- He also used his telescope to discover the four largest satellites of Jupiter, the phases of Venus, and sunspots on the sun.
- He developed a great interest in broadcast noise, especially during sunspots.
- It went on to warn that further flares are likely in the next week, and because the sunspot is moving into line with Earth, the risk of disruptions is even greater as the solar activity will strike the planet head-on.
Sunspots are regions of lower surface temperature and are believed to form where loops in the sun’s magnetic field intersect the surface; an individual spot may persist for several weeks. The number of sunspots on the solar surface fluctuates according to a regular cycle, with times of maximum sunspot activity recurring about every eleven years
Definition of sunspot in:
- The US English dictionary