The crescent Moon, bright Venus and the star Spica appeared close together over Poland's Tatra Mountains in a photograph taken this week. Such meetings are called conjunctions: planets move against the fixed stars, so they sometimes pass near other objects in our line of sight. They are not coincidences but follow the precise laws of celestial mechanics. The word 'planet' comes from the Greek for 'wandering star'. Spica, in Virgo, is one of the brightest stars in the sky, about 250 light-years away. It was found in 1890 to be a binary of two massive blue stars orbiting every 4 days, and earlier this year it was reported to be a triple system.

Israeli reports also say the cabinet directed the military to prepare for a possible new attack on Iran.

Angkor, near Siem Reap in northern Cambodia, was the capital of the Khmer Empire, which ruled much of mainland Southeast Asia between roughly the 9th and 15th centuries. At its height the city spread across about 3,000 square kilometres, making it the largest pre-industrial city on Earth by area. Its growth depended on water: huge reservoirs called barays, along with canals and embankments, stored monsoon rain and carried it to rice fields. That system let farmers harvest more than once a year and fed a very large population through the dry season. The temple complex of Angkor Wat, built in the early 12th century, is the best-known monument and still stands at the heart of the park.