Modern astronomy tells us that we live on a more-or-less typical
planet, orbiting a standard-issue star, lying in a decidedly
run-of-the-mill galaxy. In short, we’re nothing special.
And yet, modern astronomy also assures us that our ordinary little
world is part of something very special--a pageant of cosmic
evolution stretching back some 13.7 billion years to the big bang
itself. Indeed, most of today’s astronomical research is
devoted to filling in the details of that story.
For example, evidence suggests that primordial gas began
to condense into galaxies fairly quickly after the big bang, within
a billion years or so. But precisely when and how did these first
galaxies form, and how have they evolved since then?
Likewise, it seems that some of these galaxies accumulated so
much gas at the core, that their central regions literally collapsed,
forming gigantic black holes with millions or billions of times
the mass of our sun. For a time, moreover, at least a few of these
black holes continued to swallow up even more gas, thereby generating
so much heat and light that we call them "quasars," and "active
galaxies," and we can see them over vast distances. But precisely
when and how did these black holes form? How common are they? And
did they form in every galaxy? Is there actually a
monster black hole in our galaxy?
Meanwhile, whatever fireworks might have been going on at the
center, every one of these newborn galaxies was also beginning
to light up around the edges with stars, as the primordial hydrogen
and helium condensed to the point where thermonuclear reactions
could begin. Those reactions, in turn, began to fuse the hydrogen
and helium into heavier elements such as carbon, oxygen, silicon
and iron. But precisely when and how did those first stars form?
And precisely how has all that heavy-element production changed
the composition of the universe over time?
NSF-supported astronomers are working to answer all these questions
and more. In particular, the agency's National
Optical Astronomy Observatory, together with the international Gemini partnership,
offer astronomers some of the finest telescopes in the world for
studying the universe in visible and infrared light. Its National
Radio Astronomy Observatory, together with the Arecibo telescope
in Puerto Rico, offer equally world-class facilities for probing
the universe at radio wavelengths. The National
Solar Observatory allows them to conduct detailed studies of
the sun, which is not only the closest star to Earth but the key
to understanding all the other stars. And the new National
Virtual Observatory is attempting to democratize astronomical
research by making the archived data available to everyone over
Of all the projects that NSF supports, however, few have captured
the imagination quite as much as the search for planets that orbit
Are We Alone? [Next]