James Webb Space Telescope now capturing images in focus and at maximum quality: ready to make history
The James Webb Space Telescope is getting closer and closer to making history as it begins to show us what the first galaxies and stars in the Universe were like more than 13 billion years ago. After reaching L2 orbit and, among other tasks, completing the alignment of the 18 segments of the main mirror, the team in charge of the $10 billion observatory has given the go-ahead for science instruments to be commissioned.
The James Webb mirrors are now directing light collected from space to each of the instruments. As we can see in the photo below, the instruments are already capable of capturing fully focused images with the incoming light. These images, as NASA explains in its official blog, have a “diffraction-limited” quality, which means that the maximum level of detail possible in relation to the size and capabilities of the telescope has been achieved.
Before the telescope begins science operations and researchers begin observing the universe, the commissioning team had to ensure that each instrument was capable of delivering images that were completely sharp and in focus. To do so, they pointed the James Webb at part of the Large Magellanic Cloud, a dwarf galaxy 163,000 light-years away that contains a field of hundreds of thousands of stars.
The James Webb sensors, pointing at a slightly different part of the sky, resulted in the set of images seen above, which represent the relative arrangement of each of the instruments in the telescope’s focal plane. Each of the captures is labeled with the name of the three optical instruments (NIRCam, NIRISS and MIRI) and the telescope’s single spectrograph (NIRSpec).
We also see an image captured by the Webb’s fine guidance sensor, a device whose main mission is to track the guide stars in order to orient the observatory with great precision. That is, its use is not intended to take scientific images, but to accurately measure and calibrate subtle image distortions and alignments between sensors as part of the overall space telescope calibration process.
Now that the James Webb alignment is complete, only routine adjustments will be made to the main mirror. The team is now focused (never better said) on getting the science instruments up and running. This is a task that requires setting up the necessary parameters to make the telescope ready for science. This process will take about two months and, if all goes well, the researchers will be able to start their first science operations this summer.