Planet Size Compared to Earth

mars planet size compared to earth

Scientists have long studied Mars by peering through telescopes, orbiting it with spacecraft and sending rovers onto its surface. Through their work they’ve discovered many similarities between our world and Mars’.

Planet Venus shares similar dimensions, gravity and composition with Earth; yet has unique features of its own such as an oblate spheroid shape and long, cold seasons.


Mars, known as the Red Planet due to the abundance of rusty iron in its soil, stands as the second-smallest planet in our solar system and fourth planet from the Sun. Notable features of Mars include four distinct seasons and temperature variations as well as its oval shape – hallmarks of an active world! Mars features canyons, volcanoes and craters which cover its surface in red dust that winds can whip into miniature tornadoes of dust storms that appear like tornadoes.

Iron(III) oxide, found both on the surface and subsurface soils, is responsible for much of Earth’s red hue, constituting around half its mass and accounting for around 60%. Since William Herschel first used telescopes to study Earth in 1780s using telescopes as instruments of observation he first explored it scientifically using telescopes.

NASA estimates that Mars contains a dense, solid core which spans 930 to 1,300 miles (1,500 to 2,100 kilometers), with a rocky mantle beneath and crust above it. Mars’ interior composition remains unknown, although NASA suggests that its outer liquid metal layer and cool inner core could both contain iron and nickel elements.

Mars shares similar conditions to Earth in terms of atmosphere composition: predominantly carbon dioxide with some nitrogen and oxygen present. However, its gravity is roughly one-third less strong, meaning an individual would weigh less on Mars than on Earth and objects tend to fall more slowly due to the lower gravitational force.

Phobos and Deimos, discovered by Asaph Hall in 1877, were named for classical Greek and Roman war deities; Phobos represents fear while Deimos stands for terror or dread. Both moons orbit Mars approximately every 1.26 days for full cycles or “periapses,” with their respective apoapses about 23 miles (37 kilometers) further away than their periapses.


Mars has a lower mass than Earth, which results in its gravity pull being less strong on its surface. However, this does not indicate that anyone on its surface would necessarily weigh less; rather, gravity affects objects depending on their distance between their center of mass and surface – closer proximity would cause greater gravity pull for anyone standing on Mars’ surface!

Mars is a small, cold and dusty planet with no atmosphere that contains any form of oxygen breathable by humans. It experiences four distinct seasons throughout a year of approximately 687 days long. Mars features rivers, canyons and volcanoes; one of its biggest is Valles Marineris which boasts one of the solar system’s highest mountains (Olympus Mons).

As with the other terrestrial planets in our Solar System, Mars features a metallic core, rocky mantle, and solid crust. Furthermore, Mars boasts a global magnetic field and experiences seasonal temperature variations due to rotation around its polar axis.

Mars’ polar and equatorial diameters differ due to its oblate shape. If you were standing on Mars’ equatorial surface, the sun would appear much larger than at its polar surface due to reduced direct sunlight hours at its equator due to obliquity.

Even though Mars is smaller than Earth, its density exceeds that of either Mercury or Venus due to the higher silicate content in its composition compared to those planets; nonetheless, its density still falls significantly lower than that of Earth.


Mars’ atmosphere contains nitrogen, oxygen, carbon dioxide and argon with trace amounts of water vapor; its density is about one-sixth that of Earth and pressure less than one tenth as great; recent surveys indicate small amounts of methane may exist on its surface; its low gravity also leaves it vulnerable to solar wind emissions which have greatly eroded away much of its atmosphere over time.

Planet Pluto also hosts two small satellites known as Phobos and Deimos that may have formed as captured asteroids rather than due to gravitational pull of our sun; their low albedo values and composition — similar to carbonaceous chondrites — support this theory.

There is evidence to support that long ago, the Red Planet contained rivers and oceans. Today, its atmosphere consists primarily of carbon dioxide and water vapor; as such molecules allow ultraviolet radiation from Sun or other cosmic sources to reach its surface and damage any organic compounds on it directly.

Like other rocky planets, Mars is an oblate spheroid whose diameter varies across its equator and poles. At its equator it measures 4,222 miles (6,794 km), but from pole to pole its diameter shrinks significantly – measuring only 13,200 miles (2,100 km).

Mars stands out among its fellow planets due to its unique oblate shape, featuring more of an outward bulge in its middle than Earth or other rocky bodies like Mercury or Venus do, giving it its distinctive red color from orbit due to the higher proportion of iron-rich rocks on its surface.

Mars currently exists as a cold, dusty planet with four seasons similar to those seen on Earth and an annual cycle that spans about 687 days. Mars contains significant quantities of water; much of it exists as frozen forms. Due to its oblate shape, light gravity and lack of magnetic field protection, solar wind easily strips away its thin atmosphere.


Mars is a cold and dusty planet with canyons and dry river channels on its surface, as well as some volcanoes and some areas covered by water underground. Additionally, there are two polar ice caps, but additionally there are numerous areas underground filled with liquid water; its surface features many craters with red hues due to the iron in its soil.

Scientists have been exploring Mars by using telescopes, satellites and robotic spacecraft. The results of these explorations have taught us much about this planet; for instance, researchers now know that Mars contains a rocky core with a radius of approximately 3,396km and mass estimated at 5.97x1024kg; it also features silicate mantle similar to Earth’s and an outer silicate crust measuring 50 to 125 km thick.

Mars features two small moons called Phobos and Deimos that may have formed from captured asteroids. Like Earth, Mars tilts in its axis relative to the Sun causing temperature variations as well as seasons on this planet. Perihelion occurs at approximately 128,400,000 miles (227,900,000 km); Aphelion occurs about 154,900,000 miles (249,200,000 km).

Mars does not currently experience volcanic or tectonic activities, though evidence points toward past ones having existed and then disappearing at some point in its past. Large magnetic anomalies in its crust show evidence for such activity – they possess magnetization levels more powerful than those normally encountered in terrestrial rocks.

Mars shows signs of its continental past through features similar to Earth, such as striations marks on its surface that resemble those on Earth as well as ancient lava flows and impact basins. Furthermore, its relatively thick crust shows evidence of past tectonic activity; similar to what exists here. Furthermore, Curiosity discovered layers on Mars’ surface containing siderophile elements rich with iron that hint that its core may also contain increased iron levels, suggesting its density exceeds Earth’s.

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