This artistic representation illustrates the Wide-field Infrared Survey Explorer (WISE) spacecraft, encircling Earth. Under the NEOWISE mission, its primary role has been the detection and analysis of asteroids. Image courtesy of NASA/JPL-Caltech.
NASA’s space telescope dedicated to identifying and tracking asteroids and comets, utilizing infrared technology, has amassed an extensive array of data. However, it’s currently facing an accelerated end due to heightened solar activity.
Since its reactivation on December 13, 2013, NEOWISE has achieved remarkable feats, including discovering a once-in-a-generation comet, tracking over 3,000 near-Earth objects, contributing significantly to global planetary defense strategies, and supporting a NASA mission’s encounter with a remote asteroid, among other achievements.
Regrettably, the mission is nearing its conclusion due to solar influences. The NEOWISE spacecraft, known fully as the Near-Earth Object Wide-field Infrared Survey Explorer, is gradually losing its orbit because of solar activity. By early 2025, it’s anticipated to descend sufficiently into Earth’s atmosphere, rendering it inoperative and eventually leading to its disintegration upon reentry.
The Sun undergoes an 11-year cycle of heightened activity, peaking during the solar maximum. This period is characterized by increased solar events like flares and coronal mass ejections, which expand Earth’s atmosphere. This expansion increases atmospheric drag on satellites, slowing them down. With the Sun approaching its next maximum, NEOWISE is unable to maintain its orbital position.
On March 27, 2020, Comet C/2020 F3 NEOWISE was captured as a series of fuzzy red dots in a compilation of infrared images taken by the NEOWISE mission. Image Credit: NASA/JPL-Caltech.
Joseph Masiero, NEOWISE’s deputy principal investigator at IPAC, Caltech, Pasadena, California, acknowledges that the end of the mission was anticipated. He notes the Sun’s reemergence from a period of dormancy, emphasizing the spacecraft’s inevitable descent due to uncontrollable solar activity.
The Second Life of WISE
The last decade symbolizes a renewed chapter for the spacecraft. Operated by NASA’s Jet Propulsion Laboratory in Southern California, NEOWISE repurposed the original WISE mission launched in 2009. Data from both WISE and NEOWISE has been instrumental in studying distant galaxies, cool stars, exploding white dwarfs, active comets, near-Earth asteroids, and more.
In 2010, WISE successfully completed a comprehensive infrared survey of the sky, exceeding the sensitivity of previous surveys. It identified numerous supermassive black holes actively accumulating matter. WISE data also facilitated the discovery of circumstellar disks, comprised of gas, dust, and debris, around stars, through the citizen scientist-led Disk Detective project.
Infrared wavelengths, invisible to the naked eye and emitted by warm objects, were the focus of WISE’s observations. To prevent interference from its own heat emissions, the spacecraft utilized cryogenic cooling. After depleting its coolant supply and completing two sky mappings, WISE was placed into hibernation in February 2011.
Despite the absence of coolant, restricting its ability to observe the coldest celestial bodies, WISE could still detect near-Earth asteroids and comets heated by the Sun. Thus, in 2013, NASA reactivated the spacecraft with a focused objective: to aid planetary defense by surveying these objects, posing potential impact hazards to Earth.
Astronomers not only identified these objects through the mission but also analyzed their size, reflectivity (albedo), and compositional hints.
Amy Mainzer, the mission’s principal investigator at the University of Arizona, Tucson, highlights NEOWISE’s role in NASA’s planetary defense strategy and its contributions to the broader study of solar system and beyond. Mainzer is also leading the upcoming NEO Surveyor mission, a successor to NEOWISE, set for launch in 2027. This next-generation infrared telescope will search for elusive near-Earth objects, including dark asteroids and comets, and Earth Trojans. The first Earth Trojan was discovered by WISE in 2011.
NEOWISE’s Legacy and Future Impact
As NEOWISE, the mission has scanned the sky over 20 times, capturing 1.45 million infrared measurements of more than 44,000 solar system objects, including the discovery of over 3,000 near-Earth objects and 215 new findings. The mission has refined the orbits and estimated the sizes of these objects.
NEOWISE has been pivotal in studying near-Earth asteroids, notably in 2021, when it played a crucial role in an international planetary defense exercise focusing on the potentially hazardous asteroid Apophis.
The mission also discovered 25 comets, including the long-period comet C/2020 F3 (NEOWISE), a spectacular sight in the Northern Hemisphere in 2020
Frequently Asked Questions (FAQs) about NEOWISE Mission
Why is NASA’s NEOWISE Mission Ending?
The NEOWISE mission is ending due to increased solar activity, which has caused the spacecraft to gradually lose its orbit. The heightened solar events, such as solar flares and coronal mass ejections, have expanded Earth’s atmosphere, increasing drag on the spacecraft and making it unable to maintain its position above the atmosphere.
What Were the Key Achievements of the NEOWISE Mission?
NEOWISE’s key achievements include discovering a unique comet, tracking over 3,000 near-Earth objects, contributing to global planetary defense strategies, and supporting NASA missions to distant asteroids. The mission has scanned the sky over 20 times and made significant infrared measurements of solar system objects.
What Will Happen to NEOWISE After It Falls Out of Orbit?
After falling out of orbit due to solar activity, NEOWISE is expected to descend into Earth’s atmosphere by early 2025, where it will become inoperative and eventually disintegrate upon reentry.
What is the Significance of the NEOWISE Mission for Future Space Research?
NEOWISE has showcased the importance of infrared space survey telescopes in planetary defense and solar system studies. Its vast archive of observations will continue to aid future research and discoveries, similar to how previous WISE data was used long after the mission ended.
What is NASA’s Next Step After NEOWISE?
Following NEOWISE, NASA plans to launch the NEO Surveyor mission in 2027. This next-generation infrared space telescope will build on NEOWISE’s legacy, seeking out hard-to-find near-Earth objects and contributing further to planetary defense and space research.
More about NEOWISE Mission
- NASA’s NEOWISE Mission
- NEOWISE: NASA’s Asteroid and Comet Hunter
- NEOWISE Mission Overview
- NASA’s Planetary Defense Coordination Office
- NEO Surveyor Mission