As spring hits its stride, we can all look forward to shedding our coats to enjoy the sunshine and fresh air. And what better way to take advantage of the great outdoors than with an afternoon of DIY tinkering? These 10 projects are simple enough for kids to help out with, or even try on their own. (We also threw in a bonus eleventh idea that’s a little more complex.) Science geeks can even use some of these projects as jumping-off points to discuss concepts like solar energy and microbes.

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Portable garden

As plants come back to life after the cold winter, green thumbs may begin to itch. But not every home has enough room for a garden plot. Luckily, would-be gardeners can turn to another option: a DIY portable garden. It’s small enough to fit in a corner, and light enough to bring with you on a road trip.

Stay Dry

Photographs of the Rainworks sidewalk art created by Peregrine Church

Solar oven

The sun’s rays don’t just warm your skin. You can collect solar energy in an insulated cardboard “oven” that can get hotter than 200°F. At that temperature, food will take a while to cook, but you can bask in the knowledge that it’s cooking with science. At the same time, the DIY solar oven can get hot enough to singe little fingers, so make sure to take safety precautions.

Bacterial zoo in a bottle

Mud isn’t just fun to splash around in—it also plays host to a variety of bacterial species. A Winogradsky column—sort of like a vertical garden for microbes—lets you nourish those microbial communities until they become visible to the naked eye. You don’t need to be a scientist to build a bacterial zoo. You can make your own Winogradsky column from a clear plastic bottle, mud, and a few other readily available ingredients.

Wiffle ball cannon

The outdoor game of Wiffle ball is a classic, and for good reason. But it could use a little update. Why not turn the competition up a notch? This Wiffle-ball cannon harnesses a leaf blower’s power to hurl light plastic projectiles (or water balloons) at up to 50 miles an hour.
A homemade stinkbug trap
A half-ring vortex in a swimming pool

A sextant made from junk

Provided you live in an area with minimal light pollution, the outdoors are just as magnificent at night as they are during daylight hours. Before you go out to look at the stars, hack together a simple sextant from supplies you have sitting around your house. It won’t rival Google Maps, but even a bare-bones sextant like this one can demonstrate how people had to navigate in ye olden dayes.

DIY eye in the sky

A birds-eye view of the ground lets you size up a situation and attack your enemies effectively. Without a satellite or drone to provide this context, MacGyver rigs up a rudimentary hot-air balloon. First, he uses a wire hanger to suspend an aluminum-foil platform from a dry cleaning bag. Below the platform, he attaches a cell phone that live-streams video of the ground below, and on top, he places a can of Sterno. When he lights the flame, the bag fills with hot air and starts floating, letting the phone serve as an airborne surveillance camera. There’s just one problem. Hot air, while it will indeed rise higher than cold air, cannot carry much weight—a cell phone and a can of fuel would drag it to the ground. “That’s one of those where conceptually it’s a valid idea,” Allain notes, “but in practice it would be stretching it.” Instead of Mac’s design, try building the fire balloon created by Popular Science contributor William Gurstelle and pictured in the above photo. It too involves a dry cleaning bag filled with hot air, but heats the air with a light dab of jellied alcohol instead of a can of Sterno. Just remember to follow the safety precautions Gurstelle suggests, and tether your fire-bearing balloon to the ground.

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