Anyone with much interest in astronomy has probably seen infographics comparing the sizes of the planets. But have you ever wanted to get a feel for the comparative masses? After all, it is mass, not diameter or volume that determines the way planets interact through gravity.

Rhys Taylor has come to your rescue, with these two pieces comparing the Earth with smaller rocky and icy worlds in one and with gas giants in another.

Although the Earth's density is slightly higher than the other inner planets, moons and asteroids, the difference is not great. It takes 18 versions of Mercury to match the Earth mainly because with a diameter almost two fifths our size Mercury's volume is one 18th as much.

The situation is different for the outer planets. Saturn is nine times as wide as the Earth, and therefore 763 times the volume, but its density is so low it would take a mere 95 Earths to match it. But it looks pretty impressive when he bounces that many Earths off Saturn.

Taylor is a postdoctoral astrophyscist, but does quite a bit of work doing outreach for NASA, including having a joke project making a potato look like an asteroid turn into something other astronomers found useful and discovering the Loch Ness Monster lurking in space.

His main project is studying the Virgo Cluster of galaxies, and he has made some pretty cool videos out of that as well.