UCSB Science Line Hi, I was wondering what planet has the most gravitational pull on the earth.
Question Date: 2020-04-02

Jupiter, mainly because it's so massive (although Venus comes close when Earth and Venus are close together in their orbits.

Jupiter exerts the largest force on Earth.

In order to get a clear idea of this answer, it will be good for you to learn about some concepts like "The gravitational attraction (F)" between any two objects, which can be determined using Newton's Law of Gravitation:
F = G * m1*m2/r2 where G = 6.674*10-11 m3/kg-s2 is the gravitational constant, m1 and m2 and are the masses of the objects, and r is the distance between the objects (and that distance is squared in the equation).

The masses of the planets are readily found (e.g., from NASA's fact sheet), and the current distances of each planet from Earth can be found here. (Note that in NASA's fact sheet the distances are from Sun, not from Earth).

I suspect the quantity actually wanted here is the acceleration due to gravity from these other planets on an object on Earth. This is given by the above law and another of Newton's Law, F = m*a -> a = F/m.

That is, to find the gravitational acceleration of each of the planets at the surface of Earth, we divide the above gravitational forces (F) by the mass of Earth (neglecting the relatively small change in r due to being on the surface of Earth instead of at the center). In this case, the value for Earth can also be calculated, using a radius of Earth of 6350 km. This is included as the last row in the following table.

Note that the units in the far left column are adjusted to make the numbers reasonable - for example, distances are in 106 km, meaning millions of km, and acceleration at Earth's surface is in 10-10 m/s2, meaning the numbers (except Earth's) should be divided by 10,000,000,000.

Bringing in the relevant data and entering it into the formulae described above (use m1 = mass of Earth)

Planet Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune
Mass (1024 kg) 0.330 4.87 5.97 0.642 1898 568 86.8 102
Distance (106 km) 160.805 93.128 N/A 213.675 786.431 1531.797 3103.570 4611.302
Gravitational force F (1015 kg-m/s2) 5.085 223.732 N/A 5.603 1222.744 96.451 3.591 1.911
Accel. @ Earth surface (10-10 m/s2) 8.517 374.761 9.88 m/s 9.385 2048.147 161.559 6.014 3.201

From this, one can see that Jupiter exerts the largest force on Earth. This is because Jupiter has such a large mass. Venus is not that much lower despite a much lower mass, because theEarth-Venus distance is far lower than the Earth-Jupiter distance. Similarly, the acceleration due to gravity of each of these planets on objects on the surface of Earth is largest for Jupiter. However, that acceleration (2048 * 10-10 m/s2) is ~50 million times lower than that of Earth.

See here on ScienceLine for a related question. The pages here and here are good reads to learn how the Moon and other planets affect your weight on Earth.    Copyright © 2020 The Regents of the University of California, All Rights Reserved. UCSB Terms of Use