After a long time of planning, engineering, many delays, and a few controversy, it’s lastly occurring: The James Webb Space Telescope is set to launch at 7:20 am Eastern on Saturday, December 25, making it a long-awaited Christmas current for scientists all over the world. (Though additional delays are potential. Earlier this week, NASA was eyeing a Christmas Eve launch however modified plans due to dangerous climate.)
After the telescope launches from French Guiana to a degree practically 1,000,000 miles away from Earth, it is going to develop into the largest telescope in space, able to displaying humanity areas of space (and time) by no means seen earlier than.
NASA, which is launching the telescope in collaboration with the European Space Agency and Canada, will broadcast the launch dwell, with a feed scheduled to begin at 6 am Eastern. You can stream it under.
Be ready for a nail-biter. The launch and subsequent deployment are high-stakes for a number of causes:
- The telescope has to pull off a tough mechanical maneuver: assembling itself, in space. The telescope is so giant — in regards to the measurement of a tennis courtroom — that it wants to launch folded up contained in the rocket. Once in space, it wants to deploy and unfold itself, flawlessly, in sequence over the course of a number of weeks. According to NASA, there are greater than 300 “single point failures” concerned within the mission. These are technical issues that, in the event that they come up, might doom the entire endeavor. (See how the Webb unfolds within the video under.)
The largest space telescope in historical past is about to blow our minds
- Because the Webb is being despatched so far-off — about 4 occasions the space of the Earth to the moon — if something goes incorrect with the telescope mechanically, scientists on the bottom will likely be out of luck. It won’t be potential to launch a crewed mission to restore it. (The Hubble Space Telescope, infamously, had to be repaired after it was launched. It’s solely 340 miles away.)
- The price. After being authorized within the early 2000s, the telescope was initially supposed to launch in 2010 and price round $1 billion. Since then, the worth tag has ballooned to round $10 billion.
If the Webb survives its journey and deploys in accordance to plan, scientists say it will likely be a paradigm-shifting telescope when it comes to our understanding of the universe.
Why the James Webb Space telescope is such an enormous deal
The Webb, which is (controversially) named after a former NASA administrator, improves on its predecessor, the Hubble Space Telescope, in two key methods. The first is simply its measurement: Hubble was in regards to the measurement of a college bus, whereas Webb is extra like the scale of a tennis courtroom. “This thing is enormous,” Amber Straughn, an astrophysicist at NASA who works on the Webb, stated earlier this yr. “Webb is by far the biggest telescope NASA’s ever attempted to send into space.”
But it’s not simply the whole measurement of the contraption that issues. When it comes to reflecting telescopes like these, the important thing part is the scale of its curved mirror. Hubble’s mirror was a powerful 7.8 ft in diameter. Webb’s lovely, gold-hued mirrors mix for a diameter of 21.3 ft. Overall, that quantities to greater than six occasions the light-collecting space.
The Webb’s different benefit is the kind of mild it collects.
Light is available in numerous completely different varieties. The human eye can see solely a slender band referred to as seen mild, however the universe comprises plenty of mild outdoors this vary, together with the higher-frequency, higher-energy varieties: ultraviolet, X-rays, gamma rays. Then there’s the lower-energy mild with longer wavelengths: infrared, microwaves, radio.
The Hubble Space Telescope collects seen mild, ultraviolet, and a bit of little bit of infrared. The Webb is primarily an infrared telescope, so it sees mild with an extended wavelength than our eyes can see. This appears nerdy and technical, but it surely’s truly what permits Webb to look additional again in time than the Hubble.
Infrared mild is typically very outdated mild, due to a phenomenon referred to as redshifting. When a light-weight supply is transferring away from a viewer, it will get stretched out, morphing into longer and longer wavelengths. Because space is continuously increasing, the farthest issues away from us within the universe are transferring away from us. “And as light travels through space from those distant galaxies, the light is literally stretched by the expansion of space,” Straughn says.
This is additionally why the Webb is being launched so far-off. Because Webb is an infrared telescope, it wants to be stored chilly. The Earth itself is heat and glows in infrared. “Anything warm glows in infrared light,” Straughn says. “If the telescope was warm, it would just glow and see itself.” So NASA and its companions are sending the telescope to orbit a degree in space referred to as a Lagrange level, a spot the place the telescope can orbit the solar, all of the whereas staying chilly and consistent with the Earth.
All instructed, these options will enable astronomers to look not solely farther out in space but in addition additional again in time. Webb will likely be ready to seek for the primary stars and galaxies of the universe, and see “cosmic dawn,” a time when the universe went from being opaque and darkish to clear and full of starlight. It will enable scientists to make cautious research of quite a few exoplanets — planets that orbit stars aside from our solar — and even embark on a seek for indicators of life there.
“We’re going right up to the edge of the observable universe with Webb,” says Caitlin Casey, an assistant professor of astronomy on the University of Texas at Austin. “And yeah, we’re excited to see what’s there.”
- For extra on the capabilities of the James Webb, how it really works, and solutions to the query “Where do you point a $10 billion telescope?” — take a look at this in-depth explainer that includes scientists who will likely be among the many first to use the telescope for observations.
- Even the highly effective James Webb has limitations, and scientists are already planning for future telescopes to observe issues it may’t, just like the cosmic darkish ages or the inferno of the early universe proper after the large bang.
Vox’s Unexplainable podcast devoted two episodes to the James Webb Space Telescope.
The first describes the technical capabilities of the telescope, and how the telescope will assist astronomers search for life on planets orbiting suns aside from our personal.
The second describes how astronomers will use the telescope to search for “cosmic dawn,” which is, as Casey explains, “the first [star] light that turned on at the very beginning of cosmic time.”
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