Controlling the Weather with Laser Beams

Researchers at the University of Geneva have developed a technique for making rain using a laser beam. Field experiments have been carried out close to Lake Geneva, with encouraging results.

So far, the technology has succeeded in creating tiny droplets of water, less than 0.01 millimeters in diameter. For the particles to be heavy enough fall as rain, they would have to be at least one hundred times bigger. However, it may be possible to induce these tiny droplets in water that is headed towards a natural feature such as a mountain range. As the air is forced to rise over the mountain range, it will cool, causing the droplets to grow larger until they are eventually heavy enough to fall as rain.

So how does it work? The laser beam causes particles of nitric acid to form in the cloud. Nitric acid forms bonds with water vapour in the air, acting as a means of bringing water molecules together so that condensation into liquid water takes place. The nitric acid-bonded water droplets have increased stability, so are less likely to re-evaporate than naturally formed droplets.

To read more about the significance of the technology, and the old silver iodide method that it could potentially replace, follow this link:

Making Rain With Laser Beams

*Image courtesy of Flickr user openuser

Opportunity Mars Rover reaches Endeavour Crater

After 3 years of slowly crawling across the bleak Martian surface, the NASA Mars rover Opportunity has reached the rim of the Endeavour crater.

West rim of the Endeavour crater photographed by the Opportunity rover.
Courtesy NASA/JPL-Caltech.

Opportunity has already visited Victoria Crater and studied the layers of rock that lie within. Endeavour is 25 times wider and much deeper than Victoria, which means that Opportunity will be able to study older Martian rocks during its time here. Scientists hope that studying rocks that were formed during an earlier era of Mars' history will answer questions about the presence of water on the Red Planet.

Just last week, strong evidence emerged for the existence of flowing water on Mars. The aim of the Martian rover's rock analysis is to determine whether liquid water has ever existed for long periods of time on the surface of Mars.

NASA press release

NASA's Jupiter-Bound "Juno" Mission Launches Successfully

Artist's Impression of Juno circling Jupiter.
Courtesy NASA/JPL-Caltech.

Just a few minutes ago, NASA successfully launched the unmanned spacecraft Juno into Space. The solar-powered spacecraft will spend the next five years travelling to its destination, the gas giant Jupiter - the largest planet in our solar system.

Juno's aim is to study Jupiter's atmosphere and its gravitational and magnetic fields. The hope is that this data will give clues to Jupiter's origins. For example, if Juno detects a high concentration of water in Jupiter's atmosphere, that would suggest that Jupiter might have formed further out in the Solar System and gradually drifted to its current position.

Juno's year-long study will end in dramatic fashion, with the probe plunging deep into the depths of Jupiter and being destroyed.

See the Juno mission page from NASA: http://www.nasa.gov/mission_pages/juno/main/index.html

The Code: Mathematics in Nature

The BBC seems to have an affinity for mathematics documentaries at the moment. As well as re-airing The Story of Maths, they are also currently running a three-part documentary, The Code.

The programme highlights of mathematics popping up in unlikely places in nature. For example, one particular species of cicadas emerges only once every 13 years, in order to minimise their chances of coinciding with another species. This works because 13 is prime and therefore shares few factors (only 1 and 13) with other numbers.

There's also a "treasure hunt" based on clues from the TV show, the online games and the blog: Treasure Hunt

Catch the final episode on Tuesday 10th at 9pm, or view the whole series on BBC iPlayer.

How to Bring Your Rocket Up to Speed

I just started writing for Brighthub, a site which provides information on science, technology and education.  I write in the Space Channel.

Check out my first article:  How is Calculus Used in Astronomy?