Mars completes one rotation on its axis in about:

Mars rotates once on its axis in about 24 hours and 37 minutes, so a day on Mars is only slightly longer than a day on the Earth.

The Martian day (sol):

Scientists call a solar day on Mars a "sol". It lasts about 24 hours 39 minutes.

Seasons on Mars:

• The axis of Mars is tilted by about 25 degrees, close to the Earth's tilt of 23.5 degrees.
• So, Mars also has seasons, but each season lasts about twice as long as on the Earth.

Year on Mars:

Mars takes about 687 Earth days (about 1.9 Earth years) to complete one revolution around the Sun.

Similarities with the Earth:

• A day of nearly the same length.
• A similar axial tilt and seasons.
• Polar ice caps made of water ice and frozen carbon dioxide.

Differences from the Earth:

• Mars is about half the Earth's diameter and has about one-tenth of its mass.
• Its gravity is about 38 percent of the Earth's.
• Its atmosphere is very thin, about 1 percent of the Earth's surface pressure, and is mostly carbon dioxide.
• Average surface temperature is about minus 60 degrees Celsius.
• It has no global magnetic field today.

Features of Mars:

• Olympus Mons, the tallest volcano in the solar system, about three times the height of Mount Everest.
• Valles Marineris, a canyon system about 4,000 km long.

Exploration of Mars:

India's Mars Orbiter Mission (Mangalyaan), launched in November 2013, entered Mars orbit on 24 September 2014. India became the first Asian country to reach Mars orbit and the first country to do so on its first attempt.

Why not the other options?

• ✗About 10 hours is the length of a day on Jupiter or Saturn.
• ✗59 days is the rotation period of Mercury.
• ✗687 days is the length of a Martian year.