The Hedron Starship, also known as W–Hedron M51a, T-HM51a, and H5194, is a large command vessel of unknown extraterrestrial origins, currently orbiting Earth at a distance of 310,502.82 km (192,937.51 miles).
On January 5th, 2018, 1:36 AM GMT, Earth's satellites start experiencing strong, simultaneous disruptions. After investigating, NORAD and other major international agencies determine that the disturbance is originating from outer space. Thousands of amateur astronomers across North America and Europe spot an enormous alien mothership that has entered Earth's orbit. News of the discovery quickly gains worldwide coverage, and all nations' militaries are put on high alert.
The Hedron Starship is capable of traversing between galaxies that are several millions of light years apart by traveling through self-generated wormholes. It is still unclear why it came to Earth, but the direct path that it took strongly suggests that the extraterrestrials manning the spaceship must have detected Earth's existence and location prior to engaging in traveling.
Nothing is known about the origins of this spacecraft, but it has been established that it comes from Messier 51a. The ship was most definitely assembled in space, and required vast amounts of resources and infrastructure to build, as well as advanced expertise in aerospace engineering.
The Hedron Starship entered the Solar System via a wormhole that originated near Neptune. Initially, it was traveling at 284,040 km/h (176,494.27 mph). The vessel began accelerating and reached a speed of 34,720,488.00 km/h (21,574,311 mph) in 9 hours and 40 minutes. The rate of acceleration was near constant at 274.78 m/s2, hence the displacement works out to be 169,247,000.00 km (105,165,210.17 miles), or 1.13 AU.
While traveling at maximum speed (9,644.58 km/s), HM51a was able to cover a distance of approximately 2,117,505,500 km (1,315,756,917.10 miles) in just 2.54 days, after which it began decelerating. During the last phase of deceleration, the ship completed several elongated, elliptical orbits around Earth before making a course correction. It came to a halt shortly after bypassing the Moon. Due to its high velocity and relatively small size (comparable to asteroid 8 Flora), it remained undetected for most of its journey, and its heat signature was picked up only when the ship's engine pointed at Earth.
W-Hedron M51a is, by Earth’s standards, of staggering proportions: shaped like a truncated tetrahedron, each side measures 118.21 km (73.45 miles), making it the largest known artificial object. At its center lies a dense sphere with a diameter of 26.30 km (16.34 miles), which contains the ship’s engines and main reactors.
The ship's exterior is almost entirely made out of titanium, though denser, unknown elements are also present. Infrared analysis reveals that the core of the sphere holds some type of unknown energy source, likely used as fuel to power the ship.
Similar to the molecular properties of methane where a carbon atom is located at the center and four hydrogen atoms at the corners, the Hedron Starship is held together by four cylindrical megastructures that originate from the surface of the sphere and connect perpendicularly to the four external triangular prisms that, when attached, form the shape of a symmetrical tetrahedron. Each of the cylinders are separated by an angle of exactly 60°, unlike most tetrahedral molecules which tend to be asymmetrical with bond angles of approximately 109.5°.