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Before you head out on your next stargazing adventure, SciShow Space has some tips for you.

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Sources:
https://books.google.com/books?id=3fhBelJk-30C&pg=PA47#v=onepage&q&f=false
http://www.space.com/27775-amateur-astronomy-guide.html
http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html
http://www.timeanddate.com/astronomy/measuring-the-sky-by-hand.html
https://books.google.com/books?id=BaMBgoKPmjAC&pg=PA30#v=onepage&q&f=false
So, like us, you're probably excited about space and you wanna see some stars with your own two eyes. But, skywatching can be tricky; it's hard to see dim objects, and it's tough to figure out where to look in the first place.

Luckily, there are some things you can do to make your experience go a little more smoothly, like taking advantage of how your eyes work. You probably heard about and experienced light pollution - even if there aren't any lights within your field of vision, any nearby light will scatter into the atmosphere, making the sky just a little bit brighter.

That's why in big cities, you might only be able to see a few stars, even on the darkest nights. There are ways to get around this problem, like using a special eyepiece for your telescope that will filter out certain wavelengths of light. But that isn't a perfect solution, especially if you wanna stargaze without a telescope.

So the first thing you wanna do is find a spot with less light pollution. Even if you're in the remotest deserts, though, light from your phone or flashlight can ruin your night vision and make you have to wait another half an hour before you can see the dimmest stars again.

Your retinas detect light using two different kinds of cells; rods and cones. The rods aren't too useful for distinguishing colors, but they're a lot more light-sensitive, so they're mostly responsible for our ability to see at night.

Rods contain a chemical called Rhodopsin, which breaks down when it's exposed to light. But, when your rods don't detect light for a while, then the Rhodopsin builds up, making your eyes more sensitive to what little light might be around.

That's a problem if you wanna say, adjust your telescope or check a star chart, because you don't wanna lose that extra Rhodopsin and have to wait for your night vision to build back up again.

One easy fix is to only use red light, like getting a flashlight with red LEDs, or by covering a regular one with red cellophane. The red light doesn't affect your night vision as much because it turns out Rhodopsin is least sensitive to light with longer wavelengths, like red light.

So, it's mostly your cones that detect red light, and the Rhodopsin sticks around. But let's say you still can't see a particularly dim star or galaxy, well you might wanna try looking out of the corner of your eye...

Because those rods in your eyes, they're arranged like tiny donuts, with the cones in the middle. That means that the most light-sensitive part of your retinas is actually about 20 degrees off-center, so if you're having trouble seeing something, try looking slightly away from it.

And if you're struggling to find something specific, it's useful to have a couple of star patterns in your head to guide you, like the Big Dipper for instance.

The Big Dipper is shaped like a ladle, and if you follow the line of stars on the edge of the scooping part, in the direction of the scooping, you'll find Polaris, the North Star.

Polaris is a fantastic tool, because it's incredibly close to the northern axis of Earth's rotation. Even though the rest of the stars move around in the sky all night as the Earth rotates, Polaris mostly stays put, so it's an easy way to orient yourself with the star chart, at least if you're in the northern hemisphere.

But Polaris is 28 degrees from the top star in that scoop of the Dipper, so to find it, you're gonna wanna be able to measure distances. For that, you have some tools at your disposal; your hands.

When you hold your hand out in different positions at arm's length, it becomes a great way to measure rough distances in degrees. This works for practically everyone, because people with bigger hands tend to have longer arms.

So, to find Polaris, you stretch out your thumb and pinky as far as they'll go - that's about 25 degrees. Your pinky alone is just 1 degree, so you can measure out exactly 28 degrees by adding 3 pinky widths. So, knowing how to measure out distances in the sky can come in... handy.

Thanks for watching this episode of SciShow Space, and especially to our patrons on Patreon, who help make this show possible. If you wanna help support this show, just go to http://www.patreon.com/scishow to learn more, and don't forget to go to http://www.youtube.com/scishowspace and subscribe!