Solar pictures amaze scientists

Magnetic arches loop over the sun's surface

Scientists have just obtained the first images from the recently-launched Trace satellite and they promise to improve our understanding of the sun. Our science correspondent David Whitehouse reports:

The Trace satellite

Trace is a small satellite launched from an aircraft on April 2. From an Earth orbit, it points its array of sensors towards the surface of the sun.

The sun's surface is a seething mass of gas at a temperature of 6,000°C (10,800°F). Above the surface is a thin atmosphere called the corona which is much hotter, many millions of degrees.

Scientists are fascinated by this part of the sun. They still fail to understand fully how the corona can be so hot.

Close-up of magnetic arches

They are also excited because the events and processes that take place in the hot gas on the sun's surface occur in many places throughout the universe.

For that reason, the sun has been called the 'Rosetta stone' of astrophysics.

In particular, magnetic fields in the form of huge tubes emerge from below the surface.

As they appear they fill up with superhot gas that shows their shape. This is what Trace's first image shows.

Flares on the sun's surface

Occasionally these 'flux tubes' become unstable and their magnetic energy collapses and explosively heats the surrounding gas spurting much of it into space. This is a solar flare.

If the particles from a solar flare reach the Earth they are funnelled to the Earth's magnetic poles and when they strike the atmosphere they can produce beautiful auroral displays.