Extraterrestrial life: Is life a lot older than we realize?

Very near to the time of the planet’s genesis is the earliest evidence of life on Earth. While many ideas try to explain the early origins of life on Earth, some scientists surmise that life that evolved long ago elsewhere may have found refuge on our planet. Let us introduce you to the idea of ”life seeds.”

Our planet is the only known celestial body that supports life.
Yes, this makes Earth special, but is it really?
Is life really so much older and more common than we initially thought?

When did life on Earth initially emerge?

Current estimates place the age of our planet at around 4.5 billion years. Approximately one-third of Earth’s early history was characterized by severe volcanic activity and meteorite bombardment. Ironically, this did not support the emergence and continuation of life.

But soon enough, things would calm down, allowing liquid water to collect and pool on the early crust of Earth.

Conditions seem to have been “just right” for the earliest “seeds” of life to arise on Earth just a few hundred million years later. Although not much is known about these extremely early lifeforms, most scientists concur that microscopic organisms most certainly governed the Earth, if not exclusively.

The earliest clear indications of life appeared about 3.7 billion years ago, give or take. To the best of our knowledge, these are the earliest fossils ever discovered, consisting essentially of a sequence of tube-like formations. Although these are controversial, significantly newer fossils of “stromatolites”—sticky microbial mats—dating from approximately 3.5 billion years ago have been found.

Now that more complex multicellular life is possible, the rest is, as they say, history. Although all of this is highly convincing, is it feasible that life existed on Earth much earlier? According to some scientists, yes.

Life: what is it?

However, we must briefly examine what life is before we can proceed with that. Life, as you most likely learned in school, is defined as anything that has the ability to move, reproduce, react to stimuli, absorb nutrients, expel waste, breathe, and develop. However, there are almost 200 scholarly definitions of what life is, which may surprise you.

Many scientists are now wondering if anything like a virus or prion is actually considered to be “alive.” They don’t meet every need listed above, but they do meet some of them.

For instance, viruses can undoubtedly proliferate, react to external stimuli (like the herpes virus), and even undergo evolution.

Nevertheless, they do not metabolize on their own and are totally dependent on a host to exist. They might be among the earliest living creatures to have evolved, it has also been suggested.

It’s crucial to note, though, that some biologists think viruses may have originated as a defect in early cell reproduction and have subsequently acted as a type of stimulant for the evolution of life on Earth. All the same, this is an extremely interesting and productive field of study.

In any event, the majority of scientists concur that everything that is generally covered by Darwinian evolution is considered life.

In its broadest sense, this is the notion that an organism or “species” would undergo changes over time, giving rise to new species and having a common ancestor.

If we accept this premise, we can start investigating the possibility that life on Earth may actually be billions of years older than life on Earth. Let’s examine how.

Is life on Earth older than it is?

Some scientists think that life may have existed on Earth long before our planet was founded. According to Harvard scientist Abraham Loeb, life may be nearly as old as the cosmos itself.

In order to respond, let’s take a brief look back at the history of the universe and consider the possible time that life first emerged. This is going to get wild, so hang on tight.

According to popular belief, following the “Big Bang,” a superheated gas known as plasma covered the universe. As the plasma cooled down over time, it began to produce light, which is now recognized as the cosmic microwave background radiation (CMB).

It was extremely hot at the beginning of time and cooled throughout time as the universe grew. The CMB’s current temperature is an astonishingly low minus 454 degrees Fahrenheit (minus 270 degrees Celsius; 3 Kelvin).

However, reasoning indicates that there was a certain stage of this cooling process, lasting roughly seven million years, during which the temperature was ideal for life to exist. A temporal “Goldilocks window,” if you will.

As Loeb suggests, the CMB’s temperature was like an Earthly summer’s day approximately 15 million years after the “Big Bang.” In approximate Fahrenheit terms, this would have been between 31 and 211 degrees (0 and 100 degrees Celsius; 273 and 373 Kelvin). This temperature range is important because in the early cosmos it might have been possible for exoplanets to support liquid water.

This is significant, according to Avi Loeb, because it implies that, if rocky planets had existed at that time, the warmth from the CMB would have been enough to keep their surfaces at temperatures appropriate for liquid water, regardless of where they were in the habitable zone of their parent star.

And it would be a great bet that life could arise there if the correct circumstances existed, just like on Earth.

Yes, ancient aliens

Although it is a fascinating theory, it does depend on the notion that rocky planets may originate in our cosmos so early on. For life as we know it to exist, it also needs enough heavier elements, such as oxygen, carbon, silicon, nitrogen, etc.

Given that the first stars were generated from hydrogen and helium within tens of millions of years after the “Big Bang,” this could be the theory’s “Achilles Heel.” Prior to that, no heavy elements would have been present for planets to form based on what we now know about the universe’s evolution.

The majority of scientists think that 12.5 billion years ago is when heavier atoms like carbon started to exist.

However, Loeb has suggested that planets around Milky Way low-metallic stars be found in order to validate his theory. It’s also possible that the CMB’s “pockets” or hot areas, sometimes known as “blue spots,” were around for billions of years, which gave heavier elements time to develop and life to emerge.

Other “holy” theories in astrophysics, like the cosmological constant and the anthropic principle, are similarly called into question by Leob’s theory. Even though the conditions in the early cosmos were very different from what we see today, he is convinced that life might have developed there.

This refutes the anthropic argument by arguing that life requires the observed value of the cosmological constant. According to Loeb, even if the cosmological constant was a million times larger than what is currently understood, life may still have developed.

Although there is much disagreement about this hypothesis nowadays, it does present some intriguing queries concerning the nature and genesis of life in the universe. It also lends credence to other intriguing theories regarding the beginning of life on Earth. For example, it might imply that there is some truth to the Panspermia theory, which holds that life originated on several worlds. For those who think there is a plethora of life in the universe just waiting to be discovered by our distant descendants, it might also provide hope.

That concludes your time for today.

Does the universe include only us then? Is this planet really as unique as we think it is? Hopefully so, for if not, we shall be disappointed and alone until the rest of time, along with our ancestors. Not a really appealing idea. Does the universe include only us then? Is this planet really as unique as we think it is? Hopefully so, for if not, we shall be disappointed and alone until the rest of time, along with our ancestors. Not a really appealing idea.

Ancient aliens: Could life be much older than we think? (msn.com)

Extraterrestrial life: Is life a lot older than we realize?

Table of Contents

When did life on Earth initially emerge?

Life: what is it?

Is life on Earth older than it is?

Yes, ancient aliens

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