The universe has remained an enigma for scientists for countless centuries. Currently, the observable universe spans a mind-boggling 94 billion light-years( 5.5×1023 miles) in diameter. Even with the drastic advancement in technology in the modern times, we have only been able to unlock a minuscule amount of information about the outer space.
The universe, as we know it, is constantly expanding and changing. However, based on extensive research and observation, scientists have been able to chalk out a rough sketch of the basic composition of the universe.
The universe is essentially made up of matters that have mass (both observable and unobservable) and energy (measurable and unmeasurable). A breakdown of all these things and their proportion in the composition of the universe is given below-Stars- Given the huge number ( a rough estimate on which scientists agree is 1,000,000,000,000,000,000,000 or 1 billion trillion) in the observable universe and the massive size of each star, we might be mistaken to think that stars are the major component of the universe. However, all stars taken together amount for only 0.5% of the total mass of the universe.
Neutrinos- These are the near-massless particles produced during the fusion reaction in the stars. They travel at near-light speed and make up about 0.3 % of the mass of the universe.
Heavy Elements- Planets like our earth and all other projectiles in space such as moons, meteorites and meteors amount for about 0.03% of the universe.
Gas- Hydrogen and helium are the two most common gases in the universe and account for about 4% of its mass.
Dark Matter- Galaxies are made up of more than just stars and planets and gas. There is a substantial mass in every galaxy that cannot be seen, but only felt gravitationally. Scientists call it dark matter, and it makes up about 25% of the observable universe.
Dark Energy- It is a hypothetical energy, with possible anti-gravitational properties, that scientists have not been able to understand yet. It is spread across the universe uniformly and accounts for nearly 70% of its mass.