How Many Stars Are In The Universe?

It can be a humbling feeling to gaze up into a clear night's sky and see just how unending and vast the universe seems to be. We know there are more than 7 billion people on the planet, so why do we feel so small when we look to the stars? Probably because the number of humans is but a grain of sand compared to the billions of living, dying and newly born stars that hover over us each day. So, exactly just how many of those twinkling stars are there? Even the most studious scientists have yet to fully answer this question, in large part because they're unsure if the universe if finite, expanding or if there are potentially multiple universes. What we are able to see extends back approximately 13.7 billion light-years—meaning there's still quite a bit out there yet to discover.

What we do know, however, is that researchers estimate that at least within our own galaxy, the Milky Way, there are more than 400 billion observable stars. Some are visible by powerful telescopes due to their distance and where they are in their lifecycle, where others serve as signature maps that help guide our way home—like constellations such as the Big Dipper. How many stars might other galaxies hold? Check out this playlist and start counting.

Key Facts In This Video

  1. The scientific term for twinkling is astronomical scintillation. 00:20

  2. Planets are farther away from us than stars, which is why they appear as discs rather than twinkling points of light. 01:05

  3. To capture clear images of objects in space, some telescopes have adaptive optics that compensate for atmospheric turbulence. 01:50

Key Facts In This Video

  1. We can only estimate the number of galaxies inside the bubble that is the observable universe. 00:09

  2. To estimate the number of galaxies in the observable universe, scientists count the stars in a small sample and average the number over 360 degrees. 00:22

  3. There is a rough estimate of as many as 500 billion galaxies in the observable universe. 01:06

Written by Curiosity Staff October 22, 2014

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