Key facts
- Scale fact
- 6,779 kmdiameter
- Estimated age
- ~4.5 billion years
- Composition
- Silicate rock, iron-rich minerals, polar ice
- Temperature
- ~210 K mean surface
Mars
6,779 kmdiameter
Visual creditRosetta 2007 / ESA & MPS for OSIRIS Team MPS / UPD / LAM / IAA / RSSD / INTA / UPM / DASP / IDA / CC BY-SA 3.0 IGOSource: Wikimedia Commons
Details
Mars is the fourth planet from the Sun, a cold, dry desert world with a thin carbon-dioxide atmosphere. Ancient river valleys, lake beds and water-formed minerals show that its surface was once much wetter.
Orbital images and rover measurements have identified ancient valleys, deltas, lake sediments and minerals that formed in water. Together they show that early Mars supported persistent surface water in multiple environments, although the duration and global extent of its warmer periods remain active research questions.
Today the carbon-dioxide atmosphere has less than one percent of Earth’s surface pressure, liquid water is unstable across most of the surface, and water survives mainly as ice or vapor.
Links
- Editorial guides
- Universe journey
- Sun & inner planets
- Preset views
- Wikipedia
- Mars on Wikipedia
Size neighbors
Objects near Mars on the scale
Sources
References for Mars
Measurements and descriptive context are compiled by the Scale of Space team from the references below. If you find an error, please let us know.
- Mars — Wikipedia
- Visual reference: Wikimedia Commons (Rosetta 2007 / ESA & MPS for OSIRIS Team MPS / UPD / LAM / IAA / RSSD / INTA / UPM / DASP / IDA, CC BY-SA 3.0 IGO)
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About
Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
Guides explain selected parts of that range, while focused views filter the objects by subject.