Is Mars bigger than Earth?

Written by David Girones

Asking ourselves or trying to compare two planets or celestial bodies is quite common, since observation from the Earth does not make it easy to know their size. For example, Is Mars bigger than Earth? Sometimes it is difficult to remember their sizes or how they compare to each other or we simply have a total lack of knowledge on the subject. 

Size of Mars vs Earth

Taking into account that planets have a spherical shape (spheroid in some cases) the best way to compare their sizes is using geometric measures such as volume, surface area or radius, and also using the Earth as a reference since it is the planet we know best.

Size of Mars

The volume of Mars is 1.631 x 1011 km³ (0.151 times the volume of Earth). The mean radius of Mars is 3390 km (0.532 times the radius of Earth) therefore the diameter of Mars is 6779 km. If we take into account the surface area, Mars is 1.444 x 108 km² (3.52 times less than Earth).

Size of Earth

The volume of Earth, the blue planet, is 1.08 x 1012 km³. The mean radius of Earth is 6371 km consequently the diameter of Earth is 12742 km. If we take into account the surface area, Earth is 5.1 x 108 km².

So answering the question:

How big is Mars compared to Earth? 

Mars is smaller than Earth, taking into account the volume which is the easiest metric to visualize. Mars is 1.631 x 1011 km³ and Earth 1.08 x 1012 km³.

How many times larger is Earth than Mars?

Earth is 6.62 times bigger than Mars taking into account the volume, and if we compare the surface of Earth it is 3.52 times larger than Mars (5.1 x 108 km² of Earth vs 1.444 x 108 km²  of Mars).

Is the mass of Mars larger than Earth?

Usually to a comparative question between two planets we want to know which of the two has a larger volume. However, there is another unit of measurement that can also be used in the comparison and that is their mass or weight.

Mass is the combination of two metrics such as volume and density.

The volume of both celestial bodies has been mentioned above, and in the case of density, we can report that the density of Mars is 3.934 g/cm³ and the density of Earth is 5.514 g/cm³. 

Considering that the volume of Mars is 0.151 times the volume of Earth and the density of Mars is 0.713 the density of Earth we can be sure that the mass of Mars is smaller than Earth.

The mass of Mars is 6.417 x 1023 kg and the mass of Earth is 5.972 x 1024 kg (Mars has a mass 9.35 times smaller than Earth).

Is gravity on Mars bigger than Earth?

Gravity is not a value for size comparison, however gravity can be compared between different planets, satellites or stars.

Gravity calculates the force with which objects with mass are attracted to each other and is usually a value calculated for all celestial bodies.

The unit of measurement used to refer to gravity is m/s² or also a standardized unit called g which is equivalent to earth’s gravity (9.80665 m/s²).

Gravity on Mars

The gravity on Mars, the red planet, is 3.72 m/s², equivalent to 0.3794 g.

Gravity on Earth

Earth’s gravity is 9.806 m/s², 1 g.

If we want to know whether gravity is greater on Mars or Earth, we must inform you that gravity is lower on Mars.

Other data of interest in the comparison between Mars and Earth

Mars and Earth orbit around the Sun. 

The time it takes Mars to make a complete orbit around the Sun is 686.98 days and in the case of Earth it is 365.26 days. 

The rotation time of Mars is approximately 1.02749125 days and the rotation time of Earth is approximately 1 day.

The distance from Mars to the Sun is 1.524 AU and the distance from Earth to the Sun is 0.997 AU. Consequently Mars is farther away from the Sun than Earth.

AU means astronomical unit and it is a unit of length, roughly the distance from Earth to the Sun and equal to 150 million kilometers (93 million miles) or 8.3 light-minutes. The distance used is the semi-major axis of the orbit of the planet around the sun.

Conclusion of our Mars vs Earth comparison

As we have seen from the data provided in the comparison, Mars is smaller than Earth. There are no metrics mentioned in which Mars can be considered larger than Earth however it is farther away than Earth from the Sun.

Mars is the fourth planet from the Sun and only larger than Mercury in the Solar System.

Other planets and satellites compared with Earth

Sources Used:

All information has been extracted from Wikipedia.

Photo by Pixabay