Aditya L1 Mission

Context:

ISRO is gearing up for launch of Aditya L1, a mission to study the Sun.

About Aditya L1 Mission:

• 1^st space-based Indian observatory to study the Sun.
• Spacecraft – Planned to be placed in a halo orbit around the Lagrangian point 1 (L1) of the Sun-Earth system.
• Launch Vehicle – PSLV rocket
• The primary payload on board is the Visible Line Emission Coronagraph (VLEC) – It was conceptualised and designed in 15 years. It will help in studying the temperature, velocity and density of the corona, understand the processes that result in heating of the corona 
• Advantages of L1 placement –
  • Continuous view of the Sun without any occultation/ eclipse
  • To observe the solar activities continuously
• Science Objectives –
  • Understanding the Coronal Heating and Solar Wind Acceleration.
  • Understanding initiation of Coronal Mass Ejection (CME), flares and near-earth space weather.
  • To understand coupling and dynamics of the solar atmosphere.
  • To understand solar wind distribution and temperature anisotropy
• Mission Uniqueness –
  • 1^st time spatially resolved solar disk in the near UV band.CME dynamics close to the solar disk to provide information consistently.On-board intelligence to detect CMEs and solar flares.
  • Directional and energy anisotropy of solar wind using multi-direction observations.

Coronal Mass Ejections (CMEs) are massive releases of charged particles and magnetic fields from the solar atmosphere into space, with the potential to disrupt Earth’s technologies and satellites; these events encompass a wide range of plasma temperatures, spanning from 104 K to 107 K.

Other Missions to the Sun:

• NASA’s Parker Solar Probe (part of NASA’s ‘Living With a Star’ programme) – To track the movement of energy and heat through the Sun’s corona and investigate the origin of the acceleration of the solar wind.
• Other active spacecraft monitoring the Sun include SOHO (Solar and Heliospheric Observatory) , ACE, IRIS, WIND, Hinode, the Solar Dynamics Observatory, and STEREO.
• SOHO is the longest-lived Sun-watching satellite to date

About Lagrange Point 1 (L1):

• One of 5 points (L1, L2, L3, L4 and L5) in the orbital plane of the Earth-Sun system.
• Positions in space where the gravitational pull of the two large bodies equals the necessary centripetal force required for a small object to move with them.
• Used by spacecraft to remain at these positions with reduced fuel consumption.
• Lies between Sun-Earth line which is approximately 1% of the Earth-Sun distance.

Source: The Hindu

Click here to read about Solar Flares

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Previous Year Question

Which of the following pair(s) is/are correctly matched?

Spacecraft: Purpose

1. Cassini-Huygens: Orbiting the Venus and transmitting data to the Earth
2. Messenger: Mapping and investigating the Mercury
3. Voyager 1 & 2: Exploring the outer solar system

Select the correct answer using the codes given below.

[UPSC Civil Services Exam – 2014 Prelims]

(a) 1 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

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