6. Rogue planets, also known as “interstellar planets,” are objects in the universe that do not move around on their given orbit, and most of them are kicked off from their path by other objects.
Rogue planets are basically sunless planets that do not have a star to orbit around. They may have had one in the past but because they were knocked out from their position from other planetary objects, they moved away from their orbits.
It is thought, however, that some rogue planets did not have orbit from the beginning. These unbound rogue planets also become the cause for creating more rogue planets when they hit the ones moving in an orbit.
The Milky Way alone has billions and trillions of such free-floating objects. Rogue planets are not heated by stars and emit their own heat, though very little.
The smallest rogue planet that astronomers have been able to observe is OTS-44 and is considered a huge milestone in the study of rogue planets because even though these objects are abundantly available in the galaxy, they are very difficult to discover. (1, 2)
7. About 95% of the universe seems “missing” or is made up of matter that we don’t see or understand. Scientists do not have any clarification for that except the possibility of the “dark fluid” theory.
The planets, stars, and galaxies make up only 5% of the entire universe. Neither astronomers nor scientists can completely explain the fabric of the cosmos or the nature of the matter from which the universe is made. It is called “dark matter” or “dark energy.”
It all started with the idea that dates back to the 1960s when astronomer Vera Rubin made the first proposition that there might be more mass in the universe than just what is observable to us.
Dr. Farnes with his team proposed the “dark fluid theory” suggesting that our current model of the universe, LamdaCDM. does not say anything about dark matter or energy. And unifying these two entities into a fluid can solve the confusion.
Such fluid would have “negative gravity” as one of its characteristics which would be the major essence to solve the mystery. In his words, “The fluid with negative gravity would suggest that the missing 95% has an aesthetic solution: We had forgotten to include a simple minus sign.” (1, 2)
8. The cosmic radiation created from the Big Bang is present everywhere in space except the cosmic microwave background (CMB). This is faint cosmic background radiation spread across all over space.
The cosmic microwave background (CMB) is also known as “relic radiation” and is said to be leftover radiation from the time when the universe began. The theory suggests that when the Big Bang took place, it went through rapid inflation and expansion.
But CMB is cold as 2.725 degrees above absolute zero or minus 273.15 degrees Celsius, and that’s the reason why it is invisible to the human eye and it is also not visible through the optical traditional telescopes.
Only sensitive radio telescopes detect faint background noise or glow that is not related to any star galaxy or other planetary bodies. The radiations of CMB are most visible in the microwave part of the electromagnetic spectrum. CMB represents the heat leftover from Big Bang.
Since CMB is the oldest electromagnetic radiation in the universe, it is an important source of data to study the early universe and it is also a strong piece of evidence for the Big Bang theory to be true.
The staggering discovery was accidental and happened in 1965. The discovery was made by American radio astronomers named Arno Penzias and Robert Wilson. The two gentlemen also won a Nobel Prize in physics in 1978 for the huge break. (1, 2)
9. New studies from the University of California have estimated that our Milky Way Galaxy has about 100 million black holes. Smaller ones have their masses ten times greater than the Sun and the larger ones are a million times larger than the Sun.
Daniel Holz, a physicist at the University of Chicago in Illinois, says that these numbers might appear very large, but there is nothing to be scared of because as per the astronomical standards, the numbers are pretty small. Moreover, if we compare, our galaxy has a thousand times greater number of stars than black holes.
A team of scientists at the University of California calculated these numbers. Included in this research, they mentioned that these black holes have masses ten times greater than the Sun and are called “stellar-mass black holes.” These stellar-mass black holes are formed when massive stars collapse. Then there are also some “supermassive” black holes that are a million times larger than the Sun and lie in the center of every large galaxy.
To count the number of black holes, the properties of stars and galaxies are considered. The size and the composition of a star determine whether or not it is going to be transformed into a black hole. The size of the black hole is also dependent on the size of the star. The size of the galaxy is important because it gives the idea of the number of stars present in the galaxy and also about their properties. (1, 2)
10. The darkest planet ever discovered absorbs 99% of the light falling on its surface and lies in our Milky Way Galaxy. It is still a mystery why the planet is so ridiculously dark.
The darkest planet is darker than the blackest lump of coal. Its name is TrES-2b. It is almost the size of Jupiter, and the matter composition of the planet is also Jupiter-like, filled with gases. Unlike Jupiter, however, it is comparatively closer to its star.
It is classified as one of the “hot Jupiters,” a class of planets. It is 750 light-years away from the Solar System and is found to be revolving around a Sun-like star GSC 03549-02811. This information was provided by NASA’s Kepler spacecraft.
It was first observed in 2011 and researches have been continuously carried out on the subject.
Some researchers say that the chemicals that absorb the light on that planet are vaporized sodium and potassium or gaseous titanium oxide, but the proposed theory has not been proved yet. For some researchers, it is a mystery why the planet is so dark and there is a high possibility that it has a chemical that we haven’t considered yet.