The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

making it the fastest wind ever measured on a planet. “We’re talking about 9 kilometres per second. The wind speed on even Jupiter is like a few hundred metres per second, so this is really an ...

In 1992 astronomers reported the first planet-size masses around a dead star, the pulsar PSR1257+12, which sits 2,000 light-years away. Three years later came news of the first known exoplanet ...