Introduction This calculation is just a rough one because galaxies vary a lot. There are also things called globular clusters that can contain hundreds of thousands of stars. I will be talking about type 0, type 1, type 2 and type 3 civilizations here. You might want to watch this video to understand exactly what that means: Kardashev scale civilizations, type 0,1,2,3 civilizations and beyond [video + music] Alien Civilizations in Universe
A graphical representation of the Arecibo message – Humanity's first attempt to use radio waves to actively communicate its existence to alien civilizations
Einstein for Everyone Nullarbor Press 2007 revisions 2008, 2010, 2011, 2012, 2013
This set of graphs shows variation in the amount and the depth of water detected beneath NASA's Mars rover Curiosity by use of the rover's Dynamic Albedo of Neutrons (DAN) instrument at different ... The image, at lower left, is annotated to show where the Dynamic Albedo of Neutrons (DAN) instrument on NASA's Mars rover Curiosity took measurement on a rock outcrop (Spot 39) and on loose soil ... The Mast Camera (Mastcam) on NASA's Mars rover Curiosity showed researchers interesting internal color in this rock called "Sutton_Inlier," which was broken by the rover driving over it.