There’s always wonder when it comes to other planets and other worlds in the universe.">

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  Out There: Other Solar Systems:  
 

 

There’s always wonder when it comes to other planets and other worlds in the universe. Do they exist? Is our solar system unique or is it an example of other stellar setups?

The Model
Take a look at our own solar system. The center is a star – the Sun – and surrounding it are major and dwarf planets, as well as dust, gas, asteroids, comets, and moons. Each planet has its own system.

As the third planet from the Sun, it takes Earth 365 days to make one complete trip around. What keeps Earth in orbit? The Sun’s gravity of course; and therein lies the clue to other solar systems: Gravity of a central star.

Gravitational Pull
The difficulty in identifying other planets has always been the fact that they generate no light of their own. They only reflect light and if so, faintly. Thus, finding them in deep space is challenging to say the least.

Fortunately, a workaround was devised.

The key was to look for similar stellar setups in space and subsequently, similar motion (a tug and pull). If astronomers could identify a star and then determine orbital movement amongst objects around that star, then a planet could be reasonably identified.

Breakthroughs
Indeed, theory and proof collided in 1992 when Alex Wolszczan and Dale Frail made the landmark discovery of three planets orbiting a pulsar. Though not a star, their breakthrough changed everything for the astronomical community. It confirmed that they were all on the right track.

Then came 1995, when Michel Mayor and Didier Queloz made their own announcement: The discovery of 51 Pegasi b, an extrasolar planet orbiting a star very much like our Sun (51 Pegasi). The confirmation of other solar systems was complete.

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  Did You Know:
  Since 1992, hundreds of other alien planets have been identified using the same observational method.

In October of 2009 alone, an incredible 32 new planets were added to the count, bringing the total to over 400!.