About Solar and Heliospheric Observatory (SOHO)
- It is a project of international collaboration between the European Space Agency (ESA) and the U.S. National Aeronautics and Space Administration (NASA).
- Launched in December 1995, SOHO was designed to study the Sun.
- In order to provide continuous observations, it was maneuvered to orbit the first Lagrangian point (L1), a point some 1.5 million km (900,000 miles) from Earth toward the Sun where the gravitational attraction of Earth and the Sun, combine in such a way that a small body remains approximately at rest relative to both.
- It carries 12 scientific instruments to study the solar atmosphere, helioseismology, and the solar wind.
- Information from the mission has allowed scientists to learn more about the Sun’s internal structure and dynamics, the chromosphere, the corona, and solar particles.
- Though its mission was scheduled to run until only 1998, it has continued collecting data, adding to scientists’ understanding of our closest star, and making many new discoveries, including thousands of comets.
- SOHO is the longest-lived Sun-watching satellite to date.
Q1) What is a Comet?
Comets are defined as icy bodies of frozen gases, rocks and dust left over from the formation of the solar system about 4.6 billion years ago. They orbit the sun in highly elliptical orbits that can take hundreds of thousands of years to complete.
Source: ESA, NASA Solar Observatory Discovers Its 5,000th Comet
Last updated on July, 2026
→ UPSC Prelims Result 2026 is now out.
→ UPSC IFoS Prelims Result 2026 is now out.
→ Enroll in Vajiram & Ravi’s UPSC Mains Test Series 2026 for structured answer writing practice, expert evaluation, and exam-oriented feedback.
→ Join Vajiram & Ravi’s UPSC Mentorship Program 2026 for personalized guidance, strategy planning, and one-to-one support from experienced mentors.
→ Join Vajiram & Ravi’s UPSC Mentorship Program 2027 for personalized guidance, strategy planning, and one-to-one support from experienced mentors.
→ UPSC Prelims Provisional Answer Key 2026 out for GS Paper 1 and CSAT.
→ UPSC Prelims Question Paper 2026 Out, Download GS Paper 1 PDF conducted on 24th May 2026.
→ UPSC Mains 2026 will be conducted from 21st August 2026 onwards, and UPSC Prelims 2027 will be held on 23rd May 2027.
→ UPSC Final Result 2025 is now out.
→ UPSC has released UPSC Toppers List 2025 with the Civil Services final result on its official website.
→ Anuj Agnihotri secured AIR 1 in the UPSC Civil Services Examination 2025.
→ UPSC Notification 2026 & UPSC IFoS Notification 2026 is now out on the official website at upsconline.nic.in.
→ UPSC Calendar 2027 has been released.
→ Check out the latest UPSC Syllabus 2026 here.
→ The UPSC Selection Process is of 3 stages-Prelims, Mains and Interview.
→ Shakti Dubey secures AIR 1 in UPSC CSE Exam 2024.
→ Also check Best UPSC Coaching in India







