10 common astronomy mistakes

New to astronomy? Sidestep these errors to become a seasoned observer.

Woman with telescope under winter night sky

Image Credit: iStock

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1

Stargazing too infrequently

It’s difficult to dedicate time to standing in your back garden, but when you’re learning your way around the night sky it’s vitally important to go outside regularly and learn not only the major stars and constellations, but also the rhythm of the night sky.

The positions of stars change constantly, rising in the east four minutes earlier each day to make space for new stars unknown to you.

So try to go stargazing once a week, even if it’s only for 20 minutes. The real art is cloud-dodging!

2

Expecting Polaris to be a bright sta

Pick up any stargazing starter manual, and you will be told to look for Polaris, the North Star.

You’ll be told to find the Plough, and then use an imaginary line from its stars Merak and Dubhe as a pointer to locate Polaris, the star around which the night sky appears to revolve when viewed from the northern hemisphere.

That makes Polaris special, but it’s not a deep-sky object that brags about its importance – it’s only the 48th brightest star in the night sky.

3

Using too much magnification

You want a close-up of the rings of Saturn through your telescope, so you find the planet with a low-magnification eyepiece and swap to a high-power one.

The result? A dim, blurry image.

Beginners often think that high power eyepieces are better for close-ups, but your telescope’s aperture (how much light it gathers) is fixed.

So if you use a high magnification all you’re actually doing is diluting the light across a wider area.

Less is more, and what power you can get away with depends on the quality of the eyepiece and atmospheric conditions.

However, the rule of thumb for ‘useful’ magnification is allow 60x for every inch of aperture. For a typical 4-inch/100mm beginner’s telescope, that’s a 240x eyepiece.

4

Using a smartphone to observe

Yes, there are some incredible planetarium apps, like Stellarium, Star Walk and Google Sky Map, that let you not only find objects in the night sky, but tell you all about them.

To have that kind of information in your hand while you’re outside stargazing is incredibly tempting – but resist it.

Every time you look at your smartphone’s white light LED screen, your night vision will be ruined.

However, some planetarium apps do have a red light mode, which will lessen the damage if you also turn the screen’s brightness all the way down.

5

Looking all over the sky for planets

The Solar System is flat, with all of the planets, including our own, orbiting the Sun in more or less the same plane. That makes them pretty easy to spot.

The Sun’s apparent path through the daytime sky goes from the sunrise point on the eastern horizon over to the sunset point on the western horizon.

This is called the ecliptic, and it’s the only place where you’ll find all of the planets (and also the Moon).

One glance at your smartphone screen and your precious dark-adapted vision is ruined! Credit: Jamie Carter
One glance at your smartphone screen and your precious dark-adapted vision is ruined!
Credit: Jamie Carter
6

Buying a telescope too soon

The chance to look deep into the cosmos is tempting, but are you ready?

Many a stargazer has purchased a telescope only for the fun to be replaced by frustration as they will struggle with aligning, aiming and focusing complex equipment rather than stargazing.

So here’s a plan; stargaze with your naked eyes for a year or two, then get some binoculars and use them for a while.

Then visit your local astronomy club to get some hands-on experience of telescopes, and knowledgeable advice on what to buy.

7

Assuming it’s easy to use a telescope

Have you ever been offered the chance to look through a large telescope and not had a clue what to do in the dark?

Many amateurs completely forget that looking through a telescope takes skill and practice, so if you’re at a star party, ask where the eyepiece is, because it differs depending on the design.

Also ask where the focus knob is because once you’re at the eyepiece that makes a huge difference.

However, the most important thing is to take your time; you looked through the telescope for a reason, so don’t be rushed, even if there is a queue.

8

Moon-watching at the wrong time

There’s nothing better than a full Moon, surely?

Watching our satellite rise every month is a real treat, but once it’s about 10° above the horizon it is so bright that it’s almost impossible to look at.

Instead of Moon-watching at full Moon, start just after new Moon, when you can watch it gradually wax from a slim crescent to a full Moon.

It will brighten slightly each night, but will be much easier to look at compared to when it’s full.

Pay special attention to the terminator line, which separates the Moon’s lit side from the dark side; it’s there that you’ll see the shadows of craters, mountains and other details.

9

Not asking those ‘stupid’ questions

For a subject as complex as astronomy, there are no ‘stupid’ questions.

When you first go to star party or any gathering of amateur astronomers, it’s normal to presume that everyone there has a degree in astrophysics. They almost certainly do not.

What they do have is years of learning, experience and a passion for the night sky they want to share.

So go to a star party, introduce yourself as someone who’s just started out or has lapsed for many years, and you’ll be amazed at how much you can learn if you’re not afraid to ask ‘stupid’ questions.

10

Relying too much on Go-To

Got a telescope with a Go-To computer that can find any object in the night sky?

Many relatively experienced amateur astronomers rely on this system to locate objects in the night sky.

However, if your goal all along was to have a working knowledge of the night sky and how it changes over the course of the year, relying only on the Go-To will not help you.

So before you punch in the name of an object you want to study through a telescope, see if you can accurately point out where it is in the night sky.

If you can’t, you may be a proficient telescope-owner, but you’re not a stargazer yet.


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Jamie Carter is the author of A Stargazing Program for Beginners: A Pocket Field Guide