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Hubble at 25 III

April 24, 2015

In 1990, estimates of the age of the universe ranged from 10 billion to 20 billion years. Today, just a quarter of a century later, there’s widespread agreement that the universe is a bit less than 14 billion years old.

That’s one of the most important discoveries made with Hubble Space Telescope, which was launched 25 years ago today. It’s provided new insights into everything from our own solar system to the most-distant quasars — giant disks of hot gas around supermassive black holes. It’s peered into stellar nurseries, stellar retirement centers, and even stellar graveyards. And it’s provided dazzling pictures of some of the most beautiful objects in the universe.

Nailing down the age of the universe may be one of its most important contributions.

To determine the age, scientists used Hubble to measure the distances to pulsating stars in other galaxies. How fast the stars pulsate reveals just how bright they are, which in turn reveals how far away they are. Hubble’s observations also determined how fast the host galaxies were moving away from us as a result of the expansion of the universe. The combination of the distance and the expansion rate helped reveal when the universe began expanding in the Big Bang.

No one knows how much longer Hubble Space Telescope will operate. All we know for sure is that, no matter how long it lasts, it’ll continue to dazzle us with its discoveries about our amazing universe.


Script by Damond Benningfield, Copyright 2015

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