Explanation: Is this an alien? Probably not, but of all the animals on Earth, the tardigrade might be the best candidate. That's because tardigrades are known to be able to go for decades without food or water, to survive temperatures from near absolute zero to well above the boiling point of water, to survive pressures from near zero to well above that on ocean floors, and to survive direct exposure to dangerous radiations. The far-ranging survivability of these extremophiles was tested in 2011 outside an orbiting space shuttle. Tardigrades are so durable partly because they can repair their own DNA and reduce their body water content to a few percent. Some of these miniature water-bears almost became extraterrestrials in 2011 when they were launched toward to the Martian moon Phobos, and again in 2021 when they were launched toward Earth's own moon, but the former launch failed, and the latter landing crashed. Tardigrades are more common than humans across most of the Earth. Pictured here in a color-enhanced electron micrograph, a millimeter-long tardigrade crawls on moss.
Their Achilles heel though are sustained high temperatures. Even desiccated tardigrades of the toughest species will succumb to sustained temps above 100C. So it is still the seeds of certain plants that will win the ultimate heat race, as tardigrades cannot withstand fire, while seeds can. Nevertheless, both can become lunch in a blink of an eye.
Wait... isn't that the full dust bag from my vacuum cleaner that I threw away just the other day? Has it grown arms and legs? (How many arms and legs, please?) And claws?
But note that you could still insert the vacuum hose in that opening. Just give it a good twist and it will stay there!
Ann
Re: APOD: Tardigrade in Moss (2023 May 21)
Posted: Sun May 21, 2023 6:00 am
by Rauf
zendae wrote: ↑Sun May 21, 2023 4:43 am
Their Achilles heel though are sustained high temperatures. Even desiccated tardigrades of the toughest species will succumb to sustained temps above 100C. So it is still the seeds of certain plants that will win the ultimate heat race, as tardigrades cannot withstand fire, while seeds can. Nevertheless, both can become lunch in a blink of an eye.
Can we digest these creatures? Do we actually eat them without realizing that?
Wait... isn't that the full dust bag from my vacuum cleaner that I threw away just the other day? Has it grown arms and legs? (How many arms and legs, please?) And claws?
But note that you could still insert the vacuum hose in that opening. Just give it a good twist and it will stay there!
Ann
I wonder what's that opening for. Eating maybe? or maybe that hole does the whole job of digestion? Or maybe something else? Or maybe it's just like the vacuum cleaner and cleans everything around??
Greetings from space A dense clump of dust in the Carina Nebula, sculpted by intense radiation of newborn stars, looks like a giant space tardigrade. Credit: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA)
Re: APOD: Tardigrade in Moss (2023 May 21)
Posted: Sun May 21, 2023 8:57 am
by Evenstar
Like any alien toward another alien--what is its anatomy? It might be an interesting though horrifying read to learn of all the little things we don't see but eat daily...or how the menu changes from different parts of the world?
Wait... isn't that the full dust bag from my vacuum cleaner that I threw away just the other day? Has it grown arms and legs? (How many arms and legs, please?) And claws?
But note that you could still insert the vacuum hose in that opening. Just give it a good twist and it will stay there!
Ann
I wonder what's that opening for. Eating maybe? or maybe that hole does the whole job of digestion? Or maybe something else? Or maybe it's just like the vacuum cleaner and cleans everything around??
The opening and surrounding apparatus is of course for the ingestion of food! From the Wikipedia link:
The tubular mouth is armed with stylets, which are used to pierce the plant cells, algae, or small invertebrates on which the tardigrades feed, releasing the body fluids or cell contents. The mouth opens into a triradiate, muscular, sucking pharynx. The stylets are lost when the animal molts, and a new pair is secreted from a pair of glands that lie on either side of the mouth. The pharynx connects to a short esophagus, and then to an intestine that occupies much of the length of the body, which is the main site of digestion. The intestine opens, via a short rectum, to an anus located at the terminal end of the body. Some species only defecate when they molt, leaving the feces behind with the shed cuticle.[24]
Re: APOD: Tardigrade in Moss (2023 May 21)
Posted: Sun May 21, 2023 2:41 pm
by johnnydeep
Two amazing things from this APOD are:
1. From the Wikipedia link:
All adult tardigrades of the same species have the same number of cells (see eutely). Some species have as many as 40,000 cells in each adult, while others have far fewer.[22][23]
Only 40000 cells (or less), and yet they are still so capable! And each individual of a particular Tardigrade species has the same number of those cells as any other individual! Hmm, so are they all then exact clones of each other? I presume not.
2. The video about DNA "rolling" architecture and DNA replication molecular machinery:
Click to play embedded YouTube video.
Re: APOD: Tardigrade in Moss (2023 May 21)
Posted: Sun May 21, 2023 3:38 pm
by zendae
Yes they always reminded me of vacuum cleaner bags. And why not? It's basically what they are, and man seemingly modeled vacuum cleaner bags after them unwittingly. I find it endlessly fascinating that even creatures as odd as these still share most of our features. I don't know if they get digested; I wouldn't think they are designed to withstand hydrochloric acid. But you'd have to eat moss to eat them. They certainly aren't poisonous. I've seen them "scurrying" about on moss; all you need is a magnifying glass. And yes, they certainly have their predators. But, boy, if anything living came from somewhere else, not having developed here, it'd be them. They could live on Mars, tho not Venus. So does life in our Solar System form and evolve the same regardless of the planet? Or did they arrive from elsewhere and are our brothers? Were they around before Pikaia, the father of the notocord?
Re: APOD: Tardigrade in Moss (2023 May 21)
Posted: Sun May 21, 2023 4:25 pm
by Jim Armstrong
I can't believe the spacefolks sent tardigrades to Phobos (failed or not) and the moon.
Where else?
Is there life on other planets?
We will never know now.
Re: APOD: Tardigrade in Moss (2023 May 21)
Posted: Sun May 21, 2023 4:34 pm
by lefthip
My request is simple and the discussion indicates that it is obtainable.
Is there a video available of these creatures in motion?
Re: APOD: Tardigrade in Moss (2023 May 21)
Posted: Sun May 21, 2023 4:39 pm
by Fred the Cat
johnnydeep wrote: ↑Sun May 21, 2023 2:41 pm
Two amazing things from this APOD are:
1. From the Wikipedia link:
All adult tardigrades of the same species have the same number of cells (see eutely). Some species have as many as 40,000 cells in each adult, while others have far fewer.[22][23]
Only 40000 cells (or less), and yet they are still so capable! And each individual of a particular Tardigrade species has the same number of those cells as any other individual! Hmm, so are they all then exact clones of each other? I presume not.
2. The video about DNA "rolling" architecture and DNA replication molecular machinery:
Greetings from space A dense clump of dust in the Carina Nebula, sculpted by intense radiation of newborn stars, looks like a giant space tardigrade. Credit: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA)
Wow, AVAO! I have been fascinated for quite some time by that bright-rimmed Bok globule in the Carina Nebula, but I never realized until now that it looks like a cosmic tardigrade!
Wait... isn't that the full dust bag from my vacuum cleaner that I threw away just the other day? Has it grown arms and legs? (How many arms and legs, please?) And claws?
But note that you could still insert the vacuum hose in that opening. Just give it a good twist and it will stay there!
Ann
I wonder what's that opening for. Eating maybe? or maybe that hole does the whole job of digestion? Or maybe something else? Or maybe it's just like the vacuum cleaner and cleans everything around??
The opening and surrounding apparatus is of course for the ingestion of food! From the Wikipedia link:
The tubular mouth is armed with stylets, which are used to pierce the plant cells, algae, or small invertebrates on which the tardigrades feed, releasing the body fluids or cell contents. The mouth opens into a triradiate, muscular, sucking pharynx. The stylets are lost when the animal molts, and a new pair is secreted from a pair of glands that lie on either side of the mouth. The pharynx connects to a short esophagus, and then to an intestine that occupies much of the length of the body, which is the main site of digestion. The intestine opens, via a short rectum, to an anus located at the terminal end of the body. Some species only defecate when they molt, leaving the feces behind with the shed cuticle.[24]
It's nice to know that that opening is merely for eating and not something else
I wonder what's that opening for. Eating maybe? or maybe that hole does the whole job of digestion? Or maybe something else? Or maybe it's just like the vacuum cleaner and cleans everything around??
The opening and surrounding apparatus is of course for the ingestion of food! From the Wikipedia link:
The tubular mouth is armed with stylets, which are used to pierce the plant cells, algae, or small invertebrates on which the tardigrades feed, releasing the body fluids or cell contents. The mouth opens into a triradiate, muscular, sucking pharynx. The stylets are lost when the animal molts, and a new pair is secreted from a pair of glands that lie on either side of the mouth. The pharynx connects to a short esophagus, and then to an intestine that occupies much of the length of the body, which is the main site of digestion. The intestine opens, via a short rectum, to an anus located at the terminal end of the body. Some species only defecate when they molt, leaving the feces behind with the shed cuticle.[24]
It's nice to know that that opening is merely for eating and not something else
Yeah, tardigrades are "bi-holey", but I think there are some organisms that only have one "opening"...
The opening and surrounding apparatus is of course for the ingestion of food! From the Wikipedia link:
It's nice to know that that opening is merely for eating and not something else
Yeah, tardigrades are "bi-holey", but I think there are some organisms that only have one "opening"...
Ann
Yeah, actually many sea creatures have only one opening for getting and discarding food but I don't want to be in their place.
Another question, is it really safe to send these creatures aboard spacecrafts to Mars and Moon??? Won't they survive and thrive in those planets, contaminating them?
It's nice to know that that opening is merely for eating and not something else :D
Yeah, tardigrades are "bi-holey", but I think there are some organisms that only have one "opening"... :lol2:
Ann
Yeah, actually many sea creatures have only one opening for getting and discarding food :D but I don't want to be in their place.
Another question, is it really safe to send these creatures aboard spacecrafts to Mars and Moon??? Won't they survive and thrive in those planets, contaminating them?
I don't think there is any reason to think that any Earth organisms are capable of surviving very long on either the Moon or Mars.
Re: APOD: Tardigrade in Moss (2023 May 21)
Posted: Mon May 22, 2023 4:13 pm
by Jim Armstrong
"I don't think there is any reason to think that any Earth organisms are capable of surviving very long on either the Moon or Mars."
I am afraid that I don't find that answer to be provable enough to take the chance.
Mars, especially, may have places where tardigrades, parts of their DNA or other things we decide to contaminate it with might survive.
Glibness is not a trait I have found often in APOD.
Re: APOD: Tardigrade in Moss (2023 May 21)
Posted: Mon May 22, 2023 4:20 pm
by Chris Peterson
Jim Armstrong wrote: ↑Mon May 22, 2023 4:13 pm
"I don't think there is any reason to think that any Earth organisms are capable of surviving very long on either the Moon or Mars."
I am afraid that I don't find that answer to be provable enough to take the chance.
Mars, especially, may have places where tardigrades, parts of their DNA or other things we decide to contaminate it with might survive.
Glibness is not a trait I have found often in APOD.
Mars is an incredibly hostile environment. Again, I can think of no lifeform that could survive there, at least no anywhere near the surface (which is where contamination would occur). Life on Earth is highly interconnected. It exists within a system. There is no organism on Earth that can survive without interacting with other species. What do you imagine a tardigrade on Mars would eat?
Re: APOD: Tardigrade in Moss (2023 May 21)
Posted: Mon May 22, 2023 6:58 pm
by orin stepanek
He does look kinda manmade; what with that telephone dial nose?
Re: APOD: Tardigrade in Moss (2023 May 21)
Posted: Mon May 22, 2023 7:32 pm
by johnnydeep
Piglet in a (moss) blanket! (Sorry, just had to say it.)
Jim Armstrong wrote: ↑Mon May 22, 2023 4:13 pm
"I don't think there is any reason to think that any Earth organisms are capable of surviving very long on either the Moon or Mars."
I am afraid that I don't find that answer to be provable enough to take the chance.
Mars, especially, may have places where tardigrades, parts of their DNA or other things we decide to contaminate it with might survive.
Glibness is not a trait I have found often in APOD.
Mars is an incredibly hostile environment. Again, I can think of no lifeform that could survive there, at least no anywhere near the surface (which is where contamination would occur). Life on Earth is highly interconnected. It exists within a system. There is no organism on Earth that can survive without interacting with other species. What do you imagine a tardigrade on Mars would eat?
They won't possibly thrive on a planet with no food and no accessible water. But what if, they go in a state of hibernation, or parts of their body like DNA or certain proteins stays intact, on the long run, maybe some part of their body on some form on the planet. I'm just thinking that it might be too early for us to just send them on another planet, at least without direct human supervision. From what I've read about Tardigrades, they will wake up even after 40 years of total dryness, while if they have water nearby, the won't live no more than a couple months. I think that if we are to send them on other planets, it should be with extreme care.
Jim Armstrong wrote: ↑Mon May 22, 2023 4:13 pm
"I don't think there is any reason to think that any Earth organisms are capable of surviving very long on either the Moon or Mars."
I am afraid that I don't find that answer to be provable enough to take the chance.
Mars, especially, may have places where tardigrades, parts of their DNA or other things we decide to contaminate it with might survive.
Glibness is not a trait I have found often in APOD.
Mars is an incredibly hostile environment. Again, I can think of no lifeform that could survive there, at least no anywhere near the surface (which is where contamination would occur). Life on Earth is highly interconnected. It exists within a system. There is no organism on Earth that can survive without interacting with other species. What do you imagine a tardigrade on Mars would eat?
They won't possibly thrive on a planet with no food and no accessible water. But what if, they go in a state of hibernation, or parts of their body like DNA or certain proteins stays intact, on the long run, maybe some part of their body on some form on the planet. I'm just thinking that it might be too early for us to just send them on another planet, at least without direct human supervision. From what I've read about Tardigrades, they will wake up even after 40 years of total dryness, while if they have water nearby, the won't live no more than a couple months. I think that if we are to send them on other planets, it should be with extreme care.
Sure, they might hibernate for a few weeks or months. But that's about it. Heck, they aren't even considered extremophile life forms!