The orbit is nearly circular and the moon is tidally locked to Jupiter with only one side continuously facing Jupiter with an orbit of 3.5 days (Space.com, 2015). While only 1,900 miles in diameter, this moon is thought to have an iron core with a rocky mantle. The most important part is the hypothetical surface ocean believed to consist of salty water. Unlike the Earth, Europa's ocean is large enough to cover its entire surface. Due to its distance from the Sun, the surface of this hypothetical ocean is covered in a thick layer of ice. This layer is believed to be around 62 miles thick (Space.com, 2015). This is caused by an average temperature at the equator never rises above minus 260 degrees Fahrenheit and its poles never rise above minus 370 degrees Fahrenheit. Another discovery enhances the probability for water ice is the oxygen in Europa's atmosphere, though thin (Space.com, 2015). This is likely caused by particles from the sun striking water molecules on the moons surface. When this occurs, the hydrogen atom is ejected from the moon while the oxygen atom is retained by the …show more content…
The one issue for surface life is the constant bombardment of radiation from Jupiter. While this would most likely destroy any life at shallow depths making it difficult for scientists to observe or find evidence of life on the immediate surface. This raises the question at what depth will life survive on Europa. For example, the daily roentgen equivalent man or rem, is 540 which would cause death in humans ("Exploration of Jupiter - Wikipedia, the free encyclopedia," n.d.). Regardless of the radiation amounts on the surface, scientists believe that Europa might be internally warmed by Jupiters gravitational pull. If this were true, then like on Earth, single celled or even multicellular life could thrive around underwater volcanos. If life exists, scientists must figure out a proposal to send a sterilized probe to Europa's surface. One such proposal was back in 2001 and was known as the cryobot and hydrobot. This subsurface submarine would have used a nuclear-powered melting probe to reach the hypothetical ocean below the thick surface ice (NASA, 1996). Once in the liquid water, hydrobot would have sent back information gathered on the chemical compounds found in the water which could have indicated signs of life. One of the areas it would primarily investigate would be