James Webb Space Telescope

James Webb is the official successor of Hubble, though it will be a very different telescope. Unlike Hubble, James Webb won't orbit the Earth but instead will orbit the sun. The giant space telescope will park about 1.5 million kilometers (932,000 miles) away from the Earth at the second Lagrange point, or L2, and stay on the dark side of the Earth, orbiting the sun along with our planet.

James Webb will have over five times the collecting area of Hubble with a mirror diameter of 6.5 meters compared to Hubble's 2.4 meters. The massive mirror will be able to detect objects 16 times fainter than Hubble. The telescope is so big, that it will need to be folded for launch, and the process to unfold its 18 massive, gold-plated mirrors will take about five months. Because the telescope will sit at such a great distance from the Earth, astronauts will not be able to reach James Webb for repairs or maintenance—at least not with current spaceflight technology—so it's critical that the unfolding, testing and cooling processes go according to plan.

The major difference between James Webb and Hubble, however, is that James Webb will take observations in mostly infrared light, while Hubble is optimized for visible and ultraviolet light. The longer wavelengths of infrared light pass more readily through debris, so James Webb will be able to peer through the gas and dust of stellar nebulae to see the stars and planets forming within.

The infrared capabilities of James Webb will also allow it to peer deeper into the universe than ever before, seeing the light from objects that formed only 100 million years after the Big Bang. That light is so old and has been traveling for so long that it has stretched deep into the infrared part of the spectrum as the universe expands. What exactly James Webb will see when we focus it on the beginning of time is anyone's guess.