Astronomy 101 The Solar System Tuesday, Thursday Tom Burbine

Course Course Website: – Textbook: –Pathways to Astronomy (2nd Edition) by Stephen Schneider and Thomas Arny. You also will need a calculator.

There is an Astronomy Help Desk that is open Monday-Thursday evenings from 7-9 pm in Hasbrouck 205. There is an open house at the Observatory every Thursday when it’s clear. Students should check the observatory website before going since the times may change as the semester progresses and the telescope may be down for repairs at times. The website is

HW #16, #17, #18, and #19 Due by April 20 th at 1 pm

Terrestrial Planets Have different surface properties –Due to size of the planet –Distance from Sun –Speed of Planetary Rotation

Why Volcanoes are larger on other planets?

Look for evidence for processes that occur on surface of a planet Geomorphology - scientific study of landforms and the processes that shape them –Important Questions: –Are features on Mars formed by volcanic processes? –Are features on Mars formed by water? Compositional –Important Questions: –Are the compositions of minerals on Mars consistent with volcanic processes? –Are the compositions of minerals on Mars consistent with forming in the presence on Mars?

Are Features –due to volcanic processes or running water? Are Rocks –contain minerals formed in volcanic processes (such as olivine or pyroxene) –Or affected by water (precipitates from solution or minerals containing water)

Formed by Lava?

Martian basaltic meteorite Looks like igneous rock

Russell Crater Dunes Taken by Mars Reconnaissance Orbiter liquid-water-on-mars/

Compositional Effects of Water Examples: 2Fe 2 SiO 4 + 4H 2 O + O 2 → 2Fe 2 O 3 + 2H 4 SiO 4 olivine + water + oxygen → hematite + silicic acid Form CaSO 4 ·2H 2 O (Gypsum, a sulfate)

Terrestrial Analogs You can use terrestrial environments to look for analogs for processes that occur on Mars

Face on Mars

Significant Mars Missions Viking 1 ( ) (NASA) (Lander) Viking 2 ( ) (NASA) (Lander) Mars Global Surveyor ( ) (NASA) (Orbiter) Mars Pathfinder (1997) (NASA) (Lander) Mars Express (2003-present) (ESA) (Orbiter) MER Spirit (2004-present) (NASA) (Lander) MER Opportunity (2004-present) (NASA) (Lander) Mars Reconnaissance Orbiter (2006-present) (NASA) (Orbiter) Phoenix (2008) (NASA) (Lander)

Viking Missions Each spacecraft consisted of an orbiter and a lander Viking 1 lander landed July 20, 1976 Viking 2 lander landed September 3, 1976 Total cost was ~1 billion

Viking 2

Red Color The red color of the planet comes from the oxidation of iron minerals in the soil. Fe 2+ is becoming Fe 3+ Iron is shiny when it is not oxidized When it loses two electrons by encountering oxygen, it becomes black or green When it loses three electrons by encountering oxygen, it becomes red Rusting

Viking 2

Four Experiments There were results that were initially positive But results could all be explained through non-biologic chemistry For example, Labeled Release Experiment –The nutrients were tagged with radioactive 14 C –Looked for emitted 14 CO 2 gas as evidence for chemical reactions that happen in living organisms to maintain life – Radioactive gases were given off immediately for the first insertion of nutrients –Subsequent insertions did not give off radioactive gases

Four Science Goals of NASA's long-term Mars Exploration Program: Determine whether Life ever arose on Mars Characterize the Climate of Mars Characterize the Geology of Mars Prepare for Human Exploration

Mars Pathfinder Landed July 4, 1997 Weight kg Lasted 3 months Discovery Mission

Objectives of Mars Pathfinder Discovery Mission - To prove that the development of "faster, better and cheaper" spacecraft is possible (with three years for development and a cost under US $150 million). To show that it is possible to send a load of scientific instruments to another planet with a simple system and at one fifth the cost of a Viking mission. To demonstrate NASA's commitment to low-cost planetary exploration finishing the mission with a total expenditure of US$ 280 million, including the launch vehicle and mission operations.

APXS Radioactive Cu-244

AXPS – Alpha Proton X-ray Spectrometer Radioactive Cu-244 source Emits alpha particles (helium nuclei), protons, and X-rays Measures the backscattered alpha particles and protons and emitted X-rays from the rock Different elements interact with alpha particles, protons, and X-rays differentlyy

Sojourner Rover is investigating Yogi the Rock The rock was the first on Mars found to be made of basalt The smoothness of the surface also suggested the past existence of water in the region.

Yogi Barnacle Bill

Spirit and Opportunity I used to live in an Orphanage. It was dark and cold and lonely. At night, I looked up at the sparkly sky and felt better. I dreamed I could fly there. In America, I can make all my dreams come true..... Thank-you for the "Spirit" and the "Opportunity" — Sofi Collis, age 9

Spirit landed in Gusev Crater – appeared basaltic (lava flows) Opportunity landed on Meridiani Planum – appeared to have lots of sedimentary rock

welcome-to-marshttp:// welcome-to-mars

Any Questions?