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Chapter 28
Mars
The god of WAR
Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Mars• Mars is the most explored planet
– Viking 1 & 2
– Mariner 4 provided the first close-up image (1965)
– ESA’s Mars Express (2003)
– Global Surveyor
– Odyssey
(aside from Earth) in the Solar System
Mars• Mars is the most explored planet (aside from Earth) in the Solar System
Viking Spacecraft and the view of Mars
https://www.youtube.com/watch?v=PseSJoicfrg
Viking 1 Spacecraft view
Viking 2 Spacecraft view
• Mars is the most explored planet (aside from Earth) in the Solar System
– Pathfinder in 1997 landed on the planet w/Sojourner
– Pathfinder’s view
• Mars is the most explored planet (aside from Earth) in the Solar System– Summer 2003
Opportunity
• Opportunity’s view
• Mars is the most explored planet (aside from Earth) in the Solar System
– Spirit rovers 1st landed in2004
• Mars is the most explored planet– Spirit panaromic view of mars– A lot of things exploring Mars…
LIKE…
– UFO sighting
• Mars is the most explored planet
– Even Bigfoot is exploring Mars!!!
• Mars is the most explored planet– WHAT is it???
• Mars is the most explored planet
– Face on Mars
Maybe it’s Megatron???
The REAL face of Mars
The REAL face of Mars
• Mars is the most explored planet (aside from Earth) in the Solar System– Phoenix in 2007 to look at one
of the poles
– View from Phoenix
• Mars is the most explored planet (aside from Earth) in the Solar System– Mars Global
Surveyor • flow of liquid
• Mars is the most explored planet– Mars Global Surveyor MAP
• Also studied flow of liquid
• Odyssey Spacecraft
• Odyssey
Globally mapped the amount and distribution of many chemical elements and minerals that make up the Martian surface.Maps of hydrogen distribution led scientists to discover vast amounts of water ice in the polar regions buried just beneath the surface.
Odyssey also recorded the radiation environment in low Mars orbit to determine the radiation-related risk to any future human explorers who may one day go to Mars.
• Most recent spacecraft was in 2012
• Curiosity landed
Click on above link to watch the landing.Click on the
link (below) to see full
Landing
• Curiosity is the first spacecraft to record a landing on another planet. The six-wheel rover arrived on Aug. 5, 2012 to begin a two-year mission to examine whether the Martian environment was hospitable for microbial life.
• The rover's ultimate destination is Mount Sharp, a towering mountain that looms from the ancient crater floor. Signs of past water have been spotted at the base, providing a starting point to hunt for the chemical building blocks of life.
• Before Curiosity journeys toward the mountain, it will take a detour to an intriguing spot 1,300 feet away where it will drill into bedrock. With the test drive out of the way, Curiosity was expected to stay at its new position for several days before making its first big drive -- a trip that will take as long as a month and a half.
• Curiosity won't head to Mount Sharp until the end of the year.
The Surface of Mars
• The surface of Mars is currently a dry, dusty place
• Plains covered with rocks ranging from pebble-sized to boulder sized!
• Lots of evidence for flowing water, rivers and salty oceans
The Surface of Mars• The surface
of Mars is reddish in color.
• This orange sand is mostly rust… (Fe2O3) due to the iron oxide within the soil
Major Features of Mars
• Mars is home to some amazing sites!– Valles Marineris
Major Features of Mars
– Valles Marineris• Named for Mariner 4• A canyon that stretches across the face of the globe• As wide as the United States!
Major Features of Mars
• Mars is home to some amazing sites!– Like:Olympus Mons
Olympus Mons• Tallest mountain of the major planets
Olympus Mons
• Extends above the bulk of the atmosphere of Mars!
• An extinct shield volcano around 250 million years old.
Map of Mars
• Four gigantic shield volcanoes are located near the equator, near a region called the Tharsis Plateau
Map of Mars
• The Tharsis bulge may have been caused by an upwelling of hot material from the interior of the planet. This created volcanoes in the region (including Olympus Mons) and may have created Valles Marineris.
Map of Mars
• The Tharsis bulge may have been caused by an upwelling of hot material from the interior of the planet. This created volcanoes in the region (including Olympus Mons) and may have created Valles Marineris.
Major Features of Mars
• Mars is home to some amazing sites!– Polar ice caps
Major Features of Mars
The polar caps of Mars are composed mostly of water ice (north) and frozen carbon dioxide (south)
Ice Caps of Mars
• They grow and shrink seasonally– Similar axial tilt to
Earth (25 degrees)– Produces seasons
similar to those on Earth
– Southern winter is much more extreme than northern, as Mars is farthest from the sun during this period.
Major Features of Mars
The northern hemisphere has sparsely cratered plains.
The southern hemisphere of Mars is a heavily cratered, highland region resembling the highlands of the Moon.
Dune Fields• Deserts ring Mars at mid-
latitudes• Winds blow surface material
into dunes, similar to those found on Earth
Water on Mars?
• Many scientists believe that Mars was once warmer and wetter than it is today
• Surface features seem to support this– Dry riverbeds– Splash craters– Gullies in crater walls– Etc!
Evidence for Water
Splash Craters are craters that form from impacts on damp soil
Gullies
Ice Floes?
Where the water is now
• If Mars was so wet, where did all the water go?
Where the water is now
– Some may be trapped just below the surface as permafrost
– May be locked up in mineral compounds
Where the water is now
– Most probably escaped to space• Evaporated from the surface
• UV photons broke apart H2O molecule
• H escaped to space
• The Martian atmosphere is very different from Earth’s– 95% carbon
dioxide, – 3% nitrogen– Surface pressure is
very low – same pressure as Earth at 35 km!
The Martian Atmosphere
The Martian Atmosphere
Clouds of water ice and carbon dioxide ice float through the sky
No rain ever falls, but it sometimes snows dry ice crystals!
In order for a planet to retain an atmosphere the 2 most important are:
Temperature of planetEscape velocityDistance from the SunAxial tiltComposition & weight of the gases.
• Temperatures range from just above freezing to 180 K (-136ᵒF)
The Martian Atmosphere
• The winds on Mars, though gentle, can carry dust far into the atmosphere.– These dust storms sometimes obscure most of the surface!
• No erosion
The Martian Atmosphere https://www.youtube.com/watch?v=PseSJoicfrg
• The winds on Mars
Interior of Mars Astronomers hypothesize that Mars has a core of iron, nickel, and possibly sulfur that extends somewhere between 1200 km and 2400 km from the center of the planet. Because Mars has no magnetic field, astronomers think that the core is probably solid.
Moons of Mars
• Mars has two moons, Phobos and Deimos.
Phobos• It’s about 15.5 miles diameter (about the size of
Houston, TX)
• Its gravity is 1/1000 of earth– You could jump off the surface (about a mile up)
and float off into space– Could lift a 900,000 pound object
Phobos• You could summersault over 3000 times BEFORE you
land 25 minutes later • Covered with a Dark dust about 3 feet deep
– Dark as charcoal
• TEMP: +30ºF to a -170ºF night• Rotation is about 8 hours
Phobos• crater (“stick me”) on the west side
– It’s a 7 mile wide which almost split the moon in half – A 200 mile wide meteor traveling at 14000 MPH hit
the West side of the moon– Larger than the United States – Could go Spelunking on Mars
Moons of Mars• DeimosMoon (dia): 7.8miles
Orbit eccentricity: 0.0002
Orbit inclination: 1.788 degrees
Rev: 30 hours
Rot: none
Mass: 1.4762 x 10^15 kg
Density: 1.471 g/cm^3
Surface gravity: 0.003 m/s^2
Escape velocity: 13 mph (20 km/h)
Chapter 28
Mars
The god of WAR
Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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