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Did you guys see eyeball world

woah these pics look amazing!!

found out about this today and i was so pissed that i missed it lol since me and my mum were literally outside in the evening til like 10pm yesterday. but i think it came later than that more like 12ish?

really hoping to see it tonight (in the uk) im gonna keep going out and checking i CANT MISS THIS. fingers crossed!

NORTHERN HEMISPHERE ARE YALL LOOKING AT THE SKY

Did some space digital art, cause I felt like it lmao

I did some space themed art, and I lowkey came up with the idea while listening to "Hallucinate" by Dua Lipa ~(°^°)~ so yea

Above image is a pride flag with every color band represented by a NASA image. White is Earth clouds, pink is aurora, blue is the Sun in a specific wavelength, brown is Jupiter clouds, black is the Hubble deep field, red is the top of sprites, orange is a Mars crater, yellow is the surface of Io, green is a lake with algae, blue is Neptune, and purple is the Crab Nebula in a specific wavelength.

Every human being has a basic instinct: to help each other out. If a hiker gets lost in the mountains, people will coordinate a search. If a train crashes, people will line up to give blood. If an earthquake levels a city, people all over the world will send emergency supplies. This is so fundamentally human that it’s found in every culture without exception. Yes, there are assholes who just don’t care, but they’re massively outnumbered by the people who do.

Edited this on a plane. Its awful but i wanted to contribute to the trash heap (/lovingly) of a meme.

Space, for writers who can’t be bothered

Space. The final frontier. The inky abyss. The great void. The black. The Big Nothing. What a fantastic playground of opportunity, especially for writers. However, even space has rules.

It's time to clarify some things about space. Too many times I have seen astronomical terms thrown about carelessly in media with no regard for their specific meanings, or space depicted as some fantastical realm where everything is possible.

It’s not.

We’ve spent hundreds of years figuring out how the heavens work, so the least you could do is a bit of googling to make sure that word means what you think it means. I know many writers of space-based fiction are, in fact, space geeks and do respect the laws of physics and the terminology laid forth by experts, and I thank you for that! But for others, here’s a crash course in the fundamentals of space and a few side notes to clear up common misconceptions.

Even if you’re a space-fantasy writer who likes to handwave physics, it’s important to understand what you’re ignoring and what that means for the rest of your world (because physics is an interdependent system- if one thing breaks, everything changes.)

Fundamental Terms

Planet

A planet is a roughly spherical object that does not experience sustained atomic fusion, and usually orbits a star (or, if it’s lucky, more than one star). They are very large compared to humans, and almost never have one single biome. Planets are only spherical, because gravity acts evenly in all directions. Any solid object large enough to be a planet will be spherical, unless engineered otherwise. Engineering otherwise is dangerous, difficult, and not highly recommended. Any irregularly shaped natural object is not a planet, and likely will not have an atmosphere either. Most often these are asteroids or comets.

Asteroid vs Comet

The line between asteroid and comet is fuzzy, yes, but there is a distinct difference. Asteroids are composed of rock and/or metals and do not sublimate (evaporate directly from solid to gas). Comets are composed of ice and maybe some rock, and definitely sublimate. Comets have tails of gas because of this. Bonus misconception factoid: Asteroid and comet fields aren’t even close to crowded, in human scale terms. Objects in the solar asteroid belt are almost always several million kilometers from the other objects, because of Rule 1, and thanks to their relatively small sizes, they’d look like dots at best when viewed from each other’s vicinities.

Star

A star is a large spherical object made of ionized gas that does experience sustained atomic fusion, and that’s why they glow. Stars are best summarized as giant slow-motion nuclear fireballs. They emit energy in the form of radiation, a small slice of which we can see as visible light. A star’s color is strictly dependent on temperature, ranging from red (cool) to blue (super hot) with orange (less cool), yellow (medium), and white-ish (sort of hot) in between. They have very strong magnetic fields, and occasionally small bits of them will violently drift off into space (that is a flare). The terms “star” and “sun” are basically synonymous, but if you want to be nuanced about it, a sun is a star that has planets.

Stellar Death and Supernovae

The death of a star is not fast. It is very, very slow. The star Betelgeuse in the constellation of Orion has been dying (in its red giant phase) for several million years, and isn’t anticipated to explode in its supernova phase for another several thousand. Supernovas themselves are not instantaneous, either; while the inciting core collapse takes just one-fourth of a second, the resulting internal shockwave will take hours to actually break the surface. The expansion of the shockwave takes months. As a dramatic device in storytelling, real supernovae are only useful when you work on extended timescales.

Star system

Star systems are composed of a central star or multiple stars orbiting each other, and occasionally they have planets. Typically, star systems do not exceed more than a lightyear or two in diameter, though complex systems close to galactic centers or in star clusters may have lightyear diameters in the double digits. A good rule of thumb is that the higher the number of stars in a system, the less likely it is to have planets. This is because the gravity interactions will be insanely complicated and the probability of stable orbits is low in complex systems. However, for systems with planets, almost all orbits will be aligned to a single plane, called the ecliptic. Additionally, almost all objects in a system will orbit and spin in the same direction, because the angular momentum from the system’s formation is preserved in its current state. Star systems also tend to be rather spaced out from each other (refer to Rule 1.) The terms “solar system” and “star system” are basically synonymous.

Star cluster

Star clusters are groups of stars numbering between the tens and the thousands that are all loosely bound to each other by their mutual gravity. Stars are generally closer to each other within star clusters than in broader galactic space, which allows radiation to accumulate instead of dissipating in open space. Star clusters typically aren’t very nice places to live if you’re allergic to ionizing radiation (which, incidentally, carbon-based life very much is.)

Galaxy

Galaxies are immense collections of star systems and nebulae, bound together by the combined mutual gravity of every object within them. Small galaxies are composed of hundreds of thousands of star systems, while larger galaxies are composed of billions or even trillions of star systems. Astronomers estimate that the Milky Way, the galaxy in which our star system lies, is composed of three or four hundred billion star systems. Earth’s star system orbits the Milky Way’s center of gravity, the galactic core, at a distance of about 25000 lightyears; just a quarter of the Milky Way galaxy’s estimated total diameter.

Star system vs Galaxy

“Galaxy” and “star system” are not synonymous, not even technically. The scale difference alone should be enough to help differentiate, but it’s also worth restating the nested relationship between the two: galaxies are composed of billions of star systems. Similarly, “intergalactic” and “interstellar” are not synonymous either. “Interstellar” means “between or among star systems.” “Intergalactic,” therefore, means “between or among galaxies.” And as you will see in the next section, the difference is very significant.

Rules

Rule 1: Space is big.

Just absurdly, incomprehensibly, brain-meltingly big. The technical term for it is humungous, or if you want to get really fancy, fuck-off huge. This is why distances between stars are measured in length units equal to the distance that light, the fastest thing in the universe (Rule 2), travels in one metric year. Light may be fast, but space is more than vast enough to make photons into snails.

Planets orbiting within the same star system may be close in the cosmic sense, but on the human scale, they tend to be dishearteningly distant. When the orbits of Earth and Mars bring them closest together (a phenomenon called opposition), they are still 54 million kilometers apart. Radio signals sent between Earth and Mars at opposition have a travel time of about three minutes. At their most separated (401 million kilometers), a signal from Earth would reach Mars in 22 and a half minutes… if the sun wasn’t in the way. Which it is, because it’s the centerpoint of the aforementioned ecliptic plane.

Star systems, as mentioned before, tend to be even more remote from each other. The closest star system to our own, the triple-star system Alpha Centauri, is roughly 4.35 lightyears away. It takes light a good four years and four months or so to get from Alpha Centauri to Earth, but it would take current propulsion technology eons longer to make the trip. The closest known black hole to our star system is 6070 lightyears away in the constellation of Cygnus, which means the radiation we observe from the plasma orbiting it was first flung in our direction right about when Eastern Europe figured out what metal was.

The distance between galaxies is even more vast, and far emptier. The starless abyss between the outskirts of the Andromeda galaxy, the closest major spiral galaxy, and the edge of the Milky Way, our home galaxy, is two and a half million lightyears. The image of the Andromeda galaxy we see when we look at it now is composed of light that left the actual Andromeda galaxy right when our dear Australopithecus ancestors first decided that walking upright was pretty neat.

It’s also worth noting that planets, too, are rather colossal. Even dwarf planets are large in human terms, with the smallest known dwarf planet (Ceres) having a surface area of 2.7 million square kilometers. The entire country of Kazakhstan, population 18 million, is 2.7 million square kilometers. Argentina is roughly the same size, and has a population of just under 45 million. Planet Earth has a surface area of 510 million square kilometers and a population of seven and a half billion, even though over half of the surface is uninhabitable because it’s just liquid water.

When the fate of the world is in the balance, it almost always comes down to one location on the planet’s surface. This is unbelievably illogical. Realistically, planetary-scale warfare would be composed of innumerable smaller conflicts, with no single battle being the sole influence of the war’s tide. The concept of real planetary warfare is horrifying in its vastness, even if planets themselves are relative dust specks in an infinite void.

In short, space is big, and so are the things within it.

Rule 2: Light is the fastest thing in the universe.

The speed of light is just under 300 million meters per second, or just over 670 million miles per hour. Only particles that don’t have mass can move at that speed, because the amount of energy needed to accelerate an object with mass to the speed of light is infinite. In order for something to move faster than the speed of light in real space, it would actually have to have negative mass, which is theoretically impossible for any number of reasons. Please don’t mess with tachyons unless you want all of physics to break.

If you absolutely must get somewhere before a photon does, don’t try to outright break the speed limit. You literally cannot. Instead, try working around it. Make a wormhole, bend space to amplify your speed, move the universe around you, or even take the scenic route through some other dimension we haven’t quite found yet. Breaking the light barrier just won’t work.

Rule 3: Everything in the universe is moving.

If you were to somehow figure out how to entirely stop moving through space, to attain a true velocity of zero relative to an absolutely fixed point in space, it would seem that everything else in the universe just started zipping about at mortifying speeds. This is because the amount of energy in the universe is finite, energy is conserved within matter, and the Big Bang at the start of time had a hell of a lot of energy to dish out. All of this comes to the takeaway that nothing is stationary, ever. Planets move around their stars, stars move around within their galaxies, galaxies move around each other. They all do this dance because of Rule 4.

Rule 4: Gravity is the conductor of the space motion ballet.

Sure you have rocket engines making thrust, and photons carry momentum (that subject is a whole separate lecture), but the ultimate arbiter of motion, even at the speed of light, is gravity. For reasons we still don’t quite understand, objects make dents in three-dimensional spacetime, and these dents affect the way that other objects move. This is why black holes exist, but their name is misleading. Black holes are not two-dimensional holes in space, not even close. They’re so much cooler than that.

Black holes are three-dimensional, spherical objects that are dense enough to bend space to the point where even photons aren’t moving fast enough to escape their gravity. Light moving in the vicinity of black holes is forced to travel in extremely distorted paths, and some may stray too close to the event horizon. The event horizon of a black hole is a sphere-shaped theoretical boundary where the speed an object needs in order to escape the gravitational pull of the black hole is equal to the speed of light.

Rule 5: Inertia can and will liquefy you.

Inertia is the property of objects to resist changing the way they are moving through space. Yes, yes, high school physics, Newton ruined everything for everyone, etc. The difference between moving about on a planet and moving in outer space is that friction does not exist in a vacuum. This is both a blessing and a curse.

Because of Rule 1 (space is big), actually getting anywhere in the cosmos within a reasonable timeframe requires moving at absolutely blistering speeds. Here is where inertia becomes the double edged sword: because there is no friction in a vacuum, getting to the speed you want is no longer a big problem, while slowing down or banking to starboard suddenly is. You can no longer rely on the ground or the atmosphere to do the work for you, which means you spend more energy maneuvering. Another fresh problem is the rate at which you adjust your motion, because humans are fragile meat gundams and inertia is a bitch.

When considering how fast you want something to move, consider first if it has humans (or other lifeforms) on or in it. This will influence how quickly the thing can accelerate, and thus the time it will take for your chosen something to reach the desired speed. Comfortably, humans can accelerate at about ten meters per second squared indefinitely, because this is the gravitational pull of Earth on the surface. Accelerating twice as fast for just as long is a little uncomfortable, but most people would survive it. Any more than fifty meters per second squared of sustained acceleration is pushing it, and 100 meters per second squared is generally the upper limit for acceleration longer than half a minute or so. Please also keep in mind that this also applies to slowing down, as mentioned previously.

Rule 6: Relativity exists, but you can ignore it if you’re sneaky.

More high school physics! This time, Einstein ruins everything by stating that time and space are the same thing, and that Greenwich Mean Time can’t be applied to the whole universe at once. This is founded on Rule 2 (light is the Speediest Gonzalez), and Einstein insisted this rule implies that time is not constant everywhere because humans have a defined frame of reference. However, if you get clever with rule 2, this rule is effectively null and void.

By traveling to a distant point in the universe in a way that’s not technically faster than light but gets you there anyways, you may see yourself leave your point of origin, but that doesn’t change the fact that you already left. It’s just a side effect of you beating an eyeful of photons in a vanity race. Bonus points if you have some sort of instant communication device with which to sync your watches to GMT back home, because that’ll really give ol’ Albert the middle finger.

To Summarize:

Google the terms you use to make sure you’re using them right, or just read this guide

Space has a few universal rules that can’t be responsibly ignored, which are as follows:

Space is big

Light is the fastest thing in existence but also space is big

Everything is moving all the time, through space, which is big

Gravity is why these things move since it’s the only force that acts on a large enough scale to do so, because space is big

Inertia sucks because space is big, but that’s okay because space is big

Relativity also sucks but you can ignore it if you get clever with Rule 2 because space is big

Galaxy Classifications

Because space is a special interest of mine (I mean, I’m the astronomer of the collective for a reason), I thought I’d spread some knowledge. So, today we’re going to be discussing galaxy classifications, what makes each unique, and I’ll be showing some examples of each.

First of all, there are three main types of galaxies; Spiral (with barred spiral being lumped in), Elliptical, and Irregular. We’ll talk about the Elliptical first.

Class- Elliptical

An elliptical galaxy is a galaxy that takes on a stretched out circle-like appearance, like an ellipse, hence the name. It’s unclear how common elliptical galaxies are, since they contain far less gas and dust than spirals, which are known for being hotbeds of star formation, and therefore fewer new (and brighter) stars are born in these galaxies. The majority of stars are much older and give off dimmer red light, and as a result, it’s tougher to see elliptical galaxies.

Example:

This is NGC 1316, an elliptical galaxy in the Fornax star cluster. Note how dim the light is around everything but its center, and how little dust there is, save for the black streaks around the inner ‘disk’ nearest the core. Given these characteristics, it becomes pretty clear why it takes longer for us to find them.

Sometimes we find elliptical galaxies that came about as a result of two spirals crashing into each other over billions of years.

Example:

Notice the two different cores of what used to be spiral galaxies. These are NGC 2292 and 2293, two spiral galaxies that collided in Canis Major, and flung their stars, gas and dust outward (note the ring of dust on the outer edge of the galaxy) and created an elliptical galaxy.

Class- Spiral Galaxy

Next, let’s talk about spiral galaxies. Everyone knows what a spiral looks like. It’s a pinwheel, with several self-perpetuating, long lived spinning arms and contains plenty of newborn and young stars, as well as a large enough amount of gas and dust to fuel star birth. Our own Milky Way is a spiral galaxy, as is the well known Andromeda galaxy, which we’re currently on a course to collide with in about 4-5 billion years.

It’s estimated that about 70% of the galaxies closest to us are spirals, and they make up most galaxies we discover. Spirals are known to be star forming factories, responsible for the majority of newborn stars, and therefore shine brighter than other galaxy types with older and dimmer stars.

Example:

This is Messier 81, or M81, a spiral galaxy in Ursa Major and the largest in its group. Note the distinct arms, the copious amounts of space dust and gasses, and the much brighter, much younger stars (as recent as a few million years old) in its arms while its oldest stars remain closer to the center.

At its center is a black hole of about 70 million solar masses, 15 times bigger than our own central black hole, Sagittarius A*. You can actually see this galaxy right now, being that it’s April at the time of posting this, through binoculars. Though, it will only look like a small, dim grey smudge. A small telescope, however, would be able to see its core if you point it in the right place.

Now. Barred spiral galaxies. Simply put, they’re just spiral galaxies that have a central bar shaped arm running through the middle made of stars and tend to look a little more squished than typical spirals.

Example:

This is NGC 1097, a barred spiral galaxy in the Fornax cluster. Note the somewhat almond shaped appearance, the strip of dust and stars running across the galaxy’s center. These bars are actually found in about half of all spiral galaxies, and a recent study headed by Debra and Bruce Elmegreen and Kartik Sheth confirms that the formation of bars is a sign of a galaxy reaching full maturity as the ‘formative years’ come to an end.

Class- Irregular

And finally, we come to irregular galaxies. The oddballs of the universe that don’t look like galaxies at all. They’re called irregular, because they can’t be placed neatly into the Hubble sequence, something Edwin Hubble came up with in 1926 to categorize galaxies. Some feature some structure, like a spiral’s arm, but not enough to place them into the sequence cleanly. Most have no distinct regular shape like spiral or elliptical galaxies, with no trace of a nuclear bulge or spiral arm structure. They’re thought to be deformed spiral or elliptical galaxies, ripped apart by uneven external gravitational forces.

Example:

This is NGC 1569, a dwarf irregular starburst galaxy with constant star formation activity (as denoted by the bright pink near the ‘center’) in Camelopardalis. Note the lack of a nuclear bulge, no distinct shape, and in particular for this one, the unusual amount of star birthing activity. It’s called ‘starburst’ for how fast it puts out stars, at a rate about 10 to the third power greater than a normal galaxy.

This really is just the tip of the iceberg when it comes to exploring galaxies (I didn’t even touch on lenticular galaxies or Seyfert spirals), but I hope this little glance at the universe was informative all the same.

-Astronomer

Seeing that the astronaut applications are open and knowing that you have absolutely no chance of applying or getting in be like

Wanderer of space, writer of stories. What will this traveller do next?

Inktober Day 11: Wander

Obligatory Markiplier Post for this year, yippee

Sketch under the cut

My pens hate me <3

Do you ever think about the infinite