GEOLOGY MODULE 1
The Big Bang Theory
The current theory for how the universe was created is that it comes from a singularity, a point of incredibly hot, dense matter. This started rapidly expanding, a process which continues today. As the material began to cool down, particles and atoms were formed, which make up the elements of the universe. The most commonly accepted age of the universe (according to our latest calculations) is approximately 13.7 billion years.
(see table of properties of planets including Density, Number of Moons, Atmosphere etc.)
The Nebula Theory
The solar system formed 4500 Ma when a giant molecular cloud of gas and dust collapsed due to a nearby Supernova. The material formed a rotating disc, accretion formed outer planets to complete our solar system.
Structure of the Solar System
Rocky planets are closer to the sun than the gas giants because as the solar system was forming, only materials that could withstand the sun's heat could form close to it. The gas giants had to form such a distance from the sun that it was cool enough for them to condense into a planet. It is also possible that the sun heated the nearby planet's atmospheres to the point where gas could escape from them.
To be classified as a planet, the object must meet 3 criteria.
1. To be in orbit around a star (but not be a satellite).
2. To be near spherical in shape.
3. To have cleared the area around its orbit.
Moons are natural satellites, they are usually distinct, solid objects that orbit around a more massive body. For example, our moon was the first to be discovered and is relatively large with a diameter of about 3474.8 km.
Moon: 1969 - moon landing, oldest rocks dated to 4400 Ma. The Maria - dark area made of basalt lava flows. The Highlands - light area made of plagioclase-rich anorthosite.
Mars: Has the largest volcano in our solar system: "Olympus Mons". Mars volcanoes are bigger because the tectonic plates are fixed. 1960's - space probes Mariners 3 - 7 took photos, then spacecraft in orbit, then in 2007 a spacecraft was put on the surface.
Venus: Spacecraft has landed and mapped it using radar. Brightest planet in our sky because clouds reflect sunlight. Has high temperature and pressure. We assume Venus had volcanoes in the past, but we can't see past the thick atmosphere. Has no tectonic plates.
Mercury: May contain a liquid core, has had geological collapses in the past.
Jupiter's moon: IO The most volcanically active place in the solar system, has calderas, lava lakes, lava flows,. Roughly the same size/density as earth's moon. Entire surface covered in 100m material every 1 million years. Caused by the gravitational pull of Jupiter vs other moons, "tidal heating".
Europa, another of Jupiter's moons has a fractured surface of ice, which we believe has an…