Interview with Matt Davis
Below is a (partial) transcribed interview of mine (conducted on Oct. 16) with Matt Davis, an astronomy graduate student at the University of Washington. I asked him for tips on stargazing, which will be incorporated in an upcoming blog post.
Again, please post any questions about stargazing for Davis to this interview. I’m happy to work as an intermediary for other interested stargazers.
S: What tips do you have for someone new to stargazing?
D: Find a place where you can look at the stars. The darker the better. Then you’ll want to learn the constellations. You can get a planisphere or go to online sites that will make a sky chart [for your specific] location and time of day. Those [charts] will have names of constellations on them. He recommends going to skytonight.com or seattleastro.org.
S: Are there any specific constellations or stars stargazers should look for first as practice or to get themselves oriented with the night sky?
D: The best way to do that is to find Polaris, the North Star. When you’re facing the North Star you’re facing north, so that’s a good way to use the sky charts. Find north, and find your orientation. Because if you want to use the sky charts you have to get oriented to where you are. He said the easiest way to find the North Star is to first find the Big Dipper– which isn’t really a constellation, but an asterism that is part of the constellation Ursa Major– and to draw an imaginary line from the two stars that make up the edge of its bowl, called the pointers, because they roughly point to the North Star. Also, the North Star is the tip of the handle on another asterism called the Little Dipper, part of the constellation Ursa Minor.
S: You said something about measuring the sky with your fists when we visited the Planetarium. Could you explain that?
D: The sky is broken up into degrees, so if you want to measure how many degrees something is from the horizon you can either use a fancy instrument or you can use your fists. There are kind of a bunch of different tools you can use: your hand spread at arm’s length covers an angular size of about 20 degrees, your fist is about 10 degrees, your thumbnail is about 2 degrees and your pinky fingernail is about 1 degree. You can use that to find your latitude. If you want to know your latitude, go outside, find the North Star and find a way to measure how far the North Star is away from the horizon– [that’s] your latitude. Just start stacking fists.
S: You also said something about looking out of your peripheral vision to see stars clearer. Could you explain that?
D: The censors on the outside [part] of your retina [in your eye] are the most sensitive to light. When you look straight at something you’re using the color-sensitive parts of your eye. At night you start to lose the ability to see colors. At night everything looks gray, so we sort of switch to using the light-sensitive parts of our eyes. Your peripheral vision is most sensitive to light and dark. Stars are very faint, so we want to use the light-sensitive parts of our eyes.