NASA built a time machine! How the James Webb Telescope will see the origins of the universe

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AUSTIN (KXAN) – We could soon bear witness to the origins of the universe.

After nearly 30 years and $10 billion, the James Webb Space Telescope will take flight. Launching Christmas Day, the telescope is the largest and most powerful space telescope ever built.

The James Webb Space Telescope is 100 times more powerful than the Hubble Space Telescope, which launched into orbit in 1990. Why is Webb so much more powerful than Hubble?

The science behind the James Webb Space Telescope

It is all about light. Light comes in many forms: ultraviolet, X-rays, infrared and visible light. Visible light is what our eyes can see, but it can only travel so far before it fades. While infrared light travels much farther and isn’t as easily blocked by objects in space. Earlier this month, NASA launched a satellite capable of seeing X-rays.

There are several forms of light, but human eyes can only see visible light. The Webb telescope can see infrared

Hubble has been our premiere space telescope for decades, but it primarily sees visible light, while the James Webb Space Telescope sees infrared.

“This means it will allow us to peer through clouds of gas and dust in our own galaxy, where stars are being born today,” said Eric Smith, Program Director and Program Scientist for the James Webb Space Telescope in an interview with the Associate Press.

Because infrared light travels longer distances before fading, Smith said it will allow us to see “farther back in time, to the time where the very first stars and galaxies were being born.”

Telescopes as time machines

How can we see the birth of stars and galaxies that happened billions of years ago.

“A telescope is really a time machine because light travels at a finite speed through the universe,” said Klaus Pontoppidan, an astronomer with the Space Telescope Science Institute in an interview with the Associated Press. “We see the universe as it existed when that light is emitted.”

For instance, it takes eight minutes for light to travel from the sun to the earth. So when you’re looking at the sun, you’re actually looking at the sun eight minutes in the past.

Pontoppidan says that by looking at light through the Webb Space Telescope, we’re looking at light that’s traveled 13-billion years. “We think we’ll see the first galaxies. We will find things that we have no idea exists right now.”

How the James Webb Space Telescope will see infrared

The telescope sees using a 21-foot wide gold mirror made up of several smaller gold panels, each of which can be adjusted to be collect light. To detect infrared light, it will need to be protected from our sun’s light. To do this, Webb uses a giant Mylar (the same stuff used in birthday balloons) sun shield.

The Webb Telescope uses a sun shield to protect itself from the sun’s light.

“There are five distinct layers (to the shield),” said David J. Hedland with Columbia University’s Department of Astronomy. “On the sun-facing side of the bottom layer, the temperature is about 250 degrees Fahrenheit. On the telescope facing side of the top layer, you’ve deflected so much of the light that the temperature is -375 degrees Fahrenheit.”

Getting the Webb telescope into orbit

Getting Webb into space isn’t easy. The telescope is so large it had to be folded up inside of the rocket that is launching it. It will do its work about 1 million miles from Earth at what is known as a Lagrange point.

A Lagrange point is sort of a fixed point in space, where the gravitational force of two celestial bodies keep a third object at roughly the same location while it orbits. Basically, the gravity of the Sun and the Earth will keep Webb at a point where the Earth is always blocking the telescope from the majority of the sun’s light.

Once Webb reaches this point, it will have to unfold itself from the rocket. This process could take months, at which point the telescope will have to align itself. If the something happens during this process, the telescope will be too far from Earth for anyone to be able to fix it.

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