LESSON 4 MIDTERM MARS

•   Most popular for its bright reddish surface, and its closeness to our home
• Named by the ancient Romans for their bloody God of War due to the nature of its color in the sky
• Thought to maybe have life. 
• Space Age-notions  of life were gone as visits by robotic spacecraft have not revealed signs of any life on Mars. Not even at the microbial level.
• Smaller planet. It is about half of the Earth’s size. Its density is only a little greater than that of the Moon. T
• The core is thought to be mainly iron sulfide. Iron sulfide makes the surface of Mars. 
• It's axis turns every 24.6 hours. The equator leans to one side (almost like Earth's does)
• The planet experiences both daily and season cycles!
• Seasons are complicated. Differences in solar heating (because of the planet’s orbit) 
• The Southern Hemisphere summer occurs around the time of Martian perihelion and is warmer than summer in the Northern Hemisphere which occurs at aphelion.

• Polar caps are frozen carbon dioxide. The polar caps contains permanently frozen water, 

• The dark markings that were thought to be a network of canals, are highly cratered and eroded areas around. Surface dust occasionally blows viciously into the atmosphere.

• Mariner 9 went to Mars. (Entered orbit in 1971). A storm almost knocked it off course.

• The German Aerospace Centre has done tests to simulate the temperatures, atmosphere, minerals and light conditions of the planet’s surface based on data collected by Mariner 9.

• August 2012 AD, Curiosity Rover has landed on the surface and is taking readings of air circulation patterns, and localized weather systems. Trying to prove the existence of water on the Mars and find potential of UV radiation. Also, it is testing the possibility of life under the surface of Mars.

• Northern hemisphere is made up majorly of rolling volcanic plains, formed by eruptions involving enormous volumes of material. 

• Martian atmosphere is too thin to offer much resistance to incoming debris

• The Southern hemisphere consists of heavily cratered highlands. 

  It is assumed that the southern hemisphere is the original crust of the planet.

• Dark regions are mountainous regions in the south. Cratering in the south suggests that the northern hemisphere’s surface is younger. (3 billion years, compared to the 4 billion year old surface of the south) 

• The boundary between them is very large. The surface level can drop by 4 kilometers in height with only 100 kilometers of distance from the other.

• Tharsis bulge. The size of North America. Tharsis is on the equator.

• ^^ Rises10 kilometers higher than the rest of Mar's surface.  

• Chryse Planitia (the “Plains of Isis,” an Egyptian Goddess). --Wide depressions,  up to 3 kilometers deep. 

• No sign of plate tectonics on Mars. The absence of fault lines suggests this.

• Hellas Basin.- has the lowest point on Mars.The floor of the basin lays 9 kilometers below the rim and more than 6 kilometers below the average level of the Mar's surface. Hellas Basin is an impact feature. 

• Hellas Basin must have caused redistribution of Mar's crust. Impact occurred about 4 billion years ago.

• this is a terrestrial planet.

• Borealis Basin may be one of the largest known impacts in the solar system. Based on data from space crafts, the basin could have formed been when a giant celestial object (2000 kilometers across) struck the planet during the formation. 

• The collision might explain why the northern hemisphere of Mars is so lower than and radically different from the south.

• Valles Marineris (the Mariner Valley). Running water played no part in its formation. 

• Valles Marineris runs for 4000 kilometers along the Martian equator. 

• Valles Marineris was observed by 19^th-century astronomers that corresponded to a feature on the planet’s surface. Then known as the Coprates canal.

• Theory- Valles M. formed by the same crustal forces that caused the entire Tharsis region to bulge outward. The resulting cracks (tectonic fractures) are all around the Tharsis bulge. Valles Marineris is the largest of them. 

• Studies suggest that the cracks are 2 billion years old. Valles Marineris is estimated at around 35 billion years old.

•  Two small moons in orbit it. Phobos (Fear) and Deimos (Panic) for the sons of Ares (the Greek name of the God of War known to the Romans as Mars) and Aphrodite (the Greek name for Venus, Goddess of Love).

• American Muggle astronomer Asaph Hall in 1877 noticed these two moons orbit closely to Mars, and are only a few tens of kilometers across.

• Phobos and Deimos are both irregularly shaped and heavily cratered. 

• The larger of the two is Phobos (28 kilometers long and 20 kilometers wide) and has a 10-kilometer-wide crater named Stickney. 

• Deimos is16 kilometers long by 10 kilometers wide. Largest crater on it is 2.3 kilometers in diameter. Both moons have dark surfaces and reflect no more than 6% of the light.

• The density of the moons is around 2000 kg per square meter. 

• It is more likely that they are asteroids that were slowed and captured by the outer fringes of the early Mars atmosphere. It may be possible that they are remnants of a single object that broke up during capture.

• Phobos continues to interact with the planet’s upper atmosphere. Phobos orbit is expected to decay which will cause the moon to hit the surface in just a couple tens of millions of years.

• If they are asteroids, Phobos and Deimos represent material left over the from the earliest days of the solar system! Astronomers study them because the moons have information about the young solar system, before the major planets had formed.

Aphelion- the time when Mars is furthest from the Sun.

I have a lot of notes on that lesson so I tried to make it more organized and simple. I hope it helped.