They say that we know more about space than about Earth’s oceans. That might be true; however, it by no means implies that we know all there is to know about space. Despite what physicist Lord Kelvin declared in 1900, that there is nothing new to be discovered in physics, the field had yet to be introduced to quantum mechanics, Albert Einstein, and his theory of relativity. Scientists had to rethink their knowledge of the cosmos. Nowadays, no physicist would dare dream that we possess a complete knowledge of the universe. In fact, the more we learn, it seems the more questions arise.
Our universe is vast and impenetrably dark, home to unseen forces and phenomena that have yet to be fully documented and explained. Scientists have yet to fully understand the many space mysteries that we simply don’t have the technological capability to fully explore. Some of these mysteries are downright spooky and many challenge the currently accepted laws of physics. While we struggle to develop technologies and theories to help unravel these many space mysteries, scientists can only ponder the possibilities. What follows are just fifteen of the greatest mysteries of space that are currently being contemplated.
15 What Is Dark Energy?
Dark energy comprises about 75% of the universe; however, scientists are not only uncertain about what it is, but are also not really sure how it operates. It all began in 1929, when astronomer Edwin Hubble (yeah, the telescope was named after him…) was studying supernovae and concluded that the universe is expanding. Since then, scientists have been trying to figure out how fast. Gravity, the force that draws everything towards each other, should be slowing the expansion down; it’s not. In the 1990s, astrophysicists discovered that universal expansion was actually speeding up. Something was counteracting the force of gravity; this “something” was labeled “dark energy.”
When looking out into the universe, we can’t see this dark energy; we see the light from all the matter and the rest is empty... well... space. Therefore, this dark energy must account for a large part of the makeup of the universe. In physics, this theory is called quintessence. Quintessence hypothesizes that this negative dark energy field overpowers gravity and causes all that matter to repel each other, thusly accelerating universal expansion. It’s all a theory, as scientists really don’t know what this stuff is!
14 What Are The Fermi Bubbles?
If viewed along its plane in visible light, the Milky Way galaxy appears relatively flat. If you look at Gamma-ray emissions, you’d be quite astonished, however, to see two giant formations jutting outward from the galaxy’s center, looking like a galactic hourglass. Called the Fermi Bubbles, these two huge continuous bursts of gamma-ray emissions were first discovered in 2010. They reach out over 50,000 light years; however, their cause is unknown. They contain enough gas to create 2 million Sun-size stars. Scientists have been able to determine the bubble’s age to around 6-9 million years. As to what they are or why they exist, that is another story.
We know that most galaxies contain a supermassive black hole at the center, with our Milky Way being no exception. Our black hole is believed to be located at the location of Sagittarius A-star, or simply known as Sgr A*, and has a mass equal to about 4.5 million solar masses (size when compared to that of our Sun). Due to how space-time works, when we look out into space, what we are actually seeing is the state of the universe a long, long time ago. So when the Hubble perceived Sgr A*, it was younger, taking in huge amounts of gas and dust and shining brightly as all that matter was sucked into the event horizon on its way to the black hole. Scientists believe that today, Sgr A* is much quieter, but the Fermi Bubbles could possibly be the remnants of matter that was jettisoned out from the black hole when it was more active and the galaxy was still forming. We really don’t know.
13 Where Did Saturn’s Rings Come From?
There are approximately seven groups of rings around the planet Saturn, four main ring groups and three dimmer, smaller groups, all comprised of thousands of smaller rings. They stretch over 73,000 km around the planet. These groups of rings are divided by divisions, as observed by the Voyager spacecrafts in the 1980s. The rings are composed of many small particles of ice and rocky material, ranging in size from a micron to a meter, all in continuous orbit around the planet. That’s about all that scientists can agree upon and the rest is pure theory and the source of heavy debate.
So, while there is no consensus about how the rings were formed, some theoretical models suggest they were formed early in our solar system’s history. This model states that the debris circling the planet is the remains of a moon that failed to form, or was possibly torn apart by Saturn’s tidal stresses. Some think the proto-moon might have been struck by another large object and blown apart. However, other scientists believe the rings are still in the process of being constantly replenished. They point to one of the rings, known as the E-Ring, which has been witnessed being refreshed by icy material ejected by a cryovolcano - basically an ice volcano - from the south pole of the nearby moon, Enceladus. Maybe one day sufficient evidence will be discovered to put the question to rest.
12 What Are The Mysterious Noises From Space?
Sound does not travel in space, that being said, space apparently is a very noisy place. In May 1969, the Apollo 10 astronauts were orbiting the moon. The three astronauts heard and recorded strange sounds while circling around the dark side of the moon. They said it sounded like whistling or music. It creeped them out and the men discussed whether or not they should inform Mission Control. I mean, there is not supposed to be any sound out there and the fate of their future mission status might be in jeopardy if they reported crazy stuff! The men opted for full disclosure and gave their report. An engineer calmed the men and responded that the sounds were most likely radio interference. But was it? Later, Apollo 11 reported the same mesmerizing sounds. Again, it was dismissed as interference. Apollo 15 astronaut Al Worden heard it also and disputes the interference explanation. Scientists agree that the universe is a noisy place and that every galaxy and celestial body emits some sort of radio waves. They insist that this must be what the astronauts are hearing.
Then in 1977, a radio signal from space was detected. It only lasted 22 seconds but its intensity was off the charts. Called the “Wow!” signal, it was tracked to a point near the Sagittarius constellation. It’s been searched for ever since but has never repeated. Later, in 2014, NASA launched a hydrophone array into space to record any space signals. When it was recovered, it was found to have recorded hissing, crackling, whirling, even whistling sounds. Are these the galactic radio waves scientists refer to; gravity waves and planetary radio emissions that crisscross the universe? Or, is there some other explanation for all the strange sounds that keep being heard emanating from space.
11 The Distant Monster
In 2013, an incredible planetary discovery was made. The exoplanet, called HD 106906 b, is colossal in size. We’re talking about eleven times more immense than Jupiter. Its orbit is the largest every discovered found in a star system. This distant monster has a gaping orbit 650 AU from its star. An AU is an astronomical unit; for scale, Neptune is 30 AU from our Sun. That’s a huge orbit! It’s 650 times the average distance between the Earth and the Sun.
The planet’s very existence raises a ton of questions. It just doesn’t fit into current planetary formation models. Usually planets that orbit close to their parent star, such as Earth, began as smaller, rocky bodies in space that came together and coalesced around a young star. However, this process takes too long to explain the existence of giants that formed so far away from their star. An alternative theory suggests that maybe these distant planets formed like a mini binary star system. These form when two clumps of gas collapse to form stars, close enough to exert a mutual gravitational pull on each other, binding them together in orbit. However, this doesn’t quite fit either because, as far as we know, the difference between the masses of two stars in binary systems is no more than 10-to-1. In this case, the mass ratio is over 100-to-1! We do know that HD 106906 b is only 13 million years old, and is still glowing from its formation (for comparison, Earth formed 4.5 billion years ago). This new exoplanet needs a lot of study before we can fully understand just what it is or how it came to be.
Nemesis is a theoretical dwarf star that some scientists believe is a companion to our Sun. This theory was put forward to explain the cycle of mass extinctions in Earth’s fossil record. Some scientists believe that such a star could affect the orbit of objects in the outer solar system and send them hurtling inward on collision courses with Earth. Some of the basis for this hypothesis is the apparent cyclical pattern to mass extinctions, roughly every 27 million years. Such precision is believed to have a direct relationship with astronomical forces. Therefore, in 1984, Richard Muller of the University of California, Berkley suggested that the Sun’s twin, a red dwarf star 1.5 light-years away would explain this phenomena; or possibly a brown or white dwarf, with sufficiently low mass as to cast a dim light, making it very difficult to see.
It is postulated that Nemesis would exert force over the Oort Cloud, which is comprised of icy rocks, out beyond Pluto. They have a long-term elliptical orbit around our Sun. As they get closer, their ice begins to melt away, giving them an icy-cloud tail, recognizable to us as comets. If Nemesis travels through the Oort Cloud every 27 million years, it could launch comets out of the cloud and send them in our direction, some of which would impact Earth, causing mass extinctions. Proponents point to the 12,000 year orbit for the dwarf planet Sedna. They say only a massive dimly-lit star could be responsible for keeping Sedna so far from the Sun. Though some scientists find the theory plausible, others do not. Regardless, the cyclical nature of mass extinctions has yet to be explained.
9 Where Are The White Holes?
Physicist Albert Einstein’s general theory of relativity proposes that the great expanse of space should be home to numerous white holes. The hypothetical twin to a black hole, a white hole is an area of space-time which cannot be entered from the outside, though matter is spewed from it. This is in direct opposition to a black hole which can only be entered and from which nothing, not even light, can escape. Logic supports Einstein’s theory, but scientists have yet to find evidence of their existence. Some claim we might have already seen them but that they have the same radiation levels as other cosmic phenomena, leading scientists to erroneously identify them as something else.
Though we have never observed one, Einstein’s mathematical proof dictates that if black holes exist, so must their hypothetical opposite. Of course, once we do find one, that would ultimately unleash a whole new set of questions. Where does the matter come from? Does this actually prove that the matter sucked into a black hole is transported across space-time unseen to exit out of a white hole? If so, how many light-years away is the adjacent black hole? Would they even exist in the same space-time continuum? Are they trans-dimensional gateways? Hopefully we’ll find definite proof of one soon. The directions scientific research could take from the point of discovery is the stuff of wild imagination!
8 Why Does Titan Have An Atmosphere?
Titan is the sixth and largest of Saturn’s moons. It is slightly larger than our own moon, but much more massive (density wise), and is often considered more planet-like than any other moon in our solar system. The reason being is not only that Titan appears to possess stable liquid oceans, but because the moon is the only one to have an atmosphere! Jupiter’s moon Ganymede is larger than Titan and also is believed to possess liquid oceans, albeit underneath an icy surface. However, Ganymede lacks any sort of atmosphere. Why does the smaller Titan have one?
Extending 600 km above the surface of Titan, the atmosphere is composed mainly of nitrogen, similar to that of Earth’s atmosphere, with some hydrogen and methane. Due to this, scientists are excited about the possibility of finding evidence of signs of life. Of course, we still do not know how an atmosphere could have formed on Titan. Some theories credit its existence to Saturn’s distance from the Sun. This is due to when Titan formed, the lack of the Sun’s head allowed unstable gases to be trapped in layers of ice, and were later slowly released over time, creating the atmosphere. Another theory suggests that due to Titan’s proximity and amount of time spent within Saturn’s magnetosphere, it has been sufficiently shielded from solar winds that would’ve otherwise stripped it of its atmosphere. There are currently numerous proposals being considered for unmanned research missions to Titan. Who knows what we might find?
7 The Great Attractor
There’s a point in the universe, about 200 million light-years away, that is baffling scientists around the world. This mysterious cluster in space, dubbed “The Great Attractor” is pulling our whole Milky Way galaxy towards it. Ever since the creation of the universe, it has been expanding constantly, we know this. What’s freaking everyone in astrophysics out is that we’re heading in the wrong direction. This gravitational anomaly is pulling us towards it. For something so far away to exert such gravitational force it has to be something incredible! Whatever it is, it’s yanking us towards it at a mind-boggling 600 km/s (kilometers per second)!
Okay, so you would think that someone would point the Hubble telescope towards it, at the center of the Laniakea Supercluster, in the direction of the constellation Centaurus. Well, the problem is our own galaxy, the Milky Way, with all its gas, dust, and stars, blocks our view of that portion of space and whatever is out there that is drawing us towards it. Astronomers have labeled that area of space the Zone of Avoidance, and the Great Attractor (gotta love these names) lies smack dab in the middle of the zone. First discovered in 1970, it should take billions of years before we reach our destination; however, what will happen when we get there? Well, scientists don’t really believe that will ever happen. If we did, the Milky Way will probably join other galaxies and become part of a supercluster; however, they believe that equally mysterious dark energy will destroy whatever cluster currently occupies that space in the Laniakea Supercluster. But ultimately, we don’t really know.
6 Tabby’s Star
It’s officially called KIC 8462852, but this interesting star is known by a better name, Tabby’s Star, and it’s an enigma 1,500 light-years away. Ever since they discovered Tabby’s Star, it’s baffled scientists. It seems that about 20% of the light that the star emits is being blocked from our view. Due to the amount of light being blocked, scientists are pretty sure it’s not a planet obscuring our view. Even a planet as large as Jupiter would only block about 1% of the light of a star of Tabby’s size. So what could be the culprit? Well, some have speculated it might be something called a Dyson Sphere. Well, technically maybe a Dyson Swarm, a less complete version of a Dyson Sphere.
What is a Dyson Sphere? It’s a technologically-advanced megastructure that is built around a star to harvest the star’s energy output. I know that sounds more like science fiction than science fact; however, we pretty much know how one would work, even if we lack the technological know-how to actually build one. Some other scientists are less quick to jump to the alien technology answer, and are holding out for a more mundane answer. We’ll have a better idea of what’s actually happening with Tabby’s Star when NASA launches the James Webb Space Telescope in 2018. Until then, Dyson Swarm sounds like a pretty exciting explanation!
5 What Happens Inside A Black Hole?
What happens to all the matter that is gobbled up by a black hole? Current models dictate that whatever goes in is irreversibly lost - all information gone forever. That’s due to a black hole’s gravity being so strong that not even light can escape. Now, some scientists are championing something called quantum mechanics, which says quantum information can’t be destroyed. Quantum information isn’t like normal information, like bits on a computer or knowledge in our minds. Quantum theories don’t really give a simple explanation for it. Basically, it’s theoretical and dictates the most likely location of something or the most likely result of some particular action upon something. Think of it in terms of not saying the calculated trajectory of a baseball, instead more like giving all the probable outcomes of where that baseball might possibly end up. Therefore, all of the probabilities of something occurring should add up to 1, or 100%. For instance, a 1 in 6 chance, means there are 6 possible outcomes and if you add all 6 chances, each 1/6, then you have 6/6, or 1.
Quantum theory says that if we know how a system ends, scientists can calculate how it began. Whoo! My head’s hurting already. Relating to black holes, scientists have used quantum theory and believe that quantum information of whatever got sucked in is not lost deep within, but instead remains on its boundary, the event horizon. This is called the “information paradox,” and physicists can’t really agree on a solution. So, to break it down, we still don’t know what happens to everything that goes into a black hole!
4 Are There Parallel Universes?
Some astrophysicists believe that space-time is flat, as opposed to curved, and flows on infinitely. If this is true, then what we see - commonly referred to as our universe, 14 billion light years in all directions - is just one layer in an infinite “quilted” multiverse. This is called the theory of eternal chaotic inflation, but multiverse is easier to say. The laws of quantum mechanics state that there is only a fixed set of possible particle configurations within each of these infinite cosmic layers of the multiverse. That means that some of these particle configurations are forced to repeat many times.
Basically, this means that there are an infinite number of parallel universes that are very similar, if not exactly like, our own, as well as some that differ by maybe one or two particles, and so on. However, those simple changes could result in universes that are radically different than ours. One universe might be quite similar except your engineer brother-in-law is now your graphic designer sister-in-law. Another universe might find that dolphins rule the world with humans on display in zoos and theme parks. Still other universe might exist where life never evolved at all. Radical! What do you think?
Not every scientist buys into this theory, but it is grounded in the real science of cosmic inflation and the decay of something called a false vacuum. I’m not even going to try to get into the minutiae of astrophysics, but suffice to say many physicists seriously believe other pocket universes are being generated all the time and will continue to do so infinitely. Hopefully, one day we’ll find a way to detect the presence of other parallel universes. Maybe I could give one of my other self’s a call (and remind him to stay away from that one blonde in that club that one time…).
3 Can We Travel Faster Than Light?
In 1905, Albert Einstein built his theory of special relativity around the notion that the speed of light is constant, no matter how fast something was moving in relation to the light. Einstein believed that time and space would have to expand or contract as something travelled with increasing speed. In his contemplations, he discovered a prime cosmic law: nothing can travel faster than light. His theories became the cornerstone of modern physics. Scientists have been studying this ever since. Though they’ve found evidence that some things, like dark energy, seem to travel faster than light; however, these things have no mass. Particles with mass require more energy to move them. If these particles were to travel at speeds that approached the speed of light, the amount of energy continually needed to propel them would have to increase exponentially. So, as an object nears the speed of light, its mass becomes infinite, as does the amount of energy needed to move it.
But have no fear, scientists are hard at work finding ways to cheat these laws of physics. Out of all the theories to get around Einstein’s pesky rules, the best might be one proposed by theoretical physicist Miguel Alcubierre in 1994. He proposed an Alcubierre Drive. He theorized that, by redistributing matter, you can shrink space in front of a spacecraft, the S.S. Shatner, for instance, and then stretch it behind the craft. This would create a hyper-relativistic local-dynamic space, or bubble, around the ship that would move it as fast as you want. Because space is contracting in front of the craft, the craft won’t really be moving faster than light. Instead, the craft would actually be motionless relative to the bubble. The crew of the craft wouldn’t even feel as if they were moving at all. The only problem is that to create this “warp” bubble, it would require a “weak energy condition.” Scientists can’t guarantee the stability of this kind of condition and admit it could cause weird stuff, like wormholes or time travel! But since we’ve never actually seen this type of condition, it’s all theoretical. Not impossible though…
2 Are We Alone In The Universe?
In 1996, U.S. President Bill Clinton publicly announced that fossilized microbes had been found inside a meteorite that originated from Mars. Though some scientists believe that the government jumped the gun with that announcement, as what they thought was fossils could’ve actually been the result of non-biological processes. Despite this setback, definitive proof of life beyond Earth could likely be found right around the corner! So what basis do we have for believing that there could be life elsewhere in the universe? It’s called the Drake Equation.
In 1961, radio astronomer Frank Drake created an equation to estimate the number of intelligent civilizations in our galaxy. To solve this equation, we need the following variables: the rate of formation of stars suitable for life to develop; the fraction of those stars with planetary systems; the number of planets in each of those systems with an environment suitable for life; the fraction of suitable planets where life actually emerged; the fraction of life-bearing planets where intelligent life developed; the fraction of civilizations that would release detectable signs of their existence into space; and the length of time such a civilization would continue to send those signals into space. We take all those variables and multiply them together to reach the possible number of civilizations in our Milky Way galaxy that we might be able to detect. The kicker is that we don’t actually have any certified numbers for any of these variables. Therefore, any calculation is just a rough estimate. According to this equation, even with these rough estimates plugged in, there could be as many as 50,000 alien civilizations existing today!
1 Are We The Aliens On Earth?
There is a theory, called panspermia, which says life here on Earth began out there, among the stars. This theory supposes that 3.8 billion years ago, our molten planet was hit by a rock that was carrying the primordial seeds of life. I know it sounds wild, but scientists have actually discovered meteorites that were found to contain amino acids, which are the building blocks of life. Additionally, in 2003, we took a close look at Ceres, the largest asteroid in our system. It’s coated in ice, but the surface was found to be warmer than was previously believed, which means it could support some form of life. On the surface of Ceres, there is a white spot which is believed to indicate a big piece that was ripped off - possibly by a meteor strike that occurred possibly 4 billion years ago. It is believed by some that this chunk struck Earth and released the amino acids contained therein.
To test this theory, NASA sent some terrestrial seeds into space and then later brought them back down after six months. The seeds were tested and were found to be not only viable, but they thrived! Further calculations offer the possibility of transpermia, where this type of transfer of life is happening throughout our solar system. The other planets in our solar system aren’t very hospitable for life, so any transference of amino acids was probably wasted, except for Titan. Titan is one possibility where scientists believe there is a high chance of life being discovered. Though Titan’s cryogenic hydrocarbon lakes would make any life existing there chemically different from any life on Earth, making any type of relation near impossible. Still, it is an interesting theory and a possibility.
Sources: blastr.com, livescience.com, astronomy.com, space.com, businessinsider.com