Astrophysicists estimate dark matter accounts for 85 percent to 90 percent of all the matter in the known universe. Scientists, however, have mostly been unable to detect the mystery material because its weak interactions with the electromagnetic force are intangible at best. Instead, astrophysicists have only been able to infer its existence from the gravitational effects it appears to have on normal matter. As a result, dark matter is considered a hypothetical substance likely built from a form of undiscovered subatomic particles.

This has recently led some scientists to question whether the substance exists and whether it will ever be discovered. A new study published in The Astrophysical Journal, led by the International School for Advanced Studies (SISSA), has sought to dispel the doubt surrounding dark matter. Chiara Di Paolo, a doctoral student of astrophysics at SISSA, said: “Three years ago, a few colleagues of the Case Western Reserve University strongly questioned our understanding of the universe and the in-depth work of many researchers, casting doubt on the existence of dark matter in the galaxies. “Analysing the rotation curves of 153 galaxies, principally the ‘classical’ spiral kind, they obtained an empirical relationship between total gravitational acceleration of the stars, observed, and the component which we would observe in the presence of sole ordinary matter in the classical Newtonian theory. READ MORE: The Moon is made of MAGMA and it was once part of Earth, scientists claim

Dark matter: The mystery substance is believed to be found in all galaxies

“This empirical relationship which seemed valid in all the galaxies they analysed and at any galactic radius, motivated the explanation of gravitational acceleration without necessarily calling into question dark matter, but involving for example theories of modified gravity such as Modified Newtonian Dynamics.” According to US space agency NASA, galaxies and dark matter go together like “peanut butter and jelly”.

We thought that every galaxy had dark matter Pieter van Dokkum, Yale University

Astronomers believe dark matter exists within each observable galaxy and could be one of the triggers which aid the creation of galaxies. In essence, dark matter is believed to be the glue which holds the visible matter within these galaxies together. Because of this, astronomers were surprised in 2018 to discover galaxy NGC 1052-DF2 only held about 1/400th of the expected amount of dark matter. READ MORE: Former NASA scientist claims there's a BLACK HOLE inside of Earth

Pieter van Dokkum of Yale University said: “We thought that every galaxy had dark matter and that dark matter is how a galaxy begins. “This invisible, mysterious substance is the most dominant aspect of any galaxy. “So finding a galaxy without it is unexpected. It challenges the standard ideas of how we think galaxies work, and it shows that dark matter is real: it has its own separate existence apart from other components of galaxies. “This result also suggests that there may be more than one way to form a galaxy.” READ MORE: NASA wants to probe Uranus and Neptune’s icy atmospheres

Dark matter: The invisible form of matter is considered the glue holding galaxies together

The presence of dark matter in galaxies is used to explain how stars move around and cluster together in a way, which ordinary matter cannot explain. Paolo Salucci, a professor of astrophysics at SISSA, said: “We have studied the relationship between total acceleration and its ordinary component in 106 galaxies, obtaining different results from those that had been previously observed. “This not only demonstrates the inexactness of the empirical relationship previously described but removes doubts on the existence of dark matter in the galaxies. “Furthermore, the new relationship found could provide crucial information on the understanding of the nature of this indefinite component.”

How are physicists looking for dark matter? Unlike normal matter, dark matter does not reflect or emit light and does not interact with the electromagnetic force. This makes dark matter incredibly hard to observe but scientists have been able to speculate about how the substance works. According to the physicists at CERN, the European Organisation for Nuclear Research, one theory suggests dark exists in a “parallel world” unlike our own. Another theory proposes dark matter contains so-called supersymmetric particles, which mirror those in the widely accepted standard model of particle physics. CERN said: “If one of these theories red to be true, it could help scientists gain a better understanding of the composition of our universe, and in particular, how galaxies hold together. Unfortunately, CERN’s Large Hadron Collider (LHC), which slams proton particles at near the speed of light, cannot quite yet detect the elusive material.

Dark matter: NASA believes galaxies and dark matter go hand in hand

What is the difference between dark matter and dark energy? Dark matter is the yet-to-be-discovered matter, which astrophysicists believe helps galaxies stay together. Dark matter is currently undetectable but scientists know it is there because without, galaxies would not have enough matter to produce the gravity holding the tightly together. Dark energy, on the other hand, is described as a form of energy spread throughout the universe, which is causing the expansion of space to accelerate. Astronomer Sabrina Stierwalt said: “Some researchers are searching for an explanation that encompasses both dark matter and dark energy.