Galaxy Quest

First posted on 04-21-2011

Spring is a great time to go looking for other galaxies, those sprawling systems of gas, stars, dust and planets.

In summer and winter, the Earth is positioned so that our own galaxy, the Milky Way, stretches across the night sky with the light of its 100 billion stars. Looking skyward on a warm summer evening gives clear evidence of why our galaxy has “milky” in its name.

In spring, the Earth’s tilt makes the Milky Way appear low on the horizon. Eliminating the light from all those stars makes objects, such as other galaxies, easier to find with a telescope when searching the heavens.

Cities and even suburbs have so much light pollution that finding deep space objects is an onerous task. The best viewing is in the country, away from ground lights where the sky is open and stars shine brightly and unobstructed.

Still, a few galaxies may be visible from backyards using a strong telescope. M81 is a spiral galaxy located in the Ursa Major constellation. Even at 12 million light years away, it’s still the brightest of all the galaxies visible by telescope from Earth.

Searching the night sky might yield a few results, but the best plan is to go online or purchase a book that pinpoints exactly where deep space objects may be found.

Galaxies were formed shortly after the big bang that created the universe 10 to 20 billion years ago. Only milliseconds after that explosion, gases compressed and formed the building blocks that became the galaxies. No one knows how many galaxies exist, but scientists estimate there may be over 100 billion of them in the observable universe alone.

Photo: NASA/JPL-Caltech image of galaxy Messier-81, also called M81.

Share | |