The National Aeronautics and Space Administration (NASA) has recently brought to light that a colossal asteroid, designated as 163348 (2002 NN4), is projected to pass Earth on 6th June 2020. Despite the asteroid’s approach, NASA assures that it will maintain a safe distance from Earth.
Details about 163348 (2002 NN4)
This mammoth asteroid was discovered in July 2002 and is anticipated to be closest to Earth in June 2020. The asteroid varies in diameter, falling between 250-570 meters. It is classified as a Near-Earth Object as well as a Potentially Hazardous Asteroid (PHA).
Near-Earth Objects (NEOs)
NEOs are primarily comets and asteroids that have been drawn into orbits, by the gravitational pull of adjacent planets, that bring them into Earth’s vicinity. These celestial bodies consist mostly of water ice with scattered dust particles. NEOs sporadically approach Earth during their orbit around the Sun.
NASA’s Center for Near-Earth Object Study (CNEOS) monitors and foretells the times and distances of these objects through the Asteroid Watch Widget when their approach to Earth is imminent.
Potentially Hazardous Asteroid (PHA)
A PHA is an asteroid that could potentially make threatening close approaches to the Earth. An asteroid is considered a PHA when it has a Minimum Orbit Intersection Distance (MOID) of 0.05 AU, equivalent to roughly 7,480,000 Km, or less and an Absolute Magnitude (H) of 22.0 or lower.
Risks associated with NEOs
NASA warns that large-sized objects can pose considerable risks due to the massive damage they can inflict upon impact. Avaliable data suggests that less than half of the estimated 25,000 NEOs, that are 140 metres or larger in size, have been found so far. NASA’s Near-Earth Object Observations Program is responsible for finding, tracking and characterising over 90% of the foreseen number of NEOs that are 140 metre or bigger. It is worth mentioning that no asteroid more significant than 140 metre has a “significant” chance of impacting Earth in the next century.
What are Asteroids and Comets?
Essentially, asteroids orbit the Sun and comprise small bodies in the solar system. They are primarily composed of metals and rocks and have shorter and elliptical orbits compared to comets, which contain ice and hydrocarbons. When comets come close to the sun, a part of their ice melts, and other materials vaporise due to the heat.
Scientific Significance of Comets and Asteroids
Comets and asteroids hold scientific value since they are considered as residual debris from the formation of the solar system over 4.6 billion years ago, thus providing clues about the chemical composition from which the planets were formed. A significant point to note is that an asteroid hit is one of the most plausible causes for the extinction of life on Earth. Multiple methods have been proposed over time to avert such a catastrophe.
Monitoring is Key
It is crucial to understand that even though asteroids are classified as PHAs, it doesn’t mean they will surely impact Earth. It simply signifies the potential for a threat. By continuously monitoring these PHAs and updating their orbits based on new observations, it becomes feasible to predict their close-approach statistics, thereby enabling us to assess their level of threat to Earth.
