and study the origins of life.
Apart from the above mentioned objectives, it is hoped that this space telescope will unveil lots of other mysteries of the universe.
(The writer is Punjab University Physics Department Chairman and Member Syndicate on Associate Professor’s seat. He can be reached at: email@example.com)