James Web - Space Telescope

 James Web - Space Telescope 

The James Webb Space Telescope, also called Webb or JWST, is a large, space-based observatory, optimized for infrared wavelengths, which complements and extends the discoveries of the Hubble Space Telescope. It has longer wavelength coverage and greatly improved sensitivity. The longer wavelengths enable Webb to look further back in time to find the first galaxies that formed in the early Universe, and to peer inside dust clouds where stars and planetary systems are forming today.

When was Webb launched?

Webb was launched on December 25th, 2021 at 7:20 AM (12:20 UTC).

Who was James E. Webb?

This space-based observatory is named after James E. Webb (1906- 1992), NASA's second administrator. Webb is best known for leading Apollo, a series of lunar exploration programs that landed the first humans on the Moon. However, he also initiated a vigorous space science program that was responsible for more than 75 launches during his tenure, including America's first interplanetary explorers. 

How will Webb be better than the Hubble Space Telescope?

Webb is designed to look deeper into space, In order to do this, Webb has a much larger primary mirror than Hubble (2.7 times larger in diameter, or about 6 times larger in area), giving it more light-gathering power. It also has infrared instruments with longer wavelength coverage and greatly improved sensitivity than Hubble.

 Finally, Webb operates much farther from Earth, maintaining its extremely cold operating temperature, stable pointing and higher observing efficiency than with the Earth-orbiting Hubble. 

Why do we have to go to space at all? 

The Earth's atmosphere is nearly opaque and glows brightly at most of the infrared wavelengths that Webb observes, so a cold telescope in space is required. For those wavelengths that are transmitted to the ground, the Earth's atmosphere blurs the images and causes stars to twinkle. 

How long will the Webb mission last?

Webb was designed for a mission of at least five years, with a goal of 10 years. However, after a successful launch and the completion of telescope commissioning, the Webb team determined the observatory should have enough propellant to allow support of science operations in orbit for more than a 20-year science lifetime. 

Why is Webb not serviceable like Hubble?

Hubble is in low-Earth orbit, located approximately 375 miles (600 km) away from the Earth, and is therefore readily accessible for servicing. Webb operates at the second Sun-Earth Lagrange point, located approximately 1 million miles (1.5 million km) away from the Earth, and will therefore be beyond the reach of any crewed vehicle currently being planned for the next decade. 

How big is Webb?

The most important size of a telescope is the diameter of the primary mirror, which is approximately 6.5 meter (21.3 ft) for Webb. This is about 2.75 times larger in diameter than Hubble, or about 6 times larger in area. The Webb has a mass of approximately 6,500 kg, with a weight of 14,300 lbs on Earth (in orbit, everything is weightless), a little more than half the mass of Hubble.

How does Webb communicate with scientists at Earth?

Webb sends science and engineering data to Earth using a high frequency radio transmitter. Large radio antennas that are part of the NASA Deep Space Network receive the signals and forward them to the Webb Science and Operation Center at the Space Telescope Science Institute in Baltimore, Maryland, USA.

Compiled by

Ms Naresh kuwar 

Source Link https://science.nasa.gov/mission/webb/faqs-full/