What is Europa and why might it have life?
Europa is one of the four largest satellites, or Galileon moons of Jupiter. The other three large moons are Io, Ganymede, and Calisto. Europa was discovered in 1610 by Galileo Galilei. It is the sixth largest satellite in the solar system. The following table compares Earth with Europa to provide some perspectives on the characteristics of the moon. (above from right to left: picture of Europa, color enhanced picture of Europa) Characteristic Earth Europa Diameter (km) 12,756.2 3,138 Gravity (m/s2) 9.78 1.3203 Atmospheric Gases nitrogen, oxygen oxygen Surface Temperature (degrees C) -89.6 to 58 -173 to -153 Mass (kg) 5.973×1024 4.8×1022 Thus far, Europa’s surface has been determined to be mostly water-ice. Europa’s surface is not at all like anything else in the inner solar system. It is exceedingly smooth; few features more than a few hundred meters tall have been seen. There are very few craters on Europa. So far only three crater larger than 5 km in diameter have been found. Compare
