How long does it take for the planets to orbit the sun?
Earth takes 365 days to travel one complete orbit, while Mercury takes 88 days and Venus takes 224 days, so the time between alignments will require each planet to make a whole number of orbits around the sun and return to the pattern you see in the figure above.
The orbits of the planets are ellipses with the Sun at one focus, though all except Mercury are very nearly circular. The orbits of the planets are all more or less in the same plane (called the ecliptic and defined by the plane of the Earth's orbit).
- Planetary Orbits. The orbits of the inner planets. From the center out we have the Sun, Mercury, Venus and the Earth, then Mars and Jupiter. All the planets are orbiting in a counter-clockwise direction, as seen in this view from the North Ecliptic Polar direction.
- All orbits are elliptical, which means they are an ellipse, similar to an oval. For the planets, the orbits are almost circular. The orbits of comets have a different shape. They are highly eccentric or "squashed."
- The average distance between the Earth and the Sun is 149.60 million km (92.96 million mi), and one complete orbit takes 365.256 days (1 sidereal year), during which time Earth has traveled 940 million km (584 million mi). Earth's orbit has an eccentricity of 0.0167.
The Days (And Years) Of Our Lives
|Planet||Rotation Period||Revolution Period|
|Mercury||58.6 days||87.97 days|
|Venus||243 days||224.7 days|
|Earth||0.99 days||365.26 days|
|Mars||1.03 days||1.88 years|
- Pluto, as a member of the Solar System, was formed at the same time as the rest of the planets and the Sun during the Formation and evolution of the Solar System from the protoplanetary disk around the Sun. Thus the age for Pluto is approximately 4.46 to 4.6 billion years old.
- Jupiter is the heaviest planet in the solar system, with a mass of 1.90 x 10^27 kg. The gas giant's mass is equivalent to about 318 Earths. Jupiter is so heavy that it's about two and a half times the mass of all the other planets in the solar system combined.
If the Sun and Earth were the only things in the solar system, our planet's orbit would be an ellipse of virtually constant shape and orientation in space. However, because the other planets pull on Earth, our orbit does change slightly over time, in orientation and in shape. Same for the other planets' orbits.
- The moon orbits the Earth once every 27.322 days. It also takes approximately 27 days for the moon to rotate once on its axis. As a result, the moon does not seem to be spinning but appears to observers from Earth to be keeping almost perfectly still.
Which planet in our solar system is the only one that rotates in a different direction from the others?Every planet in our solar system except for Venus and Uranus rotates counter-clockwise as seen from above the North Pole; that is to say, from west to east. This is the same direction in which all the planets orbit the sun.
- To enable life, this most special of attributes, planet Earth has a number of ideal features. It is unique among planets in our solar system for having water in its liquid form at the surface, in an amount conducive to life evolving.
Updated: 18th November 2019