Key facts
- Mean diameter
- 1,391,400 km
- Mass
- 1.988 × 10^30 kg (333,000 Earths)
- Surface gravity
- 274 m/s² (27.9 g)
- Escape velocity
- 618 km/s
- Mean temperature
- 5499 °C
- Rotation period
- 609.12 hours
Atmosphere
Photosphere, chromosphere and a million-degree corona that streams outward as the solar wind.
Composition and structure
About 73% hydrogen and 25% helium by mass, with traces of heavier elements.
Discovery and exploration
Studied by every solar observatory since Galileo. Modern missions include SOHO (ESA/NASA, 1995), Solar Dynamics Observatory (2010), Parker Solar Probe (2018), which has flown closer than any spacecraft, and Solar Orbiter (ESA/NASA, 2020).