National Aeronautics and Space Administration

What are the origin, evolution and fate of the Universe?

Two of the most profound questions that all cultures, both past and present, have asked are: where did we come from and what is our destiny?  Throughout history philosophers, theologians, and scientists have debated these questions.  NASA Science seeks to provide quantitative information pertinent to these basic elements of human curiosity by enabling scientists and engineers to construct instruments and make measurements on these topics that were once the purview of thought experiments only.

Central elements of these questions concern the birth and ultimate fate of the Universe.  To understand any topic well one must understand its background or history.  For the Universe, that history starts with the Big Bang.  Previous NASA investigations with the Cosmic Microwave Background Explorer (COBE) and the Wilkinson Microwave Anisotropy Probe (WMAP) and their measurements of the Universe when it was about 300,000 years old have given us exquisite confirmation of our theoretical models of the early evolution of the Universe.  To understand further and to test the theoretical model’s implications for how the Universe started we need to push our observations to an earlier time to learn what powered the Big Bang.

Within the past ten years we have learned that our Universe is expanding at an ever-increasing rate implying that some day - in the very distant future - anyone looking at the night sky would see only our Galaxy and its stars.  The billions of other galaxies will have receded beyond detection by these future observers.  We do not understand what the force is that is pushing the Universe apart and refer to it simply as  “dark energy”.  This dark energy is a new and mysterious component of our Universe that previous generations have not examined.  It is clear that this heretofore unknown piece of the Universe, comprising ~75% of the matter-energy content of everything, will determine the ultimate fate of all.