What? There’s a Colony of Piglets on Our Moon?
The Beresheet spacecraft crash-landed on our moon on April 11th 2019. Though unmanned, there were thousands of little passengers on board, and scientists think they have survived.
Tardigrades, also known as ‘water bears’, or even better, ‘moss piglets’, are eight-legged water-dwelling animals. They are tiny creatures, about 200 micro-meters in length. But don’t let their size fool you – moss piglets are the toughest animals on earth, and now probably the moon.
There is no way these weirdly cute animals are tougher than me…
Well, they are. Tardigrades can endure extreme conditions that would otherwise wipe out any other animal.
High temperatures? – No problem. They can survive in scorching heats of up to 151°C.
Low temperatures? – Tardigrades can handle -272°C for a few minutes.
Extreme pressures? – Can’t even feel it. They remain unscathed at the low pressures of a vacuum. And can also survive at super high pressures six times greater than at the bottom of the Mariana trench.
You get the idea, the list goes on; surviving in those extreme conditions well as dehydration, radiation and toxic waste are just what these moss piglets are good at.
So, what is the key to their superpower?
Cryptobiosis is hibernation taken to the max.
When tardigrades feel that their environment poses a threat, they retract their head and legs to become a little ball, similar to a slater bug. This is known as their tun state. Rolling up into a ball and hiding from danger doesn’t achieve much, not for the tardigrades, nor for us humans. That’s why in this tun state, tardigrades begin to synthesise special molecules called intrinsically disordered proteins (IDPs).
I like to think of IDPs as balls of wool that can be wound up into different shapes and sizes. Their role is to float around in the cell and attach themselves to other molecules and structures, like DNA, membranes, and proteins.
Tardigrades will create IDPs until their cells are filled up with them. And once filled, the cells will vitrify. Vitrification is where the insides of the cells transform from liquid to a solid glass. The glass traps all molecules and structures, locking them in position and stopping them from interacting or breaking down.
And this glass allows tardigrades to withstand extreme environmental pressures.
There are a lot of different types of cryptobiosis, but their underlying processes are all similar. Here are a few:
- Anhydrobiosis is performed during times of extreme dehydration.
- Anoxybiosis, for when there is a lack of oxygen.
- Chemobiosis is a response to environmental toxins.
- Cryobiosis is done during low temperatures.
Why send moss piglets to the moon?
An organisation called Arch Mission Foundation creates archives of human knowledge and sends them off to space. They hope to preserve the knowledge and biology of earth for billions of years to come.
Tardigrades were chosen to be archived and sent to the moon because they are microscopic and can survive for such a long time. But the spacecraft had a faulty engine and crashed, scattering the contents of the archive and the poor moss piglets on the moon.
We probably won’t be seeing a huge community of these tardigrades thriving in space though. This is because tardigrades will have to be in their tun state due to the cold temperatures and low temperatures of space – and they can’t do much beside float around.
But I can’t stop wondering what would happen if tardigrades were able to form a huge army and decide to invade earth; coming to get revenge on the humans for sending them up and abandoning them on the moon.
Here’s a fantastic video for tardigrade fanatics, credit to Journey to the Microcosmos.