Understanding Exoplanets: The Habitable Zone

January 15, 2015 9:53 PM

17 0

In this first of a series of articles to come on the scientific search for extraterrestrial life, we explore the magical place around stars called the Habitable Zone. Known by another name, the "Goldilocks Zone", this location is prime real estate for a planet to occupy. For "Exoplanets", which are those planets that circle other stars, the possibility that life as we know it exists there could be maximized if the planet's orbit falls within this habitable location. The zone is exactly that location that is not too hot and not too cold where liquid water can exist on a suitable planet. Looking at Earth for a moment, as we have all learned and confirmed life began in earnest in the oceans. Water is critical to the process if not simply because it allows for the mixing of many disparate materials which can under certain circumstances create the building blocks of life from which we are all composed. Having come from the oceans, to this very day our own bodies reflect the salinity of the ancient oceans from which our ancestors arose. We literally carry around a vestigial ocean environment within us. It is an odd thought to ponder. But water wasn't always in liquid form on Earth. Early on, the Earth's atmosphere was so dense and hot after formation that water vapor could not condense and fall as rain. Once that finally happened, and with new evidence indicating that it may have happened earlier than thought, innumerable cycles in both the thinning carbon dioxide atmosphere and deep in the growing oceans provided opportunity for life to arise.

Looking at our own Solar System helps us understand how the placement of an Exoplanet within the habitable zone of its star will drastically affect its climate. Venus sits just outside our habitable zone but its close to the inside edge. The differences however between Venus of today, once thought t...

Read more

To category page