Commissioning of the James Webb Space Telescope is nearing completion. Webb’s sunshade, mirrors, instruments, and all other components are almost ready to begin the observatory’s long-awaited science operations! This historic moment will finally begin on July 12 with the unveiling of Webb’s first full-color high-resolution images.
To see the first images of Webb on July 12 at 10:30 a.m. (EDT), tune in to NASA Live here.
Since its launch on Christmas morning in 2021, the James Webb Space Telescope has passed several crucial milestones to ensure it is ready for science. After being fully deployed, arriving at its final destination in orbit around Lagrange point 2 1.5 million kilometers from Earth, aligning its mirror segments and cooling to its optimum operating temperature of just 40 degrees above absolute zero (or -233 degrees Celsius), Webb just has to make sure his scientific instruments are fully functional.
The Webb Telescope has four scientific instruments in addition to its guiding camera, the Fine Guidance Sensor (FGS) which was provided by the Canadian Space Agency (CSA). The four scientific instruments are capable of using a number of tools, methods and techniques to study the Universe in different ways.
- NIR Cam (Near-InfraRed Camera) is a near-infrared camera provided by the University of Arizona that will be Webb’s primary imaging tool. It can also perform coronagraphy (a technique for blocking light from a bright central object to better see fainter objects around it) and acts as the telescope’s wavefront sensor that allows all 18 segments to Webb’s mirror to function as one.
- NIR spec (Near-InfraRed Spectrograph) is a near-infrared spectrograph, which breaks down light into its color or wavelength components, provided by the European Space Agency (ESA) with contributions from NASA. It can collect the spectra of many objects at once, notably through a method called integral field spectroscopy which collects spatial and spectral information simultaneously.
- MIRI (Mid-InfraRed Instrument), provided by the European Space Agency, is the only mid-infrared instrument on board Webb and can see the glow of cosmic dust and gas themselves, rather than just seeing through them as is the case with near-infrared instruments. Because it looks at longer wavelengths, it must be cooled to an even colder temperature: just 7 degrees above absolute zero.
- NIRISS (Near-InfraRed Imager and Slitless Spectrograph) is Canada’s scientific instrument and can collect both images and spectra of thousands of celestial objects at once in the near infrared. It can also use a technique called interferometry to take images of objects very close to each other. To learn about the four modes of NIRISS, check out this CSA blog or this NASA blog.
A total of 17 distinct modes across the four instruments must be checked and ticked off before Webb is considered science-ready. The Canadian team, including our director René Doyon and many other iREx researchers, were thrilled to announce that the NIRISS instrument was the first to be science-ready on June 27! The MIRI team then announced that its instrument also completed its full scientific readiness check on June 30. We expect NIRCam and NIRSpec to follow very soon in the next few days.
To mark the transition from the end of the Webb Telescope’s 6-month commissioning period to the start of its science operations, NASA, ESA, CSA and all other mission partners will release the first images in color highly anticipated from the telescope on July 12th! During a press conference on June 29, it was revealed that this first version will include the spectrum of an exoplanet atmosphere as well as the deepest image ever taken of the Universe – even deeper than the Ultra Deep Field of the Hubble Telescope.
We invite the world to share this incredible moment with the Webb team and astronomers around the world through the following events.