What is a solar flare?

A large cloud of plasma ejected from the Sun at 1,000 km/s A sudden intense burst of electromagnetic radiation (X-rays and UV) from the Sun's surface A stream of charged particles flowing continuously from the corona A visible tongue of fire rising from the photosphere

How quickly do solar flares affect Earth after they occur on the Sun?

About 1 second — light travels very fast over short distances About 1-3 days — it takes time for radiation to cross space About 8 minutes — the radiation travels at the speed of light About 1 hour — the radiation slows down as it passes through the solar wind

What is a coronal mass ejection (CME)?

A massive eruption of magnetized plasma from the Sun's corona, containing billions of tonnes of charged particles A sudden brightening of the Sun visible from Earth with the naked eye The steady stream of particles that flows from the Sun at all times An explosion in the Sun's core that sends a shockwave through the solar system

How long does it typically take for a coronal mass ejection to travel from the Sun to Earth?

About 8 minutes — the same as light About 1 to 3 days About 1 year About 2 hours

What causes the beautiful auroras (northern and southern lights) seen near Earth's poles?

Sunlight reflecting off polar ice and snow into the atmosphere The Earth's magnetic field glowing when it is compressed by the solar wind Charged particles from the Sun, guided by Earth's magnetic field, collide with atmospheric molecules and cause them to glow Lightning in the upper atmosphere caused by solar radiation heating the polar regions

During a major geomagnetic storm, satellites in low Earth orbit experience problems. What causes this?

CMEs physically hit and damage satellites in orbit The geomagnetic storm cuts off the satellites' electrical power Geomagnetic storms heat and expand the upper atmosphere, increasing drag on satellites and causing their orbits to decay faster The Sun's gravity temporarily increases during a CME, pulling satellites closer to Earth

What was the Carrington Event of 1859?

The first solar flare ever observed by astronomers, in 1859 The most powerful recorded geomagnetic storm, caused by a massive CME that knocked out telegraph systems worldwide and produced auroras visible from the tropics A period of 30 years with no sunspot activity, named after Carrington The discovery of the solar wind by Richard Carrington in 1859

How can solar flares disrupt radio communications on Earth?

Flares physically knock satellites out of alignment, disrupting communication links The Sun's magnetic field during a flare changes Earth's compass readings, confusing navigation Intense X-rays from flares ionize the upper atmosphere, disrupting the layer that reflects radio waves used by aviation and maritime navigation Radio waves are absorbed by particles ejected from the flare as they pass through space

What organisation monitors the Sun 24 hours a day and issues space weather warnings?

NASA's Hubble Space Telescope operations team The International Astronomical Union (IAU) NOAA's Space Weather Prediction Center (SWPC) The European Space Agency's solar observation department

Why are GPS systems affected by strong solar storms?

CMEs physically move GPS satellites off their correct orbital positions Solar storms change the density of the ionosphere, causing delays in GPS signals that produce errors in calculated position The Sun's electromagnetic radiation directly jams GPS receiver circuits GPS does not work at all during any solar activity