Scientists learn what makes Northern Lights flare

The multicolored aurora borealis and aurora australis -- the Northern Lights and Southern Lights -- represent some of Earth's most dazzling natural displays.

Now scientists using data from five NASA satellites have learned what causes frequent auroral flare-ups that make this green, red and purple light show that shimmers above Earth's northernmost and southernmost regions even more spectacular.

Writing in the journal Science, the scientists said on Thursday that explosions of magnetic energy occurring a third of the way between Earth and the moon drive the sudden brightening of the Northern Lights and Southern Lights.

There had been debate among scientists dating back decades about what triggers these auroral flare-ups.

The findings from the THEMIS satellites and a network of 20 ground observatories in Canada and Alaska confirmed that it is due to a process called "magnetic reconnection." THEMIS stands for Time History of Events and Macroscale Interactions during Substorms mission.

Auroral displays are associated with the solar wind -- electrically charged particles continuously spewing outward from the sun. Earth's magnetic field lines reach far out into space as they store energy from the solar wind.

The researchers said that as two magnetic field lines come close together due to the storage of energy from the sun, a critical limit is reached and the lines reconnect, causing magnetic energy to be turned into kinetic energy and heat. The release of this energy sparks the auroral flare-ups.

"We showed that the process begins far from Earth first and propagates Earthward later," said Vassilis Angelopoulos of the University of California at Los Angeles, who led the research.

The moon is located about 240,000 miles from Earth, and this process is occurring roughly 80,000 miles from Earth.

The same mechanism causing the auroral brightening also can cause problems for satellites, power grids and communications systems on Earth and could endanger astronauts in space, the researchers said.

Puppet classes make learning science fun

What do puppets have to do with rain harvesting, fissures in the earth’ surface and environmental issues?

A lot, if you ask the participants at the just concluded workshop organised by the Indian Science Communication Society at the Regional Science City in Lucknow.

The 35-odd students from various schools mastered the art of ‘Joyful Science through Puppetry’. They made puppets, then wrote scripts on issues related to science and then did a bit of acting to convey the message to the audience.

“The workshop was designed to familiarise children to issues that concern their lives. We brought in puppetry because it made the whole experience of learning science rather joy ful. It was a unique marriage of science and arts and the children enjoyed it thoroughly,” says Mr P. K. Jain, education officer at the Regional Science City.

The participants, all of them from class 7 and above, took up the issue of rain harvesting and water conservation and enacted it through a puppet skit titled Pakdo, Pani Bhaga. The issue of the earth surface developing fissures due to excessive ground water exploitation was also addressed by the children.

Pahada Pa Ka highlighted the relationship between tree and water while Kahan Se Kahan Tak underlined the pollution due to increasing vehicular traffic. It also urged people to understand the need for a clean environment. Niyati Das, a class 9 student who participated in the workshop, found the experience ‘unique and interesting’.

“We got to learn how to make puppets, how to write scripts for plays and how to act.

Somewhere in between, we also learnt about science and its impact on our lives. With my friends, I now plan to star a similar workshop in my colony,” she says.

Mr Jain says that the idea of the workshop was top spread the message through children.