EARTH is the only planet we know that blooms with life – but that may soon change.
According to a new study, distant planets may may not just host life, but even more life than exists on our own planet.
That’s because they may have better conditions for life to thrive than Earth itself, say scientists from the University of Chicago, USA.
The team came to their conclusion while searching for the perfect conditions a world needs to host aliens.
They modelled planets outside the Solar System, known as “exoplanets”, to find the best possible environment for life.
A rocky world with a dense atmosphere, slow rotation and the presence of continents was found to be best.
The nearest know exoplanet is Proxima Centauri b (artist’s impression), which is roughly 4.25 light years from Earth[/caption]
That’s because these conditions encourage the healthy flow of nutrients through oceans, said study lead author Dr Stephanie Olson.
“Life in Earth’s oceans depends on upward flow, or “upwelling”, which returns nutrients from the dark depths to the sunlit portions of the ocean,” Dr Olson said.
At this upper sea layer, photosynthetic life – tiny creatures that need sunlight to survive – are plentiful, she added.
“We found that higher atmospheric density, slower rotation rates, and the presence of continents all yield higher upwelling rates,” Dr Olson said.
“More upwelling means more nutrient resupply, which means more biological activity. These are the conditions we need to look for on exoplanets.”
As scientists dug into what makes a planet perfect for life, they came to a stark conclusion.
Despite hosting a wide variety of living creatures, Earth does not boast the ideal conditions for growing life.
That means that while life on Earth is very diverse, on other planets, the range of creatures could be even greater.
“Earth might not be optimally habitable – and life elsewhere may enjoy a planet that is even more hospitable than our own,” Dr Olson said.
What is an exoplanet?
Here's what you need to know…
- An exoplanet is a planet that is located outside of our Solar System and one that is orbitting its own star, like how Earth orbits the Sun
- They are very hard to see with telescopes because they are often hidden by the brightness of their star
- Nasa sent the Kepler space telescope into orbit with the purpose of finding Earth sized exoplanets that might support life
- Over 4,000 exoplanets have been discovered so far and more missions to find even more exoplanets are planned
- A good way to spot an exoplanet is to look for “wobbly” stars because a disruption to star light can indicate that a planet is orbitting it and therefore blocking out light on occasion
- Expoplanets are very common in the Universe and the more we find that look like Earth the closer we get to knowing if we’re not alone out there
The scientists say their findings could help in the search for alien-hosting planets by directing what telescopes should be looking for.
“Nasa’s search for life in the Universe is focused on so-called Habitable Zone planets, which are worlds that have the potential for liquid water oceans,” Dr Olson said.
“But not all oceans are equally hospitable – and some oceans will be better places to live than others due to their global circulation patterns”.
The research was presented at the Goldschmidt Geochemistry Congress in Barcelona.
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In other news, Nasa recently uncovered 18 Earth-sized planets lurking outside our Solar System – and one offers hope for life.
Watery ‘Super Earths’ may hide ‘unfathomably deep’ bottomless oceans – with alien life lurking inside.
And, an ‘alien’ grain of dust fired at Earth by ancient exploding star has been found buried in Antarctica.
Do you think there is life out in the Universe? Let us know in the comments…
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Alien planet could have greater variety of life than EARTH, shock study claims