Which planet has the longest day?
Venus has the longest sidereal day of the eight planets—about 243 Earth days—and it rotates retrograde. Mercury’s solar day is even longer (~176 Earth days), but its sidereal spin is ~58.6 Earth days.
Which planet has the shortest day?
Jupiter has the shortest day among the eight planets—about 9.9 hours (0.414 Earth days) at the equator. Saturn is next at roughly 10.7 hours.
How long is a day on Mars?
One Mars sol (mean solar day) is about 1.026 Earth days—approximately 24 hours 39 minutes. Rover teams track sols because the offset from 24 hours accumulates over multi-week missions.
What is a Martian sol?
A sol is the mean solar day on Mars—the time from one noon to the next, about 24 h 39 m 35 s. Mission schedules and rover logs count activity in sols rather than Earth days.
Why is Venus so slow?
Venus rotates once every ~243 Earth days (sidereal) and spins backward (retrograde). Tidal interactions and atmospheric drag from its thick atmosphere likely slowed and flipped its rotation over billions of years.
Is a day on Mercury longer than a year?
Mercury’s solar day (~176 Earth days) is longer than its year (~88 Earth days). However, its sidereal rotation period is ~59 Earth days—shorter than a Mercury year. The long solar day comes from Mercury’s 3:2 spin–orbit resonance.
How many Earth days is 1 Jupiter day?
About 0.414 Earth days—roughly 9.9 hours. Jupiter’s equatorial region spins once in under ten hours, so one local day is much shorter than Earth’s.
How long is a day on Mars compared to Earth?
One Mars sol is about 1.026 Earth days (~24 h 37–39 m). Ten sols span about 10.26 Earth days, which is why mission schedules drift relative to Earth clocks.
What is Mercury day length in Earth days?
Sidereal rotation: ~58.6 Earth days. Solar day (sunrise to sunrise): ~176 Earth days. This converter uses the sidereal value for ratio math unless you are comparing solar-day literature.
What is Venus day length?
Venus’s sidereal day is about 243 Earth days (retrograde). Its solar day is about 117 Earth days. One Venus sidereal day is longer than a Venus year (~225 Earth days).
What is Jupiter day length?
Jupiter rotates in about 0.414 Earth days—near 9 hours 55 minutes at the equator. It is the fastest-spinning planet in the Solar System.
How do I convert Earth days to planetary days?
Set From to Earth, To to your target planet, and enter Earth days. The tool divides by the target’s day length in Earth-day units. Results update live—no button required.
What is the difference between a sidereal day and a solar day?
A sidereal day is one spin relative to distant stars (~23 h 56 m on Earth). A solar day is noon-to-noon relative to the Sun (24 h on Earth). Mars uses its mean solar sol in this converter; Earth is 1.000 solar day.
What does retrograde rotation mean?
Most planets spin counterclockwise when viewed from above the north pole. Venus and Uranus rotate retrograde (clockwise in that view). Direction does not change day-length math—we compare durations in Earth days.
What is a sol converter?
A sol converter translates Martian solar days to Earth days (or other planets). Set Mars as the source and Earth as the target, enter sols, and read the Earth-day equivalent—about 1.026× your sol count.
Can I convert days between any two planets?
Yes. Choose any source and target, enter a day count, and use Swap to reverse direction. All pairs use the ratio of rotation lengths in Earth days.
Does this tool calculate my age on other planets?
No—this converter compares rotation lengths (local days and Mars sols), not orbital age. For birthday-style years on each planet, use Age on Other Planets; for year-length ratios only, use the Planetary Year Converter.
Are my inputs sent to a server?
No. Conversions run entirely in your browser; nothing you type is uploaded.