News

The case of the missing Ceres craters

Ceres is covered in countless small, young craters, but none are larger than 175 miles (280 kilometres) in diameter. To scientists, this is a huge mystery, given that the dwarf planet must have been hit by numerous large asteroids during its 4.5 billion-year lifetime. Where did all the large craters go?

News

X marks the spot at the centre of the Milky Way

Astronomers have uncovered the strongest evidence yet that an enormous X-shaped structure made of stars lies within the central bulge of the Milky Way. Previous computer models, observations of other galaxies, and observations of our own Galaxy have suggested that the X-shaped structure existed, but no one had observed it directly.

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

How comets break up and make up

For some comets, breaking up is not that hard to do. A new study indicates that the bodies of some periodic comets — objects that orbit the Sun in less than 200 years — may regularly split in two, then reunite down the road. This may be a repeating process fundamental to comet evolution.

News

Rosetta’s Comet 67P contains ingredients for life

The possibility that water and organic molecules were brought to the early Earth through cometary impacts has long been the subject of important debate. Now, ingredients crucial for the origin of life on Earth, including the simple amino acid glycine and phosphorus — key components of DNA and cell membranes — have been discovered at Comet 67P/Churyumov-Gerasimenko.