Reading & Watching to Learn

Read the short article NOAA article "Are there Oceans on Other Worlds?" and the linked articles listed below:

You may view these materials EITHER by clicking through the links provided above OR by scrolling through this Canvas page.

As you view, you are encouraged to describe the conditions necessary for a planet to support a stable ocean and discuss the presence or absence of oceans on other worlds.

So get out your pen and paper and get ready to take notes as you read!

Are there Oceans on Other Worlds?

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

IMAGE CAPTION: 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. (Image Credit: NASA/JPL/Ted Stryk).

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.

Evidence points to water on other planets in our solar system. In 2015, NASA confirmed that liquid water flows intermittently on present-day Mars. Also in 2015, scientists used data from NASA's Cassini mission to discover that a global ocean lies beneath the icy crust of Saturn's moon Enceladus. Scientists believe that Jupiter's moon Europa has a subsurface ocean as well.

Finding liquid water beyond our solar system may indicate the existence of extraterrestrial life. Using data collected by NASA's Kepler spacecraft and the W.M. Keck Observatory, scientists have determined that 22 percent of solar-type stars in our galaxy have Earth-sized planets in their habitable zone and could host life. Some of these planets are a mere 12 light years away and can be seen with the naked eye in the night's sky.

In the next section, we will begin to explore the history of the Earth. Let's get ready to go back in time!