The James Webb Telescope quietly captured a beautiful photo of Jupiter

James Webb Jupiter

The James Web Space Telescope team is fresh from the exciting unveiling of the telescope’s first full-color photos, but these images aren’t the only ones the observatory has captured. Star photos of Jupiter were hidden in its commissioning report.

While the Webb telescope is primarily interested in objects much more distant and well outside of our solar system, which it can detect with significantly better visual accuracy than Hubble, the observatory’s team tested its capabilities by pointing it at objects , which are much closer to Earth. In this case, Webb took these photos 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 Commissioning Report discovered by science alertand show Jupiter and three of its moons: Europa, Thebe and Metis.

“JWST has a Tier 1 requirement to track objects within the solar system at speeds of up to 30 milliarcseconds 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 tracking and scientific instruments for moving targets, including dithering and mosaicking,” the commissioning report said.

The Webb team reports that all tests with moving targets were successful and there was no evidence of poor tracking. The photos of Jupiter were taken because, first, the team expected that observing a bright planet and its satellites and rings would be challenging for Webb, since the stray light could affect his instruments. But secondly, the fine guidance sensor would also have the task of tracking guiding stars in the vicinity of a bright planet.

James Webb Space Telescope

As can be seen from the clear infrared images, the test was successful and the exposure time for the images was 75 seconds, during which Webb had to closely track the relatively close-up, fast-moving object. The image on the left was captured with Webb’s near-infrared (NIRcam) camera with a filter that emphasizes short wavelengths, while the image on the right was captured with a filter that emphasizes long wavelengths of light, also captured by NIRcam.

While the photos of Jupiter are interesting in their own right, the fact that Webb was able to capture them accurately means it’s suitable for observing and accurately capturing near-Earth objects like comets and asteroids.

Webb continues to exceed expectations

The commissioning report also shows that, in most cases, the James Webb Space Telescope can see faster and further than expected. Several factors contributed to a significantly better sensitivity for most instrument modes than assumed in the exposure time calculator for observing 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 operational for between five and 10 years, meaning the observatory’s current status is double the original life expectancy of the largest and most powerful orbital observatory known to mankind ever put into space.

There is so much James Webb will show scientists, and his journey has only just begun.


Photo credit: NASA, ESA, CSA and STScI

Leave a Comment

%d bloggers like this: