How much would a boy weigh on Pluto?
Someday in the future we may be able to hop around the Solar System and experience the conveniences and the inconveniences of other worlds. The force of gravity is different on each planet, which means that the weight of a space traveler will be different every time he sets down on a new world. His weight will also vary every time he lands on one of the moons of the Solar System.
Let’s say that this boy weighs 100 pounds on earth. If he hops a space ship and lands on a planet more massive than the earth, he will weigh more than 100 pounds. If he lands on a planet less massive, he will weigh less than 100 pounds. We can estimate exactly what he will weigh on seven of the other planets. But we can only make a guess at his weight on faraway little Pluto.
This is because Pluto is more than 3,000 million miles away from us, which makes the little planet very difficult to study. The weight of young spacemen landing on Pluto would come from the surface gravity of the planet. The gravity depends upon the mass of the planet. Mass is the density or amount of matter packed into a certain space, or volume. We have this data on all the other planets, but figures on Pluto are far from exact.
The little planet at the outside rim of the Solar System was discovered only 32 years ago. The 200 inch telescope reveals it as a tiny dot of light slowly moving amid other tiny dots of light which are distant stars. On the basis of careful detective work, the size of Pluto is estimated to be something between that of the earth and the planet Mercury. Some courageous astronomers boldly state that Pluto has a diameter of 3,600 miles, but arc are not certain.
Some factors suggest that Pluto is a very dense planet, maybe having ten times the density of the earth Other factors contradict this. For lack of reliable information, we can make only a rough guess at the gravity, and therefore the weight, of an object on Pluto.
Most likely; the mass of the outer planet can be compared with the mass of Mercury, the little planet on the inside of the Solar System. On Mercury we know that a boy weighing 100 earth pounds would weigh only 25 pounds. On Pluto he may weigh a little more than this, but for all we know he may weigh half a ton. Tile solution to this problem, like the Age of Space Travel, belongs in the future, It is one of the many quandaries left for the scientists of your generation to solve.
On Uranus, lighter than water. but almost four times wider than the pound earth, a 100 ~boy would weigh only 95 pounds. On giant Jupiter he would weigh 264 pounds, on Saturn 117 pounds. He would weigh 112 pounds on Neptune, 85 pounds on Venus and only 36 pounds on little red Mars.