As my favorite comic strip artist once said, "The surest sign that intelligent life exists
elsewhere in the universe is that is none of it has tried to contact us."
But as it turns out, we earthlings may be luckier than we previously thought.
Scientists have new evidence that one element in particular may be essential to creating
life, and that it could be pretty scarce in the rest of the universe.
So, are we really all alone out here on our blue dot?
There are a handful of chemical elements that are the primary building blocks of most life
on Earth, and some of the big ones are oxygen, carbon, hydrogen, and nitrogen.
Those four are a few of the so-called 'bulk' elements that make up our muscles and organs
and that we need to consume a lot of to stay alive.
(You may have noticed that breathing is pretty important).
But the another element, phosphorus, also has an essential task: it's the key additional
piece that makes up our DNA and RNA (our genetic makeup inside which the rest of our existence
is encoded) and our ATP, which is how we store and use energy.
It's like if you were a book being written by hand by a monk who's looking at instructions
in another book.
Without phosphorus, not only is there no instruction book, but there's no monk.
And all the pages are on the floor.
Maybe this wasn't the best metaphor.
So.
Phosphorus is necessary to create and sustain almost all life as we know it.
But hold on--let's back up.
How is it that Earth has these essential elements in the first place?
Before the Big Bang, there was nothing.
Then the Big Bang, and there was A LOT of really hot something, mostly super-light elements
like hydrogen and helium, which together make up 99% of the matter in the universe .
NASA scientists have determined that the other life-giving elements are created inside the
core of stars that then become supernovae, which is when massive, dying stars explode
and eject their mass out into the universe in a catastrophic eruption, spitting out all
kinds of stuff...including the heavier elements needed for life.
Scientists think that meteorites carrying phosphorus came from a nearby exploding star
and plonked down onto Earth at just the right time to get included in making Earth's "proto-biomolecules",
or the precursors to what we now recognize as the basic molecules that make up our living
systems.
The thing is, new evidence indicates that phosphorus-creating supernovae may be kinda
rare.
Researchers observing the Crab Nebula, which is the remnant of a supernova so big and so
bright it was first noticed by us Earth-dwellers in the year 1054, have found that it contains
much less phosphorus than our models have predicted.
Using telescopes to observe infrared light readings from the phosphorus and iron traces
in the Crab Nebula, researchers compared it to a previously studied supernova remnant,
Cassiopeia A. The Crab Nebula phosphorous readings are far lower than those for Cass
A, suggesting that supernovae contents could vary dramatically.
This means that even if a planet has habitable qualities similar to Earth's, they may not
be near a supernova, and even if they are, that supernova may be spitting out different
elements than the ones we were touched by, meaning life like ours may be even more uncommon
than we thought.
And we've always thought we were pretty darn lucky.
But I mean, what about other kinds of life?
What if there's life out there that uses the elements we know of in vastly different
ways and doesn't need DNA because it's a life structure we can't even comprehend?
Or if there are elements we haven't even discovered out there in the universe creating
life that we have no idea how to picture?
There's no scientific evidence for this, at all, but I'm just saying, it's cool
to think about.
Thanks for tuning in and don't forget to subscribe to Seeker for more SPACE...Check
out this video about sending a submarine to Titan, and.
Fun fact, the neutron star (or ex-supernova) at the center of the Crab Nebula is as massive
as our Sun, but is only the size of a small town.
That's so dense that a single teaspoon would weigh a billion tons.
I'm Maren, thanks for watching Seeker.
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