In 2013, NASA launched the NEOWISE mission, an ambitious project aimed at cataloging and studying near-Earth objects, such as asteroids and comets. After just over ten years of operation, the mission officially came to an end in November 2024. This conclusion was attributed to a combination of technical and natural factors, marking the end of a key chapter in space exploration and planetary defense.
The program began in 2009 with the launch of the Wide-field Infrared Survey Explorer (WISE) space telescope. Designed to map the sky in the infrared spectrum, the telescope was built to identify stars, galaxies, and other celestial bodies with unprecedented detail. During its initial mission, WISE completed two full surveys of the sky, capturing detailed images of over 750 million cosmic objects.
However, in 2011, the telescope faced a setback: the depletion of its cryogenic coolant, which was necessary to operate at extremely low temperatures and ensure the accuracy of its infrared measurements. Despite this limitation, NASA engineers recognized that the equipment still had potential for additional missions. After a period of reassessment, it was reactivated in 2013 with a new purpose: to monitor and catalog near-Earth objects (NEOs). Thus, the NEOWISE mission was born, reconfiguring the telescope into a hunter of asteroids and comets orbiting near our planet.
For over a decade, the NEOWISE mission collected an impressive volume of data, having a profound impact on astronomy and planetary defense. The telescope made over 1.45 million infrared measurements, covering around 44,000 objects in the Solar System, many of which had not been previously identified.
Among its greatest achievements was the discovery of hundreds of new near-Earth objects, including the comet C/2020 F3 NEOWISE, which gained notoriety in 2020 by providing a rare celestial spectacle visible to the naked eye in various parts of the world. Additionally, the collected data were essential for scientists to analyze the physical and chemical characteristics of these celestial bodies, including their orbits, sizes, compositions, and trajectories relative to Earth.
Most importantly, the mission played a central role in planetary defense by identifying and monitoring potentially dangerous objects. This information allowed NASA and other space agencies to develop risk mitigation strategies to avoid possible catastrophic collisions with our planet.
The end of the NEOWISE mission was inevitable and the result of two main factors:
Increased Solar Activity
In recent years, the Sun entered a phase of heightened activity, known as solar maximum, characterized by intense solar flares and stronger solar winds. This increase in activity caused the Earth’s upper atmosphere to expand, a phenomenon that created more atmospheric drag on the NEOWISE telescope, which orbited about 500 kilometers above Earth’s surface. This drag made it difficult to maintain the telescope’s stable orbit.
Technical Limitations and Natural Wear
Originally designed for a short-term mission, the NEOWISE telescope faced natural wear and tear after more than a decade of operation. Over the years, the instruments became less efficient, and the lack of an active propulsion system to correct its orbit made it impossible to compensate for the effects of atmospheric drag.
These limitations culminated in the telescope’s return to Earth’s atmosphere. In early November 2024, NEOWISE reentered the atmosphere and was completely destroyed as it burned up during the process, marking the official end of the mission.
Despite the mission’s conclusion, NEOWISE’s scientific impact is undeniable. Its data continues to be used in astronomical studies and planetary defense. Furthermore, the mission laid a solid foundation for new projects that will carry forward its original purpose.
One such project is the NEO Surveyor, a next-generation space telescope designed specifically to detect smaller and harder-to-find objects. Scheduled for launch in 2027, the NEO Surveyor will have enhanced capabilities to identify asteroids and comets that could pose threats to our planet.
Unlike NEOWISE, which was an adaptation of an existing telescope, the NEO Surveyor is being developed from the ground up with the goal of monitoring near-Earth objects. It will be equipped with advanced technology capable of detecting even small asteroids hidden in the Sun’s glare, a task that is currently a significant challenge for astronomers.
The NEOWISE mission not only expanded our knowledge of the Solar System but also played a crucial role in protecting the planet. Its ability to identify and monitor near-Earth objects provided a model for future planetary defense initiatives. Although its end was inevitable, the legacy of the mission lives on in the data it provided and the new technologies it inspired.
With the arrival of the NEO Surveyor and other initiatives in development, humanity is better prepared to monitor and respond to potential space threats. Therefore, the end of NEOWISE marks not only the conclusion of a mission but also the beginning of a new era in the exploration and protection of our planet against the mysteries of the cosmos.
