The Sun By the Numbers - NASA Solar System Exploration The Sun is the star at the heart of our solar system Its gravity holds the solar system together, keeping everything – from the biggest planets to the smallest bits of debris – in its orbit
In Depth | Sun – NASA Solar System Exploration Without the Sun’s energy, life as we know it could not exist on our home planet From our vantage point on Earth, the Sun may appear like an unchanging source of light and heat in the sky But the Sun is a dynamic star, constantly changing and sending energy out into space
Planet Compare – NASA Solar System Exploration NASA’s real-time science encyclopedia of deep space exploration Our scientists and far-ranging robots explore the wild frontiers of our solar system
In Depth | 1P Halley – NASA Solar System Exploration Halley's orbit period is, on average, 76 Earth years This corresponds to an orbital circumference around the Sun of about 7 6 billion miles (12 2 billion kilometers) The period varies from appearance to appearance because of the gravitational effects of the planets