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The Sun Facts
- The Sun is the star at the center of the Solar System.
- It is a nearly perfect sphere of hot plasma, mainly composed of hydrogen (about 74% of its mass) and helium (about 24%).
- The Sun's diameter is about 1.39 million kilometers (864,000 miles), making it about 109 times the diameter of Earth.
- It has a surface temperature of about 5,500°C (9,932°F) and a core temperature of about 15 million °C (27 million °F).
- The Sun generates energy through nuclear fusion, where hydrogen nuclei fuse into helium, releasing vast amounts of energy.
- It has a complex magnetic field that drives solar activity such as sunspots, solar flares, and coronal mass ejections.
- The Sun's energy supports life on Earth and drives Earth's climate and weather patterns.
- Solar radiation, including visible light, ultraviolet radiation, and heat, emanates from the Sun in all directions.
- The Sun is about 4.6 billion years old and is roughly halfway through its life cycle as a main-sequence star.
- It orbits the center of the Milky Way galaxy, taking about 225-250 million years to complete one orbit (galactic year).
- The Sun's mass accounts for about 99.86% of the total mass of the Solar System.
- Solar eclipses occur when the Moon passes between the Earth and the Sun, blocking out its light partially or entirely.
- The Sun's luminosity gradually increases over time as it continues to burn hydrogen in its core.
- NASA and other space agencies study the Sun using satellites like the Solar Dynamics Observatory (SDO) and Parker Solar Probe.
- The Sun's surface exhibits granulation, sunspots, and solar prominences, visible during solar observations.
- Future missions aim to study the Sun's outer atmosphere (corona) and its effects on space weather.
- Solar flares and coronal mass ejections can impact Earth's magnetic field and technological systems, causing geomagnetic storms.
- The Sun's energy output varies over an 11-year solar cycle, affecting space weather and Earth's climate.
- Scientists study the Sun to understand stellar evolution, the origin of the Solar System, and the habitability of other planets.
- The Sun is essential for photosynthesis in plants and provides the primary source of energy for most ecosystems on Earth.