GS Paper 3
Syllabus: Awareness in space.
Source: The Hindu
The first image from NASA’s new space telescope offers the deepest look of the cosmos ever captured.
About James Webb:
- Infrared observatory that will be much more powerful than the presently deployed Hubble space telescope.
- JSWT will observe in near-infrared light rather than light in the visible part of the spectrum (unlike Hubble) and thus it will have a much greater capacity to see obscure stars and galaxies
- Collaboration: It is a joint venture of NASA (US), ESA (Europe), and CSA (Canada)
- Webb was formerly known as the “Next Generation Space Telescope” (NGST) and it was renamed in 2002 after a former NASA administrator, James Webb.
Significance of new Astronomical discoveries:
- Provides a look into the past: Part of the image is light from not too long after the Big Bang, which was 13.8 billion years ago.
- James Webb can see backwards in time to just after the Big Bang by looking for galaxies that are so far away that the light has taken many billions of years to get from those galaxies to our telescopes
- JSWT has the largest mirror in space and it will look deeper into the universe – and thus further back in time – than is possible with a presently deployed telescope such as Hubble
- Decipher mysteries of the Universe: Mysteries such as what made the universe expand so quickly less than a nanosecond after the Big Bang
- Explore the Dark Age of the Universe: The Dark Ages is the period before gravity formed the first stars and galaxies that eventually began to emit the first light.
- Understand the formation of the planetary system and look for signs of life on exoplanets: JSWT can achieve it with much greater accuracy owing to its large mirror and superior Infrared Spectrograph instrument
Difference between JWST and Hubble Telescope
|Orbit||It will not orbit the earth but will sit at Lagrange Point 2 (over millions of KMs away):
· This will allow it to shield from the light of the Sun, Moon, and Earth and thus avoid light interference
|Orbits Low Earth Orbit (597Km)|
|Light Mirror||Much bigger at 6.5m diameter: This allows it to capture light 6 times greater than Hubble can.
· It will be able to study Old and distant galaxies, which is not currently possible with Hubble
|At 2.4m diameter|
|Strength||It is 100 times more powerful than Hubble is.
· It will show images from 250 million years after Big Bang- taking us closer to the starting point of the Universe
|Shows images formed 400 million years after the Big Bang|
|Spectrum||Infrared- It will reveal clearer details about objects in distant places
· Analogically, Hubble can see the equivalent of “toddler galaxies” and the James Webb Telescope will be able to see “baby galaxies”.
|Mostly ultraviolet (visible) light|
Other missions to explore the universe:
- Hubble Space Telescope (1990): Observation in Visible and Ultra-violet
- Compton Gamma-Ray Observatory (CGRO): Observation in Gamma Ray
- Chandra X-Ray Observatory (CXO)
- SPHEREx’s (to be launched in 2023): It aims to search for the fundamentals of life — such as water and organic matterwithin the Milky Way
- Wide-Field Infrared Survey Telescope (WFIRST, to be launched in 2027): It aims to study dark energy, explore exoplanets, and perform galactic and extragalactic surveys
Q. The James Webb telescope is an exemplar of collaborative science and human ingenuity. Discuss its significance to the scientific community. (10M)
Q. Consider the following statements: (UPSC 2018)
- Light is affected by gravity.
- The Universe is constantly expanding.
- Matter warps its surrounding space-time.
Which of the above is/are the prediction/predictions of Albert Einstein’s General Theory of Relativity, often discussed in media?
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Albert Einstein proposed three tests of general relativity, subsequently called the “classical tests” of general relativity, in 1916: the perihelion precession of Mercury’s orbit. the deflection of light by the Sun. the gravitational redshift of light (universe expansion)
According to Einstein’s General Theory of Relativity, matter bends the fabric of space and time. The distortion of the space-time continuum even affects the behaviour of light. General relativity predicts that the path of light will follow the curvature of spacetime as it passes near a star. So, the light will be affected by gravity.
Which of the following is/are cited by the scientists as evidence/evidences for the continued expansion of the universe? (UPSC 2012)
- Detection of microwaves in space
- Observation of redshift phenomenon in space
- Movement of asteroids in space
- Occurrence of supernova explosions in space
(a) 1 and 2 only
(b) 2 only
(c) 1, 3 and 4
(d) None of the above
Evidence for the continued expansion of the universe:
- Cosmic microwave background(CMB): It is radiation left over from the early stages of the formation of the universe. As the universe is expanding the light has changed its wavelength and currently, it can be detected in the microwave region of the radio spectrum.
- Redshift and blueshift describe the change in the frequency of a light wave depending on whether an object is moving towards or away from us. When an object is moving away from us, the light from the object is known as redshift, and when an object is moving towards us, the light from the object is known as blueshift.