The Darwin Mission By Alex Tilley, Kyle O’Brien, and Penny Wu

Vital Stats Fourteenth moon from Saturn Sixth largest Discovered in 1789 by William Herschel 550 km diameter Located in the densest part of Saturn’s E ring Mass is 1.8*10^-5 of Earth Average Density is 1.61 g/cm³ Escape velocity of km/s PIA07724.jpg

Relationships It has a mean motion orbital resonance with Dione of 2:1 which is most likely responsible for its tidal heating It is most likely the creator of Saturn’s E ring It provides oxygen to Titan’s atmosphere There is an electrical connection between Saturn and Enceladus

The Surface The surface is made of ice It has an average albedo of 1.4 There is a large variety of surface types ranging from very smooth to laden with craters The southern polar region has long lines of geysers known colloquially as ‘tiger stripes’ assini.jpg

Craters The oldest craters are thought to be over 4 billion years old and reside in the heavily cratered areas The smallest and youngest craters are found in the southern polar region. The wide variety of craters indicate possible ongoing geologic activity

Tiger Stripes They are located in the southern polar region The plumes being ejected from the surface come from these stripes The space between them is 10% brighter than the rest of Enceladus

Plumes The material is made of water vapor, hydrocarbons, and other elements. The material that escapes the atmosphere becomes Saturn’s E ring Sources are either sublimating ice or boiling water

Pioneer 11 Launched April 1973 Surveyed Saturn Sept 1979 Took the first close-up pictures of Saturn Mapped magnetic field of Saturn Measured the temperatures of Saturn’s and Titan’s atmospheres Survey the environment of the ring plane Discovered two of Saturn’s smaller moons Extensively imaged Saturn’s rings

Voyager 1 & 2 Voyager 1 Reached Saturn in November, 1980 Voyager 2 in August, 1981 Fly-by missions to better image the rings of Saturn Discovered Prometheus and Pandora Paved the way for the Cassini mission Revealed half and half terrain of Enceladus

Cassini Present Mission Sent Huygens probe to surface of Titan Discovered atmosphere on Enceladus Confirmed geologic activity on Discovered “Yellowstone- like” geysers Determined that Enceladus “rolled-over” Discovered electrical connection between Saturn and Enceladus

More Questions Answer the following questions: – What is the driving force behind the geologic activity (tectonics)? – What lies beneath the ice shell? – What causes the formation of geysers on the surface? – Is there any evidence of life, past or present? – Is it likely that there will be life in the future?

Goals for the Darwin Mission Collect expelled material from geysers Develop lander Develop method to drill and sample ice Measure and quantify seismic activity of Enceladus Take sample of atmosphere Test electric connection between Saturn and Enceladus Drill at tiger stripes to breach ice shell Develop method to send samples back to earth

Power and Movement RTG power Orbiter with lander and detachable rover Antenna

Dust Samples Cosmic Dust Analyzer Send dust samples back

Drilling Drill through ice at southern polar region Send ice samples back register.html

Seismic Activity and Craters Seismograph Send rock samples back Panoramic Cameras

Atmosphere Magnetometer Magnetosphere Imaging Instrument

Ethical Concerns Fuel leakage Leaving rover or other parts behind

Cost Cassini-Huygens mission ~ $3.3 Billion Darwin Mission ~ $5 Billion

Sources Cassini, Cassini FAQ, Mars Rover, Status of Outer Planet Flagship Mission Studies, Frictional heating explains plumes on Saturn's moon Enceladus, Cassini Solstice Mission, NASA Cassini, NASA Voyager, NASA Pioneer, Cassini Observes the Active South Pole of Enceladus,