Solar Impulse, the world's most advanced solar aircraft, is trekking across the United States. It's already made it from the Bay Area to Phoenix, Ariz. Check out photos from its U.S. flights, and read more about the all-solar plane's journey.

The Salton Sea was once California's biggest tourist attraction -- now, with some of the highest rates of unemployment in the country, it's the state's rustiest, dustiest failed region. With water usage in Southern California at a premium, the accidentally human-made sea is drying up, with its only significant inflow coming from nearby farm runoff. It's still vital wetlands for 400 species of migratory birds, but the sea is poised to evaporate into a 365-square-mile dust bowl right next to Palm Springs within just a few years. And while it may not be blowing airborne toxins all over southern California and Arizona just yet, it's already assaulting Los Angeles with its powerful poison "odor events," which scientists predict could only grow more intense. (You can read some background on the Salton Sea in my comic above, an excerpt from the [free!] December issue of Symbolia Magazine.)

Now for the first time in a while, politicians are actually sounding hopeful about mitigating the sea's degradation. (Sorry, disaster tourists.) “We have a united vision. For the first time, there’s a chance to make some progress,” says one local county supervisor. But they have very different ideas on how to do it.

One week ago, residents of rural Mayflower, Ark., found a river of reeking, black oil flowing through their backyards and streets. ExxonMobil, the company that owns the ruptured pipeline, evacuated the neighborhood and quickly instated something like martial law, evicting wildlife rescue workers, threatening reporters with arrest, and even winning a temporary no-fly zone over the spill. Here's what the company is hiding, care of the EPA's on-site coordinator web page -- which was locked down shortly after we retrieved these photos. (UPDATE: The page is unlocked again. Feel free to peruse the whole collection.)

Ever wonder who cooked up the idea of digging up all of Canada’s tar sands and piping them across the continent? All of your questions are answered here, in a single, cartoon-tastic slideshow.

Houses come in many shapes, but at Grist, we sure do love 'em tiny. The reasons are obvious: Beyond being just. so. darn. adorable, they promote sustainable living, energy efficiency, and serious envy in your lame McMansion-owning neighbors. And they're hotter than Hansel, as both elite industrial designers and industrious teens alike have engineered marvels of mini to cater to every taste. Here are some of our recent favorites.

Humans might adapt to climate change through some mixture of mitigation, adaptation, and suffering (like relocating Coney Island several miles into interior Brooklyn, or saying goodbye to chocolate). But the animal kingdom? Many species are already coping with rising temperatures by physically getting smaller [$ub req].

The reasons are complex and vary between species, but the CliffsNotes version is this: Animals (especially cold-blooded ones) often develop faster metabolisms in warmer temperatures, so they burn calories more quickly and reach maturity at smaller sizes. Additionally, smaller animals could have a distinct advantage when competing for dwindling food supplies; like Anne Hathaway, they simply need less to survive. There's also Bergmann's rule, which basically amounts to "colder environments support species of larger morphological size BECAUSE I SAID SO."

As part of this month's Get Small theme, we're profiling minimizing mammals, reducing reptiles, itty-bitty insects, and belittled birds the best way we know how: with a bunch of pretty-ass pictures.

Green Thing encourages people to walk more, cut back on meat, buy less, turn down the thermostat, waste and fly less, and unplug vampire electronics. So every day until Earth Hour on March 23, the London-based nonprofit is publishing a poster to promote those green habits.

And some big designer names contributed to the project, including Google Creative Director Tom Uglow and London 2012 Olympics logo designer Patrick Cox. Green Thing knows "that a dig, joke, or nudge is way more effective than another weeping seal cub,” Cox said in a press release for the project. Follow the project on Green Thing.

Writer Steve Hawk and photographer Ami Vitale traveled to the mountains of West Virginia, small-town Michigan, and a reservation in Nevada to match human faces and stories with the cost of coal. The resulting photos and interviews appeared in Sierra, the Sierra Club's monthly magazine. We picked out some of our favorite shots (you can check out the full slideshows and interviews here).

We’ll be the first to admit that urbanism has become a parody of itself lately. (Dumpster garden, anyone?) But kudos to our fellow city denizens who have reclaimed parking spots for humankind on this annual celebration of street theater/ good-natured protest -- a.k.a. PARK(ing) Day. Here are a few the more creative reuses, gleaned from the interwebs.

Yesterday, we reported on the problem of toxic green algae in America's lakes. Today, we're following up with images from around the country. Want to learn more? Join Food Editor Twilight Greenaway on Thursday, Sept. 20, for a live Twitter chat about toxic algae at 1:00 EST, with hashtag #greenslime. (Photos and text compiled by Resource Media.)