Today, a small team of researchers is announcing that its correspondingly small telescope picked up something that theoreticians had only suggested might exist: a signal produced by the very first stars in our Universe. Their radiotelescope, only two meters across, didn’t image the stars directly. Instead, it picked up an imprint on the Cosmic Microwave Background left by the matter that these stars interacted with.

And, while the signal had been predicted by theoreticians, calculations had suggested that it would be substantially smaller than it actually is. If the results hold up, then it could be a sign that dark matter looks very different from what we had expected.

Ignition

The Cosmic Microwave Background was produced when the Universe cooled enough to allow electrons to settle down into the Universe’s first atoms, releasing radiation as they did. It famously captures the state of the Universe when it was formed, telling us about the Big Bang that produced it, as well as the composition of the Universe’s contents. But in many ways, it’s the gift that keeps giving, as subtle details in the Background provide further details of the Universe’s physics, and theorists regularly think up ways to extract more information from it.