Near-Earth Object Wide Field Infrared Survey Explorer

active Mission
Spacecraft above Earth with the Sun and comets in the background.

A space telescope’s second act, NEOWISE was assigned to monitor asteroids and comets, especially those that might threaten Earth. Launched in December 2009 as WISE (the Wide-field Infrared Survey Explorer), and expected to last about 10 months, it scanned the distant universe until February 2011 – identifying the most luminous galaxies in the cosmos, finding millions of hidden black holes, and discovering the coolest class of stars. In late 2013 it was taken out of hibernation, repurposed, and renamed NEOWISE, for the near-Earth objects it would hunt. But now increasing solar activity is affecting its orbit, and NEOWISE is expected to burn up in Earth's atmosphere by 2025.


Space Telescope


Dec. 14, 2009


Earth orbit


Search for near-Earth asteroids and comets


NASA's WISE (Wide-field Infrared Survey Explorer) spacecraft was an infrared-wavelength astronomical space telescope active from December 2009 to February 2011. In 2013 the spacecraft was assigned a new mission as NEOWISE, to help find near-Earth asteroids and comets.

  • NEOWISE hunts near-Earth objects from low-Earth orbit.
  • The spacecraft orbits Earth once every 95 minutes – 15 times per day.

United States of America (USA)
Low-Earth Orbit
Spacecraft Mass
1,457 pounds (661 kilograms)
Mission Design and Management
Launch Vehicle
Delta 2
Launch Date and Time
Dec. 14, 2009 | 14:09 UT
Launch Site
Vandenberg Air Force Base, California (USA)
Scientific Instruments
Cryogenic Telescope with Four Megapixel Infrared Cameras

Key Dates

Dec. 14, 2009: Launch

January 2010 to February 2011: Primary mission

Feb. 17, 2011: Spacecraft placed in hibernation

Late 2013: Spacecraft reactivated, and assigned new mission as NEOWISE

June 30, 2021: NEOWISE gets a two-year mission extension

Dec. 13, 2023: The NEOWISE team celebrates the 10th anniversary of its second life as a planetary defender, while also announcing its impending end of mission, saying it will burn up in Earth's atmosphere by 2025.


NASA's WISE (Wide-field Infrared Survey Explorer) spacecraft was successfully launched to near-Earth orbit on Dec. 14, 2009, to serve as an infrared-wavelength astronomical space telescope.

WISE surveyed the full sky in four infrared wavelength bands (3.4, 4.6, 12, and 22 μm) until the frozen hydrogen cooling the telescope was depleted in September 2010. During its run, it discovered the most luminous galaxy in the universe, shining with the light of more than 300 trillion suns, undermined theories about the existence of a hidden Planet X lurking in the farthest reaches of our solar system, uncovered millions of hidden black holes, and spied elusive brown dwarfs, peculiar and cold objects that are neither stars nor planets. All these and more are among the three-quarters of a billion objects WISE cataloged during the two full-sky scans it completed, mapping the universe in every direction surrounding Earth. But without the hydrogen coolant, the telescope began to warm up – at one point reaching minus 334 degrees Fahrenheit (minus 203 degrees Celsius) – and its own infrared signature threatened to drown out the scant heat detectable from objects billions of light-years away.

The spacecraft was placed into hibernation in February 2011, having completed its primary astrophysics mission.

An all sky mosaic with beautiful blues amid the dark of space.
This mosaic shows a 360-degree view of the universe around us, a full-sky map compiled by the Wide-field Infrared Survey Explorer (WISE). Infrared light refers to wavelengths that are longer than those visible to the human eye; instead, we detect infrared energy as heat. In the mosaic, the Milky Way galaxy runs horizontally across this map. The galaxy is shaped like a disk, with our solar system located about two-thirds of the way toward the edge from the center. In this image, looking toward the center, we are observing more of the disk than when we look at angles away from the center; that's why more stars (colored blue-green) are seen closer to the middle of the image. The red dot at bottom left indicates the planet Jupiter.

In late 2013, the spacecraft was assigned a new mission by NASA’s Planetary Science Division. Now called NEOWISE, the spacecraft began helping NASA identify and describe near-Earth objects (NEOs). NEOs are comets and asteroids that have been nudged into orbits that allow them to enter Earth's neighborhood. Potentially hazardous asteroids (PHAs) are asteroids that could one day threaten Earth. Near-Earth objects are classified as PHAs based on their size and how closely they can approach Earth's orbit.

NEOWISE went back to work in December 2013, and just six days later it had discovered its first potentially hazardous near-Earth asteroid: 2013 YP139.

The image shows a star field in space, hundreds of scattered dots of greenish white, of varying sizes and brightnesses, against a black background. Lined up horizontally in the upper third of the image are six evenly spaced small red dots, with blue circles dran around each to set them off. A small, blue-lined box at the bottom of the image shows a magnified view of one of the red dots, and the stars surrounding it.
This composite picture shows the movement of the first near-Earth asteroid discovered by NEOWISE (NASA's Near-Earth Object Wide-field Infrared Survey Explorer), after the spacecraft came out of hibernation in December 2013. The red dots show the asteroid 2013 YP139 moving across the sky; the inset shows a zoomed-in view of one of the detections of 2013 YP139. It was discovered by NEOWISE on Dec. 29, 2013. The mission's sophisticated software picked out the moving object against a background of stationary stars. The image is about 1.5 degrees across. Asteroid 2013 YP139 was traveling across the sky at about 3.2 degrees per day when these images were taken. For reference, the full moon is about 0.5 degree across.

On June 30, 2021 – International Asteroid Day – NASA announced it was extending the NEOWISE mission.

“At NASA, we’re always looking up, surveying the sky daily to find potential hazards and exploring asteroids to help unlock the secrets of the formation of our solar system,” said NASA Administrator Bill Nelson. “Using ground-based telescopes, over 26,000 near-Earth asteroids have already been discovered, but there are many more to be found. We’ll enhance our observations with space-based capabilities like NEOWISE and the future, much more capable NEO Surveyor, to find the remaining unknown asteroids more quickly, and identify potentially hazardous asteroids and comets before they are a threat to us here on Earth.”

NEOWISE has provided an estimate of the size of more than 1,850 NEOs, helping us better understand our nearest solar-system neighbors.

“NEOWISE provides a unique and critical capability in our global mission of planetary defense, by allowing us to rapidly measure the infrared emission and more accurately estimate the size of hazardous asteroids as they are discovered,” said Lindley Johnson, NASA's Planetary Defense Officer and head of the Planetary Defense Coordination Office (PDCO) at NASA Headquarters in Washington. “Extending NEOWISE’s mission highlights not only the important work that is being done to safeguard our planet, but also the valuable science that is being collected about the asteroids and comets further out in space.”

As of February 2024, NEOWISE had made more than 1.5 million infrared measurements of 43,926 different solar system objects, including 1,571 near-Earth objects and 282 comets, and had completed 45% of the scanning for its 21st full-sky map of the universe around us.

Among its many accomplishments after its reactivation, NEOWISE also discovered Comet NEOWISE, which was named after the mission and dazzled observers worldwide in 2020.

Comet NEOWISE appears in a sky streaked with purple and green aurora
Comet NEOWISE is visible in an aurora-filled sky in this photo by citizen scientist Donna Lach, a NASA Aurorasaurus Ambassador. The photo was taken early on July 14, 2020, in western Manitoba, Canada. The comet was named for NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) space telescope, which discovered the icy visitor on March 27, 2020. It was one of 34 comets the mission found through early 2024, while hunting celestial objects that could threaten Earth.
Donna Lach

The NEOWISE telescope’s replacement, the next-generation NEO Surveyor, is currently scheduled to launch in 2028, and will greatly expand on what we have learned, and continue to learn, from NEOWISE.

“NEOWISE has taught us a lot about how to find, track, and characterize Earth-approaching asteroids and comets using a space-based infrared telescope,” said Amy Mainzer, the NEOWISE principal investigator. “The mission serves as an important precursor for carrying out a more comprehensive search for these objects using the new telescope we’re building, the NEO Surveyor.” Mainzer is also the lead of the NEO Surveyor mission.

The NEOWISE project is managed by NASA’s Jet Propulsion Laboratory in Southern California, a division of Caltech, and by the University of Arizona, supported by NASA’s Planetary Defense Coordination Office.

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