Near-Earth Object Wide Field Infrared Survey Explorer

active Mission

A space telescope’s second act, NEOWISE was assigned to monitor asteroids and comets, especially those threatening Earth. Launched in December 2009 as the Wide-field Infrared Survey Explorer, or WISE, it surveyed the distant universe until February 2011. In late 2013, it was taken out of hibernation, repurposed and renamed NEOWISE, for the near-Earth objects it would hunt.


Space Telescope


Dec. 14, 2009


Earth orbit


Search for near-Earth asteroids and comets
Illustration of a gold and blue spacecraft orbiting Earth
NEOWISE, short for Near-Earth Object Wide-field Infrared Survey Explorer, surveys near-Earth asteroids and calculates radiometric diameters and albedos for almost all known asteroids. 


NASA's WISE (Wide-field Infrared Survey Explorer) spacecraft was an infrared-wavelength astronomical space telescope active from December 2009 to February 2011. In September 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, Calif. (USA)
Scientific Instruments
Cryogenic Telescope with Four Megapixel Infrared Cameras

Key Dates

Dec. 14, 2009: Launch

Jan. 2010 to Feb. 2011: Primary mission

February 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


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.

The spacecraft was placed into hibernation in February 2011 after completing its search of the inner solar system.

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.
The six red dots in this composite picture show the movement of the first new near-Earth asteroid seen by NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) after the spacecraft came out of hibernation in December 2013. 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. As of September 2023, the NEO-hunting space telescope marked 10 years since its reactivation, and had completed 60% of the scanning for its 20th full-sky map of the universe around us.

“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 over 1,850 NEOs, helping us better understand our nearest solar system neighbors.

As of March 2021, the mission had made 1,130,000 confirmed infrared observations of approximately 39,100 objects throughout the solar system since its restart in 2013. Mission data is shared freely by the IPAC/Caltech-led archive and the data has contributed to over 1,600 peer-reviewed studies.

“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.”

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

NEOWISE’s replacement, the next-generation NEO Surveyor, is currently scheduled to launch in 2026, 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 the University of Arizona, supported by NASA’s PDCO.

Key Resources

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