James Webb’s tools reach the temperature they need to work – the science

The last of these steps to cool its instruments and the last to achieve this was MIRI, an infrared instrument developed by NASA and the European Space Agency (ESA), which finally reached -266 degrees Celsius, the ideal working temperature. NASA reports.

MIRI was able to cool down to that temperature thanks to a Webb’s canopy shade (the size of a tennis court) and the added help of a coolant that sped its cooling to -266°C.

The lower temperature is important for Webb’s instruments because they all detect infrared light, which is emitted by distant galaxies, stars hidden in dust clouds, and exoplanets.

If Webb’s instruments weren’t cool, the heat from the telescope itself would mask the infrared emissions it’s supposed to be looking at. In the case of MIRI, since it detects infrared wavelengths that are longer than the other three devices, it has to be much cooler.

Another reason Webb’s detectors need to be cool is to suppress something called dark current, or electric current, caused by vibrating atoms in the detectors themselves that can be confused with false signals or masking of signals astronomers want to find.

And just as MIRI has a greater ability than the rest of the devices to detect longer infrared wavelengths, it’s also more sensitive to dark current, so it needs to be cooler than other tools to eliminate this effect completely, the site explains. NASA.

When the four instruments had cooled down to their ideal working temperature, the scientists performed a series of checks to make sure the telescope’s detectors were working properly.

“We’ve spent years training to this point, carrying out commands and checks in MIRI,” explains Mike Ressler, MIRI project scientist at NASA’s Jet Propulsion Laboratory (JPL).

researcher says.

But the team will face more challenges before MIRI begins its science mission.

Now that the instrument has reached operating temperature, team members will take test images of stars and other known objects that can be used to calibrate and verify the instrument’s operations and functions.

The team will make these preparations along with the calibration of the other three instruments, and if all goes well, the telescope will send out the first scientific images this summer.