05/11/10

The size of the sun in comparison


It is the fire of life. It can be kind but it can get angry. But it never throws its weight around. It is the sun. And although it is 330,000 more massive than earth and contains 99.8% of the mass in our solar system, it is small in comparison with some other stars.
The sun never cease to amaze us with its theatrics, its lava flares dancing across its surface in a ballet of nuclear fusion, sometimes leaping millions of miles into the air. And although the sun is big, its intense heat and light makes it difficult to capture good images with normal instruments. So NASA scientists use an Helioseismic and Magnetic Imager and an Atmospheric Imaging Assembly detector to view the ultra-violet (UV) and extreme ultra-violet lithography (EUV) wavelengths released by the sun. The resulting images are spectacular.

Earth in comparison to the sun
Earth’s distance from the sun varies between 91.4 million miles – in January – and 94.4 million miles – in July. The average distance of 92,955,887.6 miles (149, 597, 870.7 kilometers) is called 1 astronomical unit (AU), a measurement that is used to report distances to other planets and stars as well. In short, it’s not a weekend drive.
NASA puts the size of earth to the sun in perspective like this: Suppose the radius of Earth were the width of an ordinary paper clip. The radius of the sun would be roughly the height of a desk, and the sun would be about 100 paces from earth.


The size of the sun in comparison
Our sun is one of billions in the entire universe. It also is fairly small in comparison with other big stars. In fact, our sun is classified as a G2 dwarf star. Sirius, the brightest star in the night sky, is twice as massive as the sun and 25 times more luminous. And Sirius is dwarfed by Pollux, which is eight times the radius of the sun. And Pollux is dwarfed by Arcturus, which is almost 26 times the size of the sun.



It’s a big, big universe
But there are bigger stars yet. When compared to Antares, our handsome sun is a mere pixel on a map. And Antares is not even the biggest star. That title is thought to belong to a star called VY Canus Majoris. It is about 2,000 times the size of the sun, or more than twice the size of Antares.


How big is the universe?
The Wilkinson Microwave Anisotropy Probe calculated the age of the known universe at 13.7 billion years old, based on its radius of 13.7 billion light years. And it is growing bigger every day, at a speed of 71 km/s/Mpc. The size of the whole universe is estimated to be 78 billion light years. If you start traveling today at 60 miles per hour (100km/h) you’ll get to the end of your first coffee stop, the end of one light year, in nine trillion years. Then you just keep going for another 77.999 999 billion light years. Or you could stay here, look after our beautiful planet… and enjoy the sun !!



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