West LA Times

NASA's NEOWISE spacecraft, known for its contributions to near-Earth object (NEO) discovery, is set to be decommissioned this week. Over nearly 11 years, the spacecraft captured 27 million infrared images and discovered 215 NEOs, including the notable NEOWISE comet in 2020. The Jet Propulsion Laboratory will shut down the spacecraft due to solar activity that has lowered its orbit, leading to an expected atmospheric burn-up by year-end.

Amy Mainzer, a UCLA planetary scientist and NEOWISE project leader, is spearheading NASA’s next mission, NEO Surveyor. This mission aims to identify potentially hazardous near-Earth objects.

The NEOWISE mission began as WISE (Wide-field Infrared Survey Explorer) in 2009 under UCLA astrophysicist Edward Wright. Its initial goal was to map the sky at infrared wavelengths with unprecedented sensitivity. After completing two scans and making 700 million observations of various celestial bodies, the telescope was put into hibernation due to coolant depletion.

Mainzer proposed reactivating WISE in 2013 using its remaining functional bands to detect faint NEOs. Renamed NEOWISE, it focused on planetary defense by surveying cosmic bodies close to Earth’s orbit. Over its extended mission, NEOWISE provided critical data on dark and light objects alike.

“We’re at the mercy of the sun,” said Mainzer. “It’s going to be weird when it’s gone because it’s been such a constant presence.”

One significant discovery was Earth’s first-known Trojan asteroid, 2010 TK₇. Mainzer described it as being trapped by Earth's gravity in a stable orbit for thousands of years.

NEOWISE also contributed valuable population studies on asteroids and comets, enhancing understanding of their sizes, compositions, and relationships within the main asteroid belt between Mars and Jupiter.

Reflecting on the NEOWISE comet's visibility during the COVID-19 pandemic, Mainzer shared her experience observing it from the Santa Monica Mountains: “It was a tough time... but we were all together watching the comet.”

Mainzer now leads NEO Surveyor, set for launch in 2027. This mission will use a 50-centimeter diameter telescope operating at infrared wavelengths to detect dark asteroids difficult for other telescopes to find. It aims to discover two-thirds of NEOs larger than 140 meters over five years.

“It’s strange to say goodbye to NEOWISE,” Mainzer remarked. “But we have the next one on the way.”