PLANETARY DEFENCE MISSION
ISRO is looking at working in some capacity to study the asteroid Apophis when it is 32,000 km away from Earth in 2029 in order to prepare for planetary defense efforts to prevent the asteroid from crashing onto Earth, ISRO scientists said.
The Indian Space Research Organisation (ISRO) intends to enhance its planetary defence capabilities, which encompass the identification, monitoring, and possible reduction of hazards posed by near-Earth objects (NEOs), such as asteroids.
This program is in line with international efforts to protect Earth from potentially catastrophic celestial impacts.
Planetary Defense
It describes initiatives and plans intended to shield Earth against possible impacts by Near-Earth Objects (NEOs), such as comets and asteroids.
Numerous techniques are used, including deflection, impact assessment, tracking, and detection.
Need of planetary defense: Depending on their size, speed, angle, and impact region, NEOs that cross Earth's orbit have the risk of endangering billions of lives both directly on impact and by subsequent tsunamis, earthquakes, and fires.
Detection and Tracking of NEOs
Ground-Based Observatories:
Various observatories around the world are dedicated to monitoring NEOs.
Among the most notable are he Pan-STARRS and Catalina Sky Survey 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.
Missions, such as the NEOMIR mission, aim to identify asteroids hidden in the Sun's glare.
Mitigation Strategies
Kinetic Impact: It involves sending a spacecraft to collide with an asteroid to change its trajectory.
Nuclear Deflection: This method involves using a nuclear explosion near the asteroid to alter its course. It is considered a last-resort measure due to the complexities and risks involved.
Gravity Tractor: It involves a spacecraft hovering near an asteroid, using its gravitational pull to slowly alter the asteroid's trajectory over time.
Asteroid Apophis
In 2004, observatories detected a 340-meter object named Apophis with a potential impact risk more than one in 100 probability.
Apophis has an orbital period of approximately 360 days, making it frequently observable near Earth.
On April 13, 2029, Apophis will pass within 32,000 km of Earth.
The asteroid is expected to return in April 2036, potentially at a greater distance from Earth.
There is concern that changes in its orbit due to gravitational effects could increase the risk of impact in 2036.
ISRO has initiated efforts focused on planetary defense to monitor and mitigate such risks.
ISRO's Plans for Apophis
Joint Apophis Asteroid Mission: ISRO aims to collaborate with JAXA, ESA, and NASA on the Apophis asteroid mission by contributing instruments or support.
Objective: ISRO seeks to participate, learn, and expand its knowledge base through involvement in international missions.
Future Goals: ISRO intends to position India for future asteroid missions, including potential planetary defense actions.
Learnings from NASA’s DART Mission: The DART mission successfully altered the orbit of asteroid Dimorphos, demonstrating asteroid deflection technology.
Follow-up: ESA’s Hera mission will launch in 2024 to study the aftermath of the DART impact.
Upcoming NASA Mission: The NEO Surveyor mission aims to identify 90% of near-Earth objects with diameters of at least 140 meters within 10 years.
Global Planetary Defense Efforts
NASA’s Double Asteroid Redirection Test (DART): It is the first-ever mission dedicated to investigate and demonstrate one method of asteroid deflection by changing an asteroid’s motion in space through kinetic impact.
The targets were Asteroid Didymos and its moonlet Dimorphos.
OSIRIS-APophis EXplorer (OSIRIS-APEX): After the successful completion of its mission to gather a sample of asteroid Bennu, NASA’s OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer) was sent to study Apophis and renamed OSIRIS-APEX.
International Asteroid Warning Network: Established in 2013 to create an international group of organizations involved in detecting, tracking, and characterizing NEOs.
NEO Coordination Centre by European Space Agency: It is the central access point to an entire network of European NEO data sources and information providers.
Asteroid Day
Asteroid Day is observed every year by the space community on June 30 on account of a huge air blast from an asteroid flattening 2,200 sq km of forest in Siberia, Russia, on June 30, 1908. Asteroids are hypothesized to have caused the extinction of dinosaurs.
ISRO’s intention to join such an endeavour displays its growing confidence in taking on newer challenges, and contributing proactively to global space objectives. It is also a reaffirmation of its continuing evolution into a well-rounded space agency, with capabilities that match the best in the world
