James Webb Telescobe

The James Webb Space Telescope is the largest, most powerful space telescope ever built. It will allow scientists to look at what our universe was like about 200 million years after the Big Bang. The telescope will be able to capture images of some of the first galaxies ever formed. It will also be able to observe objects in our solar system outward from Mars, peer into dust clouds to see where new stars and planets are forming, and study the atmospheres of planets orbiting other stars.

-PROPERTIES-

JWST has about half the mass of the Hubble Space Telescope, but is larger than Hubble's, with a primary mirror of 18 beryllium-coated hexagonal mirrors, a diameter of 6.5 meters, and a surface area of 25.4 square meters. It is infrared astronomy. However, depending on the instruments in the device, it can see the mid-infrared region as well as the orange and red visible light. The design focused on the near and mid infrared for three main reasons:

• visible emissions of high-redshifted objects are shifted to infrared

• cold objects such as debris disks and planets emit strong infrared

• this infrared band is difficult to study from the ground or with existing space telescopes such as Hubble.

Earth's atmosphere makes it difficult for ground-based telescopes to study infrared bands. Many of the chemical compounds targeted for observation of objects in space, such as water, carbon dioxide, and methane, are also present in Earth's atmosphere, complicating observation from the ground. Existing space telescopes such as Hubble emit strong infrared light because their mirrors are not cold enough (the Hubble mirror is kept at about 15 °C) and cannot study these bands. The telescope will operate near the Lagrangian point (Earth-Sun L2), about 1,500,000 kilometers from Earth. For comparison, Hubble orbits 550 kilometers above Earth's surface and the Moon is roughly 400,000 kilometers from Earth. This distance makes it almost impossible to repair with existing spaceships in case of a post-launch problem. SpaceX claims that its newly developed Starship launch vehicle is capable of sending satellites and space telescopes even larger than James Webb and is designed to reach Mars orbit. Objects near this Lagrangian point orbit the Sun simultaneously with Earth. This allows the telescope to stay at a roughly fixed distance and use a single sun shield to block out heat and light from the Sun and Earth. This orbit will keep the spacecraft's temperature below the −223.2 °C required for infrared observations.

It's been a busy time for the $10 billion telescope since its launch on Dec. 25, 2021. First, Webb had to rocket to deep space, a process that took almost a month, and then it had a complex, seven-step alignment process to get through. Each milestone has gone pretty much to plan, with only minor tweaks required along the way.alignment process to get through. Each milestone has gone pretty much to plan, with only minor tweaks required along the way.

GÜLENUR SAVAŞ