Local Gravity for different Places and Planets

In this article I would like to contrast the local gravity also known as the gravitational acceleration, the local mass difference, the location factor, respectively the acceleration due to gravity for different locations.

In the next sections you will find a table for each the

• Local Gravity of different Places on Earth, the
• Local Gravity of the Planets in our Solar System as well as the
• Local Gravity of the Moons in our Solar System.

After that, we will have a look at the practical effects of these different gravitational accelerations on the time and speed of the fall and finally we briefly discuss the calculation of the local gravity as well as the calculation of the time and speed of the fall. Unless otherwise stated, the values ​​in the tables are specified in m/s².

Local Gravity of different Places on Earth

The mean surface gravity on the Earth is 9.81 m/s², 9.807 m/s² or 9.8067 m/s², depending on whether you want to calculate with two, three or four decimal places. The local gravity for a constant height is smallest at the equator, while the gravitational acceleration increases towards the North Pole and the South Pole, and is greatest at the poles. This results in a difference of 0.045 m/s² between the poles and the equator. If you want to know why this is the case, you can find an answer here.

Place	Local Gravity
Earth Surface Mean Value	9.807 (9.81)
Earth Surface at the Equator	9.787
Earth Surface at the Poles	9.832
10 km above the Surface	9.72
100 km above the Surface	9.52
1,000 km above the Surface	7.33
2,000 km above the Surface	5.68
5,000 km above the Surface	3.08
10,000 km above the Surface	1.49
50,000 km above the Surface	0.13

The higher we rise from the earth's surface, the smaller the gravitational force respectively the earth's gravity becomes. While at 10 km above the surface of the earth we still can find a gravitational acceleration of 9.72 m/s², which is almost comparable to the equator on the surface, at 1,000 km above the earth's surface the gravity is only 7.33 m/s² and at 5,000 km above the earth's surface it is only 3.08 m/s². As the distance from the earth increases, the gravitational acceleration continues to decrease and is, as an example, with just 0.13 m/s² barely measurable at an altitude of 50,000 km.

Local Gravity of the Planets in our Solar System

There are even greater differences when we look at our neighboring planets (and in the case of Eris, Ceres, Haumea, Makemake and Pluto, dwarf planets) within our solar system. The following table shows the surface gravity of all eight planets in our solar system, including the five known and officially recognized dwarf planets as well as our sun, in descending order. For comparison, I have also added our moon to the list of these celestial bodies.

Additionally, the table also contains information about the mass (in kilograms) and the radius (in kilometers) of the respective celestial body, as this information is required to calculate the local gravity for your own. Specifications such as 5.9722E24 are to be understood as 5.9722*10²⁴. For celestial bodies that are not perfectly rounded, such as Ceres, Haumea and Makemake, the radius is specified as an average value.

Place	Local Gravity	Mass	Radius
Sun	274.1	1.9884E30	696.342
Jupiter	25.93	1.8981E27	69.911
Neptune	11.28	1.0241E26	24.622
Saturn	11.19	5.6834E26	58.232
Earth	9.807	5.9722E24	6.371
Uranus	9.010	8.6810E25	25.362
Venus	8.872	4.8673E24	6.052
Mars	3.728	6.4171E23	3.389
Mercury	3.703	3.3011E23	2.439
Moon (Earth)	1.625	7.3477E22	1.737
Eris	0.827	1.6466E22	1.163
Pluto	0.620	1.3025E22	1.188
Makemake	0.450	3.1000E21	715
Haumea	0.401	4.0060E21	780
Ceres	0.284	9.3839E20	469

As we can see, the difference between the dwarf planet Ceres, with an average surface gravity of just 0.284 m/s², and our sun with 274.1 m/s² is enormous. On Ceres, we would feel 34 times lighter than on Earth, while on the sun we would feel 28 times heavier than on Earth (assuming we could even make it to the scales at the temperature there).

A person with an earth weight of 75 kg would therefore, mathematically speaking, only have to carry 2.17 kg on Ceres, but impressive 2.1 tonnes on the Sun (the masses would of course remain constant regardless of the environment). On Pluto it would be 4.7 kg and on Jupiter 198 kg.

On our moon, the difference to our home planet would not be quite that great. Here the gravitational force is only six times less than on Earth. This means that our 75 kg test person would only have to carry a sixth of their body weight, that is around 12.5 kg. The difference between Earth and Venus, Uranus, Saturn and Neptune would be even smaller. Here the local surface gravities are between 8.87 m/s² and 11.28 m/s² and are thus almost at the same level as on our home planet. In the next section, we would like to look at what it looks like on the moons of the other planets in our solar system.

Local Gravity of the Moons in our Solar System

In the following, we would like to look at the local gravity of the most important moons of all the planets in our solar system, including the moons of the dwarf planets Pluto and Eris. All moons with a diameter of more than 500 kilometers are listed, as well as other important smaller moons of celestial bodies without larger moons, each with its associated planet in the second column and its number in the third column.

The fifth and sixth columns contain the mass (in kilograms) as well as the radius (in kilometers) of the respective moon. For non-circular moons, an average radius is given, and for very distant moons such as Charon and Dysnomia in particular, the values ​​are only approximations with a large uncertainty factor. So, for example, Dysnomia is assumed to have a size of about 615 +/- 55 km and a mass of (8.2 +/- 5.7)*10¹⁹ kg, which makes calculating the local gravity difficult there. The list is sorted from the sun to the edge of our solar system, from the inside out.

Moon	Planet	No	Local Gravity	Mass	Radius
Moon	Earth	I	1.625	7.3477E22	1,737
Phobos	Mars	I	0.0057	1.0600E16	11
Deimos	Mars	II	0.003	1.5100E15	6
Io	Jupiter	I	1.789	8.9319E22	1,821
Europa	Jupiter	II	1.314	4.7998E22	1,560
Ganymede	Jupiter	III	1.426	1.4819E23	2,634
Callisto	Jupiter	IV	1.235	1.0759E23	2,410
Mimas	Saturn	I	0.064	3.7509E19	198
Enceladus	Saturn	II	0.113	1.0803E20	252
Tethys	Saturn	III	0.146	6.1749E20	533
Dione	Saturn	IV	0.232	1.0954E21	561
Rhea	Saturn	V	0.264	2.3064E21	763
Titan	Saturn	VI	1.346	1.3452E23	2,574
Hyperion	Saturn	VII	0.017	5.5510E18	135
Iapetus	Saturn	VIII	0.223	1.8056E21	735
Ariel	Uranus	I	0.246	1.2331E21	579
Umbriel	Uranus	II	0.252	1.2885E21	584
Titania	Uranus	III	0.379	3.4550E21	788
Oberon	Uranus	IV	0.347	3.1104E21	761
Miranda	Uranus	V	0.076	6.2930E19	236
Triton	Neptune	I	0.779	2.1389E22	1,353
Nereid	Neptune	II	0.071	3.5700E19	170
Charon	Pluto	I	0.288	1.5897E21	606
Dysnomia	Eris	I	0.058	8.2000E19	307

As you can see, the surface gravities of the moons are on average significantly smaller than those of the planets. This is naturally due to the smaller size and consequently the lower mass of the moons compared to the size and mass of the planets they orbit. Jupiter's moon Io has the largest gravitational acceleration of all the moons of the planets in our solar system with a surface gravity of 1.789 m/s², while our own moon closely follows on the second place of this ranking with 1.625 m/s².

However, the moon in our solar system with the lowest gravitational acceleration is difficult to determine, as there are just too many small and tiny moons, which, on the one hand, have not yet been fully explored, while, on the other hand, new ones are constantly being discovered. So far, over 145 moons of Saturn, as well as 95 moons of Jupiter, 28 moons of Uranus and 16 moons of Neptune have been discovered. Many of them are so small that they remained undiscovered for a long time or have only been given a number instead of a proper name. For example, Saturn's moon Aegaeon, which was only discovered in 2009, has a diameter of just 540 to 780 meters and, with a mass of only around 80 million tons, does not even have a gravitational acceleration of 0.00005 m/s². In addition, the exact masses and diameters in particular of the small moons have not been precisely researched, and therefore the calculation of their local gravities can only represent an approximation of the true value, making an accurate list impossible. Also for this reason, I have not included all known moons into the list and have limited it to the most important ones.

By the way, the planets Mercury and Venus as well as the dwarf planet Ceres are not part of this list because these celestial bodies do not have their own natural satellites.

Gravitational Acceleration in Fall Time and Speed

But what do the values ​​presented here mean in practice? How do the different local gravities manifest themselves on the various planets and moons? It is not for nothing that we also refer to the local gravity as the acceleration due to gravity, gravitational acceleration or gravity acceleration, because the higher the local gravity, the faster we accelerate in free fall.

To illustrate this with a practical example, I have therefore compared some of the planets and moons in the next table in this regard and calculated how long a fall from a height of 100 meters would take under the different conditions (the different gravitational accelerations) and what the maximum speed would be at the end of the free fall after 100 meters:

Celestial Body	Local Gravity	Time	Speed
Sun	274.1	0.85 s	843 km/h
Merkur	3.703	7.4 s	98 km/h
Venus	8.872	4.8 s	152 km/h
Erde	9.807	4.5 s	159 km/h
Mond (Erde)	1.625	11.1 s	65 km/h
Mars	3.728	7.3 s	98 km/h
Phobos (Mars)	0.0057	187.3 s	3.8 km/h
Deimos (Mars)	0.003	258.2 s	2.8 km/h
Ceres	0.284	26.5 s	27 km/h
Jupiter	25.93	2.8 s	259 km/h
Io (Jupiter)	1.789	10.6 s	68 km/h
Europa (Jupiter)	1.314	12.3 s	58 km/h
Ganymede (Jupiter)	1.426	11.8 s	61 km/h
Callisto (Jupiter)	1.235	12.7 s	57 km/h
Saturn	11.19	4.2 s	170 km/h
Mimas (Saturn)	0.064	55.9 s	13 km/h
Enceladus (Saturn)	0.113	42.1 s	17 km/h
Tethys (Saturn)	0.146	37.0 s	19 km/h
Dione (Saturn)	0.232	29.4 s	25 km/h
Rhea (Saturn)	0.264	27.5 s	26 km/h
Titan (Saturn)	1.346	12.2 s	59 km/h
Hyperion (Saturn)	0.017	108.5 s	6.6 km/h
Iapetus (Saturn)	0.223	29.9 s	24 km/h
Aegaeon (Saturn)	0.00005	2000 s	0.36 km/h
Uranus	9.010	4.7 s	153 km/h
Ariel (Uranus)	0.246	28.5 s	25 km/h
Umbriel (Uranus)	0.252	28.2 s	26 km/h
Titania (Uranus)	0.379	23.0 s	31 km/h
Oberon (Uranus)	0.347	24.0 s	30 km/h
Miranda (Uranus)	0.076	51.3 s	14 km/h
Neptun	11.28	4.2 s	171 km/h
Triton (Neptune)	0.779	16.0 s	45 km/h
Nereid (Neptune)	0.071	53.1 s	14 km/h
Pluto	0.620	17.9 s	40 km/h
Charon (Pluto)	0.288	26.4 s	27 km/h
Eris	0.827	15.6 s	46 km/h
Dysnomia (Eris)	0.058	58.7 s	12 km/h
Haumea	0.401	22.3 s	32 km/h
Makemake	0.450	21.1 s	34 km/h

As we can see, we experience the most extreme gravitational acceleration (how could it be otherwise) on our sun, which, as we know, has by far the largest mass and the largest surface gravity of all the celestial bodies compared here. A fall from a height of 100 meters on the sun would take less than a second (0.85 seconds) and in this short time, when you reach the ground, you would have already reached a speed of 843 kilometers per hour shortly before your impact.

Compared to that, we would fall the slowest on many of the smaller moons and of course on our small dwarf planets. Of the dwarf planets in our solar system, Ceres has the lowest acceleration due to gravity, with a surface gravity of only 0.284 m/s², which would mean that we would need 16.7 seconds for a free fall from a height of 100 meters and would only reach a final speed of 27 kilometers per hour. In comparison, on Earth we would have reached the ground after just 4.5 seconds and would have reached a speed of 159 km/h at that time. On our moon, with 11.1 seconds falling time and a maximum final speed of 65 km/h, we would fall about twice as long.

Even longer, the fall would take on many of the countless tiny moons in our solar system. Due to the large number of these moons, however, our comparison only shows the most important and largest moons of the individual planets and, only as an extreme example, Saturn's moon Aegaeon, which is just a few hundred meters in size. On this moon, the "free fall" from a height of 100 meters would with 2,000 seconds take over half an hour and with 0.36 km/h (0.1 m/s), not even a single kilometer per hour would be achievable as a final speed. However, it must be said that this calculation is based only on estimates, since the exact mass and dimensions of Aegaeon have so far only been determined with a certain degree of uncertainty. So, for Aegaeon, a mass of about (7.82 +/- 3)*10¹⁰ kg is assumed, which makes it difficult to calculate its gravitational acceleration precisely. Also this speaks in favor of restricting the calculations to the large planets and moons for which more precise physical characteristics are available.

Calculation of the Local Gravity

Finally, I would like to briefly explain how you can calculate the values ​​shown in the tables for your own.

To calculate the local gravity g for a location of an arbitrary distance from the center of a celestial body, for example for a location on the surface of a celestial body or for a location at a certain height above the surface of a celestial body, in addition to the gravitational constant G, we only need the mass and the radius respectively the distance of the location from the center of the celestial body to be calculated. For this reason, in the tables of planets and moons, I have also listed their mass and their radius in addition to the surface gravity already calculated, so that you can use this information for your own calculations.

I present the exact formula for calculating a local gravity, which includes these three values, in the info about calculating the local gravity, in which I show not only the formula but also some examples for calculating various location factors.

Calculation of the Fall Time and Fall Speed

Also the time of fall as well as the speed of fall, which we saw in the section on the Gravitational Acceleration in Fall Time and Speed, can easily be calculated. For a given way, we only need the local gravity respectively the gravitational acceleration in order to be able to calculate the time and the speed required for this way. I have put together the necessary formulas spiced with some examples of their application in my info about calculating the free fall for you.