Science & history · Looking at the Sun
From spots to the solar wind: four centuries of solar science
Most of what we know about the Sun was worked out in the last four hundred years, much of it in the last seventy.
Seeing it
In 1613 Galileo's Letters on Sunspots argued that the spots were features on the Sun, not planets passing in front of it. In 1817 Joseph von Fraunhofer began labelling and studying the dark lines in sunlight. In 1868 Pierre Janssen saw an unknown line in the Sun's spectrum during an eclipse; it was named helium, after the Greek for Sun, and found on Earth only in 1895.
Understanding it
On 1 September 1859 Richard Carrington saw a white-light flare; the storm that followed is the first documented geomagnetic storm linked to a coronal mass ejection. George Ellery Hale showed in 1908 that sunspots are magnetic. Coronagraphs, which make artificial eclipses, arrived in 1931. In 1958 Eugene Parker predicted the solar wind, and NASA's Mariner 2 confirmed it. Earlier, between 1645 and 1715, sunspots had all but vanished: the Maunder Minimum.
Sources
- NASA History Spots, Waves and Wind: A Solar Science Timeline (opens in a new tab) for Galileo 1613, Fraunhofer 1817, Schwabe 1843, Carrington 1859, Janssen 1868, Hale 1908, coronagraph 1931, Parker 1958, Maunder minimum · checked 2 October 2026