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The length of day on Mercury is 58.646 Earth days. That's the rotation time, which is the sidereal day, but there's also the solar day. The solar day on Mercury is 176 Earth days.
That planet is Venus. The rotation period of Venus is 243 Earth days. That's called a "sidereal day". On Earth the sidereal day is about 23 hours and 56 minutes. There is also the "solar day", based on the position of the Sun in the sky. On Earth, that's exactly 24 hours. On Venus the solar day is about 117 Earth days in length. As you can see, there is a huge difference in the lengths of the two days on Venus. That's because Venus rotates very slowly.
Instead of a similar rotational period to Earth's 24 hours, Venus takes 243 Earth days to rotate once. That's called a "sidereal day". In other words, a "day" on Venus is longer than its "year". This is the longest day in the entire Solar System. (Don't forget the "solar day" though. That's only about 117 Earth days on Venus.)
There are two main definitions of "day" for a planet:1) Sidereal day. That's the time taken to rotate once.2) Solar day. That's the time taken for the Sun to complete one apparent journeyaround the sky. Usually it's given as the "mean solar day", which is the average value.The solar day depends on the planet's orbital motion, as well as its rotation.Here are the details, with slight approximations:Mercury : sidereal day, 58.65 Earth dayssolar day, 175.94 Earth daysVenus: sidereal day, 243.02 Earth dayssolar day, 116.75 Earth daysEarth: sidereal day, 23.934 hourssolar day, 24.000 hoursMars: sidereal day, 24.623 hourssolar day, 24.660 hoursFor these planets both days are nearly the same length:Jupiter: 9.92 hoursSaturn: 10.66 hoursUranus: 17.24 hoursNeptune: 16.11 hours
The Sun crosses the meridian (the imaginaryline in the sky from due north to due south and passing directly overhead) at solar noon. The period between two successive solar noons is a "solar day". When you reckon the period of time between two successive meridian transits of a distant star, or the vernal equinox, that is a "sidereal day". In simple terms the sidereal day is the rotation period of a planet.
It is about 117 Earth days (for the "solar day") or 243 Earth days (for the "sidereal day").
243 days on earth
A mercury day (sidereal rotation period) is 58.646 earth days = 1407.5 hours.
The length of day on Mercury is 58.646 Earth days. That's the rotation time, which is the sidereal day, but there's also the solar day. The solar day on Mercury is 176 Earth days.
Yes.
The sidereal day is about 243 Earth days. That is the time for the planet to rotate once . The solar day is 117 Earth days,roughly. That is a big difference. On Earth the difference between these two days is only about 4 minutes. The reason for the big difference on Venus is that Venus rotates very slowly. The solar day depends on the rotation of a planet AND its orbital motion. The slow rotation makes the effect of the orbital motion much greater on the length of the solar day. Incidentally Venus rotates in the opposite direction to Earth. That's why the solar day is shorter than the sidereal day. On Earth it's the other way round.
243 Earth days is the rotation period of Venus. That's its "sidereal day" length. The other main definition of a "day" is called a "solar day". For Venus that's only about 117 Earth days in length.
The length of day on moon is (27.32 EARTH DAYS)27.32 days is the length of a sidereal day.The length of a lunar solar day (the time it takes the sun to appear in the same spot overhead) is 29.5 days. This is because as the moon turns, it also travels along its orbit about the sun.
That planet is Venus. The rotation period of Venus is 243 Earth days. That's called a "sidereal day". On Earth the sidereal day is about 23 hours and 56 minutes. There is also the "solar day", based on the position of the Sun in the sky. On Earth, that's exactly 24 hours. On Venus the solar day is about 117 Earth days in length. As you can see, there is a huge difference in the lengths of the two days on Venus. That's because Venus rotates very slowly.
Instead of a similar rotational period to Earth's 24 hours, Venus takes 243 Earth days to rotate once. That's called a "sidereal day". In other words, a "day" on Venus is longer than its "year". This is the longest day in the entire Solar System. (Don't forget the "solar day" though. That's only about 117 Earth days on Venus.)
There are two main definitions of "day" for a planet:1) Sidereal day. That's the time taken to rotate once.2) Solar day. That's the time taken for the Sun to complete one apparent journeyaround the sky. Usually it's given as the "mean solar day", which is the average value.The solar day depends on the planet's orbital motion, as well as its rotation.Here are the details, with slight approximations:Mercury : sidereal day, 58.65 Earth dayssolar day, 175.94 Earth daysVenus: sidereal day, 243.02 Earth dayssolar day, 116.75 Earth daysEarth: sidereal day, 23.934 hourssolar day, 24.000 hoursMars: sidereal day, 24.623 hourssolar day, 24.660 hoursFor these planets both days are nearly the same length:Jupiter: 9.92 hoursSaturn: 10.66 hoursUranus: 17.24 hoursNeptune: 16.11 hours
Venus. The rotational (day) period is243.2 earth days, and the sidereal (year) period is 224.7 earth days, the only planet in our solar system that has a year that is shorter than a day.