A day on Earth is 23.943 hours. Their names mean “fear” and “dread”.
The Martian year is also longer than that of the Earth because it takes Mars longer to orbit the sun. Mars passed its perihelion in June 2007 and its aphelion in May 2008. Yikes! Because it's closer to the Sun than Earth is, the planet has a 225-day year. As a result, Mars has seasons like the Earth, though on Mars they are about twice as long given its longer year. Phobos orbits Mars in just 7 hours. • As a result of Mars being situated further away from the Sun than the Earth, Mars is considered to be cooler than the Earth. Mars passed its perihelion in June 2007 and its aphelion in May 2008. Mars takes 687 earth days to go around the Sun. That’s less than one Earth day! • Earth takes 365 days to go around the Sun. Venus rotates much more slowly than Earth does, so a day on Venus is much longer than a day on Earth.
Compare the Sizes of Mars, Earth, and Moons A year on Mars lasts 669.6 sols, which is the same as 687 Earth days. So, the day is actually longer than a year, which means that Venus residents would only get to see two sunrises per year. Mars is the most Earth-like other world known, yet the two planets are really a world apart. Planet Venus spins so slowly on its axis that one day on the planet lasts nearly 243 Earth days. As Mars orbits the Sun, it completes one rotation every 24.6 hours, which is very similar to one day on Earth (23.9 hours). A day on Venus lasts for 243 Earth days or 5,832 hours!
In addition, Earth has a mass that is 10 times greater. Venus also rotates backwards compared to the Earth and most of the other planets. One Martian sol is about 24.63 hours, while an Earth day clocks in at 23.94 hours. Mars is nearly twice as large as the Moon and a little over half the size of Earth, according to the Center for Mars Exploration. At proper scale, they would be even smaller than the dots shown. Deimos orbits Mars in 30 hours. In other words, the period Mars takes to go round the Sun is greater than the period Earth takes to go round the Sun. The diameter of Mars is about 6,786 kilometers (4,217 miles), compared to that of Earth, which is about 12,756 kilometers (7,926 miles). Martian days are called sols — short for "solar day." The Moon orbits Earth one time each month. One year on Mars is about 687 earth days compared to the the 365 days in a year on Earth. Phobos and Deimos: The tiny moons of Mars.