Astronomy 101
The Solar System
Tuesday, Thursday
Tom Burbine
tomburbine@astro.umass.edu
Course
• Course Website:
– http://blogs.umass.edu/astron101-tburbine/
• 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
http://www.astro.umass.edu/~orchardhill/index.html.
HW #16, #17, #18, and #19
• Due by April 20th 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?
http://athena.cornell.edu/images/scientists/lava_flow_chart.jpg
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?
http://cdn.physorg.com/newman/gfx/news/hires/lavalikelyma.jpg
• Martian basaltic meteorite
• Looks like igneous rock
Russell Crater Dunes
• Taken by Mars Reconnaissance Orbiter
http://blogs.discovermagazine.com/badastronomy/2010/04/12/new-evidence-of-transientliquid-water-on-mars/
Compositional Effects of Water
• Examples:
• 2Fe2SiO4 + 4H2O + O2 → 2Fe2O3 + 2H4SiO4
• olivine + water + oxygen → hematite + silicic acid
• Form CaSO4·2H2O (Gypsum, a sulfate)
Terrestrial Analogs
• You can use terrestrial environments to look for
analogs for processes that occur on Mars
Face on Mars
http://www.guidescope.net/solarsys/mars_map2.jpg
Significant Mars Missions
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Viking 1 (1976-1982) (NASA) (Lander)
Viking 2 (1976-1980) (NASA) (Lander)
Mars Global Surveyor (1993-2006) (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.
• Fe2+ is becoming Fe3+
• 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 14C
– Looked for emitted 14CO2 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:
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Determine whether Life ever arose on Mars
Characterize the Climate of Mars
Characterize the Geology of Mars
Prepare for Human Exploration
Mars Pathfinder
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Landed July 4, 1997
Weight - 870 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
http://www2.jpl.nasa.gov/snc/a-mgsivsalsi5.gif
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
• http://www.hulu.com/watch/23352/novawelcome-to-mars
Any Questions?