What is normal or ‘ordinary’ matter? When astronomers talk about normal matter, we’re referring to baryons. By that, we just mean ‘the stuff of atoms’ – things like protons and neutrons. How did we fi

When the James Webb Space Telescope (JWST) launched on Christmas Day 2021, astronomers hoped it would revolutionise our understanding of the early stages of the Universe. And they were right. Almost a

Astronomers love a challenge. They place their observatories on the highest mountains, in the driest deserts, on the coldest ice shelves, beneath the deepest oceans, in orbit around Earth and the Sun,

Yes. On cosmic timescales, comets hit Earth frequently, but because they’re largely made of ice rather than solid rock, they tend not to leave obvious craters. A small comet is more likely than an asteroid to break up as it plunges into Earth’s atmosphere and heats up, often resulting in an explosion called an airburst that can devastate large areas of the landscape but doesn’t leave a crater. Perhaps the most famous such event happened over the Russian region of Tunguska in 1908, when an exploding comet flattened some 770 square miles of Siberian forest. A comet would have to be pretty big in order to hit the ground intact.

How our knowledge of these worlds beyond the Solar System has exploded in the last three decades

Sometime in the next year or so, if predictions are to believed, you’re going to be hearing a lot about a famous star. T Coronae Borealis, or T CrB for short, was the first well-observed nova, blossom