An medium-size solar flare erupts from the right side of the sun in this image in the early morning of 13 January, 2015 (British time). The image was recorded using two wavelengths (171 and 304 angstroms) of light too energetic for our eyes to see, as captured by NASA's Solar Dynamics Observatory. Credit: NASA/Solar Dynamics Observatory

The sun emitted its first notable solar flare, peaking in the early morning of 13 January, 2015. Solar flares are powerful bursts of radiation – a sort of non-visible light.

NASA’s Solar Dynamics Observatory, which watches the sun constantly, recorded this image of the flare. Harmful radiation from a flare cannot pass through the Earth’s atmosphere to physically affect humans on the ground.

However, if the flares’ radiation is strong enough, it can cause problems for communications on Earth and between the Earth and satellites.