Astronomers have long known that the universe consists of two types of matter: dark matter, which is invisible and only detectable through its gravitational effects, and ordinary matter, such as gas, dust, stars, and planets. However, locating all of the ordinary matter has been a challenge, with about half of it unaccounted for. Recent research has now revealed the whereabouts of this 'missing' matter.

The missing matter was found to be thinly spread out as gas in the vast spaces between galaxies, known as the intergalactic medium. This discovery was made possible by studying powerful bursts of radio waves originating from various locations in the cosmos.

Previously, scientists had estimated the total amount of ordinary matter based on light remnants from the Big Bang. However, they struggled to physically locate half of this matter. The recent study, published in Nature Astronomy, sheds light on the mystery, indicating that a significant portion of the missing matter exists in the cosmic web, far from galaxies.

It was also discovered that some of the missing matter is present in the halos surrounding galaxies, including our own Milky Way. Ordinary matter is made up of baryons, which are essential for building atoms and form the basis of people, planets, and stars.

The study's lead author, Harvard University astronomy professor Liam Connor, explained that while ordinary matter is well understood, dark matter remains a mystery. The violent processes occurring in galaxies, such as supernovas and black hole activities, play a role in dispersing ordinary matter across vast distances in the universe.

The researchers utilized fast radio bursts (FRBs) to detect and measure the missing ordinary matter. These powerful radio wave pulses, originating from distant points in the universe, provided valuable insights into the distribution of matter. By studying 69 FRBs, scientists were able to pinpoint the location of the missing matter and determine its distribution within intergalactic space, galaxy halos, and galaxies themselves.

With the discovery of the missing ordinary matter, researchers can now focus on unraveling other mysteries of the universe, including the nature of dark matter and the challenges associated with its direct measurement.