The potentially rocky exoplanet size comparison
This is a chart I've made of various rocky exoplanets, compared to Earth. They are:

WD 1145+017 b: the smallest known exoplanet, its about the size of Haumea

Draugr, Poltergeist, and Phobetor: These were some of the first few exoplanets ever discovered, and they orbit a dead star called a pulsar. Draugr is about the size of Mercury and Poltergeist and Phobetor are 4x bigger than Earth.

Kua'kua: Also known as LHS 3844 b, this is an exoplanet about the size of Earth, which has been studied by the James Webb Space Telescope and was confirmed to have almost no atmosphere.

Kepler-452 b: a potentially habitable exoplanet 5x the mass of Earth.

Janssen: this one's also known as 55 cancri e, but is properly named Janssen. It's a lava planet 8x the mass of Earth.

Kepler-22b: another potentially habitable exoplanet, about 9x the mass of earth

Enaiposha: This planet, also known as GJ 1214b, is the most likely candidate we have for a planet made almost entirely of water, or an ocean planet. "Enaiposha" literally means "large body of water" in the Maa language.

TOI-849b: the largest known rocky planet, at 40x the mass of Earth. It's most likely the exposed core of a gas giant that got its atmosphere blown away by radiation. This is also known as a Chthonian Planet.

Here's part one of the Colonization of the Asteroid Belt, part of my Colonization of the Solar System series im uploading to youtube!
www.youtube.com/watch?v=l-TA3LQef9A

Just found a second size comparison I thought was cool

This is the planet Janssen compared to Earth and Mars.
Janssen is a giant lava planet 8x more massive than Earth orbiting a star called Copernicus.

These are 10 real gas giant exoplanets in our galaxy, with jupiter for comparison.

All 10 of these planets are "hot Jupiters" meaning they're large, gas giant planets that are scorching hot. Some of these reach over 2,000 degrees.
(Also note: other than HD 189733 b, we dont know what these planets look like, these are just artists interpretations. Even for HD 189733b, we only know that its blue in color, not what its clouds look like)

india has become the first country to land on the south pole of the moon with their successful chandrayaan-3 mission today

Telling Minecraft players about planets 16
technically this is like 20 but i didnt count the last few so whatever

Today's planet is Perwana

Perwana is a gas giant planet orbiting a star called Shama. It's about half the mass of Jupiter and orbits its star between the distance Earth and Mars orbit the Sun.
Shama, the star, is smaller than the Sun and only half as bright.

"Shama" is an Urdu word for "lamp" or "flame", and Perwana is another Urdu word meaning "moth". The planet and star were named by astronomers from Pakistan in 2019. They're also called HD 99109 and HD 99109 b respectively, but the Perwana and Shama names are less boring and recognized as official, so I'll use them.

So, Shama and Perwana make up a pretty typical stellar system. A small star orbited by a small gas giant. If it was just this, the system would be pretty unremarkable, we know of hundreds just like it.
What makes it unique is what could be there.

A study from 2007 suggests that Perwana could host Earth-sized trojan planets in its orbit.
But first, what is a trojan planet?

A trojan is a type of object caught in the orbit of a larger planet, trapped in places called Lagrange Points, where the gravity of a planet and the star it orbits are equal, making the objects stay in place. All the planets in our solar system have trojan asteroids caught in our orbits. Earth has a few, Jupiter has a few thousand. Theoretically, a planet could form in these Lagrange points, making the two planets share an orbit.
However, this is usually unstable, as the gravity of the two planets eventually cause them to collide.
However, with Perwana, its different. Because of the size of the planet and the star, as well as Perwana's distance, stable trojan planets are possible. They could even be the size of Earth.

These trojan planets are only hypothetical, and havent been seen, but they could even potentially be habitable, because Perwana is inside the outer edge of Shama's habitable zone, where the temperature is right for liquid water to exist on a planet's surface.
This means that, optimistically, Perwana could potentially have two Earth-sized habitable planets in its Lagrange points, immediately doubling the chances for life to exist in the system.

The loneliest stars in the Universe

Most stars form inside galaxies. A galaxy is just a massive conglomeration of millions or billions of stars with a lot of gas, dark matter, and usually, a really big black hole in the middle.
But galaxies arent peaceful. Galaxies collide with each other, merge, destroy each other, etc. When you look at the Universe on large time scales, the galaxies are constantly fighting each other. Our galaxy, the Milky Way is going to collide with the much bigger Andromeda Galaxy in 4 billion years.

Luckily, galaxy collisions are mostly safe. Galaxies are very spread out, so even when they collide, the chances of individual stars or planets hitting each other is very, very low.
Key word there is mostly safe.

Sometimes, gravitational disturbances from galaxy collisions can throw stars out of galaxies entirely. Like, for example, a star is in the path of the Andromeda Galaxy's central black hole as its moving toward the center of the milky way. the gravity from that black hole could slingshot the star out of the galaxy entirely.

These types of stars are called rogue stars, or stars without galaxies. They are the loneliest objects in the universe. Some of them could have planets, but those planets are equally lonely. For any aliens that could exist on a planet orbiting a rogue star, they would be trapped there forever, unable to ever leave or expand, because all the other stars would be too far away.

Two facts make this even scarier.

1. Some estimates say half of all the stars in the universe are rogue stars.
2. When the Milky Way/Andromeda collision happens in 4 billion years, its estimated that our solar system has a 12% chance of being ejected from the galaxy and becoming a rogue star.

Constellations vs. actual constellations 
another space post wow

I’m sure most of you know what a constellation is. It’s a group of stars in our sky that look like they make up some sort of shape. But what some people don’t know is that the stars in constellations don’t actually have anything to do with each other.

Most stars in constellations don’t stay in their constellations forever, and move around the galaxy on million year-long journeys. In just a few hundred thousand years, this “stellar drift” will make all of our constellations unrecognizable. The dinosaurs saw a completely different set of stars than we do now.
The exception to this rule is the Big Dipper. Unlike the other constellations, almost all the stars in the big dipper (except for Dubhe and Alkaid) actually are moving together and are close to each other. They’re a part of a large group of stars called the Ursa Major Moving Group. A moving group is a bunch of stars that formed at the same time in the same area, and are moving in the same direction.

The Sun is actually inside outskirts of the Ursa Major Moving Group right now. But it’s not a part of it, as the solar system is 12 times older than the rest of the moving group. A few million years ago, the Sun just so happened to wander into the moving group, but we’re on our way out now.

There are a lot of moving groups in our sky, and sort of act like constellations that are better than constellations, because the stars in them are actually linked. The most well known moving groups are the Beta Pictoris Moving Group, the Arcturus Stream, and the Pleiades. They’re named after the brightest stars in the group, that being Beta Pictoris and Arcturus (the Pleiades means “seven sisters” because there are seven bright stars in it)

The Sun used to be a part of its own moving group, but as it aged, the moving group eventually fell apart as the stars drifted around the galaxy. But some stars from our ancient moving group are still around today. The siblings of the Sun are somewhere in the Milky Way, waiting to be discovered.

So, TLDR:
Constellations are lame, moving groups are better

on this episode of telling minecraft players about planets: What the heck is TOI 849 b

TOI-849b is a real planet discovered by the TESS telescope. It orbits way too close to its star to be habitable and is a few thousand degrees in temperature. We know of a lot of planets like this, so this isn’t that surprising.

What is surprising is its size.
The radius of the planet is about 3x bigger than earth’s, smaller than Neptune and making it a rocky planet, not a gas giant.

Rocky planets are usually only 8x bigger than earth in mass, maximum. That means the biggest rocky planets are only about 8 times heavier than Earth. Two examples of that are the planets Janssen and Enaiposha, both rocky planets 8x the mass of earth (though Enaiposha is thought to be an ocean planet).

TOI 849b is forty times the mass of Earth

It’s a planet made of rocks that’s heavier than Uranus and Neptune combined. That’s really not possible. It’s by far the largest rocky planet we’ve ever found.

There’s only one theory we have to explain TOI 849b: it used to be a gas giant, but all the gas was blown away into space from the radiation from its star, leaving nothing but the planet’s massive core behind.
This would make TOI 849b a very rare class of planet called a Chthonia, or a gas giant planet without any gas, just a rocky core. So far, it being a Chthonia is the best explanation for how it exists.

Fun fact: there are things called cotton candy planets that actually exist

A cotton candy planet, also called a puffball planet or a superpuff, is a planet with extremely low density. For example, the planet Dimidium, which has a mass half of Jupiter's (meaning it "weighs" half Jupiter does) but is bigger than jupiter in radius. Its physically larger in size, but weighs less. This means its density is very low.
We dont really know why puffball planets get so big while being comparatively light, but we think it has something to do with their temperature. Dimidium, for example, is over 1,000 degrees. So, very hot gas giant planets like Dimidium are usually puffy.

bUT THEN KEPLER 51 HAD TO RUIN IT ALL

Kepler-51 is a star that has three known planets orbiting it. None of them have official names and so are just called Kepler-51 b, c, and d. All of them are about 3-6x heavier than Earth, which should make them rocky planets like Earth, but for some reason are the size of jupiter
(For comparison, jupiter is 300 times heavier than earth, but these planets arent even a tenth of that but are the size of jupiter)
this is the first system we know of to have three puffball planets. These planets, due to their mass, should be only a bit bigger than earth in radius (much smaller than neptune in that picture at the bottom) but for some reason aren't.

To complicate things even more, Kepler-51's planets arent even hot. Their temperatures range from 200-600 degrees fahrenheit, which sounds hot, but is very cold compared to Dimidium and the other puffball planets we've found. Those temperatures shouldnt be hot enough for puffball planets as we know them to form. So, we need a new theory for how these planets formed, and so far, we dont have one.
there are the planets compared to our solar system

the next few billion years will be fun

so many of you might know about the collision with the andromeda galaxy the milky way will have in about 4 billion years. If you don’t, here’s a quick explanation:
The milky way galaxy, our galaxy, is on a collision course with the bigger andromeda galaxy. The two will collide in about 4 billion years. The solar system will survive, and a new galaxy called Milkomeda will form.

But that’s not the only collision the milky way or andromeda will have.
In about 2.4 billion years, the milky way will collide with the Large Magellanic Cloud, a galaxy that orbits the milky way like a moon orbits a planet.

This is less certain, but in about 2.8 billion years, andromeda will collide with the triangulum galaxy, the third largest galaxy in our local group. (andromeda is first, milky way is second, triangulum is third, large magellanic cloud is fourth)

Those are the major collisions we can look forward to, but there will also be a few minor collisions with small dwarf galaxies with only a few thousand stars.



The milky way and andromeda collision will be the last major collision for the local group ever. After that, all the remaining small dwarf galaxies will slowly merge with Milkomeda until the only thing left in our local group is one giant super-galaxy. No new galaxies will form or collide, because the expansion of the universe has made all other galaxies and the material to form them too spread out. Milkomeda will be the last galaxy humans will ever inhabit.

But yeah, galaxies aren’t super stable, they’re constantly colliding and merging and throwing stars everywhere

Just made a trailer for my Colonization of the Solar System series, here it is: www.youtube.com/watch?v=oS0CSCU_cNw

Third wall post in a day wow
whatever i thought this was worth sharing

This is ExoColors, a post someone made on Discord that I thought was cool. This shows what we believe to be the true colors of various gas giant planets around our galaxy.
Note that I don't think this was a professional, just someone far more knowledgeable than I am. Either way, it seems to be pretty accurate with the data I can find.

my personal favorite colored planet would be WASP-103b or Astrolabos. Tell me yours in the comments

I’ve made part 2 of my colonization of mars series
https://youtu.be/y8nAfKhTWkE
I’d say it’s pretty good

I also have the colonization of the moon and future of earth for this whole future of humanity project i’m doing, so any support is really appreciated