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So What All Is Out There, Anyway? The untold story of Alice’s Adventure in Wonderverse She went on growing, and growing, and very soon had to kneel down on the floor: in another minute there was not even room for this . . . She looks down and sees Earth The Moon comes into view Soon she can see the Sun . . . . . . and the other inner planets There’s the asteroid belt! The outer planets . . . . . . the Kuiper Belt . . . . . .and the Oort Cloud comprise our solar system The closest star, Proxima Centauri, is a red dwarf 4 light years (LY) away Other stars with planetary systems Our galaxy, the Milky Way, is ~100,000 LY across Clusters of galaxies: Our Local Group Clusters of galaxies: The Virgo Cluster Superclusters of galaxies Filaments of Superclusters Distance = Time Proxima Centauri is ~ 4 LY away. Light leaving star takes 4 years to arrive at Earth. Result: We see Proxima Centauri as it looked 4 years ago! The Sun 8 Minutes Ago The Andromeda Galaxy 2.2 million years ago NGC 1399, 65 Million Years Ago • Just Suppose: – There is a planet in NGC 1399 – That planet is exactly like Earth – We could see that planet from Earth • What might we see? Abell 1825 13.2 billion years ago