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NASA and ESA’s SOHO Identifies 5,000th Comet
A comet, discovered on March 25, 2024, by a citizen scientist in the Czech Republic through an image from the Solar and Heliospheric Observatory (SOHO), has been officially recognized as the 5,000th comet revealed by SOHO data. This significant event comes 28 years after SOHO was launched, a mission that did not primarily aim to discover comets.
The discovered comet, composed of rock and ice, orbits the Sun within a few years and has been classified within the “Marsden group” of comets, first identified by the late Brian Marsden. This subset relates to comet 96P/Machholz, which is observable by SOHO every five years. It is noted that out of the 5,000 comets discovered by SOHO, only approximately 75 are part of the Marsden group.
SOHO, a collaborative mission between NASA and ESA launched in December 1995, initially aimed to explore the Sun and its corona. Its Large Angle and Spectrometric Coronagraph (LASCO) has been instrumental in viewing “sungrazing” comets by blocking solar glare and enabling SOHO to spot comets when they’re too close to the Sun for other observatories to detect.
The remarkable comet-finding capability of SOHO has classified it as the top comet-discovering spacecraft, attributing to more than half of the known comets. This unexpected talent of SOHO led to the establishment of the Sungrazer Project, a NASA-funded initiative introduced in the early 2000s that enables public contributions in reporting newly spotted comets in SOHO images.
Hanjie Tan, the citizen scientist and participant of the Sungrazer Project, is credited with discovering the 5,000th comet. Tan, initially from Guangzhou, China, and a current doctoral student in Prague, has been an active comet-seeker in the project since he was 13. He has discovered over 200 comets and finds the pursuit exhilarating.
The contribution of international volunteers, many without scientific training, has been pivotal in reaching SOHO’s landmark of 5,000 comet discoveries. Karl Battams, space scientist at the U.S. Naval Research Lab and the Sungrazer Project’s principal investigator, reflects on the dramatic increase from the couple dozen known sungrazers before SOHO to this milestone. The project’s vast comet database allows for significant scientific analysis and insight into the Sun’s influence on comet paths.
Credit: NASA’s Goddard Space Flight Center
Learning from the comet discoveries, scientists gain understanding of the sungrazing comet population and how these small celestial bodies act like probes diving into the solar atmosphere. The comets’ trajectories provide a unique dataset contributing to solar science.
The impressive milestone coincides with the Heliophysics Big Year, extending to the end of 2024, underlining the opportunity for public involvement in NASA science initiatives. For those interested in contributing to future discoveries or learning about SOHO and related projects, the following resources are available:
- NASA SOHO mission website
- ESA SOHO website
- The Sungrazer Project
- Why ESA and NASA’s SOHO Spacecraft Spots So Many Comets
- 4,000th Comet Discovered by ESA & NASA Solar Observatory
- NASA Citizen Science
by Vanessa Thomas
NASA’s Goddard Space Flight Center, Greenbelt, Md.
FAQ Section
- What is the SOHO mission?
- The Solar and Heliospheric Observatory (SOHO) is a mission jointly conducted by NASA and ESA aimed at studying the Sun’s atmosphere and solar activity.
- How does SOHO discover comets?
- SOHO utilizes an instrument called the Large Angle and Spectrometric Coronagraph (LASCO) that blocks out the Sun’s glare, allowing it to spot comets that are close to the Sun, which would otherwise be invisible against the bright solar light.
- Can the public help discover comets?
- Yes, the public can contribute to comet discoveries through the NASA-funded Sungrazer Project, which accepts reports from volunteers who spot comets in SOHO imagery.
Conclusion
The discovery of the 5,000th comet by the SOHO observatory is a testament to the power of collaborative efforts between scientists and citizen scientists. This milestone not only contributes to our understanding of cometary groups and their interactions with the Sun but also exemplifies the value of citizen science in expanding our knowledge of the universe. The impact of volunteers and enthusiasts through the Sungrazer Project continues to reveal the dynamic and ever-changing environment of our solar system.