Getting started
Stargazing rewards patience more than money. Start with your eyes, add binoculars when the patterns feel familiar, and buy a telescope last.
The path
Step 1 · Free
Constellations, planets, meteors, the Milky Way, the Andromeda Galaxy from a dark site.
Spend your first few nights here. Knowing the patterns makes every later tool more useful.
Step 2 · Modest
Craters on the Moon, Jupiter’s moons, star clusters, bright nebulae and hundreds of fainter stars.
A 7×50 or 10×50 pair is the classic astronomy choice: wide, bright and easy to hold.
Step 3 · An investment
Saturn’s rings, cloud belts on Jupiter, double stars, galaxies and planetary nebulae.
Aperture matters most. A 150–200 mm Dobsonian is the most telescope for the money.
Night vision
Your pupils widen within seconds, but the chemistry that makes your eyes really sensitive takes 20–30 minutes to build up, and it keeps improving for a while after that. A single glance at a bright screen undoes it.
Red light disturbs it least, which is why astronomers use red torches. Try the red light mode on this site (the eye button at the top) before you head out.
To see something faint, look slightly to one side of it. This “averted vision” uses the more sensitive edge of your retina.
Measuring the sky
Star charts give distances in degrees. Hold your hand out at full arm’s length and it becomes a surprisingly consistent ruler, because people with bigger hands tend to have longer arms.
The whole sky from horizon to overhead is 90°, about nine fists.
| At arm’s length | Covers | For example |
|---|---|---|
| Little finger | 1° | Twice the width of the full Moon |
| Three middle fingers | 5° | The gap between the Big Dipper’s pointer stars |
| Closed fist | 10° | Across the top of the Big Dipper’s bowl, Dubhe to Megrez |
| Spread hand | 20° | Pinkie to thumb: roughly Orion from Betelgeuse to Rigel |
Buying advice
Binoculars
The first number is magnification, the second is the width of each front lens in millimetres. Bigger lenses gather more light; higher magnification shakes more in your hands.
Divide the two to get the exit pupil: 50 ÷ 7 ≈ 7 mm, which matches a young, dark-adapted eye. Above 10× you’ll want a tripod.
Telescopes
Aperture, the diameter of the main lens or mirror, decides how much you can see. The highest useful magnification is roughly twice the aperture in millimetres, and the atmosphere usually limits you to less.
A box that boasts “675× power” on a 60 mm telescope is a warning sign. A solid mount matters more than any accessory.
Light pollution
John Bortle’s 2001 scale rates how dark a site is by what you can see. Most of us live under class 6–9 skies; a short drive can make a dramatic difference. The limiting magnitude is the faintest star visible to the naked eye.
The Milky Way casts shadows; zodiacal light is obvious.
The summer Milky Way is richly structured.
Some glow on the horizon; the Milky Way still looks complex.
Light domes over towns; the Milky Way is visible but plain.
The Milky Way is weak and vanishes toward the horizon.
The Milky Way is only faintly visible overhead, if at all.
The sky is greyish white and the Milky Way is gone.
Only the brighter constellations can be traced.
The Moon, planets and a handful of bright stars.
Before you go
A comfortable observer stays out longer, and staying out longer is how you see more. Use a light-pollution map to find the nearest dark spot, and tell someone where you’re going.