Big Questions for Astro Observatory (ASTRO 1 & 2) In order to
understand how the Universe has changed from its initial simple
state following the Big Bang (only cooling elementary particles
like protons and electrons) into the magnificent Universe we see
as we look at the night sky, we must understand how stars,
galaxies and planets are formed. Following the Big Bang and the
gradual cooling of the Universe the primary constituents of the
cosmos were the elements hydrogen and helium. Even today, these
two elements make up 98% of the visible matter in the Universe.
Nevertheless, our world and everything it contains—even life
itself—is possible only because of the existence of heavier
elements such as carbon, nitrogen, oxygen, silicon, iron, and
many, many others. How long did it take the first generations of
stars to seed our Universe with the heavy elements we see on
Earth today? When in the history of the Universe was there a
sufficient supply of heavy elements to allow the formation of
prebiotic molecules an