Can M-type red dwarfs have habitable planets?

Artist’s illustration of a young red dwarf stripping away a planet’s atmosphere. Credit: NASA, ESA, and D. Player (STScI) (ScitechDaily.com/Discovery Could Dramatically Speed Up the Search for Extraterrestrial Life)

Young  M-type star erupts very often. And those eruptions can strip the atmosphere off their planets. But otherwise, those small stars are extremely long living. And there is always the possibility that those exoplanets could re-form their atmospheres. The reason for that is when an M-type red dwarf goes more mature. It turns restless. 

But young M-type red dwarfs are very active. And that makes forming life on their planets very hard. Also, the gravitation of a red dwarf is not as powerful as the Sun's gravitation. So if an exoplanet form too far from the M-type star it can just fly away and turn into a rogue planet. 

In this text, the main focus is on the forming of liquid water. That thing is one of the primary elements that make the form of life possible. The primary element in this process is that the temperature on the planet is suitable so that hydrogen and oxygen can burn and form water. 

When the planet is locked, there is the possibility that the heat of the star will blow its atmosphere away. The supermassive exoplanets or super-earth can also have oceans, but there is the possibility that those oceans are so hot that there are no lifeforms. When we are thinking about Gliese 436 B, an exoplanet that has hot ice on its surface. In that case, the planet's gravitation will pull water to ice. In those conditions, the gravitation denies the vaporization of the hot ice. 

There is also the possibility that some massive water worlds have conditions where there is ice on the bottom of the ocean. In that case. Massive gravitation with water pressure makes ice to the ocean's bottom. And if the ocean covers the entire planet. It acts like the gas giant's atmosphere. 

Gas giants' atmosphere rotates at different speeds in each latitude. That thing is visible in image two where you can see Jupiter and its stripes. The windspeed in each latitude is different. 

And that forms stripes in their atmosphere. A similar effect can happen in water planets' oceans if it covers the entire planet. That means there would be sectors where the water speed is different and that causes massive friction. 

And if the deep water layer covers the entire planet, the friction between different water layers will turn that giant ocean into an extremely hot place. And in the case of large super-earths gravitation will keep water liquid even if its temperature is far higher than the vaporization point on earth. 

Image 2 Jupiter is a typical gas giant. 

Those giant oceans are forming clouds and the nightside of the planet is freezing. So those things stabilize the temperature of that planet. But then we must realize that gravitation on that planet must be suitable so that the vaporization of water happens in the absolute right temperatures. That temperature is important for enzymes. Also, if the planet's gravitation is strong, it will pull the atmosphere to flat. Of course, the gas in that atmosphere is extremely thick.

But there is also a super-earth with no atmosphere for some other reasons. In the cases when there are exoplanets without water there are no clouds. And clouds are things that protect the planet's surface from powerful radiation. Also, the atmosphere transports heat to the night side of the locked exoplanets. And the gas layer will stabilize the temperature of the exoplanets. 

If a very young exoplanet goes too close to the M-type dwarf that thing can blow the gas layers from the exoplanet. The M-type dwarf is one of the most typical stars in the Universe. And almost all researchers said, that there could be no lifeforms on those planets. The reason for that is those planets are locked. 

But as we know, many variables affect the forming of the atmosphere. There is a time window when the water can form in the atmosphere of exoplanets. If the planet is too hot the radiation from the star can blow its atmosphere away. 

In the case that the planet is too cold. Water cannot form from oxygen and hydrogen. 

Image 3. Planet Mercury

So researchers think that M dwarf blows the atmosphere away from its planets that are in the habitable zone. So in those cases, the planets share the fate of Mercury. 

Planet Mercury is a very small planet. There is the possibility that Mercury ever had an atmosphere. The radiation pressure that comes from the Sun is higher than red, M-type dwarfs. The sun is a G-type star with a surface temperature of 6000 K. And it's much hotter than M- type red dwarfs. The surface temperature of M-type red dwarfs is 2,400–3,700 K. 

And an M-type dwarf is not anything like the Sun at all. It's far smaller and it's colder than our sun. So the data collected from the Sun should not compare with M-type dwarf stars. 

The solar systems of those stars are small. In the solar or stellar system of the Gliese 581, three confirmed exoplanets would fit inside Mercury's orbital. There is the possibility. That there are Earth-size exoplanets with an atmosphere around the M-type dwarfs. 

https://scitechdaily.com/discovery-could-dramatically-speed-up-search-for-extraterrestrial-life/

https://www.sciencenews.org/article/water-world-extrasolar-planet-loaded-hot-ice

https://en.wikipedia.org/wiki/Gliese_581

Image 1: https://scitechdaily.com/discovery-could-dramatically-speed-up-search-for-extraterrestrial-life/

Image 2: https://en.wikipedia.org/wiki/Jupiter

Image 3: https://en.wikipedia.org/wiki/Mercury_(planet)

https://astronomyandtechnology.blogspot.com/

Why Tau Ceti and Epsilon Eridani was selected to target for Ozma message?

Why Tau Ceti and Epsilon Eridani was selected to target for Ozma message?

The "Project Ozma" (1)from the year 1960 was the first attempt to make contact with other civilizations. It was the pilot experiment for the SETI (2)-program and another kind of interesting stuff. When this program was failed to making the contact, that means that things like searching the exoplanets got the scientific basement, and at that time, we didn't have a single observation of the exoplanet. Today we know thousands of exoplanets, and maybe we would make contact with another civilization. 

The famous "Ozma" message to another star was sent to Tau Ceti (3) and Epsilon Eridani (4). The attempt was to make contact with super civilizations, and the idea was that those stars and their solar systems were so different than our own that those civilizations would not threaten us. If the solar system would not have oxygen, there would be no water and the "Ozma" researchers thought that they could find the civilization, what would be the silicon-based, what means that the hypothetical civilization would not even want to land on our planet. 

Epsilon Eridani was another object, where the scientists send so-called "Ozma-Message". The thing is that the Epsilon Eridani is too young to be the home of the advanced civilization is putting brakes to those people's operations, who are working with SETI-program. 

And sometimes people would ask, why those researchers selected the Epsilon Eridani to target for "Ozma-message"? The star was too young for the intelligent civilization, and the answer would not even be hoped to get.

If the answer to Ozma-message would come near the young star, that means the answerer is the colony of a very advanced civilization. "Ozma" was projected, what mission was to look for intelligent and advanced civilizations. And it was the pathfinder for a modern way to make science. Today we know that most of the stars might have some kind of planets around them, and the thank to this thing would belong to the "Ozma"-team. 

The dust and ice makes difficult to see the planets near Epsilon Eridani

They opened the eyes of the people to see, that there would be something, that we don't know. In modern times the way to make science is that the team would research and make observations before we would not laugh or punch anybody. The thing is that the Tau Ceti, Epsilon Eridani, and Alpha Centauri have at least suspected planets orbiting them. And the Tau Ceti and Alpha Centauri (5) have confirmed planets, and Epsilon Eridani has suspected followers. The disk of dust and ice makes difficult to see planets, what are orbiting it.

So the answer is that the scientists thought that if the answer for those messages would come from Epsilon Eridani, the hypothetical answer to out message would come from the transmitter from the very advanced civilization. This hypothetical civilization had the technology, which allows them to create colonies to another star system. 

And if the answer would come near the young star, that must be the colony, what will answer to the message, what the scientists have sent. The target stars would be carefully selected, because "Ozma" was looking for intelligent and advanced civilizations. So the thing, what those people had to find was the star, where is no planet, what has endemic lifeforms. 

(1)

https://en.wikipedia.org/wiki/Project_Ozma

(2)

https://en.wikipedia.org/wiki/Search_for_extraterrestrial_intelligence

(3)

https://en.wikipedia.org/wiki/Tau_Ceti

(4)

https://en.wikipedia.org/wiki/Epsilon_Eridani

(5)

https://en.wikipedia.org/wiki/Alpha_Centauri

Image: 

https://en.wikipedia.org/wiki/Project_Ozma#/media/File:Howard_E._Tatel_Radio_Telescope_-_side.jpg

The planet of water drops

The planet of water drops

The "water drop alien" (or robot) is mentioned in one book, and the thing is that this kind of organism is not so imaginational as we might want to believe. One version of those things is the structure, which seems a little bit like sea-urchin. This structure would have long cilium, which keeps the water above it, and the water makes the protective core for the body of the organism.

Or actually, it might seem like the fluff and the kinetic particle would be inside the water drop. If we are thinking about the alien, what wants to move the fetus in the stomach of some other organism, it can simply create this kind of semen. The mission of the water drop is to deny the operations of the detectors, what mission is to warn the living organisms about the bio danger. And that kinetic semen might be transparent.

Here we must realize that those things might be systems, what mission is to transfer the nerve cells to the body of the other species. So if they are artificial, they might be creatures, that are created by using highly advanced bio- and robotics technology, and they might be very deadly systems. The thing is that those machines could make the layer between the brain core and the inner brains, and that allows taking the body to the control. Or they just can release the morula to the stomach, of the creature, what eats them. So this kind of thing is really dangerous, and that would give breaks for the plans of the journeys to the other solar systems.

Do you know, why I'm talking about structure? The thing is that when we are talking about exobiological systems, we might also mean things like automatized factories, what are left on the planet when living organisms have been gone somewhere. In this case, the hypothetical aliens would simply fill the water storages and make repairments in the solar system before they would continue their journey.

So if we are thinking about the case that some alien civilization could make the base to some water planet that thing means that some kind of systems like "Von Neumann" factories might be below the surface, and if rescue crew doesn't know about them, they can leave those robot factories below the surface. In this case, the robot factories would continue their mission.  Or the aliens would just forget to cut the power when they are disbanding their systems to some planet.

But this kind of system is also interested in the military because that kind of thing allows delivering poisonous material like nerve gas to some bases. In those cases, this kind of hairy ball robots would transfer the nerve agent to the military base, and sensors would not be alarmed, because those systems would be covered by water. And when the water drop is drying those robots would release the poisonous agent in air.