Mars Exploration Rovers and Mars

Evidence for Liquid Water on Mars (in remote past)

• Valley networks

• Outflow channels

• “Northern Ocean”

Controversial suggestion: northern Mars ocean is an ancient seabed

And the “Face on Mars” prove ancient aliens were on Mars

Mineralogy: Key to hydrological history of Mars

• Magnetite: Fe3O4

• Hematite: Fe2O3

• Olivine: Fe2SiO4

• Pyroxine: CaFeSi2O6

Minerals tell about hydrological history, what chemical reactions were occurring

Landing Sites for “Spirit” and “Opportunity”

• Spirit: Gusev crater, crater with water flows

• Opportunity: Meridianum Plani: reflectance spectra of hematite

Gusev Crater: A Noachian Site with Evidence of Flowing Water

Spirit on Mars

Opportunity Landing…Bedrock

Rocks at Opportunity Landing Site Show Evidence of Water

Opportunity at Endurance Crater…old bedrock formations

More Mossbauer spectra from Mars

Results from MER spacecraft

• Evidence of water at Meridiani from the outset: haematite chondrules, sedimentary rocks with chemically weathered compositions: “there are other possible scenarios; they all require liquid water and acidic conditions”.

• Early results from Gusev seemed to argue against water; high abundance of pristine olivine. “the ubiquitous presence of olivine in the soil suggests that physical rather than chemical weathering processes…”

Recent results from MER (cont)

• More recent results from Gusev, coatings on rock with 2-5 times high S & Cl concentrations than interior, crystalline haematite.

• “The physical and chemical characteristics provide evidence for limited by unequivocal interaction between water and the volcanic rocks of the Gusev plains”

Current status of results from surface of Mars. There probably was standing water on the

surface of Mars for extended periods of time in the Noachian period. The highly acidity of

the water apparently generated sulfur-dominated chemistry rather than carbonate-

dominated chemistry. Time (and future missions) will tell. Stay tuned.

The Jovian planets…where are they?

Expanding the scale…the domain of the Jovian planets

Sizes of the Jovian planets

What do they look like? -Jupiter

Band structures visible in small telescopes

Jupiter: closeup of cloud structures

Saturn

Cloud bands and the ring

Saturn up close…atmosphere and rings

Picture from the Cassini spacecraft…more about the ring later

The atmosphere of

Saturn

Also evidence of cloud bands…. We see the top of the atmosphere…but what kind of atmosphere?

The spectrum of Jupiter…clue to its composition