"Cosmos" airs on Sunday on Fox and is hosted by Neil deGrasse Tyson. Fox

In the latest episode of "Cosmos," host Neil DeGrasse Tyson explores the tiniest particles that make up the universe. In the "Deeper Deeper Deeper Still" preview clips, Tyson hunts for elusive neutrinos and the distant, early universe.

According to Fox's synopsis of the new "Cosmos" episode, "The Ship of the Imagination ventures on an epic voyage to the bottom of a dewdrop to explore the universe on the smallest scale and observe exotic life forms invisible to the naked eye. Then, host Neil deGrasse Tyson explains the neural network in our brains which determine our sense of smell and memory, and later, he travels deep beneath the surface of the Earth to discover the most mysterious particle we know."

In the first "Cosmos" clip, "Stalking the Wild Neutrino," Tyson explores the underground neutrino observatory Super-Kamiokande, located underneath Mount Kamioka in Japan. Neutrinos are subatomic particles, and while they are abundant in the universe they are difficult to study. Observatories are buried deep underground to reduce background radiation and cosmic rays from interfering with the observation of neutrinos. While other particles cannot penetrate the thick underground walls of the observatories, neutrinos can easily pass through these barriers.

The next clip from "Deeper Deeper Deeper Still," explores the early universe. The speed of light is constant and finite, and as astronomers observe distant stars and galaxies, they are also peering into the early universe. In 2012, the Hubble and Spitzer Space Telescopes observed the most-distant-galaxy candidate ever. The galaxy, MACS0647-JD, is approximately 13.3 billion light years away and formed approximately 450 million years after the universe was created. The most-distant verified galaxy, z8_GND_5296, is located 13.1 billion light-years away.

The "Cosmos" promo for "Deeper Deeper Deeper Still" gives viewers a quick look at an ancient empire and the origin of life on Earth. "Cosmos" airs on Sunday at 9 p.m. EDT on Fox and on National Geographic on Monday at 10 p.m. EDT on Monday.