Context: An asteroid that is on a collision course with Earth could come very close to the planet, according to the Center for Near Objects Studies at NASA’s Jet Propulsion Laboratory. 
About 2018VP1, the ‘Election Day Astroid’

• The asteroid, dubbed 2018VP, was first discovered at the Palomar Observatory in California’s San Diego County two years ago. A 13-day observational arc followed, after which the asteroid was not detected again. 
• When it was discovered, the asteroid — which has a two year orbital period — was around 2,80,000 miles away from the Earth, according to Science Alert. This year, however, the asteroid could be as close as 4,700 miles according to NASA’s close approach database. 

Asteroid 2018VP1: Should we be worried? 

• NASA has said there is a 0.41 per cent, or 1 in 240 chance that 2018VP1 would impact the Earth. Even if the asteroid does enter our planet’s atmosphere, it is unlikely to cause any harm on November 2. 
• According to The Planetary Society, there are estimated to be around 1 billion asteroids having a diameter greater than 1 metre. Objects that can cause significant damage upon impact are larger than 30 metres. The Chicxulub impactor, the celestial object that caused the sudden extinction of most dinosaur species 66 million years ago, had a diameter of over 10 kilometres. 
• 2018VP1 has a diameter of all but 2 metres, around the size of a small automobile, and would likely burn up into an impressive fireball after entering the Earth’s atmosphere before reaching the ground. According to NASA, such an event happens about once every year. 
• As per NASA’s Near-Earth Object Observations Programme, asteroids that are 140 metres or larger (bigger than a small football stadium) are of “the greatest concern” due to the level of devastation their impact is capable of causing. However, it has been pointed out that no asteroid larger than 140 metres has a “significant” chance of hitting the Earth for the next 100 years. 

Deflecting asteroids 

• Scientists have suggested ways like- to blow up the asteroid before it reaches Earth, or deflecting it off its Earth-bound course by hitting it with a spacecraft.
• The most drastic measure undertaken so far is the Asteroid Impact and Deflection Assessment (AIDA), which includes NASA’s Double Asteroid Redirection Test (DART) mission and the European Space Agency’s (ESA) Hera.
• The mission’s target is Didymos, a binary near-Earth asteroid, that could pose the most likely significant threat to Earth.

Double Asteroid Redirection Test

• In 2018, NASA announced it had started the construction of DART, scheduled to launch in 2021.
• Aim: To slam into the smaller asteroid of Didymos binary system at around 6 km per second in 2022.

About Hera

• Hera scheduled to launch in 2024, will arrive at the Didymos system in 2027.
• Aim: To measure the impact crater produced by the DART collision and study the change in the asteroid’s orbital trajectory.