The European Space Agency’s (ESA’s) Hera mission is set for a new record by becoming the first spacecraft to explore a binary asteroid — the Didymos pair.
The moon orbiting Didymos, called ‘Didymoon’ — almost the size of the Giza Pyramid in Egypt, measuring just 160 metres in diameter—will be the smallest asteroid ever explored.
National Aeronautics and Space Administration (NASA) in USA will also launch the Double Asteroid Redirection Test (DART) between 2020 and 2021, which will target Didymoon as part of its planetary defence programme. The programme, designed to protect Earth from dangerous comets and asteroids, aims to crash DART into Didymoon in 2022 to alter its orbit around Didymos.
The collision will change the speed of the moonlet in its orbit around the main body. Following the collision, Hera would explore the asteroid in 2026 and check the impact and deflection created by DART.
Asteroid are relatively small, inactive, rocky body orbiting the Sun. Didymos is a binary asteroid and it was chosen because of its close proximity to Earth and its size. These both missions are part of the Asteroid Impact and Deflection Assessment (AIDA).