Dark matter is the invisible things that make up about 85% of the mass of the universe. As its name suggests, dark matter is “black” and does not absorb, emit, or reflect light. And most importantly, dark matter has never been directly detected, or “seen.”

But astronomers have always seen the influence of gravity on an object in countless cosmic objects – a difference that dark matter resolves. ALSO convenient. What this means is that, for many astronomical observations, accounting for dark matter has become the key to better understanding black holes, supernovae, distant galaxies, or even the universe in general. Although we never found anything. Nor understand its true form.

For astronomers, however, the stakes can be very high. As you can see, the deep presence of dark matter in the universe means that this list addresses a small-but-important part of the cosmic enigmas for which this hypothetical concept serves as the best solution.

1. The whole universe

Yes, I’m serious. The whole premise of dark matter starts from the missing 85% of the mass of the entire universe. Ordinary matter—so whatever we see, like planets and stars and people—consists of only 15%, so it’s not even half.

This explains a lot about how and why scientists believe dark matter explains the other objects on this list. When dark matter makes up 85% of the mass of the universe, it has a huge gravitational influence on visible matter, meaning it’s hard to find anything. not which is being pushed by this invisible force.

2. Spiral galaxies

as in says, “Although not all astronomers agree on what dark matter is, its existence is widely accepted.” Dark matter became mainstream consensus in the 1970s, when American astronomer Vera Rubin showed how, without dark matter, spiral galaxy like our Milky Way behaving in ways that don’t match the current laws of physics.

According to ancient astronomical wisdom, the faster a star’s orbit, the more mass—gravity—there must be in any given section of the galaxy. Based on the visible content of about 60 galaxies studied by Rubin, he expected to see only rapidly rotating stars in the center, where the starlight is concentrated.

But in fact, the stars on the edge are moving very fast. That doesn’t make sense, because the combination of visible matter dictates that, if these velocities are true, the galaxy should tear itself apart—unless there is an invisible mass, like dark matter, that holds the galaxies together.

3. The Galactic Center

Astronomers believe that dark matter may be responsible for more than just the shape of the Milky Way. Some studies have proposed we exaggerate how much dark matter is in the Milky Way. However, astronomers believe that the total abundance of objects can help to investigate the unknown characteristics of our galaxy.

Last year, for example, a team from Johns Hopkins University proposed that a mysterious gamma ray excess at the Galactic Center is produced by the collisions of dark matter particles. Just this month, a study from the Institute of Astrophysics La Plata in Argentina contended which, statistically speaking, is surprisingly reasonable to assume that a large “dark matter core” of the Galactic Center controls the local stellar population.

4. Gravitational lensing

According to general relativity, gravity is a distortion of spacetime. Heavyweight cosmic entities such as stars or galaxies generate enough gravitational force to bend spacetime. When light travels along these curved paths, the light appears bent to Earthbound observers.

Because dark matter also has mass – and a huge amount – it often shows up in gravitational lensing observations. This phenomenon, used by astronomers as a convenient visualization technique, uses gravity’s light-bending properties to observe celestial objects that often difficult, if not impossible, to see. But when dark matter enters the scene, it creates reflections that make spacetime seem like it’s flashing to astronomers—like this unique five point Einstein Cross.

5. The Bullet Cluster

In 2006, NASA’s Chandra X-ray Observatory released a unique composition of the galaxy cluster 1E 0657-56, nicknamed the Bullet Cluster, which was formed in one of the most powerful events observed by man since the Big Bang.

The hot gas produced during the collision interacts electromagnetically, so we need to track how and where it moves. But gravitational lensing reveals that most of the cluster’s mass (shown in blue) is located around the galaxies—not in the center, where the gas (shown in pink) is.

After Rubin’s foundational work on dark matter astrophysics, the Bullet Cluster image became one of the loudest demonstrations on the influence of dark matter in the universe.

6. Supersymmetry

Particle physicists believe that dark matter and supersymmetry may be intimately connected. This idea predicts that energy-carrying particles (like photons) and matter particles (like protons) should pair up, which helps clear up some other important differences in the nearly perfect Standard Model of particle physics.

According to CERNmany supersymmetric theories hypothesize that these partner particles will be stable, electrically neutral, and weakly interact with visible matter—the exact criteria for finding dark matter. CERN’s own LHC was discovered there is no direct evidence for supersymmetry, but the phys still hoping connections between supersymmetry and dark matter exist.

7. Quirks in the cosmic microwave background

the cosmic microwave background is a relic of the explosive birth of our universe—the Big Bang. It is a nearly uniform beam of radiation that acts as a record for astronomers to track and study how matter evolves over time in the universe.

But more sensitive detectors have caught strange temperature differences, which scientists believe represent the imprints of dark matter. Although dark matter does not directly interact with radiation, the effect of its gravitational force leaves imperfections, or anisotropies, in the cosmic microwave background.

And the distribution of those anisotropies is how scientists define the basic physical properties of the shape of the universe—so as far as defects go, it’s very useful.