An aerial view of Puerto Rico's Arecibo Observatory dish, featured in the 1997 movie "Contact" about extraterrestrial contact.H. Schweiker/WIYN and NOAO/AURA/NSF

Education isn't all about buying notebooks and sitting in stuffy classrooms. With a couple of hours of time a week and an Internet connection, anyone can make a substantial contribution to schooling about the universe, from Mars to M31. Members of the public have been published in academic journals and thanked in the media for their work -- and there also is the satisfaction of helping with science!

Read this slideshow for ways that you can involved. If we've missed anything, let us know in the comments below.

Back in 1999 -- the days when most houses were on dial-up -- the SETI@home project launched. The effort makes use of idle computer time to search for interesting signals that could be evidence of extraterrestrials. In more than 15 years of work, over three million people took part. No bogeys yet, but we all know that good science takes time. Here is how to participate.

MORE: The Hunt for Alien Intelligence is Going Infrared

Comet Hyakutake passes by the sun in this Solar and Heliospheric Observatory (SOHO) image in May 1996. The comet was discovered long before it passed by the sun, but many are discovered in SOHO images by amateurs. ESA/NASA/SOHO/GSFC

For nearly 20 years, there's been a venerable comet-discovering spacecraft that wasn't actually designed to search for comets. Called the Solar and Heliospheric Observatory, it just happens to be pointing in the right direction to see "sungrazers" pass by our closest star. Nearly 3,000 comets have been discovered to date, mostly by amateurs looking through pictures. Here's how to participate.

MORE: Ace Solar Observatory to Make 3,000th Comet Discovery

The Hubble Space Telescope is serviced by astronauts one last time by the STS-125 crew, in 2009.NASA

Hubble turned 25 this year and we have learned so much from its stargazing, including the real age of the universe and the (startling!) fact that the universe has an accelerating expansion. And there are a few citizen scientist projects that use its data, such as The Andromeda Project (which charts our future collision with this huge galaxy) and Star Date: M83 (which looks at the age of stars). Here's how to participate.

MORE: Hubble at 25: Space Telescope's Top Science Discoveries

Gale Crater on Mars (including the Curiosity landing ellipse, shown in yellow) is surrounded by other craters.NASA

Craters are everywhere in the solar system: on planets, on asteroids, on moons, and more. But it's hard to figure out just how old these craters are because the rate of collision can change depending on if there is an atmosphere -- and where the object is positioned. But you can help scientists figure this out through Cosmoquest on Mercury, the moon, Mars and asteroid Vesta. Here's how to participate.

MORE: How YOU Can Put YOUR Mark on the Cosmos

When galaxies nearly collide! NASA/ESA and The Hubble Heritage Team (STScI)

How did galaxies like our Milky Way come to be? What happens when galaxies crash into each other, or run out of gas? These are all questions that the greater astronomical community is trying to figure out. Getting there requires a lot of telescope time and comparing images. Zooniverse has many projects of this type, such as Disk Detectives or Galaxy Zoo. Here's how to participate.

MORE: Star Birth Watered-Down in Galaxies with Bars

A member of the public asked for this picture of the edge of Olympus Mons, and got it through the HiWish program. NASA/JPL-Caltech/University of Arizona

While NASA is a big organization, there's a lot of science to go around through it and partner organizations. Want to help pick out a picture on Mars? Try submitting a request through the HiWish program. You can also observe clouds to help monitor global weather, combat light pollution that is blotting out our skies, or even tag photos that are sent from Mars rovers. Here's how to participate.

PHOTOS: The Psychedelic Landscape of Mars

A variable star pops up in this iseries of images of the Andromeda Galaxy (M31) taken by the Hubble Space Telescope. NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

If you have more professional astronomy equipment, there's a place for you as well! You can monitor the brightness of variable stars to help astronomers better figure out the internal structure of these objects. Or you can watch for new craters on the moon and take pictures of planets in our solar system. The Planetary Society has a comprehensive list of astronomy-based citizen science groups where you can participate.