In outer space, the appearance of the James Webb Space Telescope was revealed by this European space exploration project.
The European Space Agency's Gaia spacecraft, known for its mission to survey over a billion stars, made a surprising discovery on February 18, 2022. It captured an image of the James Webb Space Telescope (JWST) in space.
Gaia, which is primarily designed for astrometry—measuring precise positions and motions of stars—was able to track and image the JWST due to its capability to observe relatively bright objects within the Solar System and nearby space. This remarkable feat was possible because Gaia's sensitive optics and detectors can detect faint reflected sunlight from spacecraft surfaces, enabling it to take an image of the JWST as a distinct point of light moving across the star field.
The imaging was no coincidence but a result of calculations made by Uli Bastian of Heidelberg University and Francois Mignard of Nice Observatory. They calculated the opportunity to capture an image of the JWST using Gaia spacecraft, taking into account the telescope's position at the Sun-Earth L2 Lagrange point.
Gaia orbits at this Lagrange point, approximately 1.5 million kilometers from Earth in the direction away from the Sun. This location stabilises the Gaia spacecraft's position relative to the two bodies—Earth and the Sun—allowing it to maintain a constant view of the telescope as it moved in its orbit.
When the image was taken, Gaia was approximately 1 million kilometers away from the JWST. In the image inset, the bigger white speck is the JWST, and the other three specks are cosmic ray particles picked up by Gaia's CCD camera.
In addition to its primary mission, Gaia is also capturing detailed data on asteroids. This image capture demonstrates the versatility of Gaia's astrometric capabilities and the complementary roles ESA missions play in space exploration.
While Gaia primarily surveys stars, its ability to image the JWST highlights the potential for future collaborative endeavours between ESA missions and flagship missions like JWST.
[1] This explanation aligns with ESA statements about Gaia’s precision astrometry and observational capabilities. However, the technical capture method is not explicitly detailed in the recent documents.
[1] The exciting discovery of the James Webb Space Telescope (JWST) by the European Space Agency's Gaia spacecraft showcases the unparalleled space-and-astronomy technology at work, as Gaia's exceptional capability to observe bright objects in the Solar System and nearby space was instrumental in tracking and imaging the JWST.
[2] This significant achievement in space-and-astronomy, facilitated by the collaborative efforts of Uli Bastian and Francois Mignard, underscores the potential for future science collaborations between ESA missions and flagship space-and-astronomy projects, such as the JWST.
