An international team of researchers have produced new maps of the stardust located between the stars of the milky way. This dust and gas are left behind when a star dies and supplies the fuel for new stars and planets.

Astronomers analyze the bands of starlight that pass through space to determine the composition of stars and other space materials. However, in 1922, astronomer Mary Lea Heger noticed that some of that light was missing. Dark bands known as diffuse interstellar bands, or “DIBS” contained no starlight. This indicated that some material was preventing the light from being seen. To date more than 400 DIBS have been identified, but what the bands are made from has remained a mystery.

Researchers believe that, based on the absorption of starlight, the bands must be made of large, complex molecules but no hard evidence of this has been found. Evidence of the nature and composition of the material could provide clues about the chemistry of the spaces between stars, as well as information about how stars and galaxies form.

“There’s an old saying that ‘We are all stardust,’ since all chemical elements heavier than helium are produced in stars. But we still don’t know why stars form where they do. This study is giving us new clues about the interstellar medium out of which the stars form,” said Rosemary Wyse, a Johns Hopkins professor of physics and astronomy who played a prominent role in the research, in a statement.

The new maps were created using data collected over a 10-year period by the Radial Velocity Experiment (RAVE). RAVE used the Schmidt Telescope in Australia to gather spectroscopic information from clusters of stars, as many as 150 at a time. In all, data related to 500,000 stars was gathered.

The size of the sample allowed researchers to determine the distance of the material causing the DIBs and map how the material is distributed.

The maps crated from this data is described as “pseudo-3D” because a mathematical form is used to calculate the distribution of the vertical dimension that describes the distance from the plane of the Milky Way.

The techniques developed in creating the maps should allow future researchers to build additional maps, possibly determining where DIBS are located and what materials they contain.

“To figure out what something is, you first have to figure out where it is and that’s what this paper does. Larger surveys will provide more details in the future. This paper has demonstrated how to do that,” said Wyse.

The findings of Wyse and her colleagues appear in the August 15 edition of the journal Science.