THERE'S been a fascination with stars since the dawn of man, looking to the heavens to find clues to answer questions about our existence.
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Our concept of the universe has radically changed in the last 100 years from a flat unchanging tapestry of stars to one that is constantly expanding and evolving.
Do you think you're sitting still right now? Well, you're not! You're on a planet that is orbiting a star at 30 kilometres a second. That star is orbiting the centre of a galaxy at 250 kilometres a second.
Now, that galaxy is moving through the universe at a rate of 600 kilometres a second! Since you started reading this, you've travelled about 3,000 kilometres. Feeling giddy?
Australia Day falls on Monday and no doubt our minds will be on the ground, not the stars. But while you celebrate we'll welcome a visitor to our planet from the depths of the solar system.
A large asteroid over half a kilometre wide will zip past planet Earth that morning, close enough to be seen in binoculars. Then, as silently as it came, it will vanish without a sound!
Although easily far enough away to be safe, the flyby counts as a narrow encounter in astronomical terms. It will be the closest any asteroid comes to Earth until the predicted fly past of another large rock 1,000 metres across in 2027. That encounter will be really close, just brushing past some of our closest satellites. Whew!
Asteroids are something special. Not only did asteroids provide Earth with the building blocks of life and much of its water, but in the future, they will become valuable resources for mineral ores and other vital natural resources.
Asteroids like this are also dangerous and have the potential to end life on this planet if they hit us.
The 'Aussie Day asteroid 'is classed as a city killer. An impact could easily destroy almost any large city in Australia in a second.
They come in at 30 kilometres a second and have one hundred times the explosive power of the atom bomb dropped on Hiroshima! Enjoy you day.
The good news is NASA's near Earth object programme, also known as 'Spaceguard', searches for objects that might potentially pose a hazard to the planet and logs them giving advance warning of any danger.
Hey, why not call in and meet me and my Mid North Coast Astronomy Group on Port's Town Green on Australia Day. We'll be doing free safe solar viewing through large filtered telescopes and explaining the awesome power of our closest star to locals and visitors.
