Solar System
The Solar System is the gravitationally bound system of the Sun and the objects that orbit it, either directly or indirectly. Of the objects that orbit the Sun directly, the largest are the eight planets, with the remainder being smaller objects, such as the five dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly—the moons—two are larger than the smallest planet, Mercury.
Solar phenomena
The total sum of all solar fluctuations is referred to as solar variation. The collective effect of all solar variations within the Sun's gravitational field is referred to as space weather. A major weather component is the solar wind, a stream of plasma released from the Sun's upper atmosphere. It is responsible for the aurora, natural light displays in the sky in the Arctic and Antarctic. Space weather disturbances can cause solar storms on Earth, disrupting communications, as well as geomagnetic storms in Earth's magnetosphere and sudden ionospheric disturbances in the ionosphere. Variations in solar intensity also affect Earth's climate. These variations can explain events such as ice ages and the Great Oxygenation Event, while the Sun's future expansion into a red giant will likely end life on Earth.