Astronomers create most accurate map yet of all the matter in the universe

By Georgina Torbet Published February 5, 2023

Of all the questions facing astronomers today, some of the biggest unknowns are about the stuff that makes up most of the universe. We know that the ordinary matter we see all around us makes up just 5% of all that exists, while the rest is made up of dark matter and dark energy. But because dark matter doesn’t interact with light, it is extremely hard to study — we have to infer its existence and position from looking at the way it interacts with the ordinary matter around it.

The Blanco Telescope dome at the Cerro Tololo Inter-American Observatory in Chile, where the Dark Energy Camera used for the recently completed Dark Energy Survey was housed. — The Victor M. Blanco Telescope dome at the Cerro Tololo Inter-American Observatory in Chile, where the Dark Energy Camera used for the recently completed Dark Energy Survey is housed. Reidar Hahn, Fermilab

Recent research is helping in this task by producing the most accurate map to date of how both matter and dark matter are spread across the universe. Astronomers collected information from two different telescopes, the Dark Energy Survey telescope and the South Pole Telescope, to make their map as precise as possible.

For both telescope data sets, the researchers used the phenomenon of gravitational lensing — in which a massive body like a star, galaxy, or galaxy cluster warps spacetime and acts like a magnifying glass — to detect both regular matter and dark matter.

By comparing maps of the sky from the Dark Energy Survey telescope (at left) with data from the South Pole Telescope and the Planck satellite (at right), the team could infer how the matter is distributed. — By comparing maps of the sky from the Dark Energy Survey telescope ( from left) with data from the South Pole Telescope and the Planck satellite, the team could infer how the matter is distributed. Yuuki Omori

The results brought some surprises, like the fact that matter is less clumpy than would be expected based on current models of how the universe formed. It shows that the matter is more evenly spread out that predicted. If other surveys find similar results, this could indicate that there is something missing from current theories on how the universe formed in the period immediately following the Big Bang.

“I think this exercise showed both the challenges and benefits of doing these kinds of analyses,” said one of the lead authors of the research, Chihway Chang of the University of Chicago, in a statement. “There’s a lot of new things you can do when you combine these different angles of looking at the universe.”

The research is published in three papers in the journal Physical Review D.

Topics

Tech News

Georgina Torbet

Space Writer

Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…

Space

This one instrument has surveyed 2 million objects to understand dark energy

The Dark Energy Spectroscopic Instrument (DESI) making observations in the night sky on the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory in Arizona.

The vastness of the universe is hard to comprehend, let alone map, but a cosmological project from the National Science Foundation's NOIRLab aims to do just that. The Dark Energy Spectroscopic Instrument (DESI) is designed to create a 3D map of millions of astronomical objects, and an early release of data from the project combines the thousands of exposures taken by the instrument during its validation phase in 2020 and 2021. It contains nearly 2 million objects.

The video below shows part of the survey validation data, with detailed portions of the sky shown in 20 different directions. Each "beam" of light is one part of the data, showing objects like stars, galaxies, and quasars. There are over 700,000 objects in this 3D map, and as impressive as that is, this represents just 1% of the total volume that will be mapped out in the DESI survey.

Space

Image of darkness and light shows new stars being born in Lupus 3 nebula

The two young, low-mass proto-stars HR 5999 and HR 6000 illuminate nearby dust, creating the reflection nebula Bernes 149. These stars grew out of the dusty dark cloud of Lupus 3, part of a larger complex of as many as nine dark clouds.

A gorgeous new image of a nebular 500 light-years away gives a peek into the process of star formation.

This image from the Dark Energy Camera shows both the dark cloud of Lupus 3 and the shining bright young stars of the nebula Bernes 149. The dark cloud here is essential to the star formation process, as it is a collection of gas and dust which provides the building blocks for new stars to be born. Known as a dark nebula because of its density, Lupus 3 obscures the light of the stars behind it, giving the impression of a swath of black across the starry sky.

Space

Astronomers discover Earth-sized exoplanet covered in volcanoes

Exoplanet LP 791-18 d, illustrated in this artist’s concept, is an Earth-size world about 90 light-years away. A more massive planet in the system, shown as a small blue dot on the right, exerts a gravitational tug that may result in internal heating and volcanic eruptions, like on Jupiter’s moon Io.

Astronomers have discovered an Earth-sized planet that is highly volcanically active -- an unusual finding that means it could possibly support life. The newly discovered planet, LP 791-18d, is thought to be covered in volcanoes and could be as active as Jupiter's moon Io, which is the most volcanically active body in our solar system.

Exoplanet LP 791-18 d, shown in this artist’s concept, is an Earth-size world about 90 light-years away. A more massive planet in the system, shown as a small blue dot on the right, exerts a gravitational tug on the exoplanet that may result in internal heating and volcanic eruptions, like on Jupiter’s moon Io. NASA’s Goddard Space Flight Center/Chris Smith (KRBwyle)