Roman around the Christmas tree | Space photo of the day for Dec. 25, 2025
All the NASA engineers and scientists need is a star on top of the telescope in the cleanroom.

The Nancy Grace Roman Space Telescope being inspected on terra firma. (Image credit: NASA/Michael Guinto)
In a scene that feels more like a midnight vigil than a routine inspection, NASA engineers and scientists gathered in near darkness inside a pristine cleanroom. Armed with flashlights and ultraviolet lamps, members of the Nancy Grace Roman Space Telescope team carefully examined the observatory's primary mirror, searching for even the smallest trace of contamination.
The eerie green glow illuminating the cleanroom wasn't festive lighting but the result of a long exposure combined with a small indicator lamp on the wall, an unassuming signal that the airflow in the room was just right.
What is it?
The Roman Space Telescope is one of NASA's next great observatories, designed to explore some of the biggest questions in modern astronomy. From probing the mysterious nature of dark energy to discovering thousands of new exoplanets, Roman will survey the universe with a wide-field view far beyond what previous space telescopes have achieved.
To do this science, Roman will employ extraordinarily sensitive optics, especially its primary mirror. Even microscopic dust particles or residues can scatter light and degrade observations. That's why inspections take place in cleanrooms that are cleaner than hospital operating theaters, under lighting conditions carefully chosen to reveal what the naked eye might otherwise miss.
Ultraviolet light causes certain contaminants to fluoresce, making them easier to spot. The team's slow, methodical work under flashlights and UV lamps ensures that the mirror meets the strict standards required for spaceflight. It's meticulous, patient labor — more "silent night" than spotlight moment — but it is essential to the telescope's future success.
Where is it?
This image was taken at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
Breaking space news, the latest updates on rocket launches, skywatching events and more!