Topic: Destroyer of worlds

[sam]

Astronomers, in addition to discovering extrasolar planets (about 500 of them currently have known orbital parameters), have detected excess, warm infrared dust emission around many stars.

http://www.physorg.com/news204552152.html

[Clive]

   The truth is out there. 

[Simon]

If the Sun is 4.5 billion years old, what was there before it, and how did it form?

[Clive]

The Sun formed as part of a cluster of stars which condensed out of the gas and dust present in our Galaxy.  It would have also picked up material from earlier stars which had exploded because of their massive size.  The planets were formed at the same time.  The first generation stars contained just hydrogen and helium and not much else.  When they exploded as supernovae, the heavier elements such as lead, copper, gold and everything else were created so without those first stars we could not exist.

[Simon]

It's difficult to grasp, but before that, there was just... nothing?

[Clive]

The Milky Way Galaxy is pretty old and formed within a couple of billion years after the Big Bang.  But there were earlier galaxies around before the Milky Way.  Before that, there were no galaxies at all because it was so close to the Big Bang itself.  But most astronomers now believe that there were countless Big Bangs and ours was nothing special.  The next generation of orbiting telescopes will get back to within a whisker of the Big Bang.  

[Simon]

A 'whisker' being a couple of million light years?