Sun activity: Fiery limbs on today’s sun

Sun activity for December 3, 2022: Fiery limbs with gorgeous prominences today on the solar disk. New sunspot AR3156. One large coronal hole.

Aurora season: Why more auroras at equinoxes?

An aurora season occurs in October and March each year, due to the way the magnetic fields of the sun and the Earth work in conjunction with sun-Earth geometry.

What causes an aurora, the northern or southern lights?

The aurora, or northern and southern lights, occur when charged particles from the sun interact with Earth's magnetic field. Read more here.

CME strikes Solar Orbiter before Venus flyby

On September 4, 2022, during a close flyby of Venus, Solar Orbiter was hit by a large CME. Fortunately, the spacecraft was unharmed.

Limb darkening is an optical effect on the sun

Limb darkening is an effect we can see on the sun where the edges of the sun are darker than the center, due to the amount of photosphere we're looking at.

Geomagnetic storms: Will you lose power where you live?

Scientists studied past geomagnetic storms to learn more about how strong storms affect the power grid. The maps here show areas most at risk.

The sun as you’ve never seen it

ESA's Solar Orbiter reached perihelion, its closest point to the sun, in March. Here are stunning closeup images as never seen before.

Why are east and west on the sun reversed?

East and west on the sun are opposite from what you might expect. On the sun, east is to the left and west is to the right. Learn why here.

A Grand Solar Minimum? Or a normal sun?

A Grand Solar Minimum happens when the peaks of several solar cycles in a row show less than average intensity. Are we in one?

What does the sun’s X-ray flux tell us?

Solar physicists often speak of the sun's X-ray flux as being high, or low. Solar flares are like waves on the background ocean of the sun's X-ray flux.