Spread the joy of astronomy with a Galileoscope

By Phil Plait | March 10, 2009 9:18 am

400 years ago this year, people first started turning the newly invented telescope to the sky, and were astonished at what they saw. Galileo, not a fool when it came to self-promotion (though he stumbled a bit later in life), drew up what he saw and published it… starting a revolution in not just astronomy but in all of science, all of humanity. The aftershocks still reverberate today.

His telescope was crude by today’s standards; lens making wasn’t nearly the craft then that it is now. But it was enough to see craters on the Moon, satellites of Jupiter, the phases of Venus, and Saturn’s rings. And now, thanks to the International Year of Astronomy, you can experience what Galileo did and, even cooler, share it with others.


One of the Cornerstone projects of IYA 2009 is the creation of the Galileoscope, a replica of what Galileo used to view the heavens. This little ‘scope sports a glass 50mm (2 inch) lens, tough plastic casing, eyepiece, and a Barlow lens which doubles the magnification. Its construction is extremely simple, so a small child can assemble it in minutes with a little help from a grown-up. I saw one recently, and I was very impressed. It was well-built and quite functional. You can see images of it in action on the Galileoscope site.

The most incredible thing about this ‘scope is the price: you can buy one for just $15! The overriding goal of this project was to make the telescopes as cheaply as possible, so that they could be bought and sent around the world, fulfilling my very favorite goal of IYA 2009: getting everyone who is physically capable of it to observe the heavens.

To make that even easier, the people behind the Galileoscope project have set it up so that you can donate a telescope anonymously for only $12.50. When you do this, some organization somewhere in the world will get a ‘scope. It may be a school in Africa, or Viet Nam, or America, or in England. But some group that needs it will get your gift.

Before writing this post, I bought three: one donated anonymously, one for me to play for a night or two and then give to The Little Astronomer’s school, and one for you. That’s right, when they get here, I will be giving one away on the blog. I’ll announce it when I do.

But in the meantime, why not check out the Galileoscope page. If you’re a teacher, especially a science or history teacher, one of these will really bring the classroom alive. And whoever you are, why not donate one to someone, somewhere on Earth? We all deserve the sky, I think, and a gift like this literally delivers to the heavens to someone who needs it.

CATEGORIZED UNDER: Astronomy, Cool stuff, IYA

Comments (85)

  1. The fact that it has plastic parts kind of detracts from the Galileo mystique. How much would it cost for an actual replica?

  2. Romeo, it would cost a lot. The idea here was to make them cheaply enough that literally a million of them could be made and sent around the world. They struggled heroically to keep the costs down. $15 is amazing.

  3. i ordered one a couple of weeks ago and i’ve been in suspense. i’m told they ship in april.

    i’m hoping i can mount a camera on it… somehow…

  4. I have sent a quote request one week ago for an initial kit of 150 units, using their Form, and still haven’t received a single answer from them.

    I emailed back and now I’m waiting again. I really hope to have a prompt answer soon.

    :: sighs ::

  5. Phil, if you find Deathscope useful, you may also like Galileobuzz: http://pipes.yahoo.com/amoroso/galileobuzz

  6. Bryan

    I’m pleased that it uses the standard 1 1/4″ eyepiece.

  7. I hope the experience these telescopes provide is a good one. There is always the fear that a cheap, low-powered scope without a proper mount will do more harm than good. I can remember hours of frustration spent trying to use an inexpensive “Comet Kahoutek” scope in the 1970s. It very nearly killed my budding interest in astronomy.

    But if this item is all the good doctor makes it out to be, and they truly can be delivered so cheaply, more power (light gathering?) to them!


    Phil Plait: “It’s construction is extremely simple…”

    That should be: Its construction is extremely simple…


  9. What a neat idea! Thanks for the info, which I will (of course) plagiarize shamelessly over at Hot Chicks.

  10. Yuk Lau

    If you go to the Galileoscope website, they have a video of it being taken apart and put back together. It is really slick.

    I like how simple it is, and accessible.

    Now, if they’ll only they had a reflector telescope like that!

  11. Bryan

    From the specs:

    The Galileoscope’s 50-mm f/10 objective lens is an achromat made from two types of glass. The 20-mm (25x) eyepiece employs two achromats — a total of four lenses — made from two types of plastic. This four-element configuration is similar to that of the popular Plössl eyepiece, a high-quality design rarely seen on any telescope costing less than $100.

    So the main lens is a good achromat in glass, but the eyepieces are plastic.

  12. MarkW

    Including delivery, it’s $29.20 to the UK, which is just over twenty quid. Get in!

  13. Adrian Lopez

    “There is always the fear that a cheap, low-powered scope without a proper mount will do more harm than good. I can remember hours of frustration spent trying to use an inexpensive ‘Comet Kahoutek’ scope in the 1970s.”

    One of the goals of the people behind the Galileoscope is to make a cheap telescope that’s good enough to inspire rather than frustrate beginners. The Galileoscope site itself explains its attitude toward existing cheap scopes:

    “As a first step in the Galileoscope project, we canvassed the marketplace for existing low-cost telescope kits and preassembled telescopes, many of which are marketed as toys. We found dozens of different models from various suppliers and obtained samples of each for evaluation. Most of them had problems like these:

    * Insufficient magnification for astronomical use (for example, 3x)
    * False color and other optical aberrations
    * Small or stopped-down aperture produces dim images
    * Very narrow fields of view (<1°)
    * Unstable mount, no mount, or no way to attach it to a mount
    * Poor, missing, or ambiguous assembly instructions

    Accordingly, we set about to design a new telescope kit from scratch, one that would redefine the small educational telescope and include features usually seen only on commercial instruments costing 10 times more, such as achromatic lenses, aggressive stray-light control, and a 1¼-inch focuser. We believe we've succeeded! The Galileoscope enables kids of all ages to build and observe with a telescope similar to (but much better than) Galileo's. Sharing these observations with as many people as possible, and encouraging parents, teachers, students, and others to think about their importance, addresses one of the main goals of IYA2009: Promote widespread access to new knowledge and observing experiences."

  14. DagNAPpit. I hate the it’s/its thing. I swear I know the difference, but my fingers just go and do what they want. Arg.

  15. I really think it’s much better to start off with 7×50 or 10×50 binoculars (which you can get for about 30-40$). Not only is the optics far better, greater FoW also makes it easier to locate objects of interest and get a feel for how telescopes work. Besides, if you live in parts of world where people live with ~$1/day, $15 is still way to much.

  16. roy

    The shipping charge is almost as much as the telescope. Anyone know if a major retailer will be carrying these?

  17. Cool! Phil, is this something that a just-getting-started amateur (like me) could use in lieu of, or alongside, binoculars? Or is it a just-for-kids thing? I might buy 2 – one for me and one for the world.

  18. W00t! Three on the way, one to me, 2 to whomever!

    Thanks, Phil, for the tip.

  19. BJN

    I think this a great idea, but this telescope isn’t a “replica” of Galileo’s telescopes. They’re similar in their simplicity and pay tribute to the great astronomer, but Galileoscopes don’t really resemble the originals even discounting the plastic material:


    From the specs, the Galileoscope is quite a bit better than the great astronomer’s primitive tools. I don’t see anywhere on the organization’s website where they suggest the Galileoscopes are replicas.

  20. The Mad LOLScientist, FCD

    Galileoscope FTW! I ordered mine last week. Just wish I could afford to donate a few. =^..^=

  21. dziban

    So how much are they paying you for the advertising, Phil?

  22. What a great program! I just donated 8. :-)

  23. BlackBolt

    They won’t accept a perfectly valid euro Mastercard for some reason :(

  24. knobody

    cool. now i won’t have to feel guilty for not digging my childhood telescope out for the yutes. too bad it won’t be ready in time for wednesday night’s launch (taking the 7 year old).

  25. I’m going to order one for my kids (and myself), but I’d love to hear what the “step up” from this recommendation would be (and maybe the step above that?). I’m hoping to get my kids involved (the 5 and 11 year old boys, and eventually the 3 year old daughter) and just don’t want to buy too much or too little.

    Is this above/below the $40 binocular options? Is there anything in the $60-$150 range that would be worthwhile? Is my google mojo not working to find a “Bad Astronomy Guide to Getting Started in Amateur Astronomy” post?

  26. I totally understand what you are saying 3v1l5w1n, however, this is also a connection to a bit of history. You can look at the starts (and other celestial objects) under the same type of conditions the first astronemers equiped with optics were able to do. THAT is really the purpose of this I would think.

    I know that I plan to get some for my daughter’s school as well as for her. Thanks for the write up Dr. Plait, great program. :)

  27. Yes, I am glad someone noted the fact that the objective is a glass achromat. The eyepiece lenses are plastic, but very good.

    Another feature which hasn’t been mentioned yet is that you can remove the eypiece lenses and use the Barlow, a diverging lens, as the eyepiece. This configuration is a 18x Galielean telescope. Galileo used a diverging lens for an eyepeice. A Galilean telescope is not an ideal configuration to say the least as it produces a dim image and you have to move your eye around to see the entire image. You can experience what Galileo had to deal with in making his observations!

    I have one of the prototypes and was observing with it last night. Even at 25x, the rings of Saturn are surprisingly obvious (which I was surprised at given the low magnification and the fact that they are near edge on…small, but obvious). Titan was also an easy target. I slapped a webcam on the back and made a short video of the Moon. You can find my video on my blog at http://halfastro.wordpress.com/2009/03/10/300/

    Another (more skilled) observer in Norway also made a short video of the Moon with the Galileoscope you can find at http://www.youtube.com/watch?v=GU47zpattVI (and he had the advantage of getting the Moon near first quarter instead of a day before full!) You can see a video of Doug Isbell (US Single Point of Contact or SPOC for the IYA) talking about the Galileoscope and showing you the insides at http://www.youtube.com/watch?v=qc9Po2roJBE

  28. Shipping to .de $19.90 for two scopes … *grmbl*

    Well, i’ll think twice …

  29. nowoo

    I ordered one for myself, one to give to my friends who have three small children, and donated two more at the same time. I can’t wait until they arrive so I can show it to the kids.

  30. Supernova

    Oooh! Oooh! Maybe I can have the students in my freshman astronomy seminar next fall each buy one! SO COOL.

  31. My 13 year-old daughter made a Galileo-style telescope from scratch – cardboard tubes, scavenged lenses, and some great old looking decorations that mimic what pictures she could find in books. She used it to house a scroll which was her school project on the life and legacy of Galileo.

    Much more inspiring and educational than a plastic, not-really-a-replica, replica, don’t you think?

    I would have suggested, as an educational alternative, a kit which provided the lens and eyepiece only, with instructions on how to build the telescope out of commonly available materials.

  32. I’m in agreement with 3v1l5w1n. My first ‘telescope’, back in the late 1960s when was a snotty 6 year old, was a cheap plastic lens job from the local market stall, which suffered badly from chromatic aberration. It wasn’t until I had got a pair of 20 × 50 binoculars for my seventh birthday that I had began to appreciate astronomy fully — even in London, UK; light pollution wasn’t as bad then as it is now.

    Sir Patrick Moore often states, on his Sky At Night TV programme, that the best way to get started in astronomy is to use a pair of 10 × 50 binoculars, as mentioned by 3v1l5w1n. Also, Sir Patrick Moore often stresses the point: Never look directly at the Sun!

    Of course, Phil, I understand that the point of the replica Galileoscope is to promote astronomy to the masses, especially to those who would otherwise miss out because they can’t afford a real telescope, but if it suffers badly from chromatic aberration, it will likely put budding astronomers off the hobby, as pointed out above by kuhnigget — I remember Comet Kohoutek (click on my name), but I’m not familiar with Comet “kahoutek” :-) .

  33. I must have misread the original article; I thought the objective was plastic. my apologies, and that’s been fixed.

  34. Some of you seem to be missing the entire point of this article: to get inexpensive working telescopes into the hands of people who would otherwise never get that chance. Binoculars would be great, but they cost at least three as much. This whole Galileoscope setup takes care of everything for you, and the ‘scopes are actually decent quality.

  35. Torbjörn Larsson, OM

    This is awesome.

    Wonder if someone has come up with something similar to demonstrate evolution for the current Darwin Year, or if not why not? Presumably you could have at least a genetic algorithm simplified model of population evolution on some site.

    [I know there are youtube shows of such, and at least Panda’s Thumb have recently released a cool and really, really fast (javascript) graphic model of fixation of genes on their site. But this should be something that children can mess with and see the result in simple to understand graphics.]

  36. Sir Eccles

    I have just gived and got.

    Does anyone know if this can be claimed as a charitable donation tax deduction in the US?

  37. Sir Eccles it says the donation isn’t tax deductible (unless you give 100+ and even then you need to contact them) on the website under “Donate!”.

  38. @ Adrian Lopez and Dr. BA:

    Good on ya! Let’s hope they do the trick and get some yungins looking up.

    BTW, I bet if you duck-taped a wee mirror to the end, and fiddled with the eyepiece like so, you could make a handy device for peeking up someone’s….errrr….never mind.

  39. IVAN3MAN

    Phil Plait:

    This whole Galileoscope setup takes care of everything for you, and the ’scopes are actually decent quality.

    O.K., Phil, if you say so!

  40. Todd W.

    It would be nice if they had pics taken with the scope, rather than just simulations using Starry Night.

  41. KC

    >The fact that it has plastic parts kind of detracts from the Galileo mystique.

    You can make one fairly easily yourself, but someone was advertising a Galileo replica made of wood. The price was in the thousands of dollars! I’ll stick with the plastic one thanks!

  42. I have some bills to take care of first then I’m going to be ordering, doing the get one give on option. I have a nice big fancy scope already but this will be a fun one to use with my younger cousins (and eventually my first little niece or nephew that will be born in a the fall) or to keep in the car. Maybe loan it to my mom to use in her classroom too.

  43. lacalaca

    “There is always the fear that a cheap, low-powered scope without a proper mount will do more harm than good.”

    A short story regarding the topic. In Hungary, back in the ol’ socialist days, it was almost impossible to buy a manufactured telescope (no trade, no spending power). So everybody built his telescopes at home, with various results. The motto of that time was “to give everybody the Galilei-experience”, e.g. make people build minimalistic telescopes from cardboard or plastic tubes, some sort of optical elements like spectacles, whatever. As you could guess, not everybody was satisfied with the result, so the nickname of these “instruments” became walnut-beaters, suggesting their new use, as a stick to beat walnuts off the tree.

    As amateur astronomers do exist nowadays here (like Ladányi Tamás @ TWAN), a telescope with achromatic lens and a sufficiently strong tube will not be a great harm for the US community. 😀

  44. DPSisler

    10 donated – for a worthy cause. Hopefully, they can keep up with the requests!

  45. dre

    I can’t believe some commenters are griping about this thing. I ordered one last week about one minute after I read about it – jumped straight from some skywatching website to the order page. Just now I actually pulled up the specs and photos of the ‘scope in use… holy smokes! It’s, like, a real telescope! I thought I ordered a pirate-style spyglass, and I was happy to be buying a simple, decent-quality spyglass for $15. Now I realize I’m getting a real telescope… and some folks complain. Oh well.

  46. IVAN3MAN on the specs page they at least address
    “The Galileoscope’s 50-mm f/10 objective lens is an achromat made from two types of glass. The 20-mm (25x) eyepiece employs two achromats — a total of four lenses — made from two types of plastic. This four-element configuration is similar to that of the popular Plössl eyepiece, a high-quality design rarely seen on any telescope costing less than $100.”
    in an effort to cut back on chromatic aberration.

    Todd W:
    They bury it in the downloads page, but do have a picture taken through one:

  47. Davidlpf

    Ordered a couple for me and my nieces.

  48. Bryan

    Again, from the specs:

    “All parts except the lenses (of course) and mounting nut are black. The tube halves fit together with tongues and grooves to prevent light from seeping in through the sides, and the main tube includes multiple internal baffles. In addition, the insides of the telescope and focuser tubes are roughened to minimize internal reflections. These features, designed to reduce glare and the amount of stray light reaching the eyepiece, make the Galileoscope an ideal urban telescope for use in even the most light-polluted cities.”

    This looks to be far from the run-of-the-mill cheap ‘scope. Internal baffles alone puts this above the crowd. I’m so happy that someone has put the effort into making a decent and affordable telescope.

    And for those of you complaining about chromatic abberation: my glasses have chromatic abberation as well, and I’m sure not going to get rid of them!

  49. @ dre and Bryan:

    I can’t believe some commenters are griping about this thing.

    But…but…that’s what we do!!!

  50. Davidlpf

    And fight, ahh discuss yes that it discuss things till death.

  51. Cheyenne

    Been meaning to buy one of my own telescopes for awhile now and haven’t gotten around to it. As soon as I get home I’m buying one of these puppies (they should link in through Amazon by the way- I would have bought mine already).

    This sounds like a great little intro telescope. Can’t wait to check out Jupiter and the moon with my own eyes. Probably have to figure out a mount though.

  52. IVAN3MAN

    We BA-Bloggees are a skeptical lot.

  53. IVAN3MAN

    @ CharlesP,

    Yes, I have seen the specifications of the Galileoscope. Thanks, anyway.

  54. See my previous comment…I have multiple videos I have taken through the Galileoscope on my website and linked to one someone took in Norway through the Galileoscope. I might try some more imaging tonight if it is clear and will post it if I get anything worthwhile.

    Chromatic aberration not a major issue. The objective is an well designed achromat and, even with the barlow, you only get up to 50x. The eyepiece has decent correction so at these magnifications, you are doing pretty well.

  55. John

    As a kid, I was really into astronomy. My parents bought me a telescope for Christmas, and I remember using it mostly to look at the moon. It looked pretty great, but the ‘scope had a really wobbly mount, and I lacked the patience to find other, more difficult to see bodies, so I never really put the thing through its paces.

    I’ve wanted to get back into amateur astronomy, and this looks like the perfect opportunity.

  56. Nice stuff, thanks for contribution

  57. Sir Eccles

    Thanks CharlesP, I was meant to be working at the time so didn’t read the whole site. Still, at least someone somewhere is getting my donated scope.

  58. Ray

    This is pretty neat. Should make for a cheap spotting scope for those 1,000 yard shots down at the range.

  59. I ordered a few to get, and a few to give. While I doubt these little telescopes will rival a TeleVue, I do expect they’ll far exceed department store telescopes. I remember my first telescope, a 50 or 60 mm Tasco that claimed 150x magnification. That Tasco was not achromatic.

    So, while these won’t rival the APO Televue (or any APO, for that matter), they will still work nicely for the moon, planets and the brighter open clusters (oh, say, the Pleiades). For $15.00 US – even toy telescopes cost more than that (OK, add in the cost of the shipping, too – but still a good deal, I think).


  60. Got one, gave one. How could I not, with that pitch?

  61. Darn it. Another cool toy I won’t find at the local shops. And if I buy it online, I’d pay $23 for the shipping, and probably shell out another $15 for tariffs and importation dues. Then this toy doesn’t sound so cheap anymore. :(

  62. Nik

    Telescopes, brilliant!
    Doubt it’ll still be $15 when it’ll have to be shipped to the other end of the planet. But I sure can donate at least one.

  63. Craig

    This is very, very cool.

    (despite the shipping charge to Australia pretty much doubling the price, I still reckon it’s worth it)

    They do seem to have some issues with their ordering system, though. I’ve been trying to do a “give one, get one” buy all day, but it’s rejecting my credit card for no apparent reason.

    I’ve sent ’em an email; hopefully they’ll sort it out soon.

  64. Cher

    I wish there was a way to negotiate on the shipping. I think that 18.40 for shipping is outrageous. Couldn’t they just send it parcel post?

  65. Frak! I made my own Galileoscope last year to use at my talks, and costed me much much more in Argentina! Now I will buy one of these, thank for the link, Phil.
    (See it’s construction if you wish: http://picasaweb.google.es/g.abramson/TelescopioDeGalileo#)

  66. nice stuff on astronomy updates, thanks for Golileoscope thing

  67. Whether the final design is worth the $15 plus shipping (which is, as noted, about the same amount again for European orders) remains to be seen – when independent reviews are finally in which also address not only the optical quality (which seems to be impressive) but also the at least as important question of finding and tracking objects with the telescope, without a proper mount and by lay people.

    In any case the final price of $15 is 5 to 10 times (!) as much as what the Galileoscope was once (i.e. even in late 2007) planned to cost: It had been planned to be a cheap but good instrument of which millions would be built and put in the hands of everyone who came an IYA event. This turned out to be completely unrealistic by last spring, and the final product is a very different beast, geared primarily towards school use.

  68. Leon

    Hey, that’s great!

    It’s almost pointless for me though; my little refractor’s aperture is less that twice as big…

  69. Ron

    I ordered two… One I will give away to someone in my astronomy club. I’m looking forward to repeating some of Galileo’s observations. I currently have been repeating some of his observations like tracking comet Lulin and observing the phases of Venus with my 10X70 bino’s. It’s just too bad that these scope kits couldn’t be shipped prior to the 100 hours of astronomy!

  70. Craig

    Update: they finally seem to have sorted out their credit card issues. I just put my “give one, get one” order through…

  71. WR

    Well, the planed “Galileoscope” turned out to actually be a “Saturnscope”.
    Good for general education purposes, but far more advanced than anything
    Galileo ever had the chance to look through.

    The Kepler telescope design was announced (1611) just some month after the
    first Galileo telescope design scopes were used. The first one was built
    by Scheiner already around 1613. But it took them an other 35 to 45 years
    before it superseded the Galileo telescope design. The first basic achroma-
    tic lenses (that are partially still used this way today) came up in about
    1758 (Dollond, crown glas first) and about 1865 (Steinheil, flint glass

    The first multi-lens, partially achromatic eyepiece, minimizing spherical
    aberrations too (Hygens, two plano-convex lenses) were built in 1703. But
    the first symetrical (two identical achromatic doublets) and Ploessel-like
    (two non-identical achromatic doublets) eyepieces were designed not before
    1860. It took them nearly an other 100 years before

    So the actual optical designs used for this “Galileoscope” are “just”
    around 150 years old. If one is more generous, one could consider them
    also being “optimizations” of designs introdouced around 250 to 300 years
    ago. But for sure not as “Galilean” as he was already long dead by then.
    So any comment regarding Galileo in connection with this scope are IMO
    not really appropriate and calling them “Galileoscope” is IMO just PR to
    market this simple and inexpensive refractor in the IYA2009.

  72. Thomas Wentzel

    For 1st World countries, a solution without a problem. Binoculars with better optics than this can be easily had for less money. I just bought a pair of 10×50 last week for 7USD. For the rest of the world, a fantastic product. Donate today, the Astronomer you inspire will discover wonders.

  73. AstroKnot

    Anyone had any problems ordering? My brother ordered one for me using Mastercard but he received an error upon check out. The bad thing is that the transaction was reflected on his credit card but he did not get any confirmation e-mail. I’ve e-mailed them a couple of times but I still haven’t received any replies.

  74. To mark the International Year of Astronomy in the Philippines, my students and I have improvised several refractors using mainly bamboo, and clear glass marbles for eyepieces and donated them to poor schools in the rural areas. I wrote about it in a book I published recently:

    This Galileoscope came in a bit late. I ordered one just tonight to test it. I can’t wait to try it out; I guess I’ll get my order by July.

  75. who can please donate to me a telescope. thank you


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