In recent years a number of exo-planets – planets orbiting stars other than our own sun – have been detected in the ‘habitable zone’ of their systems. The habitable zone, or the goldilocks zone as it is also known, is the distance scientists have concluded that a planet should be from its host star to be able to support life.
The original ‘habitable zone’ theory was determined by Penn State University researcher James Kasting two decades ago. His original theory put the habitable zone between 0/96 astronomical units and 1.67 AU. However, all that is about to change because scientists using the updated databases known as HITRAN (high-resolution transmission molecular absorption) and HITEMP (high-temperature spectroscopic absorption parameters) have concluded that those figures are wrong.
The scientists now believe that the habitable zone now lies between 0.99 AU and 1.7 AU from the star which means our own planet is right on the edge of our solar system’s habitable zone. Why have scientists changed their minds on the issue? Well since the original sets of figures were calculated we have discovered hundreds of exo-planets orbiting distance stars – some exo-planets have even been discovered in multi-star systems – and all these new finds have given scientists new facts and figures to work with.
Obviously our own Earth supports a wide and diverse range of life but the new sets of figures could have important consequences for future exo-planet discoveries especially those determined to exist within the habitable zone. It could also mean scientists may need to re-evaluate some previously discovered exo-planets if these new figures on the habitable zone are accepted.
Since 1995 over 1000 exo-planets have been discovered and not all of them are distant; some of them – in galactic terms – are our neighbours. As our search for alien life and habitable worlds continue it is likely scientists will updated and adapt their understanding of the conditions needed to start/support life on other worlds as more evidence emerges.
2013: The Year We Find Another Earth? >>
[Written by Doug Lambert via Blastr]