Huge breakthrough in the search for aliens: NASA discovers a ‘super Earth’ exoplanet that could have the right conditions to support life

Image credits: NASA, CSA, ESA, J. Olmsted (STScI)

 Scientists, led by NASA, have come up with an interesting, perhaps revolutionary discovery in the quest for extraterrestrial life when they found proof of a gas formed only by living things on a distant water planet.

This cool dwarf star located in the Leo constellation is over eight times Earth’s size and 120 light-years away from our world, said to lie inside its habitable zone.

The world is thought to be “Hycean”.

What gets astronomers even more excited, however, is the presence of something else.

The atmosphere of K2-18 b, referred to as a “super Earth” due to the fact that it is larger than Earth yet much smaller than Neptune, has been found to contain a gas that is “uniquely associated with life” when found on Earth.

Image credits: NASA, CSA, ESA, R. Crawford (STScI), J. Olmsted (STScI)

This discovery, as NASA said, showed the presence of two carbon-bearing gases and the complex molecule dimethyl sulphide, which contains carbon, hydrogen, and sulfur atoms. “A mix of shock, excitement, and disbelief,” scientists expressed in discovering it.

This means, according to the space agency, ‘on Earth, this is only produced by life.’

“The majority of the DMS in Earth’s atmosphere is emitted by phytoplankton in ocean environments,”.

In fact, despite this discovery, scientists have argued that other James Webb Space Telescope observations would establish if, indeed, DMS was there.

K2-18b would become one of the moons in our solar system including Mars and icy moons of Jupiter and Saturn that are most prone to holding life outside Earth if this discovery is confirmed.

And indeed, there was a great concentration of methane and carbon dioxide in the atmosphere of the super Earth, which indicates that the planetary object may already be habitable or perhaps even inhabited.

It certainly speaks volumes of K2-18b as a “Hycean” world, but neither of these gases is evidence of life in space because they can also be produced through other inorganic processes.

This was mind-boggling – that something akin to DMS could be on an exoplanet lightyears away,” said lead author Nikku Madhusudhan.

The University of Cambridge scientist told MailOnline, “Our discovery is an important step in exoplanetary science, particularly the demonstration that we can detect carbon-based molecules in low-mass exoplanets in the habitable-zone.”

Another interesting development is that of enhanced inference that there may be an ocean on this planet.

“We were finding something so fundamental and it was such an exciting and surreal experience to see the data for the first time,” said Professor Madhusudhan.

The larger Hycean worlds have been more amenable to observations of the atmosphere for a long time in history, but the search for life on exoplanets has traditionally targeted smaller rocky planets, Professor Madhusudhan added.

Future Webb observations may confirm or rule out whether DMS does indeed exist at detectable levels in the atmosphere of K2-18 b.

The space observatory, operated by NASA, has cost $10 billion (£7.4 billion). Scientists will be able to determine what chemical building blocks a planet might contain by determining how the light coming from a host star is altered when it crosses through a planet’s atmosphere and travels to Earth.

Credit: Benoit Gougeon, Université de Montréal

But while a percentage of this sunlight is absorbed by atmospheric gases, each gas leaves unique fingerprints in the light spectrum that astronomers can later recognize.

This has often been described as a “sub-Neptune” but also classified as a super Earth.

Credit: Benoit Gougeon, Université de Montréal

All these worlds are actually a planet with the radius lesser than that of ice giant, that is the farthest from our sun, but yet not in our solar system.  Because sub-Neptunes orbit so far from Earth, they remain under-studied, and astronomers differ over the makeup of their atmospheres.

‘There are no sub-Neptunes in the solar system, but they constitute the most common type of planet identified thus far in the galaxy’, said Subhajit Sarkar, a researcher at Cardiff University.

‘We could tell what molecules might be present in the atmosphere of a habitable-zone sub-Neptune by gathering the most detailed spectrum to date’,.

A Jupiter-sized planet with a radius 2.6 times that of Earth, K2-18b is and with an interior probably consisting of a large mantle of high-pressure ice similar to Neptune, but with a thinner atmosphere rich in hydrogen and an ocean surface.

The researchers say covering the ocean worlds with water, it is likely also that the ocean could be too warm for liquid or livable.

Outside of the solar system, thousands of exoplanets-have been found since the first one was discovered thirty years ago.

Most of them are between Earth and Neptune in size and fall into sub-Neptunes, mini-Neptunes, or super Earth class. They might be mainly composed of ice and be called ice giants with atmospheres enriched in hydrogen, or they could also fit somewhere in between.

Earlier research on those planets has also proved to be futile regarding life’s survival based on high pressure and temperature as a result of their dense hydrogen atmosphere.

However, in 2021, researchers discovered that the planets might be able to harbor life, but only in specific cases.

Apart from verification of DMS existence within K2-18b, scientists now are expecting further observations of other biotic indicators, which living organisms can create, like methyl chloride.

This would really cause tremendous excitement and propel the globe to the front line in search of extra-terrestrial life.

Reference

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