Plague of oysters disrupts Tokyo Olympics

A plague of oysters is threatening a key venue at the Tokyo Olympics. The Sea Forest Waterway in Tokyo Bay, which will host the canoeing and rowing events, was ready ahead of schedule, but the oysters have caused damage costing $1.3m (£930,000) in emergency repairs. They had attached themselves to floats intended to stop waves bouncing back across the water and on to the athletes.

Asteroid to pass Earth

Nasa is tracking an asteroid twice the size of Big Ben that is heading towards Earth’s orbit. The asteroid, named 2008 GO20, will fly past on Saturday evening. Experts say it is extremely unlikely to make contact with the planet’s surface and will instead pass by Earth safely at a speed of 8km a second, or 17,895mph.

Escaped tortoise moves half a mile in a year

A runaway tortoise that had been missing for a year was found just 0.6 miles away from his family home. Maxi, 14, had absconded from his enclosure but his escape attempt was finally thwarted after dog walkers spotted him in the middle of a Wiltshire field. His delighted owner said: “Just before he came back, I had basically given up home but he got found and came back home - it's crazy.”