Do you want to explore the heavens? Learn about chemistry or biology? Delve into dinosaur fossils? There's an app for that ... and for that ... and for that as well. Chances are you wouldn't buy an electronic tablet just to study the solar system or the human body, but if you already have an iPad or are considering the new iPad 2, science-based apps can make in-depth learning as fun as playing a video game. Check out these apps for the iPad, and tell us about your own favorite educational apps for tablets or mobile devices (iPad, Android, Windows, BlackBerry, WebOS ... you name it).

Solar System (Touch Press, $14): So much has been learned about the solar system in the past couple of decades that it's no longer enough to memorize the names of eight (or nine) worlds. Thankfully, this app doesn't stop with the biggies, but goes on to include Pluto and Eris, Ceres and other dwarf planets, asteroids, Kuiper Belt objects ... all the objects we cover in our own "New Solar System" interactive, but with much greater depth. There's also an "orrery" that lets you zoom in on planets and give 'em a spin. Links to the Wolfram Alpha database give you basic stats on solar system objects, including where they are right now. It's not perfect — I'd love it if the software could work with the Web to plot the location of smaller objects. (For example, what's up with Apophis, and where will it be in 2029?) But all in all, it's a beautiful app that's well worth the price.

Exoplanet (Hanno Rein, free): What about new worlds beyond the solar system? The Exoplanet app for iPad, iPhone and iTouch shows you where the more than 500 detected exoplanets lie, and how their sizes and orbits compare. The software's tutorials explain how astronomers find distant planets, and you can set up notifications for every new discovery that's made. And you can't beat the price.

Star Walk (Vito Technology, $5 for iPad): Trace stars, planets and constellations in the night sky, and find out when and where to look for celestial objects as well as fast-moving satellites (including the International Space Station). The iPhone version costs $3 and includes an augmented-reality feature. Point the phone up into the sky to figure out what you're looking at.

The Elements (Touch Press, $14): This encyclopedia of the periodic table was produced by the same folks behind Solar System for iPad, and the touch-screen interface is similar. Beautiful photos show you the chemical elements in all their spinnable 3-D glory, plus the basic facts about each one — plus links to Wolfram Alpha for even more information.

Human Atlas HD (Blausen, $30): It's the priciest app on this list, but chock-full of videos and graphics that explain the workings of the human body. This app is designed to be used principally by physicians to help their patients understand what's ailing them, but it's also a boon to armchair anatomists (and, I suppose, hypochondriacs as well). Android, BlackBerry and iPhone versions of the atlas are somewhat less expensive ($20). 

3D Brain (CSHL, free): If it's neurons you're interested in, Cold Spring Harbor Laboratory has a free app for the iPad and iPhone that guides you through the human brain. It's a spinnable 3-D version of our own "Road Map to the Mind" interactive, but without the scary spider. There's also a Web version of 3D Brain. 

World Atlas HD (National Geographic, $2): The iPad already has maps, but every household should have a world atlas as well. It's hard to beat this price for an iPad atlas from the world's most respected geographers. And when you're connected to the Internet, you can zoom right down to street level.

Ultimate Dinopedia (National Geographic, $6): This kid-friendly app provides basic facts as well as videos, interactives and artwork covering more than 700 dinosaur species.

That's eight science-themed apps to start with, but there are plenty more in the online stores for all sorts of mobile devices. What are your favorites? Feel free to add your recommendations in the comment space below.

More iPad goodness:

• What you need to know about buying an iPad 2
• iPad 2 review: It's the tablet to beat
• 10 great games for your new (or old) iPad 

Join the Cosmic Log community by clicking the "like" button on our Facebook page or by following msnbc.com science editor Alan Boyle as b0yle on Twitter. To learn more about Alan Boyle's book on Pluto and the search for planets, check out the website for "The Case for Pluto."