James Webb Space Telescope (JWST)
1. orbits around the Earth like the Hubble Space Telescope.
2. observes lower frequencies, ranging from long-wavelength visible light (red) to mid-infrared.
3. has a mass that is about half of the Hubble Space Telescope.

Which of the statement(s) given above is/are correct?
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Question

James Webb Space Telescope (JWST)
1. orbits around the Earth like the Hubble Space Telescope.
2. observes lower frequencies, ranging from long-wavelength visible light (red) to mid-infrared.
3. has a mass that is about half of the Hubble Space Telescope.

Which of the statement(s) given above is/are correct?
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

ONLiNE UPSC · Accepted Answer

Statement 1 is not correct: The James Webb Space Telescope was launched in 2021, Unlike the Hubble Space Telescope, it does not orbit the Earth; instead, it orbits the Sun, 1.5 million kilometers (1 million miles) away from Earth, at the second Lagrange point (L2).

Statement 2 is correct: Unlike Hubble, which observes in the near ultraviolet and visible (0.1 to 0.8 &mu;m), and near infrared (0.8&ndash;2.5 &mu;m) spectra, Webb observes a lower frequency range, from long-wavelength visible light (red) through mid-infrared (0.6&ndash;28.5 &mu;m).

Statement 3 is correct: The mass of the James Webb Space Telescope (JWST) is about half that of the Hubble Space Telescope. Webb has a 6.5-meter-diameter gold-coated beryllium primary mirror made up of 18 separate hexagonal mirrors. The mirror has a polished area of 26.3 m2, of which 0.9 m2 is obscured by the secondary support struts, giving a total collecting area of 25.4 m2 . This is over six times larger than the collecting area of Hubble's 2.4 m diameter mirror, which has a collecting area of 4.0 m2. The mirror has a gold coating to provide infrared reflectivity and this is covered by a thin layer of glass for durability.

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James Webb Space Telescope (JWST)

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M Question 1	⏱ 0
James Webb Space Telescope (JWST) 1. orbits around the Earth like the Hubble Space Telescope. 2. observes lower frequencies, ranging from long-wavelength visible light (red) to mid-infrared. 3. has a mass that is about half of the Hubble Space Telescope. Which of the statement(s) given above is/are correct? (a) 1 only (b) 2 and 3 only (c) 1 and 3 only (d) 1, 2 and 3