What is the origin of galaxies?
Nobody knows with certainty whether the gas left from the Big Bang clustered together to form galaxies, or if the same gas created planets and stars which migrated through gravity into galaxies.
"White" holes
We already know about black holes that “swallow” matter, but Einstein has proved through his equations that “white” holes also exist. These holes are believed to “spit out” am incredible amount of matter from seemingly nothing, but none has been yet discovered.
Are there other Earths?
Our sun is just one of the trillions of suns existing in the universe, and each of them has several planets gravitating around. Since 2000, several planets have been discovered which might host life, such as Gliese 581d, but until we will be able to explore them, this will remain a mystery.
Dark matter
Einstein’s famous equation does not really apply to space. When we use it to determine how much matter the universe should have, we realize that we have found only 4% of the matter in the universe, the rest could be dark matter which has not been detected yet.
Dark energy
The scientists came with a theory to explain why galaxy clusters are moving farther apart instead of attracting each other as the law of gravity dictates. The dark energy supposedly has an opposite effect, drfiting galaxies apart.
Life on Mars?
It is believed that liquid oceans once covered the surface of Mars before it lost its magnetic field. Current missions to Mars try to find out whether the planet also hosted forms of life or not.
Human face in Eagle Nebula
This photo was supposed to show the birth of a star in the Eagle Nebula, however, after it was broadcasted, people started calling and claiming they see a human face in the photo. The phenomenon is still a mystery today.
Ruins on Moon?
A man who claims to have worked for the government showed how the pictures from the moon were supposedly altered and censured. He claims the pictures were depicting some structures on the surface of the Moon.
Other universes?
There is a theory which claims that there are an infinite number of universes governed by their own set of laws. However, there are no evidence in thise sense, but nevertheless there is also no evidence to disprove the theory.
Astronauts claiming UFO existence
Some astronauts claimed to have seen UFOs when they were in the outer space, but NASA officials wouldn’t allow them to give any details so as not to create panic.
