NASA Spacecraft Discovers the Universe is Less Crowded Than We Thought

An anonymous reader shares a report: While we might think of space as a vast sea of blackness, all we have to do is look up at night to see that it's punctuated by countless stars, galaxies and even a few planets visible to the naked eye. Scientists recently used data from NASA's New Horizons mission out beyond Pluto to measure just how dark the cosmic background really is. What they found has implications for what we thought we knew about the makeup of the entire universe. In short, space is so dark there can't be as many galaxies out there, adding their faint glow to the backdrop, as astronomers have previously estimated.

'It's an important number to know -- how many galaxies are there?' Marc Postman of the Space Telescope Science Institute said in a statement Tuesday. 'We simply don't see the light from 2 trillion galaxies.' That was the earlier estimate derived from Hubble Space Telescope observations, but a new study forthcoming in the Astrophysical Journal and co-authored by Postman suggests the total number of galaxies in the universe is probably in the hundreds of billions rather than the trillions. Interestingly, this is closer to an even earlier figure guessing there were around 200 billion galaxies. That was based on Hubble data from the 1990s.

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