After the current launch of the primary pictures from now being released on the Space Telescope Science Institute’s Mikulski Archive for Space Telescopes. The data includes images of
“Combined with the deep field images released the other day, these images of Jupiter demonstrate the full grasp of what Webb can observe, from the faintest, most distant observable galaxies to planets in our own cosmic backyard that you can see with the naked eye from your actual backyard,” said Bryan Holler. He is a scientist at the Space Telescope Science Institute in Baltimore, who helped plan these observations.
Clearly visible at the left is Europa, a moon with a probable ocean below its thick icy crust. It is the target of NASA’s forthcoming Europa Clipper mission. Moreover, Europa’s shadow can be seen to the left of the Great Red Spot. Other visible Jovian moons in these images include Thebe and Metis.
“I couldn’t believe that we saw everything so clearly, and how bright they were,” said Stefanie Milam, Webb’s deputy project scientist for planetary science based at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “It’s really exciting to think of the capability and opportunity that we have for observing these kinds of objects in our solar system.”
Scientists were especially enthusiastic to see these images because they are proof that Webb can observe the satellites and rings near bright solar system objects such as Jupiter,
“The Jupiter images in the narrow-band filters were designed to provide nice images of the entire disk of the planet, but the wealth of additional information about very faint objects (Metis, Thebe, the main ring, hazes) in those images with approximately one-minute exposures was absolutely a very pleasant surprise,” said John Stansberry, observatory scientist and NIRCam commissioning lead at the Space Telescope Science Institute.
Webb also obtained these images of Jupiter and Europa moving across the telescope’s field of view in three separate observations. This test demonstrated the ability of the observatory to find and track guide stars in the vicinity of bright Jupiter.
But just how fast can an object move and still be tracked by Webb? This was an important question for scientists who study asteroids and comets. During commissioning, Webb used an asteroid called 6481 Tenzing, located in the asteroid belt between Mars and Jupiter, to start the moving-target tracking “speed limit” tests.
Webb was designed with the requirement to track objects that move as fast as Mars, which has a maximum speed of 30 milliarcseconds per second. During commissioning, the Webb team conducted observations of various asteroids, which all appeared as a dot because they were all small. The team proved that Webb will still get valuable data with all of the science instruments for objects moving up to 67 milliarcseconds per second, which is more than twice the expected baseline – similar to photographing a turtle crawling when you’re standing a mile away. “Everything worked brilliantly,” Milam said.