Baltimore, Gatra.com- NASA’s James Webb Space Telescope is ready to launch and become the most powerful telescope in space. But how do the photos compare to Hubble? “It’s going to take amazing pictures, they’re going to be better than what Hubble did,” said Webb project scientist Klaus Pontoppidan. Live Science, 20/12.
The Hubble Space Telescope launched into low Earth orbit in April 1990. Over the three decades since, the famous observatory has broadened our view of the cosmos and captured our attention with the stunning images it has collected. What was once a faint and mysterious abyss becomes a detailed and colorful universe, and we can see stars and galaxies like never before.
But the James Webb Space Telescope, scheduled to launch on December 24, will do things a little differently. With a giant gold mirror and infrared light-observing apparatus, Webb is designed to “see” objects 10 to 100 times fainter than Hubble can see, according to a NASA fact sheet. So how do Webb’s views compare to Hubble’s?
Webb is often described as a successor or successor to Hubble. But despite some glitches over the years, Hubble’s science instruments are still going strong, and two large spheres are set to be observed together (albeit far apart from each other) in space.
Hubble is fairly close to us in low-Earth orbit, but Webb will travel further afield, to a gravitationally stable spot 930,000 miles (1.5 million kilometers) from Earth known as the Sun-Earth Lagrange point 2 (L2).
In addition, although Hubble and Webb are large space telescopes (although Webb is much larger), they actually “see” the universe very differently.
“It’s going to take incredible pictures; they’re going to be better than what Hubble did,” Klaus Pontoppidan, Webb’s project scientist at the Space Telescope Science Institute in Baltimore, said during a press conference in May. However, while better in some ways, Webb’s image is also fundamentally “different, because the wavelengths are different,” Pontoppidan said.
While Hubble observed light primarily at optical and ultraviolet wavelengths, Webb was designed to detect primarily infrared light.
By observing in infrared, Webb will capture beautiful unique images. “I thought it would be fantastic,” Pontoppidan said, “but it’s very difficult to predict what it would look like,” because this would be the first space telescope mission of its kind.
“It’s going to look very, very different from Hubble,” Pontoppidan said. “The stars themselves are fading, they are getting dimmer [ketika Anda] went to longer wavelengths, but interstellar clouds became brighter and brighter and brighter. “
Some of the gas and dust features thin out a bit as you start to enter the infrared portion of the light spectrum, Pontoppidan explains. But that’s not necessarily a bad thing.
“I think there might be a concern that, you know, you don’t want the image that ends up looking flimsy,” Pontoppidan said. “But it turns out, actually, if you go a little further into the infrared … the dust itself glows in thermal light. You get a glowing nebula.”
Hubble can see light in the wavelength range from about 200 nanometers (nm) to 2.4 microns, while Webb’s range will range from about 600 nm to 28 microns, according to the fact sheet, which adds that visible light ranges from 700 to 400 nm.
Although Webb mainly observed infrared light, he could still see the red/orange part of the visible light spectrum. Its mirror gold coating absorbs the blue light of the visible spectrum, but reflects the yellow and red visible light it will detect.
Although not its primary observation function, Hubble also has the ability to observe some objects with infrared, so this type of observation is not a complete start. In fact, in 2013, the Hubble team released a stunning infrared image of the Horsehead Nebula captured by the space telescope to celebrate the 22nd anniversary of its launch.
This Hubble image, taken and released to celebrate the telescope’s 23rd year in orbit, shows part of the sky in the constellation Orion (Hunter) in infrared light. Emerging like a giant seahorse from a churning wave of dust and gas is the Horsehead Nebula, otherwise known as Barnard 33.
Hubble has been providing the world with stunning images for decades and has a sharpness similar to that of Webb. “Webb’s angular resolution, or visual acuity, will be the same as Hubble’s,” according to NASA. “Webb’s images will appear as sharp as Hubble did,” he wrote. According to NASA, Webb’s resolution will allow it to see details of an object the size of a US dollar coin 24 miles (40 km) away.
Despite these similarities, the Webb has a much larger mirror – 21.3 feet (6.5 m) wide, compared to the Hubble which is only 7.8 feet (2.4 m) – state -of -the -art detectors and designed to see deeper into the spectrum infrared from Hubble.
By observing in infrared, Webb will allow scientists to see further into the universe, NASA has explained. Its larger mirrors also give it more surface area to collect light, allowing the scope to peer further into space, essentially allowing scientists to look “into the past”, at the universe billions of years ago.
Webb was designed to be able to “see” the first stars and galaxies that ever formed in the early universe. It can detect objects 10 billion times fainter than the faintest star visible without a telescope, or 10 to 100 times fainter than Hubble can observe.
Webb was equipped with four scientific instruments to help him make observations. This includes Near Infrared Camera (NIRCam), Near-Infrared Spectrograph (NIRSpec), Mid-Infrared Instrument (MIRI) and Fine Guidance Sensor/Near Infrared Imager and Slitless Spectrograph (FGS-NIRISS).
With this tool, Webb “can perform what we call imaging spectroscopy,” Pontoppidan said, “where it can take an image, but it will also pick up the spectrum and each pixel of the image.” In imaging spectroscopy, there is information about the spectrum of wavelengths present in each small part of the image. This can help scientists give clues about what elements or chemicals may have created the spectrum.
Pontoppidan adds that Webb’s unique suite of imaging tools will allow him to do all sorts of other scientific work, such as observing exoplanets transiting in front of stars or determining cloud composition in star-forming regions; he points to research that might look for ice, water, and complex organics in the atmospheres of exoplanets.
The James Webb Space Telescope is a joint effort involving NASA, the European Space Agency, and the Canadian Space Agency.
After additional delays, Webb is still on track for launch on December 24, 2021, aboard the Arianespace Ariane 5 rocket from Spaceport Europe in Kourou, French Guiana.
–
