Exoplanets orbiting distant stars may have MORE diverse lives than on Earth, finds & # 39; surprising & # 39; study
- Experts simulated the climates of different exoplanet types with a NASA model
- Worlds with oceans with efficient upwelling currents will be more habitable
- Dense atmospheres, slow rotations and continents provide more uplift
- There may be planets on which these factors are stronger than on Earth
The Earth may not be the best planet for life – with some exoplanets orbit around distant stars, which have the potential to accommodate a more varied and plentiful range of life.
This surprising conclusion came from American researchers who used a NASA climate model to investigate the most habitable exoplanets – those outside our solar system.
The team discovered that planets with a more dense atmosphere, lower rotational speeds and the presence of continents all lead to a more efficient upwelling of the ocean.
This in turn provides a more potentially welcoming ocean for extraterrestrial life.
The findings can help focus the future of our search for life on other worlds.
Scroll down for video
The Earth may not be the best planet for life – with some exoplanets orbit around distant stars, which have the potential to accommodate a more varied and plentiful range of life. Pictured, an artist & # 39; s impression of the various exoplanets in the TRAPPIST-1 galaxy
Geochemist Stephanie Olson and colleagues from the University of Chicago have used software developed by NASA to model the probable conditions on different types of exoplanet – in particular their climates and potential ocean habitats.
& # 39; NASA & # 39; s quest for universe life is focused on so-called Habitable Zone planets, these are worlds that have potential for liquid water ocean. & # 39; said Dr. Olson.
& # 39; But not all oceans are equally hospitable – and some oceans are better places to live than others because of their worldwide circulation patterns. & # 39;
The researchers were able to use their models to determine which types of planets would most likely be able to develop and sustain a variety of lives.
& # 39; We have used an ocean circulation model to determine which planets have the most efficient upwelling and therefore offer particularly hospitable oceans & # 39 ;, said Dr. Olson.
Upwelling in the Earth's oceans returns nutrients from the dark depths to the more sunlight upper areas of the seas, where photosynthetic life lives – so more impulse means more nutrient supply and, consequently, more biological activity.
& # 39; These are the conditions that we need to search for on exoplanets & # 39 ;, said Dr. Olson.
& # 39; We have found that higher airtightness, lower rotational speeds and the presence of continents all result in higher winding speeds. & # 39;
The researchers conclude from this that the Earth may not be the optimum planet for life – and that there are more hospitable worlds elsewhere in the cosmos.
& # 39; This is a surprising conclusion & # 39 ;, said Dr. Olson.
& # 39; The conditions on some exoplanets with favorable ocean circulation patterns may be better suited to support life that is more abundant or more active than life on Earth. & # 39;
The team discovered that planets with a more dense atmosphere, lower rotational speeds and the presence of continents all lead to a more efficient upwelling of the ocean
Inherent limitations in our astronomical technology will always mean that life itself occurs more often than detectable life.
Given this, said Dr. Olson, our search for life elsewhere in the universe would be best focused on those habitable planers who are more favorable to a varied and globally active life.
& # 39; Those are the planets where life is easiest to detect – and where non-detections are the most useful, & # 39; she added.
At present, we have not developed telescopes that are powerful enough to identify suitable exoplanets and to test the conclusions of the researchers – but Olson hopes that this will change soon.
& # 39; Ideally, this work will inform the telescope design to ensure that future missions – such as [NASA & # 39; s] proposed LUVOIR or HabEx telescope concepts – have the right capabilities, & # 39; she said.
& # 39; Now we know what to look for, so we have to start searching. & # 39;
& # 39; We expect oceans to be important in regulating some of the most compelling remotely detectable signs of life on habitable worlds, & # 39; said Earth scientist Chris Reinhard of the Georgia Institute of Technology, who was not involved in this study.
& # 39; But our understanding of oceans outside our solar system is currently very rudimentary & # 39 ;, he added.
& # 39; The work of Dr. Olson is an important and exciting step forward in our understanding of exoplanet oceanography. & # 39;
The full findings of the study were presented on the Goldschmidt conference 2019, which was held in Barcelona from 18-23 August.
HOW SCIENTISTS STUDY THE ATMOSPHERE OF EXOPLANETS?
Distant stars and their rotating planets often have different circumstances than everything we see in our atmosphere.
To understand this new world, and what they are made of, scientists must be able to detect what their atmosphere consists of.
They often do this using a telescope similar to NASA's Hubble telescope.
These huge satellites scan the sky and hold onto exoplanets that NASA may find interesting.
Here the on-board sensors perform various forms of analysis.
One of the most important and useful is called absorption spectroscopy.
This form of analysis measures the light that comes from the atmosphere of a planet.
Each gas absorbs a slightly different wavelength of light, and when this happens, a black line appears on a full spectrum.
These lines correspond to a very specific molecule, indicating that it is present on the planet.
They are often called Fraunhofer lines after the German astronomer and physicist who first discovered them in 1814.
By combining all the different wavelengths of light, scientists can determine all the chemicals that form the atmosphere of a planet.
The key is that what is missing gives the clues to find out what is present.
It is vital that this is done by space telescopes, because then the Earth's atmosphere would interfere.
Absorption by chemicals in our atmosphere would warp the sample, so it is important to study the light before it has had the chance to reach the earth.
This is often used to search for helium, sodium and even oxygen in alien atmospheres.
This diagram shows how light passing through a star and the atmosphere of an exoplanet produces Fraunhofer lines that indicate the presence of important compounds such as sodium or helium
. [TagsToTranslate] Dailymail