Hydrogen_Dragon

Exoatmospheric kill vehicles (EKV's) are weapons designed to destroy targets in space. Intercepting ballistic missiles in space requires immense precision because they move very fast. Explosives are heavy, so most EKV's don't have them so they can fit on a rocket. Instead, they need to impact the target directly.

I just thought it was important to mention that the current best method for destroying nuclear ballistic missiles is a literal space sword.

This drawing is traced from a 3D model I made --- because I don't know how to render. It is based on the GMD's EKV by Raytheon, with some extendable swords from the AGM-114X that I thought would look cool on it.

The hollows may be the most interesting place on Mercury. It is not well understood how the hollows formed, but they were likely formed by sublimating sulfur, leaving behind hollowed-out valleys [1]. The blue halos around the valleys are highly reflective and metallic.

It's a great place for science fiction world building.

Currently, the Bepicolombo spacecraft just arrived at Mercury. In a few months, our view of the hollows will change as more pictures arrive.

References
NASA, 2023, "Mercury’s Strange Hollows", https://science.nasa.gov/solar-system/planets/mercury/mercurys-strange-hollows/

Here is Emcon, one of my nuclear space dragon characters. She is late to work, and she works in orbit.

Antimatter rocket engines are very efficient and powerful. Science fiction usually doesn't properly scale the destructive power of rocket engines. Emcon's engine is basically a continual nuclear blast, but with more gamma rays. It's a lot, but it's what it takes to travel between stars in a reasonable amount of time.

Conduction, convection, and radiation are the three ways of heat transfer. Conduction acts through contact between materials and is determined by the temperature difference and contact area. Convection is conduction, but with a fluid. Convection depends on how the fluid moves and the temperature difference between the surface and surroundings. Radiation is heat transfer through electromagnetic waves (heat and light), and it depends on the surface temperature and exposed surface area.

Boiling is interesting because it only uses all three heat transfer ways when something has gone wrong. At high temperatures, steam blocks contact with the water, so only radiation happens. Radiation is weak at low temperatures, so heat builds up.

It's going to be fun watching SpaceX's Starship orbit for long periods of time. Space does all sorts of interesting things.

The glow is not re-entry heating; it just does that. Spacecraft orbiting near Earth are surrounded by a thin layer of plasma. Spacecraft glow is similar to Saint Elmo's Fire. However, spacecraft glow is caused by atomic oxygen reacting and forming nitric oxide and plasma, which builds up behind the spacecraft as it flies through the exosphere[1].

This drawing is based on STS-39's flight through Earth's auroras [2].

References:
[1] S.B. Mende, G.R. Swenson, E.J. Llewellyn, Ram glow: Interaction of space vehicles with the natural atmosphere, Advances in Space Research, Volume 8, Issue 1, 1988, Pages 229-241. https://www.sciencedirect.com/science/article/pii/0273117788903687

[2] NASA, APOD, 1996, "Southern Lights and Shuttle Glow", https://science.nasa.gov/image-article/apod-1996-may-06-southern-lights-and-shuttle-glow/

So the Perseverance rover may have just found granite on Mars. Granite is a metamorphic rock that is formed deep within the crust and is exposed through tectonic plate movement. This is weird because Mars doesn't really have tectonic plates, and yet here's granite. Currently, the rocks are still being investigated by geologists [1].

Look at all those chickens.

References:
[1] Mars Guy. "A deeper dive into a freakish find". https://www.youtube.com/watch?v=4pLIMNp2eo4

109P/Swift–Tuttle is the comet responsible for the Perseids meteor shower. The orbit of Swift-Tuttle crosses Earth's orbit in a retrograde direction. Given that Swift-Tuttle is ~26 km in diameter, a head-on collision with Earth would not be enjoyable [1].

Comets are dynamic environments that change violently. During the 1981 observations, this comet had outbursts like the one in this drawing a few times a month [2]. This drawing is based on the upper right image on page 1754 of source 2. Swift-Tuttle has eight emission areas that produce these outbursts [2]. Comets sometimes randomly explode!

I also drew EMCON, a nuclear space dragon below the comet. Nuclear space dragons are a science-fiction dragon species I designed. The engine plume produced by the dragon's antimatter rocket engine is ~500 km long. Very Bright, very radioactive!

References:
[1] "Comet Swift-Tuttle". Wikipedia
[2] Sekanina, Z.. 1981. "Distribution and activity of discrete emission areas on the nucleus of periodic Comet Swift-Tuttle". Astronomical Journal. Vol. 86. NTRS. https://ntrs.nasa.gov/citations/19820043059

Railguns V.S. Coilguns

Railguns and coilguns are cannons that use electricity instead of explosives. They are often used interchangeably in science fiction; however, they actually have a unique set of advantages and capabilities. Railguns and coilguns work by the Lorentz force. The Lorentz force states that an electric current creates a magnetic field curling around the wire. Magnetic fields force each other if they are perpendicular (F=ILxB)

Railguns accelerate a projectile by shorting two electrically charged rails. This causes a powerful magnetic field to form through the projectile that is perpendicular to the rails' magnetic field. The two perpendicular magnetic fields create a force that accelerates the projectile.

Railguns are good for accelerating small projectiles to very high speeds. This makes them good for hitting maneuvering targets since they can't get out of the way in time. The rails of a railgun are in contact with the projectile, so they wear out very fast. High speed, high maintenance.

Coilguns accelerate a projectile by creating an alternating series of magnetic fields. The magnetic projectile is attracted and repelled by coil magnets as it goes down the barrel.

Coilguns are great for launching large shells at slow speeds. A big shell is also a big magnet, so coilguns can reasonably accelerate large shells. The shells have to be magnetic; I recommend using martensitic metal glass (also known as the atomic trampoline). The coil magnets and timing circuits used to create an alternating magnetic field are very heavy. Heavy fire, heavy gun.

Here is Rack playing fetch with RIM-7 Sea Sparrows. Or at least that's what he thinks.

Here is a visible light drawing I made of the Sun. The Sun (Sol) is the most important object in the solar system. All other planets are just dust by comparison.

The Sun has a complex and dynamic environment. In the core of the Sun, nuclear fusion takes place through the proton-proton fusion chain reaction. The radiation from nuclear fusion travels through the radiative and convective layers until it reaches the photosphere. The photosphere is the surface of the Sun, and its temperature is around 5500 K [1]. Sunspots form in pairs from magnetic field loops, and their temperature is a cold 4000 K by comparison to the surface. The corona is the atmosphere of the Sun, and its temperature varies between 500,000 K and 1,000,000 K or more [1]! That is why it is so bright in this drawing. The corona often has holes in it when the magnetic field doesn't trap it close to the surface. The corona is being continually blasted out to space in helmet streamers, creating the solar wind. When a large amount of the corona is freed, it is called a coronal mass ejection (CME). Coronal mass ejections have enough charged plasma to break electronics in space, or on Earth if they are powerful enough.

The Sun changes often. The Sun has an 11-year solar cycle. At solar maximum, the Sun is very active and has many sunspots. At solar minimum, the Sun is less active with fewer sunspots. The Sun's activity can change over many solar cycles as well.

The Maunder Minimum lasted from 1672 to 1699 [2]. During this time, some years had no summer. The River Thames froze over. Life was very difficult for people.

Sol is a very calm star by comparison to most. Polaris A has a solar cycle that can make it too dim to see with the unaided eye. Proxima Centauri is a flare star that can blow off entire atmospheres. It's quite wild to live next to a star when you think about it. Our lives depend on something ancient and powerful.

References:
[1] NASA. 2012. "Layers of the Sun".https://www.nasa.gov/image-article/layers-of-sun/
[2] Wikipedia. "Maunder Minimum". https://en.wikipedia.org/wiki/Maunder_Minimum

The hard part of a Mars mission isn't getting there; it's getting back. Space has radiation. Solar radiation (constant sunburns) is easy to defend against because you just put your fuel tanks toward the Sun, and it blocks the radiation. Cosmic ray radiation is hard to defend against because it comes from all sides. I have heard that humans can survive somewhere between 2-4 years before accumulating a lethal radiation dose, but without long-term studies in interplanetary space, there is no way to tell.
Earth and Mars have orbital periods of 1 and 1.9 years, respectively. To get to Mars and back, you have two options. Option 1: take 6 months to get to Mars, stay on the surface for 12 months, and return in 6 months for a total of 2 years. Option 2: take 6 months to get to Mars and 18 months to get back, for a total of 2 years. Either way, the trip will accumulate a lethal dose of radiation.
Enter: the Aldrin cycler. Aldrin cyclers are a space station invented by Buzz Aldrin with a two-year orbital period. Earth orbits twice for every station orbit, so it ends up back where it started. By riding an Aldrin cycler up and taking one down, a Mars mission can be 1 year long. It takes a LOT of fuel to switch orbits, but the advantage is you can do it with a lighter spacecraft because the living space and supplies are on the Aldrin cyclers.

Light gas guns are the most underrated cannon design. Light gas guns (LGGs) are an air cannon that uses a lighter gas than air, like hydrogen. The speed of sound is much higher in hydrogen, so LGGs can shoot projectiles much faster than a normal gun. The White Sands Test Facility can get a 12.7 mm diameter projectile up to 8000 m/s.
Railguns work by electrically accelerating a projectile between two electric rails. The ATLA railgun was able to get a 40 mm projectile up to 2000 m/s.
LGGs and Railguns have similar performance; however, only railguns have been pursued for warships. That is why I think LGGs are under-rated.
The ship in this image is based on the USS Defiant concept art by the Naval Sea Systems Command.

Betelgeuse is a red giant star in the Orion constellation. Recently, the ALMA observatory was able to image Betelgeuse's surface in radio light. Betelgeuse is lumpy, unlike Polaris A, which is almost perfectly spherical.

Reference Image: W. Dent et al. ALMA. ESO. https://www.eso.org/public/images/potw2634a/

Inspired by: setiinstitute. Instagram .https://www.instagram.com/p/DcloxhQH52b/

This is the Leahy-class missile cruiser. Other than the CIWS, it has no guns, just missiles. It is designed to destroy high-altitude targets at long ranges (300 km) with the RIM-67b missiles. It basically parries incoming missiles with its missiles.

Nuclear space dragons are a hard sci-fi alien species I designed. From left to right, these are Rack and Bark. They have painted their wings/radiators to look like kite shields. They are covering a nuclear detonation in the background with the peace sign on their wings. They are well-trained soldiers with human-made armor and weapon systems. They are brothers in arms who work to break up fights and end wars through strength, skill, and persuasion.

Rack. Yes, that is a nuclear bomb bandoleer. His fighting style is shock and awe. He tosses nuclear bombs like grenades while traveling at high speeds to blind and disorient the enemy. He doesn't have armor, but he is made of short-fiber carbon-carbon composite, so it's not a big deal. Behind his arms are Zuni rockets. An IRST is bolted on his ears/radars with a 1960s-style display mounted inside his right eye cover. He also has a crosshair bolted in front of his eye.

Bark. He is covered in sensors and antennas to stalk the enemy before shooting critical parts when the time is right. He has a high-precision, near-ultraviolet laser mounted below his chin. He has an ECM jammer on top of his head with a state-of-the-art display in front of his eyes. His armor is a UHMWPE cloth Whipple shield; very light, very strong.

The Small Magellanic Cloud (SMC) is a dwarf galaxy that orbits our Milky Way galaxy. It is mostly young, blue stars. The lighter spots are open star clusters and star-forming nebulae. The nebulae on the right look like a heart.

I don't think you understand how big Olympus Mons is. That is an entire mountain range beneath it. Olympus Mons is over twice as tall as Kilauea from the ocean floor (the Big Island in Hawaii). The peak is so far away from the base that it is in a different time of day. If I drew this from the ground, you wouldn't be able to see the peak because it would curve beyond the horizon. That is a 20 km tall volcano.

The last time Olympus Mons erupted was 25 million years ago. In geologic time scales, that is not long.

Neutron stars have magnetic fields strong enough to bend light. This causes patterns of light and dark to form on the surface of the neutron star. The patterns depend on the tilt of the magnetic field compared to the rotation axis and the view angle [1]. If you were to tilt your head, you would see the patterns change. The patterns would change rapidly as the neutron star spins.

Neutron stars are very powerful. Neutron starquakes can repeatedly produce enough radiation to make space uninhabitable for several light years, with effects on planetary atmospheres extending out several tens of thousands of light years. When they aren't exploding, they emit enough radiation to ionize surrounding nebulae. Getting close enough to see a neutron star is difficult.

References:
[1] Thi H., etal. 2026, "Pulsed, Polarized X-Ray Emission from Neutron Star Surfaces: The Effects of Vacuum Birefringence in the Magnetosphere". The Astrophysical Journal, Volume 1000, Number 1. DOI, 10.3847/1538-4357/ae313c

TREE (transient radiation effects on electronics) is a side effect of nuclear radiation on warships. Gamma rays and neutrons can interact with silicon, destroying electronics. Emcon (dragon at center) has an antimatter rocket engine that almost entirely produces gamma rays. She should be a little more careful where she points her engine plumes next time. RIP ELINT dome.
Source:
"Nuclear Weapon Bursts 1991 Navy documentary". Youtube. https://youtu.be/rJgZ5vV2Lfs?si=KgltnYNtkQof7Z1r

As supermassive black holes form, they draw in matter from the dense galaxy center. This creates an accretion disk, a hot gas disk, and a dust torus. Planets can form in the dust torus like a star's protoplanetary disk.

The paper, "Active Galactic Nucleus Tori: Potential Birthplace to Millions of Planets" goes into detail. The intense magnetic field, mass of dust, and radiation pressure from the supermassive black hole allow for very strange planets to form. Rocky planets the size of stars, black holes, and immortal stars may be commonplace here [1].

There are planets all over the dust torus, and every one of them is far beyond anything seen in the rest of the galaxy.

References
[1]. Bhupendra Mishra et al. "Active Galactic Nucleus Tori: Potential Birthplace to Millions of Planets". 2026. The Astrophysical Journal, Volume 1005, Number 1. DOI 10.3847/1538-4357/ae6f0b

Image Reference
MoreInput, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons. https://commons.wikimedia.org/wiki/File:CentaurusA_Center_EN.PNG

Inspired by
"The Exotic Objects of the Galactic Center". Kyplanet. Youtube. https://www.youtube.com/watch?v=TckSX4cAb3k