Earthly Invaders

Manicouagan, Gosses Bluff, Barringer, Clearwater Lakes, Aorounga:  exotic yet familiar names to astronauts orbiting our planet. The oldest continental rocks preserve the distinctive pockmarks of past impacts by asteroids and comets. Geologists have identified roughly 180 impacts scars around the globe, some recognized from the ground, others from exploratory oil drilling, and still more from orbiting satellite imagery, Our basic knowledge of the cratering process came from studying Earth's youngest examples, like Arizona's Meteor Crater. That understanding has enabled ur enterpret on the rocky inner planets and the icy moons of the outer solar systems . The timing and frequency of alien impacts deepens in turn our knowledge of how past catastrophes have shaped the history of Earth and lide itself.

Across the Solar System

Solar System

Since Galileo first trained his telescope on the heavens in 1609, astronomers have known that the moon is scarred by thousands of craters but there origin was a subject of argument for centuries. Geologists guessed that the craters were probably volcanic, but a few thought they might have been formed by impacts from the larger cousins of the meteors we see streaking across the night sky. It was not until the early 1960s that geologists and astronomers Eugene Shoemakers. examining the mile-wider Meteor (Barringer) Crater near Winslow, Arizona, proved conclusively that it had been caused by an impact by identifying geologic evidence left by the blast, which was caused 50-yard wide asteroid fragment that struck earth with a 20-megaton blast. Meteor Crater in Arizona is probably the most famous impact structure on Earth, and despite its age of 50,000 years, its desert location has kept its outlines relatively sharp. Nasa's lunar exploration program revealed that most of the moon's craters were likewise formed by asteroids or comet collisions, and the new insights into the cratering process enabled geologists to turn up dozens of impact craters structures on our home planet(earth). We know of more than 170 such impact craters pocking the surface of the globe.

Observing Earth

Observing Earth

Geologists have always sought the high groung to assess the lay of the land, and aerial photography gave scientists a welcome vantage point. Artificial satellites took that concept to new heights, providing reconnaissance to the military(The U.S Corona series was the first, about 1960), and then giving science a global perspective with Landsat and others. On California's northwest coast lies San Francisco Bay, bisected By the San Andreas Fault, a tectonic fault where the pacific and the North American crustal plates grind past each other. Modern San Francisco stands astride the fault, which in 1906 lurched more than 20 feet, destroying more than 28,000 buildings and killing more than 3,000 people. This large image pictures the financial district, Embarcadero, and Oakland Bay Bridge, seen from IKONOS satellite. To observe this geologically important region, scientists have used not just orbital photography but portions of the electromagnetic spectrum ou eyes can't see. Visible light can show us details of street plans, vegetation patterns, and surface geology. But other wavelengths can reveal the type and health of vegetation, delineate land-use patterns, and trace unstable tectonic underpinnings of this vulnerable region. In the same way, planetary scientists examine a planet's surface using a range of wavelengths, looking for different rock types(lave, crustal bedrock, water-bearing sediments, ice buried under dust) or revealing landforms shrouded by haze or clouds.   

Our Solar System

Our Solar System is made out of The Sun, eight planets and 4 dwarf planet:

Our Solar System is in a galaxy which is called "The Milky Way Galaxy". 

Jupiter is the largest planet in our Solar System.

Jupiter, Saturn, Uranus and Neptune are known as the Gas Giants and Mercury, Venus, Earth and Mars are known as terrestrials.  

The Moon

The Moon is the earths only Natural Satellite. The Moon is the also the furtherest place humans have visited. Its' orbit takes 27 days. Our Naturel Satellite is the Fifth Largest in the solar system. The first time the moon was visited was in 1959 by the soviets. The Moon is kept orbiting the Earth because of the Earths gravitational pull, But the moon is slowly leaving the presents of the Earth at a rate of 3.8 centimeters a year.

The Moon Causes the tides with its' gravitational pull. This is an example of high tide and low tide.









The Craters are formed by asteroids and comets crashing on the Moon.

The Moon

Our Planet

Earth is the 3rd planet from the sun. It is estimated that out planet is covered out of 29% land and 71% salt water. Our planet was formed over 4.5 billion years ago an is expected to carry on its orbit for 500 million years - 2.3 billion years. Our planet is the only one that we humans know has life.

Underneath what you see today there are tectonic plates. On the borders of these plates there usually volcanoes, earthquakes and mountains. This is because the plates collide or crash into each other.

Tectonic Plates of the world

 
 On the left are the plates of the world. When they crash against each other the force causes an earthquake.

If the plates have an equal force they will start rising to the surface, this creates mountains and volcanoes.

This is the direction the plate move in.