Europa

Anton Pires

Europa

• is the sixth moon of the planet Jupiter, and the smallest of its four Galilean satellites.

• DISCOVERY AND NAME

• Europa was discovered in 1610 by Galileo Galilee.

• He used a 20x-power, refracting telescope at the University of Padua Italy.

• Europa was named similar to all Galilee’s Satellites after Greek mythology.

• Europa is named after a lover of Zeus, the Greek counterpart of Jupier. Europa is the , daughter of the king of Tyre.

Physical characteristics

• Roughly the size of earth's moon

• Surface area 3.09 × 107 km2 (0.061 Earths)

• Volume 1.593 × 1010 km3 (0.015 Earths)

• Mass 4.80 × 1022 kg (0.008 Earths)

• Surface temp.• min ~50 K • mean 102 K• max 125 K

At just over 3,100 kilometres (1,900 mi) in diameter, it is the sixth-largest moon and fifteenth largest object in the Solar System.

Primarily composed of silicate rock.

• Silicate Rock – is a compound containing a silicon bearing anion. Silicates comprise the majority of the earth’s crust, as well as most planets and moon’s.

Internal structure

•It is believed that Europa has an outer layer of water around 100 km (62 mi) thick; some as frozen-ice upper crust, some as liquid ocean underneath the ice.

•magnetic field data from the Galileo orbiter showed that Europa has an induced magnetic field through interaction with Jupiter's.

(VIDEO EXAMPLE)

•Europa probably contains a metallic iron core.

Surface Features • Europa is one of the smoothest objects in the Solar System

• There are few craters on Europa because its surface is tectonically active and young.

• the surface is about 20 to 180 million years old.

• The radiation level at the surface of Europa is equivalent to a dose of about 540 rem (5400 mSv) per day, an amount of radiation that would cause illness in human beings.

Lineae • surface features are a series of dark streaks crisscrossing the entire globe, called lineae.

• the edges of Europa's crust on either side of the cracks have moved relative to each other

• hypothesis states that these lineae may have been produced by a series of eruptions of warm ice as the Europan crust spread open to expose warmer layers beneath.The effect would have been similar to that seen in the Earth's oceanic ridges

Subsurface Oceans

•Most planetary scientists believe that a layer of liquid water exists beneath Europa's surface, kept warm by tidally generated heat similar to earth.

•Average temperature 110 K (−160 °C; −260 °F) •Equator 50 K (−220 °C; −370 °F)

Atmosphere • composed mostly of molecular oxygen (O2 ).

• The surface pressure of Europa's atmosphere is 10−12 times that of the Earth.

• In 1997, the Galileo spacecraft confirmed the presence of a tenuous ionosphere (an upper-atmospheric layer of charged particles) around Europa created by solar radiation and energetic particles from Jupiter's magnetosphere, providing evidence of an atmosphere.

• Unlike the oxygen in Earth's atmosphere, Europa's is not of biological origins.

• The surface-bounded atmosphere forms through radiolysis, the dissociation of molecules through radiation.

Video

http://www.youtube.com/watch?v=7vAUMS6VtXo

Potential for Extraterrestrial life

• Europa's unlit interior is now considered to be the most likely location for extant extraterrestrial life in the Solar System

• Life could exist in its under-ice ocean, perhaps subsisting in an environment similar to Earth's deep-ocean hydrothermal vents or the Antarctic Lake Vostok. Life in such an ocean could possibly be similar to microbial life on Earth in the deep ocean. So far, there is no evidence that life exists on Europa.

• Galapagos ALVIN exploration.

Exploration Pioneer 10 and Pioneer 11 were the first to visit Jupiter, in 1973 and 1974, respectively; the first photos of Jupiter's largest moons produced by the Pioneers were fuzzy and dim. The Voyager flybys followed in 1979, while the Galileo mission orbited Jupiter for eight years beginning in 1995 and provided the most detailed examination of the Galilean moons that is expected until the end of the 2020s

Interesting Fact • The Voyager probes

discovered three more inner satellites in 1979, so Europa is now considered Jupiter's sixth satellite, though it is still sometimes referred to as Jupiter II

Sources

•http://www.youtube.com/watch?v=7vAUMS6VtXo

•http://en.wikipedia.org/wiki/Europa_(moon)

•http://www.nasa.gov/worldbook/europa_worldbook.html

•http://www.solarviews.com/eng/europa.htm