PLANETARY DEFENCE –
SCIENCE & TECHNOLOGY
News: The
Indian Space Research Organisation (ISRO) is planning to develop capabilities
in planetary defense, an area that involves detecting, tracking, and
potentially mitigating threats from near-Earth objects (NEOs) like asteroids.
 - This
     initiative aligns with global efforts to safeguard Earth from celestial
     impacts that could have catastrophic consequences.
 
What’s in the news?
Planetary Defense
 - Planetary
     defense refers to the methods and strategies developed to detect, track,
     and mitigate the potential threat posed by near-Earth objects (NEOs) such
     as asteroids and comets that could impact Earth.
 
 - The
     primary goal is to prevent or minimize the damage that an impact could
     cause to life, property, and the environment.
 
Detection and Tracking of NEOs
 - Ground-Based
     Observatories: Various observatories around the
     world are dedicated to monitoring NEOs. The Pan-STARRS and Catalina Sky
     Survey are among the most notable for their contributions to discovering
     new asteroids.
 
 - Space-Based
     Observatories: NASA’s NEOWISE mission uses a
     repurposed space telescope to detect and characterize NEOs in infrared
     wavelengths. Future missions, such as the NEOMIR mission, aim to identify
     asteroids hidden in the Sun's glare.
 
Mitigation Strategies
 - Kinetic
     Impact: This involves sending a spacecraft
     to collide with an asteroid to change its trajectory. NASA's Double
     Asteroid Redirection Test (DART) mission successfully demonstrated this
     technique by impacting the asteroid Dimorphos in 2022.
 
 - Nuclear
     Deflection: Another proposed method involves
     using a nuclear explosion near the asteroid to alter its course. This is
     considered a last-resort measure due to the complexities and risks
     involved.
 
 - Gravity
     Tractor: This concept involves a spacecraft
     hovering near an asteroid, using its gravitational pull to slowly alter
     the asteroid's trajectory over time.
 
Asteroid Apophis