NASA’s NEOWISE celebrates 10 years, plans end of mission

The asteroid and comet-hunting infrared space telescope has gathered a powerful haul of observations, but it surely’s now on the mercy of the sun, which is accelerating its demise.

NASA’s NEOWISE has had a busy decade. Since its reactivated mission started on Dec. 13, 2013, the space telescope has found a once-in-a-lifetime comet, noticed greater than 3,000 near-Earth objects, bolstered worldwide planetary protection methods, and supported one other NASA mission’s rendezvous with a distant asteroid. And that is only a partial record of accomplishments.

However all good issues should come to an finish: Photo voltaic exercise is inflicting NEOWISE—brief for Close to-Earth Object Large-field Infrared Survey Explorer—to fall out of orbit. By early 2025, the spacecraft is anticipated to drop low sufficient into Earth’s environment that it’ll change into unusable. Ultimately, it would reenter our environment, solely burning up.

About each 11 years, the sun experiences a cycle of elevated exercise that peaks throughout a interval referred to as solar most. Explosive occasions, comparable to solar flares and coronal mass ejections, change into extra frequent and warmth up our planet’s environment, inflicting it to broaden. Atmospheric gases enhance drag on satellites orbiting Earth, slowing them down. With the sun at the moment approaching its subsequent most, NEOWISE will not be capable of preserve its orbit above our environment.

“The mission has deliberate for this day a very long time. After a number of years of calm, the sun is waking again up,” mentioned Joseph Masiero, NEOWISE’s deputy principal investigator and a scientist at IPAC, a analysis group at Caltech in Pasadena, California. “We’re on the mercy of solar activity, and with no means to maintain us in orbit, NEOWISE is now slowly spiraling again to Earth.”

WISE beginnings

The previous 10 years symbolize a second life for the spacecraft. Managed by NASA’s Jet Propulsion Laboratory in Southern California, NEOWISE repurposed a unique mission that launched in 2009: the Large-field Infrared Survey Explorer (WISE). Information from WISE and NEOWISE has been used to check distant galaxies, cool stars, exploding white dwarf stars, outgassing comets, near-Earth asteroids, and extra.

In 2010, WISE achieved its scientific aim of conducting an all-sky infrared survey with far larger sensitivity than earlier surveys. The WISE mission additionally discovered tens of tens of millions of actively feeding supermassive black holes throughout the sky. By the Disk Detective venture, citizen scientists have used WISE knowledge to seek out circumstellar disks, that are spinning clouds of fuel, dust, and rubble round stars.

Invisible to the naked eye, infrared wavelengths are emitted by heat objects. To maintain the warmth generated by WISE itself from interfering with its observations of infrared wavelengths, the spacecraft relied on cryogenic coolant. After the coolant ran out and WISE had mapped the sky twice, NASA put the spacecraft into hibernation in February 2011.

With out coolant, the space telescope may not observe the universe’s coldest objects, but it surely may nonetheless see near-Earth asteroids and comets, that are heated by the sun. So NASA reactivated the spacecraft in 2013 with a extra specialised position in thoughts: aiding planetary protection efforts by surveying and learning these objects, which may stray into our planet’s orbital neighborhood and create a possible influence hazard.

Astronomers couldn’t solely depend on the mission to hunt out these objects, but in addition use its knowledge to determine their dimension and albedo—how a lot daylight their surfaces replicate—and to collect clues in regards to the minerals and rocks they’re composed of.

“NEOWISE has showcased the significance of getting an infrared space survey telescope as a part of NASA’s planetary protection technique whereas additionally maintaining tabs on different objects within the solar system and past,” mentioned Amy Mainzer, the mission’s principal investigator on the College of Arizona in Tucson.

Mainzer can also be main NASA’s upcoming NEO Surveyor, which can construct on NEOWISE’s legacy. The subsequent-generation infrared space telescope will hunt down a number of the hardest-to-find near-Earth objects, comparable to darkish asteroids and comets that do not replicate a lot visible light, in addition to objects that strategy Earth from the path of the sun. Scheduled for launch in 2027, the JPL-managed mission may also seek for objects often known as Earth Trojans—asteroids that lead or path our planet’s orbit—the primary of which WISE found in 2011.

Comet NEOWISE and past

Since turning into NEOWISE, the mission has scanned the whole sky over 20 occasions and made 1.45 million infrared measurements of over 44,000 solar system objects. That features greater than 3,000 near-Earth objects, 215 of which NEOWISE found. Information from the mission has contributed to refining the orbits of those objects whereas gauging their dimension as properly.

Its forte is characterizing near-Earth asteroids. In 2021, NEOWISE turned a key element of a global planetary protection train that targeted on the hazardous asteroid Apophis.

The mission has additionally found 25 comets, together with the long-period comet C/2020 F3 (NEOWISE). The comet turned a blinding celestial object seen within the Northern Hemisphere for a number of weeks in 2020 and the primary comet that may very well be seen by the bare eye since 2007, when Comet McNaught was primarily seen within the Southern Hemisphere.

Future researchers will proceed to depend on the huge archive of NEOWISE observations to make new discoveries, much like the way in which researchers used WISE knowledge from 2010 lengthy after the observations have been made to characterize asteroid Dinkinesh in help of NASA’s Lucy mission earlier than its October 2023 encounter.

“It is a bittersweet second. It is unhappy to see this trailblazing mission come to an finish, however we all know there’s extra treasure hiding within the survey knowledge,” mentioned Masiero. “NEOWISE has an unlimited archive, overlaying a really lengthy time frame, that may inevitably advance the science of the infrared universe lengthy after the spacecraft is gone.”