Meteors and asteroids do not only bring valuable information from outer space. They may have been essential to our life on earth at one point – and may continue to be so in the future.
In the 20th century, the obviously wrong theory that the Hungarians came from space was widely spread. However, it may not have been completely unfounded – of course, in this case, it would be true not only about us, but about all living creatures. Examining a different aspect, two studies also found that life on earth can be closely related to the cosmos.
Life can travel on meteors
If life can spread from planet to planet — a concept known as “panspermia” — we might be able to detect it, even if we don’t know what we’re looking for, Live Science reports.
Astronomers are hunting for life beyond Earth. Although there are many promising places in the Solar System, the most likely place to find life is on a planet orbiting another star. According to NASA, there are more than 5,000 confirmed exoplanets to date.
But these researches currently face a major obstacle: we don’t know exactly what we’re looking for. We know of only one type of inhabited planet and only one type of life—Earth and the carbon-based life on it. However, according to astronomers, life can take an amazing variety of forms in the galaxy.
Not only the earthly life form can exist
Recently, some astronomers have proposed an alternative, focusing less on what life looks like and more on what it does. Their strategy is based on the concept of panspermia: life can start on one planet and spread to others by jumping on meteorites.
One of the most important characteristics of any life is its ability to alter the natural balance of the planet. On Earth, for example, we have much more oxygen in our atmosphere than there would be without life, and distant observers would notice much more green on our landmasses than otherwise.
We don’t know exactly what properties of an exoplanet would be altered by alien life – but if it is capable of panspermia, it would attempt to effect the same changes on all planets.
The researchers developed a statistical test
If they measure the properties of enough planets, they can potentially identify clusters of nearby planets that have similar properties. Because these planets, each orbiting a distant star, have no other reason to be similar to each other, this set stands out from the collection of all exoplanets.
Such a discovery would suggest that something strange is happening to these planets – and that it could be life spreading between the stars.
The researchers acknowledged that their work has limitations. First, it assumes that panspermia is possible, even though it hasn’t been tested. Second, their technique only works if we can collect enough data from a large number of exoplanets.
Life on Earth could also have started from space
Life on Earth arose from a fatal mixture of organic compounds about 4 billion years ago. How—and where—the components of the protobiological mix formed is still a matter of debate, given the timeline and surface conditions of the cool early Earth, Science Alert reports.
Recent research has shown that deep space may have formed key materials that arrived on the early Earth via meteorites and comets. According to a new study by a German and French team, this scenario is not only plausible, but also offers the most likely explanation for how life on Earth acquired certain building blocks.
The key is a building block
The study specifically focuses on the formation of peptides, short chains of amino acids. These substances are crucial for life on Earth. They are formed from unique amino acid sequences and perform various functions, such as catalyzing many biological processes.
Yet, despite the peptides’ apparent importance in the creation of life on Earth, the young planet likely did not offer a suitable environment. Water can have a disturbing effect on the formation of peptides, so it could have hindered the formation of life from non-living matter.
There is a surprisingly friendlier place for peptide formation: the interstellar medium
A region of rare matter and radiation that occupies vast space between star systems.
Led by Serge Krasnokutski, an astrophysicist at the Max Planck Institute for Astronomy in Germany, the authors of the study simulated the conditions found in the interstellar medium. They confirmed that peptide synthesis depends on three chemical components—carbon, carbon monoxide, and ammonia—the presence of which can trigger the formation of aminoketene molecules in interstellar dust clouds.
As this type of molecular cloud condenses, the aminoketene molecules assemble into chains, i.e. peptides. The thin molecular cloud then transforms into a denser protoplanetary disk. As such an object approaches a star and heats up, the molecules in the thin surface layer evaporate.
However, most of the liquefied content in the depths of a comet or asteroid cannot evaporate, so it can be ideal for the formation of aminoketene molecules.
Road to Earth
According to the authors, the peptides likely formed this way when our own solar system was developing and could have reached Earth later when the young planet was bombarded by meteorites, comets and other potentially peptide-bearing objects.
More research will be needed to unravel these findings and fill in the gaps in our understanding of the origins of life, but the authors say this study provides significant support for the idea that extraterrestrial ingredients helped spawn life on Earth.
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