Showing posts with label asteroid. Show all posts
Showing posts with label asteroid. Show all posts

Large Asteroid Craters Found in Australia

Australia has always been seen as remote. Yet new new things are being discovered about its history. It has been identified as the "target" of one of the world's largest asteroid impacts. Two craters found by Andrew Glikson and his team are thought to have been caused by a large meteor which broke into two pieces.
Dinosaurs killed extinct by asteroid
Each crater is 200 kilometers in diameter. One of these craters on its own is larger than the impact in Mexico: the Central American collision wiped out the dinosaurs. It isn't the biggest, however. The Sudbury comet did a great deal of damage, but the world's widest crater is the Vredefort in South Africa.

The twin craters in Australia have been flattened out over eons of time. They were found by geothermal research. It appears that asteroid impact covers the Northern Territory, Queensland and South Australia, a very large area. Seismic traverses is going to be applied next. This will hopefully bring new things to light.

If the asteroid damage in Mexico caused mass extinction, the severe disruption in Australia would have destroyed life as well. Its age has not yet been determined. The question is: Did the dinosaurs survive the catastrophe or were they long gone by then?
Technology by Ty Buchanan
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            Australian Blog   Adventure Australia

Japan Steps into Space

Let us wish the Japanese well in their bid to explore space. The US has had great success with their missions. It seems odd why Japan would spend money on space exploration when the economy is in such bad shape. Nonetheless, all people in the world benefit from new knowledge,

After success with its first attempt to retrieve samples from the Itokowa space rock, the second spacecraft Hayabusa2 will be launched in 2014 and closely examine asteroid 1999 JU3. The rendezvous will take place in 2018. Valuable samples will be brought back to Earth in 2020.

Japan is doing the work with assistance from other nations. The probe will be tracked by NASA's Deep Space Network. Like the first project the spacecraft will land in Australia. Powered by ion engines the craft will make a small crater in 1999 JU3. In the past this asteroid may have come into contact with water.

A German made lander called MASCOT will move over the rock's surface. Intense examination will hopefully bring to light new understanding about asteroids. The search for life elsewhere in the cosmos is still paramount.
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Asteroids Can Have Magnetic Fields

It has been found that asteroids can have magnetic fields. This was quite a surprise. Planets have magnetic fields due to a moving molten metal core. Mercury has a very strong field. The reason for this is not yet known.

Vesta is a large asteroid with a diameter of 525 kilometer. It was first identified in 1807 by Heinrich Wilheim Olbers. It is the most easily seen asteroid from Earth. Smaller asteroids hit Vesta and some of the debris falls to Earth. The fallen "rocks" can be linked to Vesta because they have the same spectral color match.

Vesta is unusual for an asteroid as it once had a crust, mantle and molten metal core. The orbiting dawn spacecraft/satellite confirms this. It is now frozen and no longer active. A meteor named Alan Hills A81001 composed of Vestan crust fell to Earth in the Arctic. When it was analysed it was found to have a weak magnetic field.  The original crust gained  a magnetic field when it cooled 3.7 billion years ago. An impact a billion years later hit the frozen crust. This melted and refroze some crust which resulted in magnetism being transferred, imprinted, on rock which became the Alan Hills meteor.
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We Would not Be Here if Dinosaurs had not Existed

If an asteroid hadn't collided with the Earth 65 million years ago we would not be here today. Reptiles would still probably rule the world and apes would never have evolved. There was so much devastation after the impact that only small animals survived - very small mammals. These small creatures only came out into the open to take over the world when it was safe after the dinosaurs had gone.

Mankind's development actually depended on the dinosaurs existence. Small animals evolved to give birth to live young so dinosaurs could not eat their eggs. Even giving milk to their young was to avoid the danger from dinosaurs. Becoming warm blooded allowed them to hunt at night which dinosaurs could not do.

After the dust had settle it was a virtual paradise for mammals. The sun came out and they basked in it. A niche for large animals was vacant so mammals grew large and were successful. The climate changed and trees disappeared. Large mammals grazed happily until an intelligent ape began hunting them. Then large mammals died out and these apes, men, bred and spread all round the globe. Unfortunately, this "intelligent" animal is now threatening small mammal with extinction.
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