All these worlds...

Started by raymoh, February 03, 2019, 03:07:50 AM

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raymoh

The last aeon

This hypothetical Earth-like exoplanet with three moons orbits a sun-like star together with several other planets.
However, the system is 2 billion years older than the solar system.
Since its formation, the parent star has already become twice as bright and is slowly moving out of the main sequence.
Due to the increasing deterioration of living conditions on the planet the higher plants and animals became extinct more than a billion years ago. Only lichen-like life forms can still withstand the current hot conditions on the surface.
The oceans that once existed have evaporated apart from a few small remnants. A few algae-like organisms still survive there.
In the cloudless sky, only the occasional high-flying ice crystal cloud remains.
There is hardly any oxygen left in the atmosphere as most of the oxygen producers have already died out. Due to the increasing radiation pressure of the brightening sun, the atmosphere will probably be completely destroyed in the next billions of years and swept into space.

We are standing at the hot and shadeless bottom of a former ocean and can see former high coastal reefs in the distance.
"I consider global warming much less dangerous than global dumbing down"   (Lisa Fitz, German comedian)

raymoh

A hypothetical view of the surface of HD 219134 c, the second planet of the HD 219134 system. The system probably has 7 planets, all uninhabitable. The star HD 219134 itself is a sun-like main sequence star at a distance of 21 light years, somewhat smaller, fainter and lower in mass than the sun.
HD 219134 c is a rocky super-Earth with more than 4 times the mass and 1.5 times the diameter of the Earth. Its gravity is twice that of the Earth and its surface temperature is over 500° C. It is so hot that there are puddles of molten metals with a low melting point, such as lead, etc. HD 219134 c revolves very close to its sun, so it has a locked rotation: One side always has day, the other always night.
If the planet has an atmosphere, it probably consists of various volcanic gases under tremendous pressure, more a very stormy dense gas envelope than a layered atmosphere.
It is probably a huge, second Venus, only even more inhospitable. However, it is probably much brighter than on Venus. Due to its proximity, HD 219134 c receives 50-60 times more light and energy from its parent star than the Earth receives from the sun.
"I consider global warming much less dangerous than global dumbing down"   (Lisa Fitz, German comedian)

Dune

Very nice. You must have quite a library of exoplanets already.

Stormlord

Indeed, there are so many planets in the universe!

Meanwhile, scientists say, that the number of planets in the universe is equal to the number of stars!
Unbelievable!

Also... with the James Web Telescope they discovered recently that the number of stars which can be seen is 10 times highter than the number of stars we already noticed!
This is due to the fact, that many stars are not so bright as the most common ones.
Also unbelievable!

STORMLORD

raymoh

It may well be that almost every star has one or more planets. NASA reports 5765 confirmed exoplanets as of March this year, along with a myriad of unconfirmed ones.
As an amateur astronomer, of course, I read information about newly discovered planets or theoretical papers. I try to imagine what it looks like there. That's how many of my pictures are created. Sometimes the picture is there first, and I'm looking for a planet to match it. In doing so, I try to stick to scientific knowledge and the laws of nature. In this respect, my representations of planets are imaginary, but they are not "science fiction" worlds where everything impossible is possible...
"I consider global warming much less dangerous than global dumbing down"   (Lisa Fitz, German comedian)