Get ready for a new way to see the universe

The James Webb House Telescope (JWST) is the following of NASA’s main observatories. It follows the road of the Hubble House Telescope, the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer House Telescope. JWST combines the qualities of two of its predecessors, the remark in infrared gentle, such because the Spitzer, and the high-resolution, such because the Hubble. Credit score: NASA, SkyWorks Digital, Northrop Grumman, STScI

1. What has occurred for the reason that telescope was launched?

After the profitable launch of the James Webb House Telescope on December 25, 2021, the workforce started the lengthy strategy of transferring the telescope to its remaining orbital location, opening the telescope – and as all the things cooled – calibrating the cameras and sensors on board.

The launch was as easy as a missile launch can occur. One of many first issues my NASA colleagues observed was that the telescope had extra gasoline left on board than anticipated for future changes to its orbit. This can enable Webb to function for much longer than the mission’s preliminary aim of 10 years.

The primary activity throughout Webb’s month-long journey to his remaining place in orbit was to open the telescope. This proceeded with none hitches, beginning with the deployment of the white hinge of the solar defend that helps cool the telescope, adopted by the alignment of the mirrors and the operation of the sensors.

As soon as the solar defend was opened, our workforce started monitoring the temperatures of the 4 cameras and spectrometers on board, ready for them to achieve temperatures low sufficient in order that we may start testing every of the 17 totally different modes during which the gadgets may function.


NIRCam, proven right here, will measure infrared gentle from distant and really previous galaxies. It was the primary instrument that got here on-line and helped align the mirror’s 18 segments. Credit score: NASA/Kris Jenn

2. What did you take a look at first?

The cameras on Webb cooled simply because the engineers anticipated, and the primary instrument the workforce turned on was the near-infrared digicam — or NIRCam. NIRCam is designed to review the faint infrared gentle produced by the oldest stars or galaxies within the universe. However earlier than it may try this, NIRCam had to assist align 18 particular person segments of a Net mirror.

As soon as the NIRCam cooled to 280 levels Fahrenheit, it was chilly sufficient to start detecting gentle mirrored off the Webb mirror clips and producing the telescope’s first photographs. The NIRCam workforce was ecstatic when the primary scans arrived. We have been in enterprise!

These photographs confirmed that every one components of the mirror have been pointing at a comparatively small space of ​​the sky, and the alignment was significantly better than our deliberate worst-case situation.

Webb’s precision-guidance sensor additionally got here into play right now. This sensor helps maintain the telescope firmly pointed on the goal – similar to picture stabilization in client digital cameras. Utilizing the star HD84800 as a reference level, I helped my NIRCam teammates hook up with align mirror segments till they have been almost good, much better than the minimal required for a profitable mission.

3. What sensors got here alive after that?

With the mirror alignment wrapped up on March eleventh, the near-infrared spectrometer – NIRSpec – and the near-infrared imager and spectrograph – NIRISS – completed cooling off and joined the social gathering.

NIRSpec is designed to measure the energy of various wavelengths of sunshine coming from a goal. This data can reveal the composition and temperature of distant stars and galaxies. NIRSpec does this by wanting on the goal object by way of an aperture that blocks different gentle.

NIRSpec has a number of slots that enable it to have a look at 100 objects without delay. Crew members started testing the place of the a number of targets, instructed the slots to open and shut, and confirmed that the slots have been responding appropriately to instructions. Future steps will measure precisely the place the cracks are pointing and confirm that a number of targets could be noticed concurrently.

NIRISS is a slit-free spectrometer that additionally splits gentle into totally different wavelengths, however is best at observing all objects within the subject, not simply these in slits. It has a number of modes, together with two which can be particularly designed to review exoplanets which can be notably near their guardian stars.

Up to now, system checks and calibrations have continued easily, and the outcomes present that each NIRSpec and NIRISS will present higher information than engineers anticipated earlier than launch.

Webb MIRI vs Spitzer Comparison Picture

The MIRI digicam, picture on the best, permits astronomers to see the mud clouds extremely clearly in comparison with earlier telescopes such because the Spitzer House Telescope, which produced the picture on the left. Credit score: NASA/JPL-Caltech (left), NASA/ESA/CSA/STScI (proper)

4. What was the final instrument you run?

The final instrument in addition on Webb was the mid-infrared instrument, or MIRI. MIRI is designed to seize photographs of distant or newly shaped galaxies in addition to small, faint objects reminiscent of asteroids. This sensor detects the longest wavelengths of Webb’s devices and have to be saved at 449 levels Fahrenheit – simply 11 levels Fahrenheit greater[{” attribute=””>absolute zero. If it were any warmer, the detectors would pick up only the heat from the instrument itself, not the interesting objects out in space. MIRI has its own cooling system, which needed extra time to become fully operational before the instrument could be turned on.

Radio astronomers have found hints that there are galaxies completely hidden by dust and undetectable by telescopes like Hubble that captures wavelengths of light similar to those visible to the human eye. The extremely cold temperatures allow MIRI to be incredibly sensitive to light in the mid-infrared range which can pass through dust more easily. When this sensitivity is combined with Webb’s large mirror, it allows MIRI to penetrate these dust clouds and reveal the stars and structures in such galaxies for the first time.

5. What’s next for Webb?

As of June 15, 2022, all of Webb’s instruments are on and have taken their first images. Additionally, four imaging modes, three time series modes and three spectroscopic modes have been tested and certified, leaving just three to go.

On July 12, NASA plans to release a suite of teaser observations that illustrate Webb’s capabilities. These will show the beauty of Webb imagery and also give astronomers a real taste of the quality of data they will receive.

After July 12, the James Webb Space Telescope will start working full time on its science mission. The detailed schedule for the coming year hasn’t yet been released, but astronomers across the world are eagerly waiting to get the first data back from the most powerful space telescope ever built.

Written by Marcia Rieke, Regents Professor of Astronomy, University of Arizona.

This article was first published in The Conversation.The Conversation