# Wide-field Infrared Survey Explorer

> decommissioned American infrared space telescope

**Wikidata**: [Q693552](https://www.wikidata.org/wiki/Q693552)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Wide-field_Infrared_Survey_Explorer)  
**Source**: https://4ort.xyz/entity/wide-field-infrared-survey-explorer

## Summary
Wide-field Infrared Survey Explorer (WISE) was a decommissioned American infrared space telescope launched by NASA in 2009. It conducted an all-sky infrared survey, mapping the entire sky in multiple infrared wavelengths before being placed in hibernation in 2011. The spacecraft was later reactivated as NEOWISE to search for near-Earth objects and operated until its decommissioning in 2024.

## Key Facts
- Launched on December 14, 2009, at 14:09:33 UTC from Vandenberg Space Launch Complex 2 West
- Operated as part of NASA's Explorers Program (Medium Explorer program, MIDEX-6)
- Weighed 661 kilograms and measured 2.0 meters wide, 2.85 meters high, and 1.73 meters long
- Conducted a full-sky infrared survey from January 14, 2010, until February 17, 2011
- Reactivated in September 2013 as NEOWISE for asteroid and comet detection
- Decommissioned on July 31, 2024, and re-entered Earth's atmosphere on November 2, 2024
- Discovered thousands of minor planets and contributed to understanding of brown dwarfs and distant galaxies

## FAQs
### Q: What was the primary mission of WISE?
A: WISE's primary mission was to conduct an all-sky infrared survey, mapping the entire celestial sphere in four infrared wavelengths to discover and characterize stars, galaxies, asteroids, and other cosmic objects that emit infrared radiation.

### Q: Why was WISE reactivated as NEOWISE?
A: WISE was reactivated in 2013 as NEOWISE to search for near-Earth objects (NEOs) like asteroids and comets that could potentially pose a threat to Earth, extending its scientific utility beyond its original survey mission.

### Q: How long did WISE operate in total?
A: WISE operated for approximately 14.6 years total, including its initial 10-month survey mission from 2010, hibernation period, and extended NEOWISE mission from 2013 to 2024.

## Why It Matters
WISE revolutionized our understanding of the infrared universe by providing the most comprehensive all-sky infrared survey ever conducted. Its observations revealed previously unseen cosmic structures, including ultra-luminous infrared galaxies, brown dwarfs, and vast dust clouds throughout the Milky Way. The mission's data has been fundamental to numerous astronomical discoveries and continues to be used by researchers worldwide. As NEOWISE, it played a critical role in planetary defense by detecting and characterizing potentially hazardous asteroids, contributing to NASA's efforts to catalog near-Earth objects. The mission demonstrated the value of space-based infrared astronomy and set new standards for survey efficiency and data quality. Its legacy includes thousands of scientific publications, educational resources, and a lasting impact on how we study both our solar system and the distant universe.

## Notable For
- First space telescope to survey the entire sky in four infrared wavelengths simultaneously
- Discovered more than 34,000 asteroids, including 135 near-Earth objects and 17 comets
- Provided the most detailed infrared map of the Milky Way, revealing billions of previously undetected objects
- Demonstrated successful reactivation and repurposing of a space telescope for planetary defense
- Created the most comprehensive catalog of brown dwarfs, including many of the coldest and nearest to Earth

## Body
### Mission Overview
WISE was designed to survey the entire sky in infrared light, detecting objects that are too cool, too distant, or too obscured by dust to be seen in visible light. The telescope used a 40-centimeter (16-inch) infrared telescope cooled to extremely low temperatures using solid hydrogen to minimize its own infrared emissions.

### Technical Specifications
The spacecraft featured a sophisticated payload including a cryostat containing solid hydrogen to cool the infrared detectors to below 8 Kelvin. It carried four infrared detectors sensitive to wavelengths of 3.4, 4.6, 12, and 22 microns, allowing it to detect everything from nearby asteroids to the most distant galaxies. The satellite operated in a Sun-synchronous polar orbit at approximately 525 kilometers altitude with a 95-minute orbital period.

### Scientific Achievements
During its initial survey, WISE discovered numerous brown dwarfs, including some of the coldest known, and identified millions of supermassive black holes across cosmic time. The mission created an all-sky atlas containing over 563 million objects, providing unprecedented infrared coverage of the universe. Its data has been crucial for studying star formation, galactic evolution, and the structure of our own Milky Way galaxy.

### NEOWISE Extension
After its initial mission ended due to depletion of cryogenic coolant, WISE was placed in hibernation. In 2013, it was reactivated as NEOWISE specifically to search for near-Earth objects. This extended mission discovered thousands of minor planets and provided critical data for assessing potential asteroid impact threats to Earth. The NEOWISE mission operated for over a decade, far exceeding its original design life.

### Legacy and Impact
WISE's comprehensive infrared survey has become a fundamental resource for astronomers worldwide, with its data being used in countless research projects. The mission demonstrated the scientific value of infrared space telescopes and influenced the design of subsequent missions. Its success in detecting near-Earth objects also highlighted the importance of planetary defense and the role space-based infrared observations play in identifying potentially hazardous asteroids.

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## References

1. [Source](https://space.skyrocket.de/doc_sdat/explorer_wise.htm)
2. [Source](https://www.jpl.nasa.gov/missions/wide-field-infrared-survey-explorer-wise)
3. [Source](https://www.sdl.usu.edu/downloads/brochures/wise.pdf)
4. Jonathan's Space Report
5. [Source](http://wise.ssl.berkeley.edu/documents/wise%20launch%202009-12-03.pdf)
6. Space-Track
7. [Source](https://x.com/planet4589/status/1852541398165180495)
8. Freebase Data Dumps. 2013
9. [Source](https://space.skyrocket.de/doc_sat/ball_rs-300.htm)
10. [Source](https://wise.ssl.berkeley.edu/news.html)
11. [Source](https://www.scientificamerican.com/article/nasa-retires-asteroid-hunting-telescope/)
12. [Source](https://www.nasa.gov/missions/neowise/nasas-neowise-infrared-heritage-will-live-on/)
13. [Source](https://www.space.com/24032-nasa-neowise-spacecraft-asteroid-photos.html)
14. [Source](https://www.jpl.nasa.gov/news/nasa-mission-concludes-after-years-of-successful-asteroid-detections)
15. [Source](https://neowise.ipac.caltech.edu/)