Asteroid 2020 ND

Subject: Geography

Context:

NASA has issued a warning that a huge “Asteroid 2020 ND” will move past Earth on July 24.

Concept:

• This asteroid is about 170 metres-long and will be as close as 0.034 astronomical units (5,086,328 kilometres) to our planet, and is travelling at a speed of 48,000 kilometres per hour.
• Its distance from Earth has placed it in the potentially dangerous category.
• Potentially Hazardous Asteroids (PHAs) are currently defined based on parameters that measure the asteroid’s potential to make threatening close approaches to the Earth. Specifically, all asteroids with a minimum orbit intersection distance (MOID) of 0.05 au or less are considered PHA.

Threats:

• NASA’s Near-Earth Object Observations Program finds, tracks and characterises over 90 per cent of the predicted number of NEOs that are 140 metre or larger which according to the space agency are of “the greatest concern” due to the level of devastation that their impact is capable of causing.
• No asteroid larger than 140 metre has a “significant” chance of hitting the Earth for the next 100 years.

Measures:

• Over the years, scientists have suggested different ways to ward off such threats, such as blowing up the asteroid before it reaches Earth, or deflecting it off its Earth-bound course by hitting it with a spacecraft.
• 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, one of whose bodies is of the size that could pose the most likely significant threat to Earth.