UPSC RELEVANCE-Mains (GS Paper 3: Science & Technology),Topic: Space Technology, Scientific Developments, and Their Applications.
Why in News
The Indian Space Research Organisation (ISRO) announced that the CHACE-2 payload aboard Chandrayaan-2’s orbiter has made the first-ever direct observation of how a Coronal Mass Ejection (CME) from the Sun affects the Moon’s exosphere (its extremely thin atmosphere).
Background
1. About Chandrayaan-2
- Launched: July 22, 2019, by GSLV Mk-III (M1) rocket.
- Objective: To study the Moon’s surface, mineral composition, and exosphere.
- Components:
- Orbiter: Still operational and conducting scientific studies.
- Vikram lander: Lost communication during soft-landing attempt.
- Pragyan rover: Lost along with the lander.
Despite the lander failure, the orbiter continues to send valuable data through its eight scientific payloads.
2. What is the Lunar Exosphere?
- The Moon has no dense atmosphere like Earth.
- Instead, it has a very thin layer of gases (called the exosphere) made up of atoms knocked off from the lunar surface by solar radiation, micrometeorite impacts, and solar wind.
- These gases are so sparse that they rarely collide with each other — hence called an exosphere rather than an atmosphere.
3. What is a Coronal Mass Ejection (CME)?
- A CME is a massive burst of charged particles (plasma and magnetic fields) released from the Sun’s corona.
- These high-energy particles can travel through space and impact planets and moons, influencing their magnetic fields and atmospheres.
- When directed toward Earth, CMEs cause geomagnetic storms, auroras, and sometimes satellite disruptions.
Key Findings from CHACE-2 Payload
1. What Happened
- On May 10, 2024, a series of CMEs were hurled toward the Moon.
- The CHACE-2 (Chandra’s Atmospheric Composition Explorer-2) instrument on Chandrayaan-2’s orbiter detected a sudden increase in:
- Total pressure of the Moon’s dayside exosphere.
- Number density (number of neutral atoms or molecules per unit volume).
2. Significance of the Finding
- This increase was more than an order of magnitude (i.e., 10 times higher than normal).
- It confirmed theoretical models that had predicted such behavior — but this is the first observational proof ever recorded.
3. Scientific Explanation
- When the CME hit the Moon, energetic particles struck its surface.
- This “knocked off” surface atoms (a process called sputtering), temporarily increasing the number of atoms in the exosphere.
- As a result, the pressure and density of the exosphere rose before eventually returning to normal.
Implications and Significance
1. For Lunar Science
- Enhances understanding of how solar activity affects airless bodies like the Moon and Mercury.
- Provides data to refine space weather models in the Earth-Moon system.
2. For Future Lunar Bases
- Demonstrates that solar events like CMEs can temporarily change the Moon’s environment.
- Lunar base designers must consider these effects when planning habitats, instruments, or human safety protocols — especially for radiation protection and equipment stability.
3. For India’s Space Research
- Highlights the continued success of Chandrayaan-2’s orbiter, despite the lander failure.
- Strengthens India’s role in lunar and planetary science, building a foundation for future missions like Chandrayaan-3 and beyond.
UPSC Prelims-style practice questions:
Q1.Consider the following statements regarding the lunar exosphere:
- The Moon has a dense atmosphere like Earth.
- The lunar exosphere is formed due to atoms knocked off the surface by solar radiation, micrometeorite impacts, and solar wind.
- CHACE-2 payload onboard Chandrayaan-2 observed an increase in exospheric pressure due to Coronal Mass Ejection (CME) from the Sun.
Which of the statements given above is/are correct?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: B – 2 and 3 only
Q2.The CHACE-2 instrument onboard Chandrayaan-2 is primarily designed to study:
(a) Lunar surface mineral composition
(b) Lunar exosphere composition and dynamics
(c) Moon’s gravitational anomalies
(d) Radiation effects on lunar soil
Answer: B – Lunar exosphere composition and dynamics
Q3.Consider the following effects of Coronal Mass Ejections (CMEs):
- They can temporarily increase the density of the Moon’s exosphere.
- They have no impact on airless bodies like the Moon.
- They can affect space weather and satellite operations on Earth.
Which of the statements given above is/are correct?
(a) 1 and 3 only
(b) 2 only
(c) 1 and 2 only
(d) 1, 2 and 3
Answer: A – 1 and 3 only
Q4.Chandrayaan-2 was launched by which of the following rockets?
(a) PSLV-XL
(b) GSLV Mk-III (M1)
(c) Falcon 9
(d) Long March 5
Answer: B – GSLV Mk-III (M1)
SOURCE-THE HINDU