"Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the drug store, but that's just peanuts to space." Douglas Adams

Magnitude:

Multiple: - thousand million billion trillion quadrillion quintillion sextillion septillion 10^27 10^30 10^33 10^36 10^39 10^42

Unit: kilometer meter centimeter millimeter mile yard foot inch

Ask

How big is 2.8 billion km ?

Equivalent to 2.8 trillion meter

More or less ...

And equivalent to ...

And, neatly, although approximately ...