David Stonehouse Science & Health

Earthlings were fortunate during the recent solar storms -- the effects could have been far more serious

By David Stonehouse

An angry sun smacked Earth with a one-two punch this week: Powerful, back-to-back solar flares that hurled huge plumes of electrically charged particles at our planet and touched off turbulent storms in our outer atmosphere.

They played themselves out in beautiful displays of northern lights in the night sky, but harnessed nasty potential. The space storms could have wreaked havoc in our electronic world, zapping power grids, knocking out cellular and other communications systems and frying satellites.

We got off lucky -- last time we saw storms like this, all of Quebec was left without electricity for nine hours.

It is not over yet, though. Space weather forecasters warn we could be battered again in the coming days.

Much is left to learn about this solar turmoil. Scientists remain divided about what exactly triggers these geomagnetic storms, and mystery still surrounds how they behave.

But a space mission now quietly being mounted by NASA and supported by Canadian scientists should peel back some of the mystery. In less than three years, five probes will be fired into the Earth's sprawling magnetic field to gather data that scientists hope will solve the puzzle and lead to better forecasting of space storms.

The probes, which will be spread out in orbits between 60,000 and 180,000 kilometres from Earth, will feed back information that can be matched with the digital images collected by Canadian researchers to interpret the chain of events that trigger what scientists call substorms.

"The idea of having the five spacecraft and the distributed array of cameras will allow us to look at what happens first, what happens second, what happens third," says Eric Donovan, an associate professor at the University of Calgary who holds the Canada Research Chair in Auroral Studies and who is leading the imaging project. "It will allow us to identify the physical process that makes the substorm happen in the first place."

A battery of digital cameras is being set up across Canada to take photographs of the aurora -- images that will help researchers pinpoint the explosive points of the storms.

"This is one of the biggest imaging projects in history," the he says.

"Certainly in our field, no one has ever done an imaging project that has generated this much data. And the idea of running 16 digital remote cameras on an ongoing basis in the wilderness is a rather daunting task."

The cameras, stretched across the north, will take images every five seconds of the night sky to capture the momentary flare-ups in the northern lights that signal storm activity.

The images will be co-ordinated with the orbits of the five probes that NASA plans to launch in 2006 to take readings of the chaotic magnetosphere that envelops the planet.

The superheated magnetic shield protects Earth from cosmic radiation. It fends off the solar wind, the energy blasts tossed at it by the sun. It is a turbulent zone, with the energy distorting the shield into a comet-like shape with a long tail that collects the solar wind until it bursts and releases accelerated particles and electron currents.

These substorm bursts we see as auroras flaring and then dancing in the night sky. What exactly triggers the rapid flaring is unclear, but a quick brightening of the aurora pinpoints where the bursts take place.

Twice in two weeks, scientists have issued warnings about unusually turbulent solar flares -- formally known as coronal mass ejections. This week was worse than last, when Everest expeditions and aircraft had their communications knocked down and the global positioning system was thrown off.

This week, we played witness to two of the most violent coronal mass ejections recorded.

The first fired off a cloud of charged particles 13 times the size of the Earth at a speed of 1.6 million km/h, slamming into the planet early Wednesday.

Rated G-5 -- the worst possible -- it was comparable to the one that shut down the entire power grid for the province of Quebec in 1989, leaving millions of people without electricity for hours. Five years later, two Canadian satellites -- Anik E-1 and E-2 -- were damaged by a similar-sized storm.

Another blast punched the planet on Thursday, but again left us relatively unscathed. A Japanese satellite was knocked off line, as was an American research satellite. The upcoming space mission -- dubbed THEMIS for Time History of Events and Macroscale Interactions during Substorms -- may help us understand better how these storms behave and affect us here on Earth. NASA is paying $173 million U.S. to mount it, a relatively small sum in the billon-dollar world of space exploration.

When the probes are launched from a rocket in the summer of 2006, it will mark NASA's first-ever "constellation-class" mission -- one involving numerous small craft sent up at once.

Vassilis Angelopoulos, a research physicist at the University of California, Berkeley's Space Sciences Laboratory and the lead investigator for THEMIS, acknowledges there are those who believe it is an impossible mission to carry off, especially on budget.

"There are skeptics out there who are saying it is challenging -- challenging technologically and challenging fiscally," Mr. Angelopoulos says. "But unless we are successful, then future constellation class-missions cannot proceed. We really need to usher in this new era."

He describes the Canadian contribution as "paramount" to the success of the mission.

"We need to know where the auroras erupt and where exactly that eruption takes place in order to put the space observations in context," he says." We will not be able to interpret the stuff we see out in space properly unless we are in the meridian of the substorm, and the Canadian efforts will tell us where the meridian of the substorm is."

For scientists like Mr. Angelopoulos, the most exciting aspect of the mission is that it promises to unglue a lingering mystery of space physics.

"This is a dream come true. This problem of where this substorm takes place is something I have heard about since my graduate studies as being the most important problem in magnetospheric physics. And to be in the midst of it all, in the process of solving it, is just thrilling."

William Liu, program scientist for space environment with the Canadian Space Agency, says it should also open insights into the behaviour of charged particles -- the electrons and ions of space plasma that make up virtually the entire visible universe.

"Understanding the stabilities and the explosive processes in this system," Mr. Liu says, "can help us understand, for example, how a supernova takes place or how a black hole works."