Dark Matter

Extracted Attributes

• Scientific Field

  Cosmology and Astrophysics

• Primary Interaction

  Gravitational interaction; non-interacting with electromagnetic radiation

• Alternative Theories

  Modified Newtonian Dynamics (MOND), Tensor-vector-scalar gravity, Entropic gravity

• Hypothesized Candidates

  Weakly Interacting Massive Particles (WIMPs), Axions, Primordial Black Holes

• Solar System Mass Estimate

  10^17 kg of dark matter within the orbit of Neptune

• Proportion of Total Universal Matter

  85% of total mass

• Cosmological Proportion (Mass-Energy Content)

  26.8% (approximately 27%) of total universe mass-energy

Timeline

• Swiss astronomer Fritz Zwicky proposed the concept of unseen mass and coined the term 'dunkle Materie' (dark matter) to explain the velocities of galaxies in the Coma Cluster. (Source: Web Search / NASA)

  1933

• Astronomer Vera Rubin provided robust observational evidence for dark matter through detailed measurements of galaxy rotation curves at the Carnegie Institution. (Source: Web Search / Department of Energy)

  1970

Dark matter

In astronomy and cosmology, dark matter is an invisible and hypothetical form of matter that does not interact with electromagnetic radiation, including light. Dark matter is implied by gravitational effects that cannot be explained by general relativity unless more matter is present than can be observed. Such effects occur in the context of formation and evolution of galaxies, gravitational lensing, the observable universe's current structure, mass position in galactic collisions, the motion of galaxies within galaxy clusters, and cosmic microwave background anisotropies. Dark matter is thought to serve as gravitational scaffolding for cosmic structures. After the Big Bang, dark matter clumped into blobs along narrow filaments with superclusters of galaxies forming a cosmic web at scales on which entire galaxies appear like tiny particles. In the standard Lambda-CDM model of cosmology, the mass–energy content of the universe is 5% ordinary matter, 26.8% dark matter, and 68.2% a form of energy known as dark energy. Thus, dark matter constitutes 85% of the total mass, while dark energy and dark matter constitute 95% of the total mass–energy content. While the density of dark matter is significant in the halo around a galaxy, its local density in the Solar System is much less than normal matter. The total of all the dark matter out to the orbit of Neptune would add up to about 1017 kg, the same as a large asteroid. Dark matter is classified as "cold", "warm", or "hot" according to velocity (more precisely, its free streaming length). Recent models have favored a cold dark matter scenario, in which structures emerge by the gradual accumulation of particles. Dark matter is not known to interact with ordinary baryonic matter and radiation except through gravity, making it difficult to detect in the laboratory. The most prevalent explanation is that dark matter is some as-yet-undiscovered subatomic particle, such as either weakly interacting massive particles (WIMPs) or axions. The other main possibility is that dark matter is composed of primordial black holes. Although the astrophysics community generally accepts the existence of dark matter, a minority of astrophysicists, intrigued by specific observations that are not well explained by ordinary dark matter, argue for various modifications of the standard laws of general relativity. These include modified Newtonian dynamics (MOND), tensor–vector–scalar gravity, and entropic gravity. So far, none of the proposed modified gravity theories can describe every piece of observational evidence at the same time, suggesting that even if gravity has to be modified, some form of dark matter would still be required.

Web Search Results

• Dark matter - Wikipedia

  In astronomy and cosmology, dark matter is an invisible and hypothetical form of matter that does not interact with electromagnetic radiation, including light. Dark matter is implied by gravitational effects that cannot be explained by general relativity unless more matter is present than can be observed. Such effects occur in the context of formation and evolution of galaxies, gravitational lensing, the observable universe's current structure, mass position in galactic collisions, the motion of galaxies within galaxy clusters, and cosmic microwave background anisotropies. Dark matter is thought to serve as gravitational scaffolding for cosmic structures. After the Big Bang, dark matter clumped into blobs along narrow filaments with superclusters of galaxies forming a cosmic web at scales [...] Dark matter is not known to interact with ordinary baryonic matter and radiation except through gravity, making it difficult to detect in the laboratory. The most prevalent explanation is that dark matter is some as-yet-undiscovered subatomic particle, such as either weakly interacting massive particles (WIMPs) or axions. The other main possibility is that dark matter is composed of primordial black holes. [...] In the standard Lambda-CDM model of cosmology, the mass–energy content of the universe is 5% ordinary matter, 26.8% dark matter, and 68.2% a form of energy known as dark energy.-10) Thus, dark matter constitutes 85% of the total mass, while dark energy and dark matter constitute 95% of the total mass–energy content. While the density of dark matter is significant in the halo around a galaxy, its local density in the Solar System is much less than normal matter. The total of all the dark matter out to the orbit of Neptune would add up to about 1017 kg, the same as a large asteroid. Dark matter is classified as "cold", "warm", or "hot" according to velocity (more precisely, its free streaming length). Recent models have favored a cold dark matter scenario, in which structures emerge by the

• Dark Matter

  ## What is Dark Matter? Dark matter is the invisible glue that holds the universe together. This mysterious material is all around us, making up most of the matter in the universe. But what exactly isdark matter? That's a question that scientists have been trying to solve for almost 100 years. Dark matter makes up most of the mass in galaxies and galaxy clusters. In fact, scientists estimate that ordinary matter makes up only about 5% of the universe, while dark matter makes up about 27%. (The rest is thought to be dark energy, which is its own mystery). It's thought that dark matter shapes the cosmos, organizing galaxies and cosmic objects on a large scale. The universe is made up of three components: normal or visible matter (5%), dark matter (27%), and dark energy (68%). [...] While the term dark matter was mentioned in earlier publications, the current concept of dark matter materialized in the early 1930s. In 1933, Swiss-born astronomer Fritz Zwicky published a paper in which he described an anomaly he observed studying a cluster of galaxies known as the Coma Cluster. He noticed that the galaxies in the cluster moved too quickly for the gravity created by its observed ordinary matter. The galaxies should have been escaping the cluster, but instead, they were staying together. After noting this discrepancy, Zwicky suggested that there might be an invisible form of matter that created the gravity holding these galaxies together. He dubbed this mysterious material "dunkle Materie," which is German for dark matter. [...] ## Dark Matter Versus Dark Energy Dark matter often causes confusion because of its name. Dark matter is not a dark color. Rather, it's called “dark” because it's invisible to us since it doesn't absorb, reflect, or emit any light. Another misconception about dark matter relates to dark energy. While the two are both cosmic mysteries with "dark" in their name, they are not the same thing. Dark matter is a mysterious type of matter that holds galaxies together. Dark energy is the name scientists have given to whatever is causing our universe to expand at an accelerating rate over time — another cosmic mystery. Dark energy isn't concentrated in galaxies or galaxy clusters, instead scientists think it’s spread throughout the universe.

• DOE Explains...Dark Matter

  Scientific evidence points to dark matter being a new type of fundamental particle or particles that interact with ordinary matter through gravity. Scientists have several candidates for the types of particles that make up dark matter. One possibility is that dark matter is made of WIMPs (weakly interacting massive particles) that would have 1 to 1,000 times more mass than a proton. Another candidate is the axion, a particle with ten-trillionth of the mass of an electron. In theory, axions would convert to a particle of detectable light (called a photon) in the presence of strong magnetic fields. Alternately, dark matter may exist in a rich and complex set of particles that would form a universe parallel to our own (the so-called Dark Sector). [...] Dark matter is very different from the ordinary matter we see and interact with every day. Dark matter interacts very weakly or almost not at all with the ordinary matter that we and our measuring instruments are made of. The exception is that dark matter does exert gravitational attraction, just like ordinary matter. Isaac Newton demonstrated in 1687 that matter attracts all other matter in the universe with the force of gravity. [...] The term dark matter was coined in 1933 by Fritz Zwicky of the California Institute of Technology to describe the unseen matter needed to explain the fast-moving galaxies in the Coma Cluster. In the 1970s, Vera Rubin of the Carnegie Institution found evidence for dark matter in her research on galaxy rotation. Today we have much more evidence for the presence of dark matter in galaxies, the interaction of dark matter halos during galactic cluster collisions, and the distribution of dark matter (and even its absence) across different types of galaxies.

• What Is Dark Matter? | NASA Space Place – NASA Science for Kids

  Link to nasa.gov Link to science.nasa.gov. Image that reads Space Place and links to spaceplace.nasa.gov. Vea en Español # What Is Dark Matter? The Short Answer: Dark matter is stuff in space that has gravity, but it is invisible and isn’t like anything else we know about. Dark matter makes up about 27% of the universe. Dark energy makes up roughly 68% of the universe. We don’t know much about dark energy either, but we do know there is a lot of it. Together, dark matter and dark energy make up almost 95% of our entire universe. The rest – everything on Earth, everything ever observed with all of our instruments, all matter we understand – adds up to less than 5% of the universe. [...] In other words, something must hold our solar system, galaxies and clusters of galaxies together. Dark matter is that invisible glue that keeps stars, dust, and gas together in a galaxy. This mysterious substance makes up the majority of a galaxy's mass and forms the foundation of our Universe's structure. A simplified illustration of a swirling dark blue galaxy says, Wow. That’s deep. Dark matter is still one of the greatest mysteries of science. Credit: NASA/JPL-Caltech ## If dark matter is invisible, how do we know it’s there?

• Dark Matter | ESA/Hubble | ESA/Hubble

  Page saved successfully Couldn't save page :( Please try again. These visuals feature artist impressions. # Dark Matter Dark matter is a form of matter that cannot currently be observed directly, but is thought to comprise about 85% of all matter in the Universe. [...] that there must be a form of matter that has not yet been observed, known as dark matter, which is holding these galaxies together. For the calculations based on observations to make sense, dark matter must make up about 85% of all the matter in our Universe, and 27% of our Universe’s total mass-energy density. It is referred to as ‘dark’ because it does not appear to interact with the electromagnetic field, and therefore does not seem to emit, reflect or refract light. [...] Word Bank: Dark Matter Image B Word Bank: Dark Matter ### Videos Description Dark Matter Dark matter is a form of matter that cannot currently be observed directly, but is thought to comprise about 85% of all matter in the Universe. ##### If you are using content from the ESA/Hubble Word Bank, it should be credited as "ESA/Hubble". Our full copyright requirements are provided here. Usage of ESA/Hubble Images and Videos Are you a journalist? Subscribe to the ESA/Hubble Media Newsletter. Privacy policy Website developed and operated by Enciso Systems Accelerated by CDN77

• Instance Of

  Q3331189