Espace. Table of Planets - windows to the universe. Dwarf Planets are listed in a separate table below.
Dwarf Planets * Negative values of rotation period indicate that the planet rotates in the direction opposite to that in which it orbits the Sun. This is called retrograde rotation. Views of the Solar System Photo Gallery. Is There a Milky-Way Galaxy/Earth Biodiversity Link? Experts Say "Yes" 1n 1999, Astronomers focusing on a star at the center of the Milky Way, measured precisely how long it takes the sun to complete one orbit (a galactic year) of our home galaxy: 226 million years.
The last time the sun was at that exact spot of its galactic orbit, dinosaurs ruled the world. The Solar System is thought to have completed about 20–25 orbits during its lifetime or 0.0008 orbit since the origin of humans. Using a radio telescope system that measures celestial distances 500 times more accurately than the Hubble Space Telescope, astronomers plotted the motion of the Milky Way and found that the sun and its family of planets were orbiting the galaxy at about 135 miles per second. That means it takes the solar system about 226 million years to orbit the Milky Way and puts the most precise value ever determined on one of the fundamental motions of the Earth and its sun. Windows to the Universe.
The Nine Planets Solar System Tour.