Emily Lakdawalla

Emily Lakdawalla is a planetary scientist, space artist and science communicator who is passionate about advancing public understanding of space and sharing the wonder of scientific discovery. Her first book, The Design and Engineering of Curiosity: How the Mars Rover Performs Its Job came out in 2018. Find her recent writing about Solar System exploration in places like Sky & Telescope and BBC Sky at Night magazines, and check out her space-inspired jewellery and sculpture.

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First planned redirection of a celestial object

Launched on 24 Nov 2021, NASA's Double Asteroid Redirection Test (DART) collided with Dimorphos, the moon of asteroid Didymos, on 26 Sep 2022. Didymos is about 780 m (2,559 ft) across; Dimorphos, about 160 m (525 ft). Although the mass of the spacecraft was tiny compared to the moon, the impact generated a huge spray of dust that acted like a rocket pushing against the moon's orbital motion. As a result, the moon's orbital speed around Didymos decreased, shrinking its orbit and making its orbital period faster by more than half an hour. The same technique, if applied to an asteroid predicted to collide with Earth, could change the time it crosses Earth's path enough to make sure it will miss, preventing a potentially major disaster.