Cosmic Chills: 25 Spooky and Uncanny Facts About Space – Part 2

The classic movie portrayal of a crowded asteroid belt in our solar system where the asteroids are only meters apart is inaccurate. In reality, the average distance between asteroids is around 965,000 km (600,000 miles) and if you were to fly through it, a collision would be unlikely. Ceres, which is supposed to be the largest object (with a 473 km radius) in the asteroid belt, alone is estimated to hold about a third of the asteroid belt's mass. In fact, the asteroid belt is so not-dense that when sending probes through it, mission control doesn’t even bother calculating a clear path. The chances of hitting something are so low that it’s a waste of time to worry about it. NASA estimates that the odds of hitting an asteroid if you just randomly shoot a probe at the asteroid belt are 1/1,000,000,000.

In 2015, scientists detected, for the first time, the merger of 2 black holes in a galaxy 17 billion lightyears away by measuring the gravitational waves emitted by the collision. As they spun around each other violently, they released more energy in the form of gravitational waves than the combined light from all the stars in the Milky Way in 4400 years.

If we were to surround a rotating black hole with a mirror and shoot a laser beam inside it, the beam would get exponentially more and more powerful by stealing energy from the hole via superradiant scattering. It could eventually overpower the mirror and result in a powerful explosion on par with a supernova. We could prevent these black hole bombs from going off by harvesting some of this energy. Using this type of energy we can theoretically power civilization for millions if not billions of years. In fact, these black hole civilizations may be the last home for any species in a dying universe.

All stars fuse hydrogen into helium. Medium stars, like our Sun will eventually fuse helium into carbon and oxygen before eventually turning into white dwarfs. It will take stars many times the mass of our Sun to fuse heavier elements. After exhausting helium they’ll burn carbon to neon in centuries, neon to oxygen in a year, oxygen to silicon in months, and silicon to iron in a day, before imploding. This implosion bounces off the iron core and causes a supernova explosion. Above iron, heavier elements are mainly created in supernovae, where there is lots of energy to spare; however, because these are short-lived and (relatively) rare events, elements above iron are rarer than those below.

After medium-sized stars like our Sun die and explode into a spectacular planetary nebula, what remains of its core will become a white dwarf. After our sun dies and becomes a white dwarf, it will only be about the size of our earth, but with a surface gravity over 100,000 times higher than Earth's. Eventually, these white dwarf stars will cool into black dwarfs, but this process is theorized to take 100 billion billion years. That’s so far into the future that no regular stars will shine anymore, galaxies will have evaporated, and only then will the first white dwarf turn into the first black dwarf. Planets around white dwarfs could be humanity's last home right before the death of the universe.

TON 618 is a hyperluminous quasar that possesses an ultramassive black hole which is the largest black hole ever found. It has been observed to be consuming galaxies' worth of matter and is shining with the brightness of a hundred trillion stars, visible from 18 billion light-years away. The back hole is 66 billion times the mass of our sun, greater than the mass of all the stars in the Milky Way galaxy combined.

The moon does rotate, but the time it takes to rotate around its axis is exactly equal to the time it takes to orbit the Earth and as a consequence, we always see the same side of the Moon. This isn’t a coincidence but this happens due to “tidal locking”, which causes the rotation of an object to sync up with its orbit. The tidal force from the Moon isn’t just making the seas and oceans move around, it also pulls at the solid bits of the Earth, ever so slightly slowing down the rotation of the Earth. If the Sun wouldn’t gobble up the Earth when it expands in 4-5 billion years, then some 50 billion years from now the Earth would be tidally locked to the Moon at which point the same side of the Earth would always be facing the Moon and the length of a day would be much longer than the 24 hours it is now.

For more than 200 years, astronomers thought that most of the stars in our galaxy were binary stars and that our sun was a unique exception. Recent discoveries however have revealed that most stars are not binary after all, although most (80%) of sun-sized stars are in pairs. Most stars in the galaxy (85%) are red dwarfs which generally form alone. Scientists also believe a few percent of stellar systems are trinary stars. Since 3-body systems are generally unstable, they only last for significant times if two of the stars are close together, with one far away (think Earth-Moon-Sun).

Dark Energy is calculated to make up 67% of the known universe, while Dark Matter makes up a further 27%, while what we can actually see and measure, i.e., conventional matter, makes up less than 5% of our universe. Therefore our current model of physics only works for 5% of the matter/energy in the universe. Dark energy should explain the expansion of the universe which is accelerating faster and faster and doesn’t match up with the expected gravity, ergo some kind of energy must be fuelling it. If it doesn’t slow down, one-day inflation of space will be exponentially faster than the speed of light.

The Boötes void, a.k.a the Great Nothing, is an enormous spherical region of space that has a very small number of galaxies. At nearly 330 million light-years in diameter, it is one of the largest known voids in the Universe. The scale of the void is such that if the Milky Way had been in the center of the Boötes void, we wouldn’t have known there were other galaxies until the 1960s. This void has opened space for many discussions of its origin, including the hypothesis of a Type III civilization in the Kardashev scale. It would be a galactic civilization that can control energy at the scale of its entire host galaxy.