Stardust and ‘time travel’: revolutionary images from James Webb show universe in new light
WASHINGTON: The cosmic cliffs of a stellar nursery, a quintet of galaxies bound in a celestial dance: the James Webb Space Telescope released its next wave of images on Tuesday, heralding a new era of astronomy.
“Every image is a new discovery,” said NASA administrator Bill Nelson. “Each will give humanity a view of the universe that we’ve never seen before.”
Released one by one, the new images demonstrated the full power of the $10 billion observatory, which uses infrared cameras to gaze into the distant universe in unprecedented clarity.
On Monday, Webb revealed the clearest image to date of the early universe, going back 13 billion years.
The first batch of full-colour, high-resolution pictures, which took weeks to render from raw telescope data, were selected by NASA to provide compelling early images from Webb’s major areas of inquiry and a preview of science missions ahead.
Nasa has revealed five breath-taking new images of the early universe, taken by the James Webb Space Telescope, including one on Monday and four on Tuesday.
Scientists say the pictures will change the way people see space.
Early universe
The first image, which was released on Monday, shows “the deepest and sharpest infrared image of the distant universe to date,” NASA said.
The stunning shot, released in a White House briefing by President Joe Biden, is overflowing with thousands of galaxies and features some of the faintest objects observed, colourised in blue, orange and white tones.
Biden conveyed a sense of awe that Webb is documenting universe imagery from some 13 billion years ago.
“It’s hard to even fathom,” the president said. “These images are going to remind the world that America can do big things and remind the American people, especially our children, that there’s nothing beyond our capacity.”
Known as Webb’s First Deep Field, it shows the galaxy cluster SMACS 0723, which acts as a gravitational lens, bending light from more distant galaxies behind it towards the observatory, in a cosmic magnification effect.
Webb’s primary imager NIRCam — which operates in the near infrared wavelength spectrum because light from the early universe has been stretched out by the time it reaches us — has brought these faint background galaxies into focus.
Webb compiled the composite shot in 12.5 hours, achieving well beyond what its predecessor the Hubble Space Telescope could in weeks.
“Fantastic — galaxies upon galaxies upon galaxies,” Jonathan Lunine, chair of the astronomy department at Cornell University, said, rejoicing with the rest of the global astronomy community.
“First image from @NASAWebb — a piece of sky covered by a grain of sand at arm’s length. 1000’s of galaxies. The strange arcs are very distant galaxies — their images distorted by the warping of spacetime caused by the closer galaxy cluster,” tweeted Brian Cox, the professor of Particle Physics at The University of Manchester.
Astrophysicist Neil deGrasse Tyson said of the picture: “The spiked objects are local stars in our own galaxy. ignore them. Everything else is an entire galaxy.”
The next set of images released on Tuesday revealed details about the atmosphere of faraway planets, “stellar nurseries” where stars form, galaxies locked in a dance of close encounters, and the cloud of gas around a dying star.
Carina Nebula
The photo shows the “mountains” and “valleys” of a star-forming region called NGC 3324 in the Carina Nebula, dubbed the “Cosmic Cliffs,” 7,600 light years away.
Captured in infrared light by Webb, this image reveals for the first time previously invisible areas of star birth.
“For the first time we’re seeing brand new stars that were previously completely hidden from our view,” said NASA astrophysicist Amber Straughn.
According to the BBC, one of Webb’s key scientific goals is to study how stars form and Carina is an excellent place to do that.
Southern Ring Nebula
A dim star at the centre of the Southern Ring Nebula was revealed for the first time to be cloaked in dust, as it spews out rings of gas and dust in its death throes.
Understanding the molecules present in such stellar graveyards can help scientists learn more about the process of stellar death.
The Southern Ring is nearly half a light-year in diameter and is located about 2,000 light-years from Earth.
This kind of structure is known as a “planetary nebula”, but it has nothing to do with planets, the BCC reported. “It’s a misnomer from the early days of telescopes when they didn’t have anything like the resolution they have today.”
Stephan’s Quintet
Webb also revealed never before seen details of Stephan’s Quintet, a grouping of five galaxies including four that experience repeated close encounters, which provide insights into how early galaxies formed at the start of the universe.
The telescope dramatically captures shockwaves as one of the galaxies smashes through the centre of the cluster.
About 290 million light-years away, the quintet is located in the constellation Pegasus. It’s notable for being the first compact galaxy group ever discovered. Four of the five galaxies within it are locked in a cosmic dance of repeated close encounters.
Hot gas giant exoplanet
The telescope also found water vapour in the atmosphere of a faraway gas planet. The spectroscopy — an analysis of light that reveals detailed information — was of planet WASP-96 b, which was discovered in 2014.
Nearly 1,150 light-years from Earth, WASP-96 b is about half the mass of Jupiter and zips around its star in just 3.4 days.
“We’ve seen the effect of what happens when a planet and its atmosphere passes in front of the star, and the star light filters through the atmosphere, and you can break that down into wavelengths of light,” said NASA’s Knicole Colon. “So, you’re actually seeing bumps and wiggles that indicate the presence of water vapor in the atmosphere of the planet.”
What is the James Webb Space Telescope?
Launched in December 2021 from French Guiana on an Ariane 5 rocket, the telescope is orbiting the Sun at a distance of 1.6 million kilometres from Earth, in a region of space called the second Lagrange point.
Here, it remains in a fixed position relative to the Earth and Sun, with minimal fuel required for course corrections.
A wonder of engineering, the total project cost is estimated at $10 billion, making it one of the most expensive scientific platforms ever built, comparable to the Large Hadron Collider at CERN.
Webb’s primary mirror is over 6.5 metres wide and is made up of 18 gold-coated mirror segments. Like a camera held in one’s hand, the structure must remain as stable as possible to achieve the best shots.
After the first images, astronomers around the globe will get shares of time on the telescope, with projects selected competitively through a process in which applicants and selectors don’t know each other’s identities, to minimize bias.
Thanks to an efficient launch, NASA estimates Webb has enough propellant for a 20-year life, as it works in concert with the Hubble and Spitzer space telescopes to answer fundamental questions about the cosmos.
Published in Dawn, July 13th, 2022