Watching minute by minute and year by year, SOHO has seen the Sun brighten, as expected, by 0.1 percent while the count of sunspots increased from 1996 to 2000. By studying the variations in detail, scientists estimate that high-energy ultraviolet rays from the Sun have become 3 percent stronger over the past 300 years. Eruptions coming our way. Most of the explosive outbursts of gas from the Sun, called coronal mass ejections, miss Earth. Only SOHO can reliably identify those heading in our direction, by linking expanding haloes around the Sun to shocks seen in the Earth-facing atmosphere.
Engineers then have two to three days' warning of possible effects in the Earth's vicinity.
Thousands of explosions every day. They result from a continual rearrangement of tangled magnetic fields. The sources of the solar wind. SOHO sees gas leaking from the corners of a magnetic honeycomb of gas bubbles, mainly in polar regions, to supply a fast solar wind. Nearer the Sun's equator, a slow wind escapes from the edges of wedge-shaped features called helmets.