First seen by Galileo Galilei in January 1610, and recognized by him as moons of Jupiter in March 1610. They are the first objects found to orbit another planet.
Europa is the smallest of those four Galilean moons. These include Ganymede, the largest moon in the Solar System, bigger than the planet Mercury. Callisto is the third largest in the solar system, after Saturn’s moon Titan. IO is the fourth largest in the solar system, closest to Jupiter. With 400 volcanoes, its the most geologically active body in the solar system.
Europa, second closest to Jupiter, is slightly smaller than Earth’s moon, and one of the most smoothest objects in the solar system.
It’s thought to harbour a global ocean 100 Km thick. That’s twice as much water than on Earth. It’s covered with ice 25 KM thick. The surface ice has cracked like an eggshell all around the surface. This was caused by the tidal forces from Jupiter being so close. The smoothness and youth of the surface is what has given rise to the hypothesis that there is a liquid ocean under the surface.
Here on Earth we have found life in the oddest places, but deep in the ocean, where there isn’t any sunlight, life thrives near hydrothermal vents.
These vents are mostly found in areas where there is volcanic activity, moving tectonic plates, and hotspots, like Hawaii and Yellowstone national park.
On Earth, these vents look like geysers on the surface, hot springs produced by geothermally heated hot water.
Traditionally, life on Earth is believed to be driven by the Sun’s energy. But, deep down in the ocean, where there is no Sun, how would this be possible? Well, there is a way. All the life stuff from the surface of the Earth eventually rains down to the ocean floor, and does provide energy for life to survive.
However, the organism density around hydrothermal vents is 10 thousand to 100 thousand times greater than the surrounding areas.
Large amounts of creatures that live near the vents eat chemosynthetic bacteria. The water from the vents is rich in dissolved minerals that just happens to support large populations of the bacteria. No Sun required…
These bacteria also consume hydrogen sulfide, which is highly toxic to people, but produce organically friendly stuff through a process called chemosynthesis.
The ecosystem is dependant on the energy produced by the hydrothermal vents, not the Sun.
Another question comes up. How did life on Earth begin? Was it from a primordial soup on the surface? Or, did it originate near deep ocean hydrothermal vents?
There’s another factor. Where did life in any form, begin? If you are Earth centric, than life began here, on Earth.
If you study deep space however, you realize that the Universe is an unimaginably big place.
Just like we learned through astronomy that the Earth was not the center of the Universe, odds are good that we will discover that the Earth is not the center of all life in the Universe either.
Life can be transported from one planet to another, no space ship required.
All that needs to happen is for a big space rock to smash into a planet and send life along with debris into outer space, until it eventually makes contact with another planet ready to support life.
A giant icy egg shell shielding a salty ocean mantle fed by a heated yolk. Sure looks like the beginning of life when put that way doesn’t it?
But how can we know for sure? We have to go there, send a robotic mission to Europa.
What would our mission be? Get into orbit, good luck with that with mighty Jupiter tugging away, but still possible.
Land on Europa, but with what? And, how many landers? What are their capabilities?
The ultimate objective is to roam Europa’s ocean, send a feed back to Earth, of extraterrestrial life, proof that we are not alone.
That’s the mission!
NASA is just beginning to socialize the idea. Their plan isto send a spacecraft to Europa for the purpose of determining if it is habitable.
It’s called the Europa Clipper. If fully funded, it will launch in five years. It will also have a lander that will dig into the ice to analyze samples for evidence of life.
Is there life on Europa? Here on Earth, everywhere there is water, there is life.
Earth is 4.5 billion years old. The earliest evidence of life go back 4.1 billion years. Where did it come from? It could have originated on Earth itself, or like everything else on Earth, it came from space.
Life happened on Earth during the time of late heavy bombardment, where there was an unusually high spike in asteroids hitting the Earth.
There was life on Earth before there was oxygen in the atmosphere, but the water was there already. Oxygen, produced by cyanobacteria, didn’t appear until 3.5 billion years ago.
The theory of life seeded from space isn’t new, and doesn’t explain how life emerged to begin with, but it is plausible.
If the DNA of life on Europa is similar to the DNA on Earth, that would support that theory.
There may be life all over the solar system and beyond, just waiting to be discovered.
Someone just has to boldly seek it out.
Thank you for reading.
Cover image: NASA Hubble spots water plumes on Europa.