The James Web Space Telescope team is fresh off the exciting reveal of the telescope’s first full-color photographs, but those images aren’t the only ones the observatory has captured. Hidden in its commissioning report were stellar photos of Jupiter.
While the Webb Telescope is primarily interested in objects that lie much farther away and well outside our solar system, which it can capture with significantly more visual fidelity than Hubble, the observatory’s team tested its capabilities by aiming it at objects much closer to Earth. In this case, Webb captured these photos of Jupiter during a performance test for its ability to track moving targets.
The photos and descriptions were included in the James Webb Space Telescope Science Commissioning Report which was spotted by Science Alertand show Jupiter as well as three of its moons: Europa, Thebe, and Metis.
JWST has a Level 1 requirement to track objects within the solar system at speeds up to 30 milliarcseconds per second (mas / s). In commissioning, tracking was tested at rates from 5 mas / s to> 67_mas / s. These tests verify tracking and science instrument performance for moving targets, including dithering and mosaicking, ”the commissioning report reads.
The Webb team reports that all tests of moving targets were successful and there was no evidence of poor tracking whatsoever. The photos of Jupiter were included because, firstly, the team expected it to be challenging for Webb to observe a bright planet and its satellites and rings due to the scattered light that may affect its instruments. But also, secondly, the fine guidance sensor would be tasked with tracking guide stars near a bright planet.
As evidenced by the clear infrared images, the testing 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 highlights short wavelengths while the one on the right is taken with a filter that highlights long wavelengths of light, also captured by NIRcam.
While the photos of Jupiter are interesting by their own right, the fact Webb was able to accurately capture them means it is suited to observe and accurately capture near-Earth objects like comets and asteroids.
Webb Continues to Outperform 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 was assumed in the exposure time calculator for observation planning.
Even more exciting, the report concludes that James Webb has enough propellant on board to last at least 20 years. When the telescope was originally launched, NASA scientists expected Webb to remain in operation for between five and 10 years, which means the current status of the observatory is double the original life expectancy of the largest and most powerful orbital observatory humanity has ever launched 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