For years, all of humankind has looked skyward towards the next frontier: space. For the most part, life would be terrible in space! Other galactic bodies such as: planets, moons, and asteroids rarely have habitable environments for life. Scientists have been finding some locations, other than Earth, that may be suitable to sustain life. These places have similar conditions that can be found on Earth such as temperature, water, sunlight, and oxygen. These conditions are known to be necessary for life to thrive.
Europa is a moon that was first discovered 400 years ago by Galileo Galilei. It is a moon that orbits Jupiter, which is the fifth planet from the Sun. Jupiter is more than twice as massive as all the other planets combined! Today, Europa is a useful location used in understanding the habitability of icy worlds. Europa is believed to be have internal salt-water oceans that may be within the spectrum of habitability. Evidence of these near surface bodies of water have been discovered by missions including: Galileo, Cassini, New Horizons, Juno and the Mars Reconnaissance Orbiter.
However, the surface of Europa is too cold for water to stay in its liquid form. However, the center of the planet is very warm and can melt the ice above, thus creating a subsurface ocean that covers the entire moon. This warm water then seeps up, heated from the planet’s mantle below, and breaks the surface ice into a jumble of large icebergs. The icebergs then flip, float and freeze in place. This is why the surface of Europa appears chaotic, with icebergs, cracks, and gigantic ice formations roughing over the would-be smooth surface of Europa.
Meanwhile back on Earth, Antarctica has over a hundred subsurface lakes much like Europa. One of these lakes, Lake Vostok, may be a possible home for exotic life on Earth and provides a location on Earth to do background research on these environments prior to scientists launching experiments over 600,000 kilometers through space. To prevent drilling fluid from reaching the lake water, scientists plug the bottom of the borehole with a fluid known as Freon, which does not react with water and does not affect the water samples. Pressure is released in the lake and then the lake water flows up the borehole, then freezing and forming an icy plug, protecting the water samples. The Freon is forced back up the drill as a way to protect the samples. If scientists were to find an abundant amount of life in Lake Vostok, they can form a realistic prediction that life will be present on Europa.
Figure one shows different forms of life that the drill found in the ice above the lake. This shows that there is a very good chance that there may be life in the lake. For example, scientists have found evidence of life such as bacteria and marine diatom, a group of algae, and one of the most common types of phytoplankton. Figure one also shows the three different layers that the drill passes through as it bores towards the bottom of the lake.
All of this science leads to one pretty exciting idea. Life on other planets! This could mean that we have neighbors waiting for us to pick them up on our next rover mission. This is a very complex experiment, but astrobiology is based on experiments and knowledge we gain here on Earth in order to accurately guess what the chances are that life is out there.
1. What layer of the ice did scientists find evidence of life: the ice sheet, the accreted ice, or the lake?
2. How do scientists insure that the drilling equipment would not contaminate the samples they take from Lake Vostok?
3. Based on figure one, what evidence of life has been found besides evidence of marine life and of bacteria?