James Webb Telescope Can Do 'Time Travel' Back 13.5 Billion Years

NASA’s James Webb Space Telescope Has Been Assembled for the First Time
March 31, 2020 Topic: Science Blog Brand: The Buzz Tags: NASAScienceSpaceJames Webb Telescope

James Webb Telescope Can Do 'Time Travel' Back 13.5 Billion Years

In less than a year, the James Webb Space Telescope (Webb for short) will be launched into space in an effort to give humankind the best understanding of the Universe yet.

In less than a year, the James Webb Space Telescope (Webb for short) will be launched into space in an effort to give humankind the best understanding of the Universe yet.

The $10 billion space telescope, a joint venture between NASA, the European Space Agency, the Canadian Space Agency and Space Telescope Science Institute, is the much-vaunted successor to the highly successful Hubble Space Telescope, which was launched in 1990. Webb was first conceived in the 1990s and was expected to launch in 2007, but it has been beset by dozens of delays.

Being 30 years younger than Hubble, the massive telescope is indeed equipped with much more advanced tools and sensors, such as a near-infrared camera and spectrograph, that will enable it to glean more comprehensive data regarding our own solar system, exoplanets, galaxies and the origins of the Universe.

The keen ability to detect infrared light is incredibly important for Webb in order to look further back in time than any other telescope so far. According to NASA, Hubble can see the equivalent of “toddler galaxies,” while Webb will be able to peer into “baby galaxies.” With this much light-gathering ability, Webb will eventually be able to share with the world the first stars that popped into existence in the Universe.

The Webb is likely to see 13.5 billion years into the past, and considering that the Universe is about 13.7 billion years old, humans will finally get a glimpse at what our Universe looked like only 200 million years after the Big Bang.

How can this be? Light doesn’t reach our eyes instantaneously, but rather it is bound by a cosmic speed limit if you will, which was first put forth by Albert Einstein’s theory of special relativity. Even at the mind-bending speed of 186,000 miles per second, if the source is far enough away, it will take time for that light to reach our eyes.

For instance, the sun is far enough away that it takes about 8 minutes for the sun’s emitted light to reach our eyes. With the Webb telescope, we will finally achieve visuals of stars and galaxies that are billions of years old, because the light from those sources hasn’t reached us yet.

How does Webb have this much power? For one, the 11-ton Hubble has a primary mirror with a diameter of 8 feet, but the 6-ton Webb comes with a primary mirror with a diameter of 21 feet (more space to gather light). Moreover, it is made up of 18 gold-plated beryllium hexagonal mirror segments, which will immensely improve infrared resolution and sensitivity compared to Hubble.

Aside from the obvious upgrades in equipment, the Webb will get a new vantage point by observing the Universe from the second Lagrange point that is positioned1.5 million kilometers from Earth (Hubble orbits 550 kilometers away).

This effectively means that Webb will be orbiting the sun, and not Earth. Because Webb will view the Universe entirely in infrared light, the chance of detecting distant, dim objects in space will be boosted if it is placed in the coldest temperatures possible, not to mention that it will enjoy an open, unimpeded view of the Universe.

Ethen Kim Lieser is a Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek and Arirang TV.