On December 14, 2009, at 14:09 UTC, the NEOWISE space telescope was launched aboard an Atlas II rocket from Vandenberg Air Force Base in California.
NEOWISE is situated in an orbit at an altitude of 525 kilometers and features a 40-centimeter-diameter infrared telescope operated by NASA’s Jet Propulsion Laboratory (JPL).
Although the mission was initially expected to conclude next year, increased solar activity has led to a warming and expansion of the upper atmosphere, which has intensified drag and caused the spacecraft to descend. The absence of a propulsion system to regain its orbit has expedited its end.
Last Thursday, JPL controllers sent the spacecraft its final command—an order to shut down its systems and transmissions. This last command marked the conclusion of a mission lasting 14 years, 7 months, and 17 days, far exceeding the initial expectations of its planners.
ORIGINAL MISSION
The mission was originally called WISE, an acronym for Wide-field Infrared Survey Explorer, and was planned to last ten months. During this period, the telescope was set to observe the sky across four different infrared wavelengths.
Throughout its primary mission, WISE detected over 158,000 minor planets, with more than 34,000 being newly discovered.
However, in September 2010, the space telescope depleted its cryogenic coolant, which was essential for preventing the heat generated by the spacecraft from interfering with its detectors’ proper functioning.
Although sky mapping continued for another four months using the two shorter wavelength detectors, all of the spacecraft’s systems ultimately entered hibernation mode in February 2011.
A SECOND LIFE
Two years later, NASA concluded that despite the absence of coolant preventing the observation of faint, distant objects, the telescope could still observe asteroids and comets that passed near Earth and emitted a strong infrared signal due to solar heating.
In December 2013, NEOWISE was reactivated for this new mission: studying the population of near-Earth objects that could pose a potential impact risk in the future.
These near-Earth objects are known as NEOs (Near Earth Objects), and the combination of this term with the original WISE mission led to the name NEOWISE, by which this sentinel of the skies has been known for its work observing asteroids and comets in our vicinity.
“NEOWISE has been instrumental in mapping the sky and understanding the near-Earth environment. The mission’s wealth of discoveries has expanded our knowledge of asteroids and comets,” stated JPL Director Laurie Lashin.
Throughout its lifetime, the telescope made a total of 1.6 million infrared measurements of over 44,000 different solar system objects, including 1,598 near-Earth objects and 291 comets.
In addition to its significant scientific legacy, the experience and knowledge gained from NEOWISE have played a crucial role in developing the first infrared space observatory specifically designed to monitor potentially hazardous asteroids and comets. This new space telescope, currently under development, will be called NEO Surveyor, with a launch scheduled for September 2027.
As Amanda Mainzer, the principal investigator of the project, said, “NEOWISE has provided unique, long-duration data of the infrared sky that scientists will use for decades to come. Its additional legacy is that it has helped lay the groundwork for NASA’s next Planetary Defense Infrared Space Telescope.”
The NEOWISE Space Telescope: A Journey Through Time and Space
On December 14, 2009, at 14:09 UTC, the NEOWISE space telescope was launched aboard an Atlas II rocket from Vandenberg Air Force Base in California. This remarkable instrument has significantly advanced our understanding of the universe, particularly in the study of asteroids and comets.
NEOWISE was positioned in an orbit at an altitude of 525 kilometers, featuring a 40-centimeter-diameter infrared telescope. Operated by NASA’s Jet Propulsion Laboratory (JPL), its mission turned out to be far more extensive than initially planned, providing invaluable data over the years.
Although the mission was expected to conclude in 2021, increased solar activity has warmed and expanded the upper atmosphere, causing increased drag that hastens NEOWISE’s descent. Lacking a propulsion system to regain orbit, the telescope’s mission ended recently with a final command from JPL controllers, concluding a remarkable journey of 14 years, 7 months, and 17 days.
The Original Mission of NEOWISE
Initially, the mission was titled WISE, which stands for Wide-field Infrared Survey Explorer. It was designed for a ten-month operational timeline during which the telescope aimed to observe the sky across four different infrared wavelengths.
- Over its primary mission, WISE made infrared detections of more than 158,000 minor planets.
- Of these, over 34,000 were entirely new discoveries, marking a significant contribution to planetary science.
However, in September 2010, WISE depleted its cryogenic coolant, essential for maintaining the sensor’s functionality. Despite attempting to continue mapping for an additional four months, by February 2011, all systems had entered hibernation mode.
A Second Life: The Transformation to NEOWISE
Two years later, NASA recognized the potential of WISE despite its coolant issues. The telescope could still observe asteroids and comets close to Earth that emit strong infrared signals due to solar heating. Reactivated in December 2013, it began its new mission focused on the study of near-Earth objects (NEOs).
These NEOs have since become a critical focus for planetary defense. The combination of WISE and NEO formed the name NEOWISE, highlighting its enhanced mission profile. “NEOWISE has been instrumental in mapping the sky and understanding the near-Earth environment. The mission’s wealth of discoveries has expanded our knowledge of asteroids and comets,” said JPL Director Laurie Lashin.
Key Discoveries and Contributions
Throughout its operational period, NEOWISE made groundbreaking discoveries, contributing to our understanding of the solar system. Here are some of the telescope’s most impressive statistics:
| Total Infrared Measurements | Total Solar System Objects Observed | Near-Earth Objects (NEOs) Detected | Comets Discovered |
|---|---|---|---|
| 1.6 million | 44,000+ | 1,598 | 291 |
In addition to scientific discoveries, NEOWISE’s data has shaped future missions focused on planetary defense, providing insights that will inform the design and objectives of upcoming observatories.
The Legacy of NEOWISE
The influence of NEOWISE extends far beyond its mission duration. The telescope’s findings have established a foundation for further advancements in asteroid and comet studies. Knowledge gleaned from this mission is paving the way for the development of the NEO Surveyor, which will be the first infrared space observatory specifically designed to monitor potentially hazardous asteroids and comets. The NEO Surveyor is scheduled for launch in September 2027.
According to Amanda Mainzer, principal investigator of the NEO Surveyor project, “NEOWISE has provided unique, long-duration data of the infrared sky that scientists will use for decades to come. But its additional legacy is that it has helped lay the groundwork for NASA’s next Planetary Defense Infrared Space Telescope.”
Benefits of NEOWISE Data for Planetary Defense
The NEOWISE mission has demonstrated the critical role that infrared observations play in our understanding of potentially hazardous asteroids and comets. Here are several important benefits derived from NEOWISE’s operations:
- Risk Assessment: NEOWISE data allows scientists to assess the potential risks that certain NEOs may pose to Earth.
- Mapping Potential Hazards: The mission has provided detailed catalogs of NEOs, aiding future mission planning and planetary defense strategies.
- Enhancing Detection Techniques: NEOWISE has improved our methods for detecting and characterizing faint and faraway celestial bodies.
- Fueling Scientific Research: The extensive datasets have fueled countless studies and publications, broadening our cosmic knowledge.
First-Hand Experience: Scientists Reflect on NEOWISE
The success and importance of NEOWISE have been echoed by scientists involved in the mission. They highlight how it reshaped our perception of the near-Earth environment:
“The contributions of NEOWISE were vital not just in confirming the existence of many NEOs but also in helping educate the public about the importance of monitoring such objects,” said Richard Binzel, a noted asteroid researcher.
These reflections emphasize NEOWISE’s role not only as a scientific instrument but also as an educational tool, inspiring the next generation of astronomers and planetary scientists.
Future Prospects in the Realm of Near-Earth Object Research
With NEOWISE having provided us with years of pivotal data, it sets the stage for future advancements in planetary defense. The upcoming NEO Surveyor will build on the foundations laid by NEOWISE, expanding our capabilities to observe and mitigate potential threats from asteroids and comets.
As we delve deeper into the cosmos, the awareness and understanding fostered by NEOWISE’s findings will remain integral to protecting our planet. Scientists continue to analyze its data as they prepare for the challenges and discoveries that lie ahead.
