solar-wind

NASA's Parker Solar Probe is the first spacecraft to fly inside the Sun's corona — here's what it has found and why it matters.

How auroras form: solar wind, Earth's magnetic field, atmospheric collisions, why they're green or red, and where and when to see them.

Apollo solar wind collectors captured particles directly from the Sun's wind, analyzing isotope ratios that revealed solar composition and isotopic variations over time.

The solar wind is a continuous outflow of charged particles, mostly protons and electrons, from the Sun's hot corona. It moves at roughly 400 to 800 km/s, bends the interplanetary magnetic field into a spiral, inflates the heliosphere, pushes comet ion tails away from the Sun, drives auroras, and helps strip planetary atmospheres. Voyager 1 crossed the heliopause, where the wind gives way to interstellar space, in 2012.

The heliosphere is a vast bubble of solar wind plasma around the Sun, reaching roughly 120 AU toward the direction we are moving. It deflects a large share of low-energy galactic cosmic rays. Voyager 1 crossed its outer boundary, the heliopause, in 2012 and Voyager 2 followed in 2018.

China had 1,827 GW of renewable power capacity at the end of 2024, 41% of the world total, per IRENA. See the top 20 countries by installed gigawatts and why capacity is not the same as generation.