Wednesday, December 21, 2011

Mind-Boggling Distance

If you think you can come anywhere near to grasping the immensity of cosmic distances: no. You really can't.

Consider: the Voyager 1 spacecraft, launched in 1977, has been travelling really really fast. Hurtling away from the sun at 38,200 mph, it's expected to cross over into interstellar space shortly (here's the latest update from NASA). It's now just over 11 billion miles away - so distant that light takes 16 hours to travel from Earth.

A light year, as you know, is the distance light travels in a year. And traveling 38,200 mph for 35 years brings you just these puny 16 light hours. So now just try to imagine a light year (Voyager will go that far in 14,000 years). And remember that the nearest star (aside from the Sun) is over four light years away.

But the mind blower is that there are galaxies billions of light years away (here's one 13 billion light years away).

Here, FWIW, is a particularly pretty one a "mere" 10 million light years away, courtesy of the wonderful Astronomy Picture of the Day site.

Previous astronomy posts:

Good Galactic News (when galaxies collide, stars don't actually crash into each other)

The Andromeda Galaxy and You (The Andromeda Galaxy occupies much more sky real estate than the moon)

Tap Dancing on Saturn (hear the sound of the Cassini-Huygens spacecraft passing through Saturn's ring dust)

The Photopic Sky Survey (sort of like Google Maps for the Milky Way)

1 comment:

Marc Parmet said...

The closer galaxy can be seen here.

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