Rebecca Boyle writes on Popular Science:
A dark matter particle smacks into an average person’s body about once a minute, and careens off oxygen and hydrogen nuclei in your cells, according to theoretical physicists. Dark matter is streaming through you as you read this, most of it unimpeded.
Dark matter is arguably the greatest mystery in modern physics. Observations from multiple sources across a few decades now shows that most of the universe is made of matter we can’t see — hence the name — but no one has been able to find it. One strong candidate for this dark material is called a WIMP, for weakly interacting massive particle, and there are a variety of observatories in Europe and the U.S. that are looking for these things. Some have found promising hints, but others have seen a whole lot of nothing.
Still, cosmologists generally agree there’s a halo of dark matter particles out there, and our solar system and our planet are flying through it.