Last Christmas, NASA gave astronomers—and humanity—a gift by launching the James Webb Space Telescope (JWST), a present that kept on giving all year.
Last Christmas, NASA gave astronomers—and humanity—a gift by launching the James Webb Space Telescope (JWST), a present that kept on giving all year. The space agency’s largest and most powerful observatory JWST has captured images of the early universe as well as up-close views of a spacecraft deflecting an asteroid only 6.8 million miles from Earth. and that’s just in the first few months.
“It’s fair to say the telescope has exceeded expectations,” said Klaus Pontoppidan, Project Scientist for the James Webb Space Telescope at the Space Telescope Science Institute in Baltimore. “We are actually outperforming the requirements almost everywhere.” They are clearer images that allow us to see further. “And it has made a significant difference.”
The telescope, a massive international effort built in collaboration with European and Canadian space agencies, required the work of 20,000 people over a 20-year period. According to Eric Smith, Webb programme scientist at NASA Headquarters, it was launched on an Ariane 5 rocket that delivered it into orbit so flawlessly that the manoeuvring fuel saved on board the spacecraft will extend its life to about 25 years, rather than 10.
“The lifetime is more than twice as long as expected,” he said, referring to JWST’s performance by almost every measure. The vision is now twice as clear. It will be about 25 to 30% more sensitive, allowing us to see fainter or achieve a higher exposure level.
“It’s more stable than we thought, about seven times more stable.” This means that astronomers have to wait less time after aiming the telescope to collect data, making their operations more efficient. “You just move it and, “boom,” you’re ready to go,” Smith explained. “That gives us hope for future telescopes as well.”
The only hiccups in Powerful JWST first six months of operation have been micrometeorite strikes. The space telescope, with 18 mirrors unfolded to a width of more than 21 feet, orbits the sun 1.5 million miles away from Earth at a stable gravitational point considered pristine in comparison to Earth’s increasingly debris-filled orbit.
However, a large micrometeorite strike in May convinced engineers to turn the observatory away from its orbital motion in order to reduce the impact of fast-moving space dust hitting its mirrors head-on. “Just like you don’t stick your face out of a moving car window,” Smith explained.
The $11 billion space telescope, which will be launched on Christmas Day 2021, overcame years of delays and cost increases to unfurl those mirrors flawlessly in a 178-step origami exercise in space before revealing its first images in July. A slew of new discoveries followed. Here are a few highlights:
Deep field
The farther away the telescope can see, the farther back in time it is looking. Powerful JWST contains galaxies that date to just a few hundred million years after the Big Bang. The view is centered on a massive galaxy cluster whose gravity bends the light from more distant galaxies into distorted, elongated, dimensions.
Fiery hourglass
The Powerful JWST has captured a stunning image of the young solar system L1527, only 10,000 years old. The image adds to observations suggesting that planets form very early in the lifetime of stars, something that was uncertain only a few decades ago. Clouds colored blue and orange in this representative-color infrared image outline cavities created as material shoots away from the protostar.
Early galaxies
The JWST’s first observations of galaxies in existence some 350 million to 450 million years after the origin of the universe found them bigger and brighter than expected. For galaxies to be so bright, they must have been born only 100 million years or so after the fading of the Big Bang’s afterglow. It’s kind of like we walked into the nursery and we saw toddlers. So it’s like, ‘What’s going on here?’ said Pontoppidan.
Pillars of creation
IThe Eagle Nebula is a stellar nursery some 6,500 light years from Earth. The new image shows off the power of a “mid-infrared” instrument aboard JWST, which takes exquisite images of light in the middle of the infrared spectrum. Within the dusty swirls of the pillars, news stars are coalescing, some of them visible in earlier Hubble images taken in visible light.
Exoplanet atmosphere
Astronomers at the James Webb Space Telescope (JWST) have seen signs of sulfur dioxide and clouds on Wasp-39b, a “hot Jupiter” orbiting its star. The planet is eight times closer to its star than Mercury is to the sun, and broils at about 1,600 degrees Fahrenheit. JWST also saw signs of clouds on another large hot planet called Wasp 96b, some 1,150 light years away.
The discovery of thousands of “exoplanets” orbiting nearby stars accompanied the JWST’s development over two decades, shifting its focus from the early universe to making discoveries in an exciting new frontier in science. Astronomers hope that a successor to Powerful JWST will detect habitable planets like Earth WS or even the atmospheric signatures of life on one of these distant worlds in the coming decades.
The discovery of atmospheric chemistry on Wasp-39b, as well as the first detection of exoplanetary carbon dioxide on a world 700 light years away, suggests that more of these measurements are on the way, according to Smith. “We now have spectra that are pushing the boundaries of what we know today.”
“That’s going to be one of Webb’s major contributions,” he added. “Ironically, it’s something we didn’t even know about when we started.” I like to say that Webb was started before there were exoplanets. Of course, they were out there. “We just didn’t know about them.”
As well, the telescope should start making spectroscopic progress on cooler, fainter, failed stars called brown dwarfs, or places where stars are forming. “It’s a murky area because we just didn’t have facilities sensitive enough to study them . So, I expect a lot of progress there, too,” said Smith.