Challenge: 3

Density Challenge for Other Planets

Instead of listing a planet’s mass by kilograms or volume by cubed kilometers, astronomers often list the masses and volumes of planets as compared to Earth for easy comparison. For example, if we consider the mass of Earth as 1, then Jupiter is 318 times more massive than Earth.

Planet	Mercury	Venus	Earth	Mars	Jupiter	Saturn	Uranus	Neptune	Pluto
Mass	0.055	0.88	1	0.107	317.8	95.2	14.48	17.2	0.005
Volume	0.054	0.814	1	0.149	1,316	755	755	44	0.0025

What are the densities of all nine planets in

To answer this question, use the information about Earth’s mass and volume from the previous challenge.

Steps

1. To help you get started, we’ll guide you into finding the density for the planet Jupiter. Remember that density (d) equals mass (m) divided by volume (v)
   
   Let’s first find the mass of Jupiter. To do this, we multiply Earth’s mass by Jupiter’s mass (as it is compared to Earth). Use Earth’s mass given from the previous challenge.

   Formula for finding Jupiter’s mass:

   Earth’s Mass	*	Jupiter’s Mass Compared to Earth	=	Jupiter’s Mass
   kg	*	317.8	=	kg

   Remember to convert from kilograms to grams.

   Formula for converting kilograms to grams:

   __________ kg * = __________ gm
   
2. Next, we find the volume of Jupiter using the same method that we used to find its mass. Use the volume that you calculated from the previous exercise as Earth’s volume.
   
   Formula for finding Jupiter’s volume:
   
   

   Earth’s Volume	*	Jupiter’s Volume Compared to Earth	=	Jupiter’s Volume
   cm	*	1,316	=	kg

   
   
3. Finally, find Jupiter’s density by dividing the mass you calculated. in step 1 with the volume you calculated in step 2.
   
   

   Jupiter’s Mass	/	Jupiter’s Volume	=	Jupiter’s Density
   gm	/	cm	=

   
   Solution
   If you did everything correctly, you should find that the density of Jupiter is 1.33
   
   To find the density of the other planets, follow the steps above, but substitute the mass and volume of Jupiter with those of the appropriate planet.

Extra Challenge!
Which planet would float in a large body of water? (You’ll need to know the density of water to answer this!)

Comparing the earth to the sun and a solar flare