Scientists are taking the James Webb Space Telescope for a test drive as they prepare to extract instruments from the most powerful space observatory on the universe.
On Monday, Webb Project scientists from NASA, the Canadian Space Agency, the European Space Agency and the Space Telescope Science Institute provided an update on the giant observatory as they prepare to begin science observations this summer.
After its launch on Christmas morning, the telescope’s 6.5-meter mirror opened, and its tennis-court-sized sunshield opened into space. The telescope is now about 1 million miles from Earth and in the final stages of commissioning.
The telescope’s commissioning phase to prepare it for scientific observation has 1,000 steps to complete, with only 200 steps left to complete, said Michael McElwen, Webb Observatory project scientist at NASA’s Goddard Space Flight Center.
“We’re really in homestretch,” McElwain said.
After releasing the first image taken by Webb of a star in April, NASA and its international partners on Monday shared a new photo taken while Webb’s instruments were operational.
The Webb science team selected the Large Magellanic Cloud, a satellite galaxy of the Milky Way, to test the telescope’s Mid-Infrared Instrument, or MIRI. The image below shows a similar view captured by NASA’s now-retired Spitzer Space Telescope’s Infrared Array Camera on the left and then on the right using Webb’s MIRI.
“Spitzer has taught us a lot, but it’s like a whole new world, just incredibly beautiful,” said Marcia Riecke, principal investigator for Webb’s Near-Infrared Camera.
Rieke, an astronomer at the University of Arizona who also worked on the Spitzer telescope, said the team knew Webb’s images would be better because it has 18 mirror segments, each larger than Spitzer’s single mirror.
“But it’s not until you really see the kind of image that it delivers that you really internalize and go, ‘Wow, just think about what we’re going to learn,'” Rike said.
ESA Web project scientist Chris Evans said Spitzer was limited by spatial resolution. He explained the superior clarity and power of Webb’s MIDI cut through the dust that would be hidden at visible wavelengths.
“So far, we’ve been limited by the angular resolution with the Spitzer display, but suddenly you can resolve them into individual stars. You can see all the structures in that image,” Evans said. “It’s just going to change our view of local galaxies, like the Magellanic Clouds. It will allow us to study the properties of stars in these different environments that are similar to galaxies in the early universe.”
After that, the public can look forward to the first color images from the telescope, known as early release observations, or EROs, said Klaus Pontopidan, Webb project scientist with the Space Telescope Science Institute.
“Their aim is to demonstrate to the world and to the public at the end of the commission that the web is fully operational and that it produces excellent results,” Pontopidan said of ERO. “It is also an occasion to celebrate the beginning of many years of web science.”
Pontopidan said the images we’ve seen so far from the web are mostly of star fields because they are used to calibrate instruments.
The ERO images will demonstrate the capability of all four Webb science instruments and cover a range of areas from early universe images to galaxies and exoplanets. The ERO should be issued in mid-July.