The seventh episode of 'Cosmos: A Spacetime Odyssey' airs on Sunday April 20 at 9 p.m. ET/PT on FOX and Monday April 21 on National Geographic at 9 p.m. ET/PT.

In "The Clean Room," host Neil deGrasse Tyson travels to the shallow waters running through the Grand Canyon a billion years ago and find the only kind of life on the planet: blue-green bacteria.

The episode synopsis reads, 'The little known but heroic story of a guy from Iowa that can't really be told without going all the way back to the time long before the Earth was formed - to the origin of the elements in the hearts of stars. The tempestuous youth of the Earth effectively erased all traces of its beginnings. How did we ever learn its true age?'

One of America's best-known scientists, astrophysicist Neil DeGrasse Tyson discovered his love for the stars at an early age. After studying at Harvard University, he earned his doctorate from Columbia University in 1991. Tyson went to work for the Hayden Planetarium in 1996 and still serves as its director. Tyson has spent much of his career sharing his knowledge with others.

You can watch the full episode of 'The Clean Room' online by clicking here. 

Watch the sneak peek video below:

The television event is a successor to Carl Sagan's Cosmos: A Personal Voyage and tells the story of how we discovered the laws of nature and found our coordinates in space and time.

The original series first premiered in September 1980 on PBS, and for 10 years was the most watched series ever on public television in America. Based on his book of the same name, and written for television by Sagan, Ann Druyan and Steven Soter, the series was a stunning and iconic exploration of the universe as revealed by science that took viewers through a galaxy of topics to help explain the universe and humanity's place in it.

Tyson said, "What the original Cosmos did and what we do, is find stories about science, about scientists, and about culture, that represent the search for truth, no matter what the consequences." But in its efforts to educate, Tyson says the new Cosmos may have a greater sense of urgency, at a time when issues such as climate change and the risk of asteroid collisions with Earth increasingly concern scientists. "Science literacy is the key to our future survival on Earth," he explains. "So Cosmos will show why science matters."

The 13 part series of Cosmos will be broadcasted every Sunday on FOX at 9/8c, and Monday at 9/8c on National Geographic. You can also watch the live stream online at FOX Now and FOX on demand. A Cosmos App is also available for download on iPhone, iPad and Andriod.

If you miss the previous episodes, you can watch them by clicking here.