# What does it mean to say that "6 tons of dark energy would be found within the radius of Pluto's orbit"?

What does it mean to say that "6 tons of dark energy would be found within the radius of Pluto's orbit"?

• Does it mean that the dark energy is orbiting the solar system?
• Or does it mean a flow of dark energy through a sphere?
• Or does it refers to an energy in a particular system of inertia in the solar system?

Or what?

Again on a mass–energy equivalence basis, the density of dark energy (6.91 × 10−27 kg/m3) is very low: in the solar system, it is estimated only 6 tons of dark energy would be found within the radius of Pluto's orbit. However, it comes to dominate the mass–energy of the universe because it is uniform across space. Wikipedia/Dark energy

• They used $E=mc^2$ to convert energy density into mass density, or so it seems. I could not guess why they did it since giving a mass of dark energy is both confusing and misleading. Best to ignore the 6 tons thing
– Jim
Nov 19, 2014 at 16:49
• What do you mean by "system of inertia?"
– user4552
Nov 19, 2014 at 16:54
• Ben Crowell: some geometrical frame with no movement relative the sun.
– Lehs
Nov 19, 2014 at 17:01