The Sky at Night – Alien Worlds investigates what we know about these alien worlds and looks at how we have managed to detect them. It is not just our sun that is circled by planets. In recent years, astronomers have found over 4,000 planets circling stars other than our own.
Professor Chris Lintott visits the UK Astronomy Technology Centre in Edinburgh to see a cutting-edge camera designed to take pictures of exoplanets. And Dr Maggie Aderin-Pocock talks to experts about the continuing hunt for alien worlds and, even, alien moons. Meanwhile, Pete Lawrence sticks to hunting for planets in our own backyard, looking for Neptune and explaining what is meant when a planet is said to be in opposition.
The Sky at Night – Alien Worlds
Earth is the only place in the universe where we know life exists. But with billions of other star systems out there, it might not be the best place for life. In a new study, astronomers modeled the potential for life on other watery planets and found some conditions that can create oceans maximized for habitability.
The model suggests that watery planets with dense atmospheres, continents, and long days — slowly rotating planets that is — were most conducive to life. These conditions stimulate ocean circulation, which brings nutrients from the depths to the surface where it’s available for biologic activity.
To date, over 4,000 exoplanets have been confirmed, and a handful of those worlds orbit at a safe enough distance from their host star to have liquid water on the surface. These habitable zone planets are at the forefront of the search for alien life and the new research, presented Friday at the Goldschmidt Conference in Barcelona, Spain, will help astronomers narrow down that search.
Previous studies looking at exoplanet habitability had largely neglected the role that oceans play in regulating global climate and heat transportation. The researchers focused in on this niche, using a computer model to compare different combinations of climates and ocean habitats that could exist on exoplanets across the galaxy. The study aimed to look for things like upwelling, a type of ocean circulation driven by wind.