Farewell, NEOWISE: A Decade of Tracking Celestial Objects and Protecting Earth
After over a decade of diligently scanning the cosmos, NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) has officially ended its mission. On August 1st, 2024, the telescope transmitted its final image – a stunning infrared view of the Fornax constellation – marking the end of an incredibly successful journey. This final image is just one of the 26,886,704 pictures NEOWISE captured during its lifetime, leaving behind a legacy of invaluable scientific data.
Launched in 2009, NEOWISE was initially tasked with mapping the infrared sky, offering scientists an unprecedented glimpse into the universe’s hidden secrets. Equipped with advanced infrared detectors, it could peer through vast clouds of gas and dust, revealing distant galaxies, stars, and white dwarfs with remarkable clarity. Unfortunately, within a few months of its launch, NEOWISE encountered a critical setback: its coolant supply, crucial for maintaining the instrument’s optimal temperature, ran out. This meant the telescope could no longer perform its initial mission in its entirety.
However, NEOWISE’s story didn’t end there. NASA, recognizing its unique capabilities, repurposed the telescope for a new, crucial objective: asteroid and comet detection. The spacecraft was placed into hibernation in February 2011, only to be reactivated in 2013 with a renewed purpose. This second act in NEOWISE’s career saw it become a vital part of NASA’s ongoing effort to safeguard Earth from potential celestial threats.
Since its reactivation, NEOWISE painstakingly catalogued over 44,000 objects within our solar system, including 215 near-Earth objects (NEOs) and 25 new comets. "The NEOWISE mission has been an extraordinary success story," stated NASA in a press release, highlighting its contributions to understanding "our place in the universe by tracking asteroids and comets that could be hazardous for us on Earth."
NEOWISE’s success extended far beyond simply detecting new objects. Its meticulous observations allowed scientists to refine their understanding of these space rocks, their characteristics, and their potential impact on our planet. The data collected by NEOWISE has been invaluable for planetary defense strategies, helping us better assess the risks associated with near-Earth asteroid impacts.
"NEOWISE was a fantastic mission that provided us with a treasure trove of data that will guide and inspire researchers for years to come," remarked Amy Mainzer, principal investigator of the NEOWISE mission at the University of Arizona. "The mission’s success not only advanced our knowledge of the solar system but also directly impacts our efforts to protect Earth from potentially hazardous objects."
Unfortunately, even the most resilient technologies eventually face their end. In December 2023, NASA announced the impending retirement of NEOWISE, triggered by a natural phenomenon: the sun’s increasing activity. The sun’s heightened activity led to a significant expansion of Earth’s atmosphere, creating increased atmospheric drag on NEOWISE. This drag, in turn, caused the telescope’s orbit to gradually deteriorate, ultimately leading to a decrease in its altitude.
Reaching a point where its orbit would be too low to collect usable data, NEOWISE was approaching a critical juncture. The risk of the telescope burning up in Earth’s atmosphere outweighed the benefits of continued operation. Thus, the decision was made to end the mission, ensuring the safety of the spacecraft and reducing the risk of potential debris in Earth’s orbit.
NEOWISE’s retirement marks the end of an era, but it also signifies the continuation of Earth’s pursuit of understanding and protecting itself from the dangers lurking in space. NASA is already gearing up for the next chapter in planetary defense with the Near-Earth Object Surveyor (NEO Surveyor), which is scheduled to launch in September 2027.
NEO Surveyor, equipped with advanced capabilities and a dedicated mission to detect and characterize NEOs, is poised to carry the torch of planetary defense forward. This new space telescope is expected to significantly improve our ability to track and understand potentially hazardous objects, building upon the foundation laid by NEOWISE.
Looking back on NEOWISE’s remarkable journey, it’s clear that the telescope’s legacy extends far beyond its scientific contributions. It embodies the spirit of human curiosity and the unwavering drive to explore the cosmos, learn from the universe, and ensure our planet’s safety in the face of cosmic challenges. While NEOWISE may have reached its final destination, its story continues to inspire us to push the boundaries of knowledge and continue seeking answers to the mysteries of the universe. As we look towards the future, we can learn from NEOWISE’s success and strive to build upon its achievements, ensuring that our journey through the vast expanse of space is a safe and enlightening one.
