This depiction of an Earth-like exoplanet showcases a rocky world with a thin atmosphere in its parent star’s habitable zone. It has oceans and continents and clouds, and could possess macroscopic life forms on its surface. At a distance of multiple light-years away, it would take a gargantuan telescope to image them, and it would only be able to see the world as it was in the distant past, not as it is right now. (Credit: NASA Ames/JPL-Caltech/T. Pyle)

What does Earth look like from across the Universe?

When you view anything at all in the Universe, you’re not seeing it precisely as it is right now: at the moment you experience seeing it. The speed…



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Ethan Siegel

The Universe is: Expanding, cooling, and dark. It starts with a bang! #Cosmology Science writer, astrophysicist, science communicator & NASA columnist.