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What is the James Webb Space Telescope?
This large infrared space telescope is scheduled for launch in 2013, replacing the Hubble Space Telescope. It will serve as the premier observatory for thousands of astronomers worldwide over the next decade. The Webb Telescope will seek out traces of visible and infrared light from the very first stars, to offer clues to the formation of the Universe.
How is the Webb Telescope different from Hubble?
There are some similarities—both Telescopes are (or will be) in space. They both seek to improve our understanding of processes like star birth and the evolution of galaxies. However, there are many differences.
To start, the Webb Telescope will primarily look at the Universe in the infrared, while the Hubble studies it at optical and ultra-violet wavelengths. The Webb Telescope also has a much bigger mirror than the Hubble. This larger light-collecting area means that it can peer farther back into time than the Hubble is capable of doing. The Hubble is in a very close orbit around the earth, while the Webb Telescope will be one million miles away at the second Lagrange (L2) point.
Specifically, what will the Webb Telescope do?
It has four scientific goals:
The End of the Dark Ages: First Light and Reionization seeks to identify the first bright objects that formed in the early Universe, and follow the ionization history.
The Assembly of Galaxies will determine how galaxies and dark matter, including gas, stars and active nuclei evolved to the present day.
The Birth of Stars and Protoplanetary Systems focuses on the birth and early development of stars and planets.
Planetary Systems and the Origins of Life studies the physical and chemical properties of solar systems (including our own).
Where will it orbit?
The Webb Telescope will be situated at the second Lagrange point (L2) of the Sun-Earth system, about one million miles from the Earth. The combined gravitational forces of the Sun and the Earth can almost hold a spacecraft at this point, and it takes relatively little rocket thrust to keep the spacecraft near L2. The cold and stable temperature of the L2 point will allow it to make the very sensitive infrared observations needed.
How large is it?
The Webb Telescope is about the size of a school bus and has a large mirror, 6.5 meters (21.3 feet) in diameter and a sunshield the size of a tennis court. Both the mirror and sunshade won't fit onto the ship fully so both will fold up and open only once the Telescope is in outer space.
Who is developing the Telescope?
The Webb Telescope is an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). NASA has overall responsibility and its Goddard Space Flight Center is managing the development effort. Over 1,000 people in more than 17 countries are working on the project.
Who is James Webb and why does he have a telescope named for him?
James Webb is a former NASA Administrator who laid the groundwork for the Apollo missions to the moon.
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