1. Minneapolis
2. Seattle
3. St. Paul
4. Denver
5. Washington
6. St. Louis
7. San Francisco
8. Atlanta
9. Pittsburgh
10. Boston

The 0.5sq-mm (0.01sq-in) nano-Bible was written on a silicon surface covered with a thin layer of gold (20nanometres thick — 0.0002mm).

It was written using a device called Focused Ion Beam (Fib).

"When we send the particle beam toward a point on the surface, the gold atoms bounce off of this point, thus exposing the silicon layer underneath," Ohad Zohar, one of the project's managers at Technion, said.

Despite the potential side effects, academics, classical musicians, corporate executives, students and even professional poker players have embraced the drugs to clarify their minds, improve their concentration or control their emotions.

"There isn't any question about it — they made me a much better player," said Paul Phillips, 35, who credited the attention deficit drug Adderall and the narcolepsy pill Provigil with helping him earn more than $2.3 million as a poker player.

The revised timing of the impact implies the terrestrial planets, such as the Earth and Mars, took longer to build up from the collision of smaller 'planetesimals' than previously thought. "The age of the Moon is also the age of Earth because the Moon-forming giant impact was the last major event in Earth's formation," says Touboul.

Alan Brandon, a scientist at NASA's Johnson Space Center in Houston, Texas, US, agrees. "It may mean that Earth and Mars took at least 50 million years, and possibly hundreds of millions of years, to reach their final mass," he comments.

The researchers also found that the composition of the Moon appears identical to that of the Earth's rocky mantle, "such that a major portion of the Moon must have been from proto-Earth", Brandon told New Scientist.

Six spacecraft around Earth and Mars detected a powerful volley of gamma rays lasting about a minute on 25 January 2007. Such explosions, called long gamma-ray bursts, are thought to be caused when massive stars explode and their cores collapse into black holes.

But follow-up observations by some of the world's most powerful telescopes failed to turn up any sign of a 'host' galaxy for the dying star. Spectral observations did show, however, that the burst, called GRB 070125, had exploded within a small pocket of dense gas.

A new weapon of intergalactic war has been found. A jet of hot gas and high-energy particles is shooting out from the core of a galaxy called 3C321 and hitting a neighbour, a new study reveals.

Galaxies have been known to ram into each other, but this is the first known example of attack by particle beam