Dimorphos asteroid to scale with Rome's Colosseum

The 160-m diameter Dimorphos asteroid compared to Rome's Colosseum. In 2022 NASA's DART spacecraft will collide with the Dimorphos moonlet, in orbit around the larger 780-m diameter Didymos asteroid, in a bid to change its orbit. In 2026 ESA's Hera spacecraft will arrive at the Didymos system to perform a close-up survey of the deflected asteroid.