How-To: Make a $20 spectrograph (from MAKE Volume 24)

Want to discover the chemical make-up of distant stars and planets? Use a spectroscope. It displays a little rainbow of visible-light spectrum that’s emitted
by a star (or reflected by a planet).

Each element in the periodic table has its own spectral signature — say, bright emission lines in the red band, or dark absorption lines in the green — so each element can be identified by its light alone.

MAKE Volume 24 shows you how to make a high-resolution spectroscope for $20 using common pipe and hardware. To turn it into a spectrograph that’ll reveal if you’re looking at a gas giant or a rocky planetoid, just team it with a digital camera and author Simon Quellen Field’s online spectrum analyzer (we show you that, too).

It’s one of a dozen cool DIY space projects in the new issue of MAKE.

Check out MAKE Volume 24:

MAKE blasts into orbit and beyond with our DIY SPACE issue. Put your own satellite in orbit, launch a stratosphere balloon probe, and analyze galaxies for $20 with an easy spectrograph! We talk to the rocket mavericks reinventing the space industry, and renegade NASA hackers making smartphone robots and Lego satellites. This, plus a full payload of other cool DIY projects, from a helium-balloon camera that’s better than Google Earth, to an electromagnetic levitator that shoots aluminum rings, and much more. MAKE Volume 24, on sale now.

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