Astronomy Digital Picture – 6 seconds, ISO 400, 8.3mm f/3, on 26 Jan 2006 8:11PM, Bangalore.
19 Jan 2007
Year is a measure of time, whereas meters and light year is a measure of distance!
When you look at stars, things are different. The distances are gigantic. 38,000,000,000,000 kilometers is the nearest star’s distance from our solar system. If this the case with closest star, what about those stars and galaxies that are billions of times far? The basic unit meter/kilometer isn’t practical unit to use, because the numbers get too big to use. Thus to measure long distances, people use a unit called a light year.
A light year is the distance that light can travel in a year, since light travels at 3,00,000 Kms per second, one light year accounts to 3,00,000 * 60 * 60 * 24 * 365 = (Approx) 9,460,800,000,000 kilometers !!!
Oh, using the fastest car on Earth it would still need thousands and thousands of years to cover one light year distance.
Earth – moon : 1.2 light seconds away
Earth – Sun : 8 light minutes away
Earth – Saturn : 80 light minutes away
Sun- Andromeda galaxy : about 200 million light years away
and so on…
Tomorrow’s picture – False Orion Belt.
Astronomy Digital Picture of the Day 