Europa: Jupiter's Icy Moon

Last week's post was my most popular post yet! Folks seem very excited about visiting Peoria's Northmoor Observatory on clear Saturday nights this summer. The members of the Peoria Astronomical Society will be happy to have you. Just remember not to go if it is overcast or cloudy. 

When you visit Northmoor, don't go expecting to see images like the Hubble Space Telescope gives us. Those pictures are long exposure photographs with the best scientific instruments humans have ever made. You will see some nice zoomed-in images of the planets and the Moon, but not nebulae or galaxies. However, you can see Jupiter and four of its moons, looking something like this:
 

Jupiter and its four largest moons, often called the Galilean Moons. Image Credit: Paul on Flicker

The second moon from the left in the above image is Europa. Europa is one of the most fascinating worlds in the Solar System. It is covered with water ice. 

Click on image to view in high resolution. Europa is stunning in near true-color. The surface of this icy world is covered in cracks. Image Credit: NASA/JPL-Caltech/SETI Institute

The reason Europa is so intriguing is that the icy surface is covered in cracks. All the brown streaks you see in the above image are cracks in the ice, leading scientists to believe that there is a liquid ocean underneath. The water would probably be salty, similar to Earth's oceans. Europa might even have more water under its crust of ice than Earth does! 

This close-up image of Europa's crust shows broken ice, refrozen in a chaotic jigsaw puzzle. The colors in this image have been enhanced. Image Credit: NASA/JPL/University of Arizona

Why do we care that Europa has water? Well, Earth is the only place yet discovered in the Solar System with stable liquid water on its surface. It is also the only place yet discovered with any sort of life on it. The search for water elsewhere in the Solar System is the same as the search for life. This video has a great explanation of how we know there is water on Europa and why that is important:

As detailed in the video, life started in Earth's oceans. If there is a ocean on Europa, there very well could be some form of life hiding under the icy crust. Just imagine the possibilities!  

Deep ocean vents such as this black smoker are driven by geothermal energy. Life exists around these vents, where sunlight never penetrates. Scientists think vents like these could exist on Europa. Image Credit: Wikipedia Commons.

NASA allocated significant money in its 2016 budget to study mission possibilities to Europa. A proposed mission that is often discussed is the Europa Clipper. If funded, the Europa Clipper would perform 45 flybys of Europa as it orbited Jupiter. The possible payload of science instruments under consideration includes radar to penetrate the frozen crust and determine the thickness of the ice shell, an infrared spectrometer to investigate the composition of Europa's surface materials, a topographic camera for high-resolution imaging of surface features, and an ion and neutral mass spectrometer to analyze the moon's trace atmosphere during flybys.

The blocky cracks in the ice are where chunks of the surface probably broke off and floated to new positions. Image Credit: NASA/JPL/University of Arizona

Europa is an amazing world with tremendous potential for life - and you can see it as a small dot through a telescope! I am continually impressed with the ability of engineers and scientists to learn about these distant worlds. We live in amazing times. Yay science! 

To learn more about the worlds of the Solar System, come to the 3:00 show at the Dome Planetarium at the Peoria Riverfront Museum, Tour the Solar System. We use our incredible Uniview software - a digital database of the entire Universe - to fly you around where ever you would like to visit in the Solar System. Learn about our current shows here. Or join us for Pub Night Under the Stars, coming up next Friday, May 22!