Aurora

The solar wind dancing in the sky

The Sun constantly shoots tiny particles into space — the 'solar wind'. Earth's invisible magnetic shield catches them and steers them to the poles. There the particles crash into the air and make it glow like a lamp: green, purple and pink curtains! See the green ring around the poles on the globe? That's where the aurora dances — at the North and South Poles at the same time.

The aurora happens when the solar wind (electrons and protons at 400 km/s) pours along Earth's magnetosphere into the polar regions and excites atmospheric atoms at 100–300 km: oxygen glows green (557.7 nm) and red (630 nm), nitrogen blue-purple. The auroral oval is a ring at 65–72° latitude around the magnetic pole, expanding to 50° during solar activity (in May 2024 it was seen from Uzbekistan). It is symmetric at both poles — borealis and australis. The 11-year solar cycle peaks in 2024–2025. Strong geomagnetic storms (the 1859 Carrington Event, Quebec in 1989) can knock out power grids and satellites. Jupiter, Saturn and even Mars have auroras.

Fun facts

• The aurora glows at both poles at once, in mirror-image shapes.
• It forms 100–300 km up — the ISS flies right through it.
• The great aurora of 1859 set telegraph wires on fire.