Planetary systems can be harsh environments in their early history. The young worlds orbit suns in stellar nurseries, clusters of stars where violent encounters are commonplace. None of this makes it easy for life to get going, but now astronomers at the University of Sheffield find one positive of this tumultuous period. A model developed by undergraduate student Bethany Wootton and Royal Society Dorothy Hodgkin Fellow Dr Richard Parker looks at how the habitable zone – the region around a star where the temperature allows liquid water to exist – changes around pairs of stars, so-called binary systems.
Since the Kepler Space Telescope was launched into space, the number of known planets beyond our Solar System (exoplanets) has grown exponentially. At present, 3,917 planets have been confirmed in 2,918 star systems, while 3,368 await confirmation. Of these, about 50 orbit within their star’s circumstellar habitable zone (aka. “Goldilocks Zone”) , the distance at which liquid water can exist on a planets’ surface.
In the last decade we have discovered thousands of planets outside our solar system and have learned that rocky, temperate worlds are numerous in our galaxy. The next step will involve asking even bigger questions. Could some of these planets host life? And if so, will we be able to recognize life elsewhere if we see it?
At approximately 3.5 billion-year-old, the oldest fossils on Earth have been uncovered in Western Australia. The microscopic fossils are the earliest direct evidence of life on Earth and — thanks to further analysis and study by researchers at UCLA and the University of Wisconsin-Madison —could deepen our understanding of the origins of life. The study was published on Monday in the Proceedings of the National Academy of Sciences (PNAS).