Outer space is not a very friendly place to live in, at least not for humans or any other living creatures that we know of. Despite this, however, it still continues to amaze and push us into looking for answers about the unknown. According to famous astrophysicist Carl Sagan, “Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people.” This is quite a scary yet amazing realization which can often become difficult for the human brain to comprehend.

From the sheer scale of the universe to looking for extraterrestrial life, there are so many unexplained mysteries, some of those that even defy everything we know to be possible. There are literally no scientific explanations for some of these events that happen throughout the vastness of space. Here we have compiled a list of 15 outer space mysteries that still continue to baffle us even to this day.

15. Life On Mars

Mars has been considered as one of the most likely and perfect candidates for setting up a human colony in the Solar System. One of the biggest reasons for this is that all of the research data gathered so far using different probes and rovers has pointed to the fact that Mars had a very Earth-like atmosphere in the past. This has also led to speculation that it might’ve even harboured microbial life at some point.

Despite discovering water on the surface of the red planet, however, we still haven’t discovered any signs of life which has baffled scientists for quite some time now. One of the reasons for this is that we’ve only covered a very small percentage of the planet’s surface and there is so much more that remains yet to be discovered.

14. Blackholes

We’re pretty sure that most of you were already expecting this to show up on the list. Blackholes, in layman’s terms, are essentially the ultimate quicksand of the cosmos. They are formed when a giant star collapses on itself, imploding into a tiny area with such extreme gravity that even light cannot escape it.

This basically means that it is impossible to observe one of these directly using any sort of telescope. The only way that we’ve been able to gather any data on these is by looking at how they affect the matter surrounding them. Despite having a sense of how they work, there is so much stuff that we still don’t know about these cosmic entities. On a side note, we do recommend watching Christopher Nolan’s Interstellar for an accurate scientific portrayal of a black hole in a Hollywood film as seen in the picture above.

13. Fermi Paradox

The famous Fermi Paradox is named after physicist Enrico Fermi who coined the term during a lunchtime remark, something that has caught the attention of every SETI researcher since then. He highlighted the apparent contradiction between the lack of evidence of alien life and the high probability estimates of such civilizations existing. We have already mentioned how big the universe is and by using mathematical calculations, it has been speculated that almost 100 million worlds exist where life has formed due to evolution.

This begs the questions that if these calculations are correct then why haven’t the aliens contacted us yet? Or could it also be that they have and we just don’t know it? It is an interesting thought and one that will most probably keep you up at night.

12. Dark Matter

A common statement that you might’ve come across when trying to understand the size of the universe is that there are ten times more stars in the night sky than there are grains of sand on earth. But what if we told you that all of the ordinary matter which includes stars, planets and everything else only accounts for 4.9% of the total mass-energy of the universe. Let that sink in for a minute. Now you’re probably wondering where the rest of the matter and energy is.

This is where things get interesting because the rest of this 95.1% mass-energy is composed of dark matter and dark energy. This hypothetical dark matter has never been directly observed but we know it exists because of its gravitational effects on ordinary matter and gravitational lensing. A lot of experiments are still being conducted to detect dark matter particles, however, none of these have been conclusively identified so far.

11. Dark Energy

We mentioned dark energy in the previous entry and while it does sound like something out of a sci-fi movie, it is also one of the most amazing mysteries of the universe. Like dark matter, dark energy is also a hypothetical form of energy that is said to exist in all of space and is accelerating the expansion of the universe. According to current measurements, it contributes 68.3% of the total mass-energy of the universe.

Much of what we know about this dark energy and dark matter comes from the observation of the Cosmic Microwave Background (CMB) which is a snapshot of thermal radiation that existed “soon” (380,000 years is very small on the cosmic scale) after the Big Bang.

10. The Giant Void

It seems as if the more we try to understand how our universe works, the more mysteries it starts throwing our way. Unlike a black hole, which is a tear in the fabric of space and time, the Giant Void is a place which is completely empty of both ordinary and dark matter. Another reason why we know this isn’t a black hole is because light can seemingly pass through this void.

What is even more mysterious is the fact that the Giant Void has an estimated diameter of 1.3 billion light years making it the largest among other voids that can be found in outer space. Scientists speculate that even though it doesn’t have matter, it still contains dark energy.

9. Tabby’s Star

One of the methods used by astronomers to see whether a planet is orbiting a star is by measuring dips in brightness caused by a planet when it passes in front of the star. While observations like this are quite common, a main-sequence star located in the constellation Cygnus showed slightly different results. The actual astronomical name given to this star located 1,500 light years away is KIC 8462852, a name that’s not very easy to remember, however, it is also known as Tabby’s star, named after Tabetha S. Boyajian.

While observing this star, astronomers noted that almost 20% of the light emitted by it is being blocked which is quite weird since a planet even as big as Jupiter would only block 1% of a star of this size. Certain scientists have speculated that a Dyson Swarm, a structure that can be used to harvest the energy of a star has been deployed by an intelligent race which is responsible for this dip in brightness.

8. Jupiter’s Great Red Spot

The Great Red Spot on Jupiter has been the most prominent feature of the planet ever since we get a clear look at it using a telescope. It is basically a massive storm which is wide enough to fit at least two Earths inside it and has been raging on for hundreds of years. “Based on current theories, the Great Red Spot should have disappeared after several decades,” says Pedram Hassanzadeh of Harvard University. “Instead, it has been there for hundreds of years.”

While we don’t exactly know how it has been able to go on for this long, some theories suggest that the Red Spot vortex can absorb smaller vortices over time, allowing it to gain more energy. There is still no complete answer to this puzzle and we can only speculate.

7. Planet X

The hypothetical Planet X, also sometimes referred to as Nibiru is believed by many to one day have an encounter with Earth, causing a possible doomsday event. This has been regarded as nothing but a hoax by astronomers, however, evidence for the existence of a ninth planet (depends on whether you consider Pluto a planet or not) has been quite strong in recent years.

In 2016, Mark Brown, who is a part of the scientist team at California Institute of Technology proposed that a planet which is 10 times the mass of Earth is lurking on the outer edges of our Solar System. The gravitational effect of this planet has been speculated to cause strange movements in the Kuiper belt.

6. The Great Attractor

We’re already aware of the fact that our universe is expanding, which explains why our galaxy would also move but it’s not in the direction that we expected. Among some of the other strange observations made by astronomers, one of the most baffling is related to the Milky Way. It seems as if something that is located almost 220 million light years away is tugging at the imaginary collar of our galaxy, slowly pulling us towards it at 1.4 million mph.

According to some theories, this gravitational anomaly is a cluster while others name dark matter as the culprit. Regardless of whatever it is, humanity will most probably be extinct by the time we get there.

5. The Sun’s Corona

It’s very common for people to believe that the surface of the sun would be hotter than its atmosphere because logically that makes sense. This was also something that astronomers believed until they found out that the sun’s atmosphere, also known as corona is almost 300 times hotter than its surface.

This is not to say that the surface is cool by any means, it’s a blistering 10,340 degrees Fahrenheit (5727 degrees Celsius), which is quite crazy when you consider the fact that the highest temperature ever recorded on Earth was 136 degrees Fahrenheit (57.8 degrees Celsius). We still don’t know why this happens and it is one of the biggest mysteries in solar physics.

4. Kepler 78b

During our search for extraterrestrial planets that might harbor life, we have come across countless candidates that all exhibit different characteristics. One of these is the planet Kepler 78b which is basically considered an anomaly, meaning that technically it shouldn’t exist.

It is 1.2 times the size of Earth but it has a very tight orbit around its star, completing a full year in just nine hours. Because of this close orbit, it is covered in molten rock and fire with temperatures reaching 4,300 degrees Fahrenheit (2,400 degrees Celsius). No explanations are currently available as to how a planet like Kepler 78b ended up so close to its parent star.

3. Gamma Ray Bursts

Gamma Ray bursts are some of the brightest explosions in the universe, releasing more energy in a few seconds than a normal star would during its entire lifetime. They have been observed in random locations throughout space and at random times for the last 40 years.

Some astrophysicists believe distant galaxies to be the source of these but no definite explanations are known right now. It is also speculated that if one of these events happens nearby and in our direction, it would easily fry our whole planet, effectively wiping out every living being on Earth.

2. Death of the Universe

The Big Bang Theory (we don’t mean the TV show here) allowed us to explain how the universe was formed after Edwin Hubble made the discovery that most galaxies appeared to be moving away from each other. What we still do not know, however, is how the universe is going to end. There are a lot of theories on how the exact event will play out, none of which are very pleasant.

Certain scientists suggest that the universe will end in a Big Freeze, meaning that it will keep expanding until it reaches absolute zero temperature while some other scenarios predict a big Crunch which is the opposite of the Big Bang, meaning everything will collapse upon itself in a singularity. The fate of our universe is then unknown and we most probably won’t be around if any such event does happen eventually.

1. Wow! Signal

Ever since humans started taking interest in the solar system and outer space, the single biggest question everyone has had on their mind is whether we are really alone in this universe or not. The search for extraterrestrial intelligence, also commonly known as SETI was put forth in the early 1900s after the advent of radio to check for an extraterrestrial communication signal. On August 15, 1977, a Big Ear telescope operated by Ohio State University came across a strong narrowband radio signal of unknown origin which was coming from the constellation Sagittarius. The signal got its name after Astronomer Jerry R. Ehman circled his readings on the printout and wrote the comment “Wow!”.

Numerous theories have since been put forth to explain what might have caused the signal and many attempts have also been made to search for the recurrence of the signal but none of these have been successful. What’s really spooky about this whole situation is that the signal which was captured carried all the characteristics that proved its extraterrestrial origin. So, was it really aliens trying to contact us? I guess we’ll never know.