DART太空船与双卫一

DART太空船与双卫一

2023年3月9日 DART vs Dimorphos Image Credit: NASA, Johns Hopkins APL, DART Explanation: On the first planetary defense test mission from planet Earth, the DART spacecraft captured this close-up on 26 September 2022, three seconds before slamming into the surface of asteroid moonlet Dimorphos. The spacecraft’s outline with two long solar panels is traced at its projected point of impact between two boulders. The larger boulder is about 6.5 meters across. While the DART (Double Asteroid Redirection Test) spacecraft had a mass of some 570 kilograms, the estimated mass of Dimorphos, the smaller member of a near-Earth binary asteroid system, was about 5 billion kilograms. The direct kinetic impact of the spacecraft measurably altered the speed of Dimorphos by a fraction of a percent, reducing its…

在太空所见的DART小行星撞击

在太空所见的DART小行星撞击

2022年9月29日 DART Asteroid Impact from Space Image Credit: ASI / NASA Explanation: Fifteen days before impact, the DART spacecraft deployed a small companion satellite to document its historic planetary defense technology demonstration. Provided by the Italian Space Agency, the Light Italian CubeSat for Imaging Asteroids, aka LICIACube, recorded this image of the event’s aftermath. A cloud of ejecta is seen near the right edge of the frame captured only minutes following DART’s impact with target asteroid Dimorphos while LICIACube was about 80 kilometers away. Presently about 11 million kilometers from Earth, 160 meter diameter Dimorphos is a moonlet orbiting 780 meter diameter asteroid Didymos. Didymos is seen off center in the LICIACube image. Over the coming weeks, ground-based telescopic observations will look for a small…