Dennis Mammana: See a Galaxy Far, Far Away | Outside

Just how far can we see on a transparent, darkish evening? If you’re an everyday reader of this column, you realize that the celebs overhead lie many trillions of miles away, however these make up solely a tiny fraction of all these in our Milky Way galaxy.

Although our galaxy spans some 600,000 trillion miles (100,000 mild years), our eyes can see solely these stars inside the nearest 1% of that diameter.

But there’s something in our autumn sky that’s significantly extra distant — far past the celebs of our galaxy — and we are able to see it with the unaided eye if we all know simply the place to look.

Astronomers name it M31 or NGC224; most of us merely realize it because the Great Andromeda Galaxy.

M31 is a spiral galaxy comparable in some respects to our personal Milky Way, and it lies so removed from us that its mild has taken 2½ million years to achieve us.

In different phrases, the faint wisps of sunshine that enter our eyes tonight left that distant galaxy lengthy earlier than people walked the face of the Earth!

It seems as a faint smudge within the path of the constellation Andromeda, however to see it, you’d higher have a transparent sky with out the results of close by metropolis mild air pollution or moonlight.

In addition, you should enable your eyes at the very least half-hour to grow to be tailored to the darkness by not wanting into any shiny mild.

If you continue to can’t see it, you could have to attempt one other trick used nightly by astronomers. It’s known as averted imaginative and prescient.

Because the human eye is unable to register dim mild close to its heart, gazing immediately at such a faint celestial object can render it utterly invisible.

Look barely off to its aspect, nevertheless, and the article will appear to pop into view.

After darkish this week, M31 seems within the northeast, and there are 3 ways to make use of acquainted stars and star groupings to direct your gaze to the proper place. Use the close by illustration that can assist you discover your manner.

One method is to look halfway up within the northeastern sky for 5 stars that define the sideways “W” of the constellation Cassiopeia.

Take the uppermost three stars and picture them to be an arrowhead, and comply with it eastward a brief distance till you see a faint smudge.

Another technique to discover it’s to find the 4 stars of the Great Square of Pegasus, then comply with a line from the sq.’s southwesternmost nook to its northeasternmost nook and proceed alongside that path about the identical distance.

A 3rd manner is to start on the star Mirach in Andromeda, and comply with it upward simply previous the star Mu Andromedae.

Long considered a nebulous cloud inside the Milky Way, it was solely in the course of the early years of the twentieth century that astronomers found it to be a galaxy unto itself, with a whole bunch of billions of stars, and considered one of maybe a trillion or extra such galaxies within the universe.

And it’s there for all to see on any clear darkish evening — if you realize simply the place to look!