Hollywood has nothing on science to surprise plot twists and unexpected discoveries. A team of astronomers learned this lesson while they were looking for the oldest stars in the universe. Their experiments not only succeeded in discovering the ancient stars, but new clues also appeared on the most mysterious things in the universe: so-called dark matter.
A window in the early universe
The story begins with a look back in time. By nature, astronomers always do this because the light we see from distant stars takes time to reach the earth. It can take light several years to reach us from the nearest stars beyond the sun and up to billions of stars in distant galaxies. A team of American astronomers decided to discover the oldest stars in the universe, more than 1
As the universe expands, the light crossing is this vast distance stretched and reaches us as radio waves. It's hard to detect the weakness of the old stars because electronic detectors also produce radio waves, Sky & Telescope added.
Where did the energy go?
To minimize the background noise, astronomers put up the store in the remote Australian Outback with their instruments, the experiment to detect the global epithelial reignion signature (or EDGES), resembling a metal table more than a telescope. The goal was not to take snapshots of individual stars, but rather to detect the extended radio signal from groups of these old stars.
In fact, the detective work was involved in finding telltale indications of missing light emanating from a process called absorption, according to the Sky & Telescope.
After years of work, the astronomers managed to discover the oldest stars in the universe. The results show that these early stars occurred when the universe was about 180 million years old.
But something astonished also astronomers. Absorption was stronger than predicted, which meant that the old interstellar gas as the starlight passed through was colder than expected. Somebody had robbed the gas for some of his energy. But what?
An Important Mystery
Enter dark matter. As Nola Taylor Redd observed on Space.com, astronomers have known for decades that most of the matter – about 80 percent in mass – are not in the universe as the common object here on earth, other planets or even stars.  We know that dark matter is out there, because we can weigh it by measuring the speed of the galaxies, which shows that the galaxies are much heavier than the combined mass of their stars and planets. Mass is actually the only one we can easily detect.
Is Dark Matter the Answer?
The discovery of the oldest stars has also given us some exciting tips on dark matter. As the Sky & Telescope declared if something unknown was to drain energy from the gas surrounding the early stars or cool down the EDGES results indicate, dark matter is the likely candidate. This means that it can interact with common objects and probably did it in the early days of the universe.
As always on the limits of science, these results are still preliminary. On the way to understanding the universe, we can only be sure that more plot twists will come.