While the Webb telescope is primarily interested in objects much further away and far outside our solar system, which it can capture with far greater optical fidelity than Hubble, the observatory team tested its capabilities by aiming it at objects much more distant. close to Earth. In this case, Webb captured these pictures of Jupiter during a performance test of its ability to track moving targets. The photos and descriptions were included in the James Webb Space Telescope Science Commission Report spotted by Science Alert and show Jupiter as well as three of its moons: Europa, Thebes, and Metis. “JWST has a Level 1 requirement to track objects within the Solar System at speeds up to 30 milliseconds per second (mas/s). During commissioning, tracking was tested at rates from 5 mas/s to >67_mas/s. These tests verified the performance of the tracking and science instruments for moving targets, including admixture and mosaicing,” the award report states. The Webb team reports that all moving target tests were successful and there was no evidence of poor tracking. The pictures of Jupiter were included because, first, the team expected that it would be difficult for Webb to observe a bright planet and its moons and rings because of the scattered light that can affect its instruments. But also, secondly, the precision guidance sensor will be tasked with tracking guide stars near a bright planet. As evidenced by the clear infrared images, the test was successful, and the exposure time for the images was 75 seconds during which Webb had to accurately track the relatively close, fast-moving subject. The image on the left was taken with Webb’s near-infrared camera (NIRcam) using a filter that emphasizes short wavelengths, while the one on the right was taken with a filter that emphasizes long wavelengths of light, also recorded by the NIRcam. While the pictures of Jupiter are interesting in their own right, the fact that Webb was able to capture them accurately means that he is well-suited to accurately observe and capture near-Earth objects such as comets and asteroids.
Webb continues to exceed expectations
The commissioning report also reveals that the James Webb Space Telescope will, in most cases, be able to see faster and farther than expected. Several factors contributed to a substantially better sensitivity for most instrument modes than assumed in the exposure time computer for observation planning. Even more exciting, the report concludes that James Webb has enough propellant to last at least 20 years. When the telescope was originally launched, NASA scientists expected Webb to remain operational for five to 10 years, meaning that the observatory’s current status is twice the original life expectancy of humanity’s largest and most powerful orbiting observatory. ever launch into space. . There is so much that James Webb will show scientists, and his journey has only just begun. Image credits: NASA, ESA, CSA and STScI
