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Alien worlds: The search for other Earths

Whistler astronomer John Nemy is will be giving a multimedia presentation on Thursday, Jan. 20 at MY Millennium Place on the topic of Alien Worlds.

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Nemy will present the latest findings and images of this planet quest along with images from the Cassini Saturn Mission. A beautiful new 6" Sky Watch Telescope donated by Vancouver Telescope Centre will be raffled off. and the monies raised will go to the Canadian Red Cross Tsunami Relief Fund. The show starts at 7:30 p.m. after a 7 p.m. meeting of the Astronomy Club. Nemy’s presentation’s are a popular attraction, so get there early. For more information go to: http://www.nemy.com/ Or call 604-938-8090.)

Humankind’s perspective of its existence here on Earth keeps changing faster than we can comprehend. In the past decade a fundamental question since the beginning of time has been answered – solar systems other than our own do exist.

Astronomers are now more certain than ever that planets like our own exist in the universe and we are on the verge of finding them.

Finding an extrasolar planet orbiting even a nearby star is extremely difficult. The problem is that a planet’s dim reflected light is washed out by the brilliance of the star it circles. Even a Jupiter-size planet, the largest planet in our solar system, is 1 billion times dimmer than the light produced by a star like our Sun.

The search for extrasolar planets had to been done in some way other than visible light. Astronomers routinely look at all the wavelengths of the electromagnetic spectrum, including visible light, to study the universe.

In 1991 the first extrasolar planet discovered was found around a pulsar-type star by studying radio waves emitted by the star. A pulsar is the exotic remains of a massive star that ended its life in a supernova explosion. Scientists at the Arecibo radio telescope in Puerto Rico found the new planet by observing variations in the radio signal from the pulsar.

The discovery of the first ever planet beyond our own solar system was exciting and bizarre. To find anything orbiting around a pulsar that could survive the ultra violent explosion of a supernova was a surprise. Mother Nature once again surpasses science fiction – discovering a planet around a pulsar was like finding a feather around a hurricane.

The hunt was now on as astronomers began to look at other "sun" like stars to see if they could find alien worlds around more familiar hosts.

Then in 1995 European astronomers Michel Mayor and Didier Queloz found a planet orbiting the star 51 Pegasi.

That discovery was also made in an indirect way. Mayor and Queloz studied the light from 51 Pegasi and found that the star was wobbling. The wobble was caused by the gravitational tug of an unseen planet in orbit around the star.

The star 51 Pegasi is visible in the evening skies at this time of year in the constellation Pegasus. It is located on the North side of the "Great Square" shape of Pegasus. It glows at the limit of naked eye detection at magnitude 5.4 but binoculars easily reveal the star. When we see the faint light of this star, never again will we wonder if we are the lone planetary system in the galaxy and the universe.

Since this discovery more than 130 planets have been found around "sun" like stars by looking for wobbles, and the search continues.

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