Europe
Asia
Oceania
Americas
Africa
An asteroid that recently crashed in Ontario hi
Planetary physicist Dr Sheila Kanani on why now is the time to spot shooting stars and a sunlit Saturn
How our knowledge of these worlds beyond the Solar System has exploded in the last three decades
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.
This October marks 50 years since a heavily shielded spacecraft, the Soviet Union’s Venera 9, parachuted into the atmosphere of Venus. Then, having landed, it did something extraordinary: it beamed ba
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,
STUART RUSSELL RECEIVES FOUR OR five emails a day from people who seem to be in the grips of psychosis, convinced their AI chatbot of choice is suddenly conscious. “It’s appointing them as its emissar