About Orbits Now

Orbits Now shows where the planets and their moons really are, in 3D, for any date from 1800 to 2050, and answers questions like how far each planet is from Earth right now.

Where the numbers come from

Everything is calculated in your browser for the moment you are looking, rather than looked up from a table.

• The 3D view places the planets using NASA JPL's published orbital elements for 1800 to 2050.

• Live distances use the open-source Astronomy Engine library, which is based on the VSOP87 planetary theory.

• Our Moon and Jupiter's four large moons also come from Astronomy Engine. Saturn's moons follow the method in Jean Meeus's Astronomical Algorithms. The moons of Mars, Uranus and Neptune use orbit models we fitted to NASA JPL Horizons positions.

How we check them

Before anything is published, we compare it with an independent source. Planet positions in the 3D view agree with NASA JPL to within about 0.2°, and live distances to better than 0.02%. Most moons agree to within half a degree; the exceptions are listed on the 3D page under “How accurate is this?”.

Where a view is not to scale, such as the enlarged sizes and spacing that make planets and moons visible, the page says so.

Contact

Found a mistake or have an idea? Get in touch.