Astronomers have tracked a large asteroid moving close to Earth.
The 45-metre-wide (150 feet) space rock, travelling at more than 30 kilometres (18 miles) per second, came within 480,000 kilometres (300,000 miles) of the planet. Although this is close in astronomical terms, there was no danger of an impact.
The asteroid made its closest approach at 0000 GMT on Friday. The rock has been given the name 2000 YA.
Professor Duncan Steel, the author of Target Earth, a book about asteroids, told the BBC that such events should not be sensationalised.
"Asteroids are discovered all the time," he said. "I've got in front of me a list of close approaches for the next year. I've got 12 listed for January alone. So these things do happen with some frequency and it's something we're becoming more and more aware of."
In September, a UK Government taskforce established to assess the threat of so-called Near Earth Objects (NEOs) called on ministers to seek international partners to build a new £15m telescope dedicated to sweeping the skies for threatening objects.
The three-metre (9.8 feet) survey telescope, based in the Southern Hemisphere, would be designed to detect objects down to a few hundred metres across.
Other recommendations of the official report included the setting up of an asteroid defence centre in Britain and working with the international community on ways to mitigate any future impacts.
The Liberal Democrat MP Lembit Opik, who campaigned for the taskforce to be set up, called for £70m ($98m) to be spent globally over 10 years on technology to track approaching asteroids.