Why in news ?
- The European Space Agency’s (ESA’s) Hera missionis set for a new record by becoming the first spacecraft to explore a binary asteroid — the Didymos pair.
- DART(Double Asteroid Redirection Test) and Hera were conceived together as part of the international ‘Asteroid Impact Deflection Assessment’ experiment.
About Hera mission :
- Hera is named after the Greek goddess of marriage .
- Moreover, it is a part of ESA mission that will be humankind’s first probe to rendezvous with a binary asteroid system.
- Due to launch in 2023, Hera would travel to a binary asteroid system – the Didymos pair of near-Earth asteroids.
- Features : Hera will also demonstrate multiple novel technologies, such as autonomous navigation around the asteroid – like modern driverless cars on Earth, and gather crucial scientific data, to help scientists and future mission planners better understand asteroid compositions and structures.
- The spacecraft would perform high-resolution visual, laser and radio science mapping of the moon, which will be the smallest asteroid visited so far
About Double Asteroid Redirection Test (DART):
- On the sidelines, the 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.
- DART will deliberately crash itself into the moonlet at a speed of approximately 6 km per second, using an onboard camera and autonomous navigation software.
- 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.
- Didymoon was chosen because of its close proximity to Earth and its size.
- Moreover, Didymoon is small and in a tight enough 12-hour orbit around its parent, that its orbital period can indeed be shifted in a measurable way.
- Didymos is a binary asteroid: the primary body has a diameter of around 780 m and a rotation period of 2.26 hours . Whereas the Didymoon secondary body has a diameter of around 160 m and rotates around the primary at a distance of around 1.2 km from the primary surface in around 12 hours.
- Besides, The moon orbiting Didymos, called ‘Didymoon’ — almost the size of the Giza Pyramid in Egypt, measuring just 160 metres in diametre — will be the smallest asteroid ever explored.