Scientists have searched for dark matter for decades. One thinks he may have caught a glimpse.

Few things in the universe are as perplexing as dark matter — the invisible and exotic “stuff” that is thought to make up most of the matter in galaxies.

Few things in the universe are as perplexing as dark matter — the invisible and exotic “stuff” that is thought to make up most of the matter in galaxies.

The theory goes like this: To reconcile our current understanding of physics with what we observe in the cosmos, there must be massive amounts of matter that we can’t see. Scientists are sure that this “missing matter” exists because of the gravitational effects it exerts, but detecting it firsthand has eluded scientists, who have had to indirectly infer how dark matter occupies the universe.

Nearly a century after dark matter was first theorized, a Japanese astrophysicist says he may have found the first direct evidence of its existence — gamma rays extending out in a halo-like pattern — in a region near the center of our Milky Way galaxy.

“I’m so excited, of course!” study author Tomonori Totani, a professor in the astronomy department at the University of Tokyo, told NBC News in an email. “Although the research began with the aim of detecting dark matter, I thought the chances of success were like winning the lottery.”

Totani’s claim of detecting dark matter for the first time is an extraordinary one that not all experts are convinced of. But the findings, published Tuesday in the Journal of Cosmology and Astroparticle Physics, offer insights into the wild hunt for dark matter and the difficulties of searching the cosmos for something that cannot be seen.