How big is the moon Titan compared to the Earth? How is the gravity different between these two planetary bodies?

1 Answer
Nov 30, 2015

Around half of Earth's radius is the radius of Titan. The surface gravity of Titan is #"1.353 m"//"s"^2#, meaning that the gravity on Titan is about 7.3 times weaker than on Earth.

Explanation:

Size:

The radius of Earth is:
#"6,371 km"# or #"6,371" * 10^3 "m" = "6,371,000 m"#

Whereas the radius of Titan is:
#"2,575.5 km"# or #"2,575.5" * 10^3 "m" = "2,575,500 m"#

Then

Difference in Size #= "Titan's Radius"/"Earth's Radius"#

#"2,575,500"/"6,371,000" = 0.404 ~= 0.5#

Meaning about half the size of Earth's radius.

Here is a comparison of the size of Titan (in the middle) compared to that of Earth and the Moon.

Earth-Titan-Moon
(from en.wikipedia.org)

Gravity:

The surface gravity on Earth is #9.807 "m/s"^2# and the surface gravity on Titan is #1.353 "m"//"s"^2#

So the difference between these two gravitational bodies is around:

Difference in Gravity #="Earth's Gravity"/"Titan's Gravity" #

#9.807/1.353 = 7.248 ~= 7.3 #

Meaning that the gravity on Titan is about 7.3 times weaker than on Earth.