Are we alone in the universe? This is perhaps the greatest unanswered question in astronomy right now. So far we have sent probes in search of life and have found nothing. Sure there is still a lot of space to search but we are still yet to find any evidence of life anywhere else in our solar system.
On Earth, life thrives, and is truly everywhere on the planet. Whether you look inside volcanoes or deep inside Antarctic ice, there are living microorganisms. If life can be found in some of the harshest environments on Earth, it’s not hard to imagine it being able to survive on a distant world too.
Any alien life would have to be suited to a large variety of environments, including the vacuum of space. Amazingly, biologists may have already found alien life, and it’s already located, here on Earth!
Tardigrades Found Everywhere On Earth
In 2007 the space shuttle Endeavour launched into space with some very special passengers and an important experiment. These passengers are commonly referred to as water bears, but their real name is the tardigrade. These little creatures are tiny, only around a mm in size. However, despite their tiny size they are perhaps the pervasive and hardiest creatures on the planet. Tardigrades are found everywhere from Antarctica to jungles to deserts. Essentially any climate you could think of on Earth, there are bound to be some tardigrades living.
Tardigrades The Hardiest Of Creatures
Tardigrades are capable of going decades without food or water. They are able to curl themselves into little balls and shield themselves from the outside world. In this state their metabolism slows to 0.01% of its normal rate. While in this state they can survive all temperatures, pressures, acidities, and levels of dryness naturally possible on Earth.
With all of these traits, it’s easy to imagine that this creature has been successful for a long time. Fossils of tardigrades have been found dating back hundreds of millions of years ago. It’s very likely that tardigrades have been around even longer than this. The Earth has gone through many phases in the last billion years and has had a variety of climates, but through it all, the mighty water bear has survived. However, none of this explains why they were included as part of a mission on the space shuttle.
Tardigrades Survive in Space
Scientists have been aware of tardigrades since the birth of microbiology. They had been studied thoroughly, and introduced to a number of different environments to see how they react and continue to live. Until recently there was only one environment that biologists had left to observe the tardigrade within, the vacuum of space. The plan was to expose water bears to space, along with all its solar radiation, and see how they did.
Amazingly, the tardigrades survived and reacted similarly to any extreme environment that they’ve been on Earth. This was truly an amazing development, the creature seemed invincible! The next step in the scientific process is to ask why. Why has the tardigrade evolved to be so hardy? Why would it ever need to evolve and develop the ability to survive in the vacuum of space? There are many theories on this subject but we will explore the most interesting and revolutionary ideas.
Did Tardigrades Originate In Space?
Evolution has one simple rule, survival of the fittest. Animals best adapted to a specific set of criteria will survive and pass on their genes to the next generation. Mutations happen from generation to generation that may give one branch of the family tree a slight advantage, which then leads to them dominating over the other parts of the tree. When applying this rule to the tardigrades, which we know are capable of surviving in the vacuum of space, then it must be likely that at some point in their history, these creatures were actually in this environment.
Perhaps tardigrades were riding on a rock through outer space. All of the tardigrades not capable of surviving these conditions died, and the ones that were went on to spread their unique traits to their offspring. What this theory is essentially saying is that tardigrades evolved the ability to survive in space because they may have actually come from space. Perhaps the tardigrades we see on Earth today are the descendants of true aliens, landing here millions of years ago.
Did Tardigrades Hitch An Asteroid Ride To Earth?
At first it may seem a little farfetched that tardigrades may have originated from off the Earth. But we have to remember that the early solar system was a volatile place. There used to be a lot more debris orbiting the Sun and colliding with other planets and moons. We know for a fact that massive asteroids were raining down on all of the planets in the solar system. When this occurred, lots of material from the pummeled planet would be thrown into space. It is then possible for some of these rocks to exit the orbit of the planet and travel great distances before landing somewhere else in the solar system.
On Earth, there have been numerous meteorites found that have been confirmed to have come from the surface of Mars, confirming the possibility of this scenario. If a group of tardigrades were in the right spot during a large asteroid strike, they could have survived the immense heat of the initial collision, survived the frigid cold and empty vacuum of space, survived more extreme heat on reentry, and then survived the impact of hitting the surface.
Are Tardigrades Proof Of Extraterrestrial Life?
All of these variables have already been independently confirmed to be possible, so there is a chance this may have happened in the past. This theory confirm would then confirm the existence of extraterrestrial life, and the fact that tardigrades are actually descendants of aliens. It would also fundamentally change our understanding of biology. Expanding our ecosystem past the limits of our atmosphere, into outer space.
The microscopic water bear may have big implications for the rest of our world. If the tardigrade did come from another planet millions, or perhaps, billions of years ago, then it is possible that life on Earth may have descended from an alien species. It is possible that other microorganisms survived the journey as well, and together with the tardigrade, jump started the biology of Earth.