Nasa has officially concluded its NEOWISE mission, marking the end of a significant decade-long effort to track and identify asteroids and comets posing potential threats to Earth. Launched originally as the Wide-field Infrared Survey Explorer (WISE) back in December 2009, the spacecraft transitioned to NEOWISE after its coolant ran out, leading to the reallocation of its mission goals. This adjustment enabled it to focus primarily on detecting near-Earth objects (NEOs).
On August 10, 2024, the last command was sent out to shut down the NEOWISE spacecraft from the Jet Propulsion Laboratory (JPL) located in Southern California. The event was attended by current and former team members as well as NASA officials, witnessing the culmination of years of scientific contributions. The command ensured all relevant scientific data had been transmitted back to Earth before the shutdown.
According to Nicola Fox, associate administrator at NASA’s Science Mission Directorate, "NEOWISE has been an extraordinary success, enhancing our knowledge of the universe and making endeavors to safeguard our planet against potential hazards.” She noted the bittersweet feeling of ending such an impactful mission.
The decision to terminate NEOWISE's operations stemmed from its increasingly low orbit around Earth. The spacecraft struggled to maintain its altitude due to heightened solar activity causing the upper atmosphere to expand, which increased drag on the satellite. Without any propulsion system to counteract this, it became impossible for NEOWISE to continue gathering reliable data, leading to its scheduled reentry and disintegration within Earth's atmosphere by late 2024.
NEOWISE played a critical role over its operational lifetime, detecting over 3,000 near-Earth objects and significantly contributing to planetary defense initiatives. One of its standout achievements was the discovery of Comet C/2020 F3 NEOWISE, which captured the public's attention with stunning views and easy visibility during its approach to Earth. The telescope managed to create comprehensive all-sky maps through over 1.45 million infrared observations, leading to the identification of many celestial objects.
Once NEOWISE entered hibernation after its initial success as WISE, it was reactivated and reassigned under NASA’s Near-Earth Object Observations Program, part of the Planetary Defense Coordination Office. This move witnessed NEOWISE return to the operational fold, allowing it to fulfill its critical mission of identifying celestial objects posing risks to Earth.
NEOWISE’s conclusion paves the way for future advancements in asteroid monitoring. A successor, known as the NEO Surveyor, is set to launch no earlier than 2027, aiming to continue and potentially expand upon NEOWISE's work. It is expected to conduct regular sky scans every two weeks and boasts enhanced capabilities, such as specialized infrared technology and solar shading to assist observations close to the Sun, which NEOWISE could not effectively assess.
Amy Mainzer, who served as the principal investigator for both NEOWISE and its upcoming replacement, expressed her appreciation for NEOWISE's legacy: “NEOWISE has provided invaluable long-term datasets and set the groundwork for future advancements.” The NEO Surveyor seeks to identify some of the most elusive near-Earth objects and would greatly improve global planetary defense strategies.
The overarching goal of NASA’s near-Earth object initiatives is to identify and characterize at least 90% of potentially hazardous asteroids over 140 meters—an objective established following the NASA Authorization Act of 2005. The success of NEOWISE has laid the foundation upon which future efforts will be constructed, including the more advanced capabilities of the NEO Surveyor.
The future of asteroid detection remains bright, thanks to the contributions and data collected from NEOWISE over the past years. Although the telescope will soon reenter Earth’s atmosphere, its findings and technological advancements will inform scientists and researchers for generations to come. Earthly threats from space won't be forgotten—as NEOWISE's data will fuel efforts for not just discovery but also for preserving the planet from unexpected cosmic visitors.
