Astronomy is the study of the stars, planets, and other celestial objects that populate the sky. It is an endlessly fascinating field, the oldest of the natural sciences, and one of the few areas of science that amateurs can directly assist the professionals. It is open and accessible for any level of interest and involvement, from folks who just want to learn how to recognize the constellations all the way to near pros with telescopes worth more than their houses.
My goal in this instructable is to provide a set of resources for anyone interested in getting started with this hobby, in the form of a step by step guide for someone who just isn't sure where to begin. When I got started a few years ago, I couldn't find any guides like this that really made sense to me, so in a way this is written to my past self. If I had this guide, I could have avoided a lot of trouble, pitfalls, useless purchases, and dead ends. Furthermore, I've been interested in astronomy since I was little, but I always assumed it was an expensive hobby that I couldn't afford to get into--I was wrong, and I wish someone had been there to tell me!
If you can think of anything I should add to this guide, make sure to leave a comment below--if I use your suggestion, I'll send you a DIY patch. If I think it's a big enough suggestion or oversight on my part, I'll also send you a coupon for a three month pro membership. Also, as I live in the northern hemisphere and only see the northern sky, if you're reading this from a southern hemisphere perspective, I encourage you to write a supplementary southern hemisphere version of this instructable. If it's up to my standards (as determined solely by me and my whims) I will link to it here and send you a coupon for a one year pro membership! I envy you, too, I'll probably never get to see the Magellanic Clouds.
Finally, please lend me your vote in the Space Contest. If you found this useful or interesting, cast a vote my way!
Step 1: Don't Buy a Telescope!
I put this step first because it's often the first thing people do, and I want to stop you before you go wrong. This is probably the biggest mistake I made, and a mistake that I believe a lot of people who are interested in astronomy make. A lot of people think that a telescope is required to be an astronomer, and they head out to Wal Mart or Target and pick up one of those $50 telescopes they always have around Christmas time.
People who have been doing this for a while have a name for those telescopes--they call them hobby killers. Those things are incredibly difficult and frustrating to use, and aren't good for much except looking at the moon, and while that's definitely worth doing, don't take that step yet. The one I bought was awful, I used it a couple of times and then put it away, convinced I was doing something wrong. It put at least a two year break between me deciding I wanted to get into astronomy and me actually doing so.
You will probably want to get a telescope some day, but you really don't need one yet, and you most definitely don't know what kind you want. There is a wealth of options out there, and you should take some time to learn about them before you settle on one to buy (more on that in a later step).
If you absolutely must spend some money on something (I know sometimes if I drop a few bucks on a new hobby I feel obliged to see it through), buy a Planisphere. This is a very useful resource you will come back to over and over again, and worth the few dollars it will cost.
****Update 8/1 -- dimtick has pointed out that another good, small investment is a green laser pointer. They are very cheap these days, and if you're planning on involving anyone else in your hobby they are great for pointing out what you're looking at. Also, they're fun!
Step 2: Look Up!
Before anything else (except stopping your telescope purchasing urge), start looking up at every chance you get. It seems obvious, but you should really make a conscious effort to point your eyes at the skies. Go outside at least once every night. Start to familiarize yourself with the objects in the sky, you don't even need to know their names yet, just try to notice patterns.
Even if you live in a big city with terrible light pollution, it should be possible for you to pick out the more obvious objects, like Venus, the moon, Jupiter, Orion, the Big Dipper, the Pleiades, and the North Star. Not all of these things will be visible all the time, but if you start spotting for them you will begin to notice how their positions change over the course of the year.
****Update 8/1 -- 94 has pointed out that I didn't really explain light pollution in this instructable! In most cities, all of the night time lights that are set up ostensibly for your safety have a tendency to create a haze that blocks out all but the brightest of stars. There are many ways that this can be combated, including working with the IDA to reduce light pollution, but what is boils down to is the fact that the night sky in the city is nothing like the night sky in the wilderness.
****Update 8/20 -- Here's an excellent image showing the different levels of light pollution: http://cache.gawkerassets.com/assets/images/4/2010/10/skychanges.png
At times throughout history, our imperfect understanding of the heavens caused people to believe that the stars were fixed points of light attached to a globe that turned about the earth. I understood intellectually why people believed this, but through looking at the sky most nights and seeing how things move and change, I now understand it on a very visceral level. When you look at the stars with the naked eye, it's quite clear that they're just points of light on a globe, the uppermost point of which rests at Polaris, the North Star, turning slowly from west to east. Not really of course, but it's a valid frame of reference for understanding the motions of the heavens in relation to the Earth. It really does look like a giant globe!
Step 3: Expand Your Mind
Once you've started looking at the sky regularly, you'll probably want to get a feel for what you're looking at. Thankfully, in these days of the internet, there are a lot of fantastic options for you!
The absolute best and at the same time, the most basic website for this is the Your Sky website. There, by inputting your location and the time you'll be outside observing, you can print off custom star charts to take outside with you. With one of these in hand, you can spot constellations, planets, whatever you like!
I cannot recommend enough that you pick up a copy of Stellarium, the free planetarium software. It is simply amazing! Using Stellarium, you can set it for your location, then it will show you what is going on overhead. You can increase or decrease the light pollution, to make it more resemble where you are, and turn on or off the constellations, planets, nebulae, and star names. It allows you to zoom into the future or the past or get a closeup on a deep sky object. Google Sky is another tool useful for this (and it doesn't require a download), but I believe Stellarium is better.
***Update 8/2 -- Nurdee has suggested Celestia as another option for astronomy software. I'm not familiar with it myself, but looking over the website, it looks pretty cool!
If you're into podcasts or audiobooks, definitely check out the excellent Astronomycast. The hosts, Fraser Cain and Dr. Pamela Gay will spend half an hour or so talking about a specific astronomical subject, or just answering listener questions. It makes for great mp3 player material while you're spending time looking up at the stars! The 365daysofastronomy podcast is also great, though much less focused.
I also like to read a couple of blogs to keep up to date on astronomical issues. I really like Phil Plait's Bad Astronomy blog at discovery, he's fun and knowledgeable and clearly holds a deep wonder about the universe. Also, and this may or may not be up your alley, he got his start in blogging debunking the idiots who think we never went to the moon, so he often tackles other scientific issues of a skeptical nature rather than just astronomy. My other favorite is Universe Today, where you will find a wealth of excellent and interesting articles about all things astronomical--the publisher is Fraser Cain, the same guy who co-hosts Astronomycast.
I'm only passingly familiar with one astronomical video show, the IRrelevant show from NASA's Spitzer Space Telescope team. What I've seen is really good, I just don't sit down to watch video all that often. Can anyone recommend a really good internet show about astronomy?
If you're more interested in physical media, definitely make a trip to the library. I have particularly enjoyed The Urban Astronomer, it has been helpful for me, living in a very light polluted area. Also, don't be embarrassed to peruse the kid's section! There are a lot of great books there to help out beginners!
Step 4: Good Stuff to Look at With the Naked Eye
- The Moon -- our closest neighbor, and often overlooked because it is so ubiquitous. Find a map and get to know Luna's more obvious features. Also, did you know it's not a man in the moon, but rather, a woman? Or a rabbit?
- Planets -- Venus and Jupiter are usually the most striking when up, though Saturn is pretty awesome, and when Mars is close, it's really red!
- The Big Dipper -- Also known as Ursa Major, the Great Bear, this is probably the most familiar constellation to anyone in the northern hemisphere. It contains or is nearby to a number of objects that are good to view through a telescope, and it can be used to find several important stars such as Polaris, Arcturus, Spica, and Vega. It is best viewed in the summertime.
- Orion -- Orion is a very obvious constellation in the winter sky, and it contains my favorite night sky object of all, the Orion Nebula. The nebula is visibly fuzzy in even poor skies, and very fuzzy from a dark sky site. Orion also contains Betelgeuse, my favorite named star, and is useful for locating a variety of stars including Castor, Pollux, Aldebaran, Sirius, and Procyon.
- The Pleiades -- An open cluster of very bright, very blue stars. They are absolutely beautiful! When I was little, I thought of them as the mini-dipper, as they kind of resemble the big and little dippers.
- The MIlky Way -- Only visible from a dark sky site, the milky way is the plane of the galaxy viewed edge on. The massive profusion of stars make it seem like a river of light spilled across the sky.
- Sagittarius -- Visible from the northern hemisphere in the summer in the far southern sky, it is supposedly a hunter, but it looks more like a teapot to me. The center of our galaxy lies in the direction of Sagittarius
- Meteor Showers -- This is something fun I like to do whenever there's an opportunity. Check out this site to find basic info about meteor showers, or this one for specific info pertaining to 2011. If you can find a clear dark sky during one of these, make sure to take some time to watch. The Perseids are particularly nice in that it's a big shower and it happens during the summer so it's warm. We're planning a campout that weekend this year, but unfortunately the stupid moon is going to be stupid full that stupid weekend.
- The ISS -- The International Space Station is really bright when it zips overhead! Check out this site to find info about when it's visible in your area.
- ****Update 8/5 -- JohnJY has pointed out another great target for the naked eye: auroras! As the solar wind streams towards our planet, the charged particles are caught up by the Earth's magnetic field and redirected to the northern and southern latitudes, where they interact with our atmosphere to create a stunning streamers of light. They are most often visible only in the far north and south, but when the sun is at it's most active (as it will be in the next year or two), auroras can sometimes be seen much closer to the equator. I have heard anecdotal reports of seeing auroras as far south as California, though I've never seen them here in Oregon--it's always too cloudy! If you'd like to spot an aurora, keep an eye on spaceweather.com.
- ****Update 8/11 -- Let's make sure to add eclipses to this list. You can keep an eye out for those on spaceweather.com as well, and there's usually a decent one every couple of years. Lunar or solar eclipses make for great viewing with a group of friends!
Step 5: Continue to Not Buy a Telescope . . . But Maybe Some Binoculars?
At this point, you still don't want to buy a telescope, but binoculars might be a good investment. Binoculars are nice because you can use them for other things than just astronomy, as it's always nice to have a pair around when you're out in the wilderness. They aren't steady like a telescope, but with some practice they are great for getting a bit of detail on the moon, the planets, or even the Orion nebula.
I've used a cheap pair of $30 binocs before, and they're pretty nice, but now I'm using a pair of the Celestron Skymasters, which are really amazing! I've spent a few evenings just lying in the back yard and exploring the sky, nothing really on the agenda, just looking up through the binoculars.
Binoculars are particularly good at teasing more detail out of naked eye objects such as the Moon and the planets, or at splitting easy binaries like Mizar and Alcor in the handle of the Big Dipper.
Step 6: Update 5-24-12: Solar Projection
I've recently posted an 'ible about how to build a simple solar projection rig. This is a great way to use your binoculars to observe our closest stellar neighbor!
So far, I've used them to take a look at a solar eclipse, and once the clouds clear up here, I'll hopefully be able to take a look at some sunspots, and one June 5 2012, I'll use this setup to observe the last transit of Venus until 2117!
Step 7: Determining Where Something Is in the Sky
There are a lot of resources for how to locate something in the night sky--but I tend to glaze over when a source starts going on about "Right Ascension" or "Declination". I honestly haven't taken the time to learn about this method of celestial navigation. I'm going to do so eventually, but at this point I have been successful with less precise ways of determining location.
What I do like is degrees above the horizon, as most resources for amateur astronomers will give you a rough direction to look for your target and let you know how far above the horizon it can be found. There is a very simple rule of thumb to help you measure this: your fist held at arm's length is about 10 degrees wide. Therefore, if you stack one fist on another, it takes about 9 to get to directly over head, which is 90 degrees. One finger makes about 2 degrees.
Therefore, if something is described as being about 24 degrees above the horizon, that means it is two fists and two fingers above the horizon. The neat thing is that this works for anyone, no matter how big they are, as someone with small hands will tend to have short arms, and therefore their hand is closer to their eyes and still takes up about 10 degrees.
Step 8: Find an Astronomy Club
This is the point at which you move on to the next level. Getting involved in an astronomy club was a big step for me, as I'm really shy in person and have a very hard time interacting with people I don't know. Still, it was a very beneficial experience, and though I've stayed away for a while due to time constraints on the evening they do meetings, I am planning on getting back into it.
There are a number of websites that aggregate astronomy clubs, but I recommend you first try just googling "<your city> astronomy club". The Eugene Astronomical Society has a web page, but they aren't listed on several of the aggregators. I didn't even realize we had an astronomy club until quite a while after I'd been doing astronomy in my back yard.
It turned out that not only do they have a monthly meeting where they talk about astronomy, have guest speakers, do telescope workshops, etc, they also have monthly star parties! Each friday nearest the new moon, the EAS brings a bunch of telescopes up to college hill here in town and point them at the sky. In fact, last weekend was the annual Dark Sky Party, outside of town at a state park, where we got to see some really great things in a really dark sky--it was amazing!
Being involved in an astronomy club has a lot of benefits. You get to go to the meetings and the parties, but many clubs also offer help with your telescope and even lend telescopes from their collection. Perhaps most importantly, you'll be joining a group of people who are enthusiastic about the same subject you are interested in and more than willing to "talk shop" with you. My local club also has an email mailing list that has more than once given me a heads up about some interesting thing coming up in the night sky.
****Update 8/1 -- dimtick has pointed out that you don't actually have to JOIN an astronomy club to attend the star parties! I just reread this section, and realized that the way I've worded things makes it seem like you have to be an active member to attend, but the monthly star parties are more for public outreach than for members. Find out when and where they are, and just stop on by!
Step 9: A Quick Word About Reality Versus Processed Images
What I saw in the telescope was an indistinct puffball, grayish blue and lacking in detail. Even though I knew better, there was a part of my brain expecting to see the professional image, and I was . . . not disappointed, but kind of confused for a half second, and made a comment about it being small. I think this made the telescope's owner a bit self conscious, so I pointed out the fact that I've been a bit spoiled by Hubble images.
The simple fact of the matter is, what you see through a telescope will never, ever match the pictures you can find taken by Hubble, Spitzer, and other great observatories. There are a number of reasons for this:
- Atmosphere -- Unless you live atop the Andes or in space, you've got fickle, wavery, distorting air between you and what you're looking at.
- Aperture -- The biggest telescope I've ever looked through was 18". It was huge, and made the Lagoon Nebula look absolutely amazing. At 18 inches, that's a light gathering area of about four and half feet. Hubble not only has no atmosphere to deal with, it has a light gathering area of 48 square feet.
- Exposure Time -- Your eyes can only gather so many photons at once, even with the help of a big light bucket. A telescope hooked up to a CCD camera can stack images, enhancing them way more than your eyes ever could.
- False color -- Nearly everything you see through a telescope will look kind of bluish. Observatory images will have different colors added in to represent light gathered from infrared or x-rays, or the emission lines of hydrogen and oxygen. Your eyes probably can't see in those wavelengths, and are probably unable to separate out light from excited helium atoms.
The point is, don't be expecting glossy, false color magazine prints inside your telescope. You will still see amazing things, but don't be spoiled by Hubble. If all you want from astronomy is the full color glossies, don't buy a telescope or you will be consistently disappointed, and that's okay. There are plenty of places in amateur astronomy for folks without a telescope!
Step 10: (Finally) Buying a Telescope
At this point, you are probalby considering investing in a telescope. Definitely attend the star parties, and try out different scopes that the members bring. They will be happy to talk to you about their setup and its advantages and disadvantages. This way, if you do decide to invest in a telescope eventually, you will have a feel for the kind you will most enjoy using. If your club has a lending library, take advantage of that before you start throwing money around!
Talk to the folks in your club. Chances are they've all got extra scopes gathering dust, and may want to part with one for a pittance. Also, since they are real and current enthusiasts, their telescopes are probably in pretty good condition.
The first place to check after that is craigslist. Astronomy is a hobby that, much like homebrewing, people fall in and out of and involves a lot of expensive equipment that takes up a lot of space. People are often reluctant to give it up, but secretly want it out of their garage.
I got my current telescope by placing a want ad on CL that basically said I would be interested in renting someones' telescope for a month or two before potentially buying it--this was before I knew there was an astronomy club here to lend me a scope. Within 12 hours of posting the ad, I had two people call me asking if I would take their scopes away with only the promise that I would use them rather than let them gather more dust. I took one of them up on the offer and drove away with a 10" Newtonian reflector with a clock drive equatorial mount. I later discovered that this set up cost around fifteen hundred dollars when he bought it in the seventies, and would have cost even more today. It took a lot of careful cleaning and some help from the astronomy club to get things set up, but it is now in great working order, parked in my back yard in the hopes that it will eventually not be cloudy here.
If craigslist fails you, try astromart. It's kind of a craigslist just for astronomy stuff.
I am a cheapskate and not rolling in the cash, so I will always do my best to do something like this as cheaply as possible. That means I don't mind doing a little extra work to avoid buying new. I know however that a lot of, perhaps most, people would prefer to have a new item, especially something delicate and tricky to repair like this. If you want to go that route, first talk to the people in the astronomy club to get ideas about where to buy your specific scope. As far as I know, Oregon only has one business that specializes in telescopes. It would have meant a drive over the mountains to Bend if I wanted to examine something before I bought it, otherwise I would have to buy sight unseen from the internet. Having not purchased from any online markets for telescopes, I don't have one I can recommend. Does anyone have a suggestion?
Step 11: Good Stuff to Look at With a Telescope
Here is a list of good, easy targets for your telescope. I have seen all of them through my 10" while trapped in Eugene's terrible light pollution, so you should have no problem finding them:
- The Orion Nebula -- Absolutely my favorite thing to look at in the sky. The middle "star" in Orion's sword, this is actually a star forming region, filled with bright hot stars illuminating the gas around them. It looks absolutely stunning even in a weak telescope or binoculars.
- Saturn -- Also my favorite thing to look at in the sky (so are the moon and Jupiter). Saturn with it's huge rings look so shockingly different from everything else when viewed through a telescope, it gives you kind of a "Wow!" moment. The rings are beautiful, and sometimes you can tease out details of the planet.
- The Moon -- The best time to look at the moon is when it's less than a quarter full. That way, the light won't be painfully bright, and you can spend time following the terminator (day-night line) and examining the shadows on the craters and mountains.
- Jupiter -- Jupiter is incredible to observe. 2-4 of its major moons are usually visible. You can usually see cloud detail, even the great red spot! If you're really lucky you'll get to see a transit of one of its moons (I watched Io transit last summer, which was honestly one of my best astronomy moments, it was truly amazing).
- Mars -- If Mars is near, you can start to see some of the major features in a decent scope. If not, you won't see much more than an orange blur. If your'e really lucky (and prone to fantasy), maybe you'll see canali!
- Venus -- Venus is difficult to observe due to it's relative nearness to the sun, but it's pretty awesome when you can. You may even be able to see phases like the moon! Also, since it's orbit is relatively small, it changes in size pretty quickly which makes observation over the course of several nights interesting, as you can observe the changes in phase, brightness, and size changing pretty quickly.
- The Great Cluster in Hercules -- a tricky but worthwhile target in early to mid summer. About 2/3 of the way between Arcturus and Vega you should be able to find this relatively bright globular cluster of several hundred thousand stars about 25000 light years away. It is a triumph to find, and very pretty to look at.
- The Pleiades -- Also known as the Seven Sisters, this open cluster of bright blue stars looks amazing through a wide angle lens, showing hundreds of stars mixed in with the seven really bright ones. I like just exploring this region with a wide angle lens to see the profusions of stars.
- Mizar and Alcor -- If you have very sharp eyes and a very dark site, you might be able to split (see that there is more than one star) Mizar and Alcor without a telescope. With a telescope, you will find that MIzar has a companion as well, making this pair actually a triplet. These stars are usually observed as the middle star of the handle of the Big Dipper.
- The Andromeda Galaxy -- A very tricky object to observe in the city, at least in my city--the major sky glow is to the north of me, which is where you will find Andromeda, the nearest major galaxy to our Milky Way. Definitely worth seeing if you're able to find it!
- The Messier Catalog -- Charles Messier, a comet hunter in the 1700's and early 1800's, cataloged and large number (103) of faint fuzzy objects that might be mistaken for comets, but weren't. This catalog has come to be known as the Messier Catalog, and contains a wealth of objects for observers to view.
Step 12: Helping the Pros
Now we're beginning to tread on unfamiliar territory for me, so we're drawing near to the end of this instructable. Here are a number of ways you can help professional astronomers, and make real discoveries of your own.
First and foremost, just by observing the sky and watching out for anything unusual you can help a great deal. There have been many amateur astronomers who have been the first to spot new comets, asteroids, supernova, and even impacts on Jupiter.
You might also help the AAVSO (American Association of Variable Star Observers) keep tabs on the behavior of their peculiar targets. Variable stars, as the name suggests, change in brightness over time, and the AAVSO needs citizen scientists to help keep tabs on these changes.
The International Dark Sky Association also needs your help. Simply by helping them to catalog sky glow in your area, you can help them work to understand how light pollution has affected our view of the night skies, and also help the affect change in the future.
Finally, you might help the fine folks over at Galaxy Zoo try to classify galaxies. Human brains work better at certain things (such as galaxy classification) than
our robot overlords computers. This can be a fun game that you play by yourself, or even get your kids involved! I recommend looking up the story of Hanny and the Mystery of the Voorwerp to read a fascinating tale of a schoolteacher who discovered an entirely new class of cosmic objects simply by checking out pictures on Galaxy Zoo.
****Update 2/22/12: Nurdee has suggested another great site I overlooked: Zooniverse! There are a variety of projects you can help out with here, from studying how galaxies merge, to helping to find more targets for the probe that'll be shooting by Pluto in 2015.
Step 13: Web Resources
I've covered most of these resources on previous steps, but here they all are plus a few extras to help you on your quest to become an amateur astronomer. Special thanks to google and wikipedia for most of the sources I used in writing this instructable!
General information and pictures
Astronomy Picture of the Day
Astronomy news, podcasts and blogs
Calendars, star charts, and other info
Astronomy Weather Forecasts <------ THIS IS REALLY USEFUL!
Tracking the ISS
Daily Sun, Moon, and Planet set and rise times
This Week's Sky at a Glance
Helping the Professionals
Step 14: Final Thoughts
Thanks as always for reading! I hope I have inspired you to consider taking up astronomy as a hobby, or a the very least, look up and better understand what you see.
Please take a moment to rate, subscribe, comment and vote! I love reader feedback and would be quite interested to know what you think of this one. All the photos, including the moonshots, were taken with my cheapy kodak, which is going to be an instructable in its own right one day. When I finish it.
Remember, if you can think of anything I should add to this guide, leave a comment below--if I use it, I'll send you a DIY patch. If I think it requires a major overhaul or rewrite, I'll also send you a coupon for a three month pro membership. Since I'm from the northern hemisphere and only see the northern sky, if you're reading this from a southern hemisphere perspective, I encourage you to write a supplementary southern hemisphere version of this instructable. If it's up to my (arbitrary) standards I will link to it here and send you a coupon for a one year pro membership!
Please make sure to vote for me in the space contest, I'd really love to get my hands on that first prize telescope!
Most importantly, step outside tonight and look up!
Runner Up in the
Celestron Space Challenge
sandeep yadav made it!