NASA’s Neowise Captured This Final Picture Before Shutting Down

On Thursday, scientists and engineers in Southern California got an exclusive glimpse at a recent snapshot of Fornax, a constellation of stars in the Southern Hemisphere.

The image itself is not particularly exciting, at least not to the untrained eye. But to those gathered, the image represented the last light of NASA’s Near-Earth Object Wide-field Infrared Survey Explorer, or NEOWISE, a telescope orbiting the Earth that spent more than a decade scrutinizing the skies for any asteroids and comets that could one day pose a threat to our planet. At the end of last month, the spacecraft’s survey concluded, and it closed its telescopic eyes for the final time.

“This was the little space telescope that could,” said Amy Mainzer, an astronomer at the University of California, Los Angeles, and principal investigator for NEOWISE. “We were really lucky to get to do this work.”

When the mission was launched in 2009, it was known simply as WISE. It spent the next year peering at faraway objects in the universe radiating infrared light, including supermassive black holes, brown dwarfs, dying stars and one of the most luminous galaxies in the cosmos.

WISE was never meant to study objects closer to Earth, but during its cosmic scans, scientists realized “it was pretty good at looking at asteroids, too,” Dr. Mainzer said. On one scan, WISE discovered the first asteroid to share an orbit with Earth, known as a Trojan. It also serendipitously observed a space rock named Dinkinesh, gathering data that came in handy years later on a recent NASA flyby of the object.

After its original survey, Dr. Mainzer and her colleagues successfully proposed that NASA extend the mission for a few months, with a focus on asteroid detection. Rebranded as NEOWISE, the spacecraft observed the solar system’s main asteroid belt until the space agency put its systems into hibernation in 2011.

NASA revived the telescope in 2013 for a mission explicitly prioritizing planetary defense. It spent the next 11 years cataloging more than 44,000 objects in the solar system, including a comet named after the NEOWISE spacecraft, which streaked through our night skies in 2021.

Having formerly orbited at an altitude of 310 miles, NEOWISE now sits just 217 miles above Earth’s surface, its descent spurred by increasing solar activity. This orbital degradation, which affects NEOWISE’s ability to collect useful data, led mission specialists to end its scientific survey on July 31. Eight days later, the team shut off its data transmitter for the last time.

The spacecraft is expected to burn up in the Earth’s atmosphere by the end of this year.

But for scientists on Earth, there are years of work left to do. “For us on the science team, our mission is far from over,” Dr. Mainzer said, adding that NEOWISE’s final data set will be released in the fall, and that several scientific papers are forthcoming.

And though she has been on the mission for over two decades, Dr. Mainzer doesn’t lament the loss; rather, she is excited for NASA’s next-generation planetary defender, the Near-Earth Object Surveyor, a space telescope that is to launch no earlier than 2027. Unlike its predecessor, NEO Surveyor will be specifically designed to hunt asteroids and other potential hazards close to home.

“It’s the end of an era,” Dr. Mainzer said, “but the beginning of a new one.”