News

Mystery solved: Martian moons formed by a giant impact

Where did the two natural satellites of Mars, Phobos and Deimos, come from? For a long time, their shape suggested that they were captured asteroids. However, the shape and course of their orbits contradict this hypothesis. Two independent and complementary studies now provide an answer: these satellites formed from the debris of a gigantic collision between Mars and a protoplanet one-third its size.

News

Chaotic orbit of Comet Halley explained

Halley’s Comet, officially designated 1P/Halley, is visible from Earth every 75–76 years. Despite this regular return, the comet’s orbit cannot be predicted exactly due to processes inside the comet and its chaotic interaction with the planets and minor bodies in the solar system. A team of Dutch and Scottish researchers has now found an explanation for the chaotic orbital behaviour of 1P/Halley.