G-type main-sequence star
The Sun
The star at the center
The Sun is the star at the center of our solar system and the source of nearly all energy for life on Earth. It is a nearly perfect sphere of hot plasma, about 4.6 billion years old and roughly halfway through its life. The Sun holds 99.8% of all the mass in the solar system; about 1.3 million Earths could fit inside it. In its core, hydrogen fuses into helium, releasing the energy that reaches us as sunlight about 8 minutes later.
Quick facts
- Diameter
- 1.39 million km (109x Earth)
- Day length
- ~27 days (rotation at equator)
- Avg. temperature
- 5,500 C surface / 15 million C core
What's it like there?
The Sun has no solid surface; what we see is the photosphere, a glowing layer of plasma at about 5,500 C. Above it, strangely, the outer atmosphere (the corona) is millions of degrees hotter — a mystery missions like Parker Solar Probe are studying. Sunspots, solar flares, and eruptions of plasma called coronal mass ejections ripple across its surface, driving space weather that can affect satellites and power grids on Earth.
Fun facts
The Sun accounts for 99.8% of the mass of the entire solar system.
Light from the Sun takes about 8 minutes 20 seconds to reach Earth.
About 1.3 million Earths could fit inside the Sun.
The Sun converts about 4 million tonnes of matter into energy every second.
In about 5 billion years the Sun will expand into a red giant.
Exploration history
SOHO 1995+
ESA/NASA observatory monitoring the Sun continuously for decades.
Parker Solar Probe 2018+
Fastest human-made object; flies through the Sun's corona.
Solar Orbiter 2020+
ESA mission imaging the Sun's poles for the first time.
The Sun vs Earth
| Property | Earth | The Sun |
|---|---|---|
| Diameter | 12,742 km | 1.39 million km |
| Mass | 1x | 333,000x Earth |
| Surface temperature | 15 C | 5,500 C |
| Age | 4.5 billion years | 4.6 billion years |
Scientific Sources & Provenance
All data is verified against official space agency records (NASA, ESA, and IAU).
- NASA Science / Mission Datahttps://science.nasa.gov/sun/
- ESA Datahttps://www.esa.int/Science_Exploration/Space_Science/Solar_Orbiter