Well, it depends on where they are orbiting! Planets that orbit closer to the Sun than Earth have shorter years than Earth. Planets that orbit farther from the Sun than Earth have longer years than Earth. A planet orbiting close to its star has a shorter year than a planet orbiting farther from its star. NASA needs to know how other planets orbit the Sun because it helps us travel to those planets!
For example, if we want a spacecraft to safely travel to another planet, we have to make sure we know where that planet is in its orbit. Scientists who study Mars also need to keep a Martian calendar to schedule what rovers and landers will be doing and when. Mars and Earth are always moving. So, if we want to land a robotic explorer on Mars, we have to understand how Earth and Mars orbit the Sun. Watch this video to learn more about the Martian year.
How Long is a Year on Other Planets? According to Nebular Theory , the Sun and all the planets of our Solar System began as a giant cloud of molecular gas and dust called a solar nebula. Then, about 4. From this collapse, pockets of dust and gas began to collect into denser regions. As the denser regions pulled in more and more matter, conservation of momentum caused them to begin rotating, while increasing pressure caused them to heat up.
Since temperatures across this protoplanetary disk were not uniform, this caused different materials to condense at different temperatures, leading to different types of planets forming. As a result, planets like Jupiter, which are located beyond the Frost Line, condensed out of denser materials first like silicate rock and minerals , then were able to accumulate gases in a liquid state.
We have written many articles about Jupiter here at Universe Today. We have also recorded an episode of Astronomy Cast about Jupiter. You can listen here, Episode Jupiter. All of the Jovian planets offer examples of pretty extreme physics that exist below the level of stellar physics. See Uranus and its But this is mitigated by the fact that seasonal changes are far greater on Mars, owing to its eccentricity and greater axial tilt This is due to temperature variations and the complex exchange of carbon dioxide between the Martian dry-ice polar caps and its CO 2 atmosphere.
As a result, Martian seasons vary greatly in duration than those on Earth, change roughly every six months, and do not start on the same Earth day every Martian year. Jupiter is another interesting case. Whereas the gas giant only takes 9 hours 55 minutes and 30 seconds to rotate once on its axis, it also takes alson This means that a year on Jupiter is not only the equivalent of 4, Much like Venus, Jupiter has an axial tilt of only 3 degrees, so there is literally no seasonal variation between the hemispheres.
In addition, temperature variations are due to chemical compositions and depths rather than seasonal cycles. Much like its fellow gas giant Jupiter, Saturn takes it time completing a single orbit of the Sun, but rotates on its axis very rapidly. All told, a year on the planet lasts the equivalent of 10, Earth days or about 29 1? But since it only takes 10 hours, and 33 minutes to complete a single rotation on its axis, a year on Saturn works out to 24, Cronian days.
Due to its axial tilt of almost 27 degrees slightly more than Mars , Saturn experiences some rather long seasonal changes. But due to it being a gas giant, this does not result in variations in temperature. Combined with its distance from the Sun at an average distance of 1, Uranus has some of the strangest annual and seasonal variations of any planet in the Solar System.
But since the planet takes 17 hours, 14 minutes and 24 seconds to complete a single rotation on its axis, a year on Uranus lasts 42, Uranian days. This results in seasonal changes that are quite extreme, and unique to Uranus. In short, when one hemisphere is pointed towards the Sun i.
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