Understanding Mars’ gravity and its affect on terrestrial beings is an important first step if we want to send astronauts, explorers, and even settlers there someday. However, ongoing research into the effects of microgravity on astronauts has shown that it has a detrimental effect on health – which includes loss of muscle mass, bone density, organ function, and even eyesight. Implications:Īt present, it is unknown what effects long-term exposure to this amount of gravity will have on the human body. Based on the Earth’s own surface gravity, this works out to an acceleration of 3.711 meters per second squared. The surface gravity of Mars can therefore be expressed mathematically as: 0.107/0.532², from which we get the value of 0.376. It also has a mean radius of 3,389.5 km, which works out to 0.532 Earth radii. These proportionalities can be expressed by the formula g = m/ r 2, where g is the surface gravity of Mars (expressed as a multiple of the Earth’s, which is 9.8 m/s²), m is its mass – expressed as a multiple of the Earth’s mass (5.976♱0 24 kg) – and r its radius, expressed as a multiple of the Earth’s (mean) radius (6,371 km).įor instance, Mars has a mass of 6.4171 x 10 23 kg, which is 0.107 times the mass of Earth. The Mars Gravity Model 2011 (MGM2011), showing variations of gravity accelerations over Mars’s surface. When applied to a spherical body with a given average density, it will be approximately proportional to its radius. When applied to a spherical body like a planet with a given mass, the surface gravity will be approximately inversely proportional to the square of its radius. Scientists have calculated Mars’ gravity based on Newton’s Theory of Universal Gravitation, which states that the gravitational force exerted by an object is proportional to its mass. Even though Mars has almost the same land surface area as Earth, it has only half the diameter and less density than Earth – possessing roughly 15% of Earth’s volume and 11% of its mass. This difference in surface gravity is due to a number of factors – mass, density, and radius being the foremost. At just 0.376 of the Earth standard (or 0.376 g), a person who weighs 100 kg on Earth would weigh only 38 kg on Mars. On top that, the gravity on Mars’ surface is much lower than it is here on Earth – 62% lower to be precise. Image credit: NASA/JPL-CaltechĪnd while the length of a Martian day is roughly the same as it is here on Earth (24 hours 37 minutes), the length of a Martian year is significantly longer (687 days). The average surface temperature is also lower on Mars, ranking in at a frigid -63 ☌ compared to Earth’s balmy 14 ☌.Īrtist rendition of the interior of Mars. For instance, atmospheric pressure on Mars is a tiny fraction of what it is here on Earth – averaging 7.5 millibars on Mars to just over 1000 here on Earth. The differences between Mars and Earth are all crucial for the existence of life as we know it. Understanding the effect this will likely have on human beings is of extreme importance when it comes time to send crewed missions to Mars, not to mention potential colonists. One of these is the fact that gravity on Mars is just a fraction of what it is here on Earth.

In Mars’ case, this evidence points towards it once having a viable atmosphere and liquid water on its surface.Īt the same time, our two planets are really quite different, and in a number of very important ways. Additionally, both planets present strong evidence of having undergone climate change in the past. Both planets have roughly the same amount of land surface area, sustained polar caps, and both have a similar tilt in their rotational axes, affording each of them strong seasonal variability. The planet Mars has few things in common.

Gravity on mars