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| Space on Sep 15, 2009

Can I see our galaxy from Earth?

On a very dark clear night – and if you look in the right direction – you can see a bright region of our own Milky Way galaxy.

Yes. It’s a rare sight nowadays, but a trip to the country at the right time of year can bring you a beautiful view of the starlit trail of our Milky Way galaxy.

The edgewise view into the galaxy translates in our sky as a starlit trail – like a river of stars stretched from one horizon to another. The galaxy is all around us in space, but some parts of it appear brighter than others. The most dramatic place to look is toward the center of the galaxy – toward what we see as the constellation Sagittarius.

This part of the sky comes into view each year before dawn in early March – and rides high in the sky each evening in July and August – only to be behind the sun again by New Year’s, all as Earth orbits the sun. Under a dark, clear sky – when the galaxy’s center rides highest in the sky, you’ll recognize it as a broad, bright part of the starlit trail of the Milky Way. It looks almost like billowy clouds of steam.

We can only look toward the galaxy’s center. We can’t see the exact center because it’s obscured by dark curtains of interstellar dust. So when you look at this broadest part of the Milky Way – in the direction of the constellation Sagittarius – you’re not looking at the actual core of the Milky Way. Instead, you’re gazing at part of one of the prominent spiral arms of our galaxy, called the Sagittarius Arm.

In this direction, you’ll see this spiral arm of the galaxy studded with countless bright stars, clusters, and nebulae. Just remember, dust prevents us from looking directly at the galaxy’s center, which lies 27,000 light-years away.