The 60-page James Webb Space Telescope (JWST) commissioning report features two new photos of Jupiter, including its moons Europa, Thebes and Metis appear.
The bright snapshots of the gas giant were taken by the telescope’s NIRCam instrument as it was being tested. The report states that the images “demonstrated that JWST can track moving targets even when there is scattered light of a bright Jovian planet”.
NASA chose nine targets to test the telescope capacity to track fast-moving objects, which move at speeds of up to 67 milliarcseconds per second.
Other onboard instruments tested include the Near-Infrared Imager and Slitless Spectrograph (NIRISS) and Mid-Infrared Instrument (MIRI), which detect and stabilize different wavelengths.
Jupiter was the slowest targetmoving at just 3.3 milliarcseconds per second, but all tests were successful.
These images also demonstrate its ability to capture details like rings and moons around bright planets.
The commissioning report explains: “Observing a bright planet and its satellites and rings was expected to be challenging, due to scattered light that can affect the science instrument employed, but also the fine guidance sensor (FGS) must track guide stars near the bright planet.
“These observations verified the expectation that guide star acquisition works successfully as long as Jupiter is at least 140” from the FGS (Fine Guidance Sensor), consistent with the preflight model.
Success in this test opens up the possibility for the telescope to track near-Earth asteroids (NEAs), comets, and other interstellar objects.
