The Webb Telescope is already challenging what astronomers thought they knew


The James Webb Space Telescope, performing beautifully as it scans the universe, has astronomers scratching their heads. The very distant universe looks a little different than expected.

The telescope, launched eight months ago and orbiting the sun about a million miles from Earth, captured images of extremely faint galaxies that emitted their light during the first billion years or so after the big bang. Observing these “early” galaxies is one of the telescope’s main missions – to see deeper into space and further back in time than any previous telescope.

The first scientific results have emerged in recent weeks, and what the telescope has seen in deepest space is a bit puzzling. Some of these distant galaxies are surprisingly massive. A general assumption was that the first galaxies – which formed soon after the first stars were lit – would be relatively small and distorted. Instead, some of them are big, bright, and well-structured.

The Webb telescope is amazing. But the universe is even more so.

“The models just don’t predict that,” Garth Illingworth, an astronomer at the University of California, Santa Cruz, said of the first massive galaxies. “How do you do that in the universe at such an early time? How do you form so many stars so quickly?

This is not a cosmological crisis. What’s happening is a lot of fast science, conducted “in real time,” as astrophysicist Jeyhan Kartaltepe of the Rochester Institute of Technology puts it. Data from the new telescope is gushing out, and she’s among the legions of astronomers posting new papers, quickly posting them online ahead of peer review.

Early space telescope contributor James Webb explains how newly released images allow us to explore the origins of the universe. (Video: Hadley Green, Hope Davison/The Washington Post)

The Webb sees things no one has ever seen in such fine detail and at such enormous distances. Research teams across the planet are sifting through the published data and racing to spot the most distant galaxies or make other remarkable discoveries. Science often advances at a majestic pace, advancing knowledge incrementally, but the Webb dumps tons of tantalizing data on scientists at the same time. Preliminary distance estimates will be refined after further review.

Kartaltepe said she’s certainly not worried about any tension between astrophysical theory and what the Webb sees: “We might scratch our heads one day, but a day later, ‘Oh, it’s all gone. makes sense now’.”

NASA unveils first images from the James Webb Space Telescope

What surprised astronomer Dan Coe of the Space Telescope Science Institute are the number of well-formed disc-shaped galaxies.

“We thought the early universe was this chaotic place where there were all these clusters of star formation, and everything was jumbled together,” Coe said.

This early universe hypothesis was due in part to Hubble Space Telescope observations, which revealed clumped and irregularly shaped early galaxies. But Hubble observes in a relatively narrow portion of the electromagnetic spectrum, including “visible” light. Webb observes in the infrared, gathering light outside of Hubble’s range. With Hubble, Coe said, “We were missing all the coolest stars and the oldest stars. We really only saw the hot youngsters.

The simplest explanation for these surprisingly massive galaxies is that, at least for some of them, there was a miscalculation – possibly due to a light trick.

Distant galaxies are very red. They are, in astronomical jargon, “red-shifted”. The wavelengths of light from these objects have been stretched by the expansion of the universe. Those that appear the reddest – those with the highest redshift – are presumed to be the furthest away.

But dust can skew the calculations. Dust can absorb blue light and cause the object to glow red. It could be that some of these very distant, strongly redshifted galaxies are just very dusty, and not as distant (and as “young”) as they seem. This would realign observations with what astronomers expected.

Or another explanation might surface. What is certain is that, for now, the $10 billion telescope – a joint effort of NASA and space agencies from Canada and Europe – is providing new observations not only of these galaxies distant, but also closer objects like Jupiter, a giant asteroid and a newly discovered comet.

Webb’s latest discovery was announced on Thursday: carbon dioxide was detected in the atmosphere of a distant giant planet named WASP-39b. This is “the first definitive detection of carbon dioxide in an exoplanet’s atmosphere,” according to NASA Webb Project scientist Knicole Colon. Although WASP-39 b is considered far too hot to be habitable, the successful detection of carbon dioxide demonstrates the acuity of Webb’s vision and holds promise for future examination of distant planets that may harbor life.

The telescope is controlled by engineers from the Space Telescope Science Institute in Baltimore. The mission operations center is on the second floor of the institute, which borders the campus of Johns Hopkins University.

On a recent morning, only three people were on staff in the flight control room: Operations Controller Irma Aracely Quispe-Neira, Ground Systems Engineer Evan Adams, and Command Controller Kayla Yates. They were seated at a row of workstations with large screens loaded with data from the telescope.

Take a cosmic tour inside images captured by NASA’s Webb Telescope

“We don’t usually order the live action,” Yates said. In other words, nobody controls the telescope with a joystick or anything like that. It operates largely on its own, completing an online shadowing schedule about once a week. A command is sent from the flight control room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. From there, the command travels to NASA’s Jet Propulsion Laboratory in Pasadena, California, and then to the Deep Space Network – radio antennas near Barstow, California, Madrid and Canberra, Australia. Depending on the rotation of the Earth, one of these antennas can transmit the command to the telescope.

The crowds of people who were present the morning of the telescope’s launch last Christmas have long since disappeared from the mission’s operations center in Baltimore.

“It’s a testament to how it works that we can go from several hundred people to just three of us,” Adams said.

The observing program is largely driven by the desire to be efficient, and that often means looking at things that appear close to each other in the sky, even if they are billions of light years apart. .

A visitor will be disappointed to find that the flight control team cannot see what the telescope sees. There is no big screen showing, for example, a comet, or a galaxy, or the Dawn of Time. But the flight control team can read data describing the orientation of the telescope – for example, “32 degrees right ascension, 12 degrees declination”. And then consult a sky map to see where the telescope is pointing.

“It’s between Andromeda and whatever that other constellation is,” Adams said.

‘Incredible’ images of Jupiter revealed by NASA’s James Webb Telescope

Here is a sample of some Webb observations, which should yield new images, as well as scientific reports, in the coming months:

The Cartwheel Galaxy: A strikingly beautiful and rare “ring” galaxy about 500 million light-years away. Its unusual structure is due to a collision with another galaxy. It was one of the first images the Webb team processed to show what the telescope can do.

M16, the Eagle Nebula: It is a “planetary nebula” within our own galaxy that is home to a structure dubbed the “Pillars of Creation” that was photographed by the Hubble Space Telescope. It became one of the most famous Hubble images, showing three towering pillars of dust illuminated by hot young stars outside the image frame, all angled by NASA to produce what, to the human eye , looks like a landscape. The Webb will likely produce a similarly framed image but with new resolution and detail, thanks to the ability to harvest light in the infrared wavelengths inaccessible to the Hubble.

Ganymede, the largest moon of Jupiter: It is the largest moon in the solar system and it is even larger than the planet Mercury. Scientists believe it has an underground ocean with more water than all the oceans on Earth. Webb project scientist Klaus Pontopiddan said the telescope will look for plumes – geysers similar to those that have been spotted on Jupiter’s moon Europa and Saturn’s moon Enceladus.

Comet C/2017 K2: Discovered in 2017, it is an unusually large comet with a tail 500,000 miles long, heading towards the sun.

The Great Barred Spiral Galaxy: Officially “NGC-1365”, this is a classic and beautiful “bar” galaxy – a spiral with a central bar of stars that connects two prominent, curved arms. It’s about 56 million light years away.

Trappist-1 planetary system: Seven planets orbit this star, and several are in the “habitable zone”, that is, they are at a distance from the star where water could be liquid on the surface. Astronomers want to know if these planets have atmospheres.

Draco and Sculptor: They are dwarf spheroidal galaxies close to the Milky Way. By studying their movement over a long period, astronomers hope to learn more about the presence of dark matter, invisible but with a gravitational signature.

This is only a partial list. There is a lot to see there.

“It’s non-stop, 24/7, just science coming back,” said Heidi Hammel, planetary astronomer and vice president for science of the Association of Universities for Research in Astronomy. . “And that’s a huge scientific diversity. I saw Jupiter’s Great Red Spot – but two hours later we are now looking at M33, this spiral galaxy. Two hours later, we are now looking at an exoplanet whose name I know. It’s very cool to watch this.

#Webb #Telescope #challenging #astronomers #thought #knew

Leave a Comment