Earth is the only known planet to have bodies of liquid water on its surface.

Europa is thought to have subsurface liquid water. Scientists hypothesize that Europa’s hidden ocean is salty, tidal, and causes its ice surface to move, resulting in large fractures which are clearly visible in the above image. Although Europa is thought to have the ingredients needed to support life — water, energy, organic compounds — it lies outside of our solar system’s habitable zone.

Currently, Earth is the only known planet (or moon) to have consistent, stable bodies of liquid water on its surface. In our solar system, Earth orbits around the sun in an area called the habitable zone. The temperature, along with an ample amount of atmospheric pressure within this zone, allows water to be liquid for long periods of time. Read more

Some people like to stick to the sand when they go to the beach. The ocean can harbor sewage-related fecal contamination and a random infectious bacteria infestation or two. But it turns out that those who stay beach-side are actually making the more disgusting choice. New research shows that sand can be even more contaminated than ocean water.

Chemists from the University of Hawaii recently learned that levels of fecal bacteria in beach sand can be up to 100 times higher than in the water nearby. And, being scientists, they immediately set out to discover why. Their task was more daunting than they initially thought: a majority of studies on marine beach bacteria have taken place in water, not sand. Read more

For most people in the developed world, getting access to clean drinking water is as simple as turning on a tap. Would that paying for water were so simple. But when we think about the water we consume, few of us realise that as much as 80% of its cost is associated with electricity use – a figure that’s as high in Britain as in drought-prone California.

It is surprising, then, that the energy argument rarely features in discussions about preserving water. Yes, water is itself a valuable and vulnerable resource. But when we wash our clothes, have a shower or simply rinse a mug, we should also keep in mind that energy is going down the drain. Let’s talk about our water future alongside our energy future. Read more

If you’re the type of cruiser whose daytime entertainment needs to go beyond a dip in the pool, then you’ll want to take note of these five adrenaline-pumping water rides. Complete with twists, turns, drops — even some surprises! — these slides can add some excitement to your sea day, and make you feel like a kid again:

1. AquaDuck

Disney Dream and Disney Fantasy, Disney Cruise Line

Located on Deck 12, this water slide is dubbed an “aqua coaster” due to its roller coasterlike warren of twists and drops. As you ride through the 765-foot course, you can take in views high above the ocean until your single or double raft drops into the lazy river at the end. Read more

It might be Bryce Canyon National Park in Utah, or perhaps Colorado’s Garden of the Gods. The eerie landscape, tucked into the foothills of California’s Sierra Nevada, boasts spectacular topography. California park ranger Ken Huie flashes an ironic smile. “Isn’t nature wonderful?” he says jokingly.

In fact, the striking sculptures of Malakoff Diggins State Historic Park are not the handiwork of Mother Nature, but of her children. Dating back a mere 140 years, their haunting if hideous beauty testifies to an early case of environmental assault—but one in which the good guys finally won. Here was fought one of the first successful environmental lawsuits in U.S. history. Read more