New Clues to Universe's Structure Revealed

What is our universe made of, and has its composition changed over time? Scientists have new insights about these fundamental questions, thanks to an international collaboration of more than 400 scientists called the Dark Energy Survey (DES).

Map of dark matter made from gravitational lensing measurements of 26 million galaxies in the Dark Energy Survey. The map covers about 1/30th of the entire sky and spans several billion light-years in extent. Red regions have more dark matter than average, blue regions less dark matter. Image Credits: Chihway Chang/Kavli Institute for Cosmological Physics at the University of Chicago/DES Collaboration

Leading models of the universe suggest it is mostly composed of entities we cannot see: dark matter and dark energy. Dark matter acts like invisible glue, holding galaxies and galaxy clusters together gravitationally, while dark energy is thought to be responsible for the accelerated expansion of the universe.

Some of our best predictions for how much dark matter and dark energy are in the universe come from the European Space Agency's Planck satellite, which looks at the light from about 400,000 years after the Big Bang.

Now, the Dark Energy Survey has examined the composition of the recent universe. Remarkably, the new results are close to forecasts made from Planck measurements of the distant past, allowing scientists to understand more about how the universe has evolved over approximately 14 billion years.

Scientists find that about 70 percent of the energy in the universe is contained in dark energy. About 25 percent is composed of the mysterious dark matter, with normal matter making up the remainder. All of this agrees with precise measurements made to date. So far, DES has found no evidence that the amount of dark energy has changed over time -- a finding that is consistent with Albert Einstein's idea of a "cosmological constant."

The results are especially important to the scientific community because they mark the first time that observations from the more recent universe -- the "adult" universe -- by a technique called gravitational lensing and galaxy clustering, have yielded results as precise as those from the cosmic microwave background radiation -- light from the "infant" universe.

To measure dark matter, scientists first created maps of galaxy positions. Then, they precisely measured the shapes of 26 million galaxies to directly map patterns of dark matter over billions of light years, using gravitational lensing and galaxy clustering.

The DES team developed new ways to detect the tiny lensing distortions of galaxy images. In the process, they created the largest guide to spotting dark matter in the cosmos ever drawn. The new dark matter map is 10 times the size of the one DES released in 2015 and continues to grow. (NASA)

YOU MAY ALSO LIKE

New Mechanism of Cell Movement Revealed

Cells in the human body often need to move in particular directions. Cell movement is crucial for embryo development, immune defense, and tissue repair and regeneration. It’s also key in cancer progression, as metastatic cells spread throughout the body.

Mysterious New Type of Human Brain Cell Discovered

A new type of human brain cell was discovered by Scientists that has never been seen in mice and other well-studied laboratory animals before.

"Mini Supernova" Explosion Could Have Big Impact

Using NASA’s Chandra X-ray Observatory, astronomers have studied one particular explosion that may provide clues to the dynamics of other, much larger stellar eruptions.

Coral reefs shifting away from equatorial waters

Coral reefs are retreating from equatorial waters and establishing new reefs in more temperate regions.

No limit to life in deep sediment of ocean's "deadest" region

Scientists have found oxygen and oxygen-breathing microbes all the way through the sediment from the seafloor to the igneous basement at seven sites in the South Pacific gyre, considered the "deadest" location in the ocean.

Ozone-depleting compound persists

NASA research shows Earth's atmosphere contains an unexpectedly large amount of an ozone-depleting compound from an unknown source decades after the compound was banned worldwide.