Size isn't everything for galaxies. The Milky Way is about 100,000 light years across and holds hundreds of billions of stars, while dwarf galaxies are about a tenth as wide and hold only a few billion, yet they are the most common type of galaxy in the universe. NGC 4449, imaged by the Hubble Space Telescope, is one of them. It and similar dwarf galaxies are missing more oxygen than models predict, which suggests that their stellar winds and supernova explosions are unusually good at blowing oxygen and other heavy elements out into space.

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.