ISRO’s Plans to Venture into Planetary Defense UPSC

PLANETARY DEFENCE

Source: Space.com

Disclaimer: Copyright infringement not intended.

Context

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.

Details

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.

*Country*	*Agency/Organization*	*Key Initiatives/Projects*	*Description*
United States	NASA	Planetary Defense Coordination Office (PDCO)	Established in 2016 to manage efforts to detect, track, and characterize NEOs and develop mitigation strategies.
		Double Asteroid Redirection Test (DART)	Mission to demonstrate the kinetic impactor technique by crashing into the asteroid Dimorphos to change its orbit.
		NEOWISE	A space-based infrared telescope repurposed to detect and characterize NEOs.
		OSIRIS-REx	Redirected to observe asteroid Apophis during its 2029 flyby after completing its primary mission to asteroid Bennu.
	SETI Institute	Asteroid Terrestrial-impact Last Alert System (ATLAS)	A ground-based system designed to detect incoming asteroids that could impact Earth, providing advance warning.
European Union	European Space Agency (ESA)	Hera Mission	A mission to follow up on NASA's DART impact, studying the effects on the binary asteroid system Didymos and Dimorphos.
		Flyeye Telescope	A ground-based telescope in Italy designed to detect and track NEOs with wide-field optics.
		NEO Coordination Centre	Central hub for data on NEO observations and risk assessments, facilitating international collaboration.
Russia	Roscosmos	Automated Warning System	A system to monitor and provide warnings about potential asteroid threats.
		Observational Programs	Various ground-based telescopes and observatories dedicated to tracking NEOs.
China	CNSA (China National Space Administration)	Planetary Defense Initiative	Announced plans for a planetary defense system including asteroid detection, monitoring, and potential deflection missions.
		Ground-based Observatories	Expansion of ground-based infrastructure for NEO detection and tracking.
India	ISRO (Indian Space Research Organisation)	Planetary Defense Workshop	Held workshops and expressed interest in planetary defense, potentially collaborating with other agencies for missions like observing asteroid Apophis in 2029.
		Space Situational Awareness & Management (SSAM) Directorate	Plans to include planetary defense within its broader space situational awareness efforts.
Japan	JAXA (Japan Aerospace Exploration Agency)	Hayabusa2	Mission to asteroid Ryugu, collecting samples and returning them to Earth. This mission provided valuable data on asteroid composition and behavior.
Germany	DLR (German Aerospace Center)	Space Situational Awareness Program	Includes efforts to detect and track NEOs, collaborating with international partners.
Italy	Italian Space Agency (ASI)	NEO Surveillance	Collaboration with ESA on projects like Flyeye Telescope and other ground-based observation systems.
United Kingdom	UK Space Agency	NEO Detection Research	Involvement in ESA's Hera mission and support for ground-based telescopes and observatories.
Australia	Space Environment Research Centre (SERC)	Observational Programs	Efforts to detect and track NEOs using ground-based observatories and collaborations with international partners.
Canada	Canadian Space Agency (CSA)	Near-Earth Object Surveillance Satellite (NEOSSat)	A microsatellite dedicated to tracking and monitoring NEOs from space.

Asteroid Day

Held annually on June 30th, Asteroid Day raises global awareness about asteroids and planetary defense. It involves educational programs and expert discussions on the latest research and strategies.

Asteroid Apophis

Asteroid Apophis, formally designated 99942 Apophis, is a near-Earth asteroid that gained notoriety due to initial predictions of a potential collision with Earth.
Discovered on June 19, 2004, by astronomers Roy A. Tucker, David J. Tholen, and Fabrizio Bernardi at the Kitt Peak National Observatory, Apophis measures approximately 450 meters in diameter.
When first observed, Apophis was calculated to have a 2.7% chance of impacting Earth during its close approach on April 13, 2029.
This probability was the highest ever for a large asteroid and caused significant concern among scientists and the public.
Updated Risk AssessmentsSubsequent observations and refined calculations have eliminated the possibility of an impact in 2029, 2036, and 2068.
Apophis will make a very close approach to Earth on April 13, 2029, passing at a distance of about 32,000 kilometers (19,800 miles), close enough to be visible to the naked eye and within the range of some geostationary satellites .

Physical Characteristics

Size and Composition: Apophis is approximately 450 meters wide and is believed to be composed of silicate materials, typical of S-type asteroids. Its size and composition suggest that an impact would have catastrophic effects.
Rotation: Apophis has a rotation period of approximately 30.4 hours. Understanding its rotation is crucial for assessing potential future trajectories and impact risks .

Asteroids, comets, meteors, meteorites, and meteoroids

*Category*	*Definition*	*Location*	*Composition*	*Notable Characteristics*
Asteroids	Rocky objects orbiting the Sun, primarily found in the asteroid belt between Mars and Jupiter	Mainly in the asteroid belt	Rock, metal	Generally irregular in shape; vary in size from small rocks to large objects
Comets	Icy bodies that release gas and dust, forming a glowing coma and tail when near the Sun	Kuiper Belt, Oort Cloud	Ice, dust, rocky material	Display a visible coma and tail; often highly elliptical orbits
Meteoroids	Small particles from comets or asteroids	Throughout the solar system	Rock, metal	Smaller than asteroids; typically less than a meter in diameter
Meteors	Meteoroids that enter Earth's atmosphere and burn up, creating a streak of light	Earth's atmosphere	Rock, metal	Known as "shooting stars"; visible as bright streaks in the sky
Meteorites	Fragments of meteoroids that survive passage through the atmosphere and reach Earth's surface	Earth's surface	Rock, metal	Can be stony, metallic, or a combination (stony-iron); valuable for scientific study

Sources:

IndianExpress

PRACTICE QUESTION

Q: Consider the following statements regarding planetary defence mechanisms:

Planetary defence involves strategies to protect Earth from potential asteroid impacts.
The Double Asteroid Redirection Test (DART) mission aims to demonstrate the kinetic impactor technique for deflecting asteroids.
Nuclear detonation is a widely accepted method for asteroid deflection due to its precision and minimal environmental impact.

Which of the statements given above is/are correct?

a) 1 and 2 only
b) 1 and 3 only
c) 2 and 3 only
d) 1, 2, and 3

Answer: a)