Questions are raised about the search for intelligent life beyond the Earth, with UFOs and other close encounters refuted in favor of communications through SETI and radio telescope such as the Arecibo Observatory. The probability of technically advanced civilizations existing elsewhere in the Milky Way is interpreted using the Drake equation and a future hypothetical Encyclopedia Galactica is discussed as a repository of information about other worlds in the galaxy. The Cosmos Update notes that there have been fewer sightings of UFOs and more stories of abductions, while mentioning the META scanning the skies for signals.

From steamy jungles to dry deserts, amphibians have taken their first footsteps onto land using their bizarre life histories to break their ties with the water and invade the earth.
This episode delves into the extraordinary and intimate lives of the soft skinned amphibians. This includes the marsupial frogs, a peculiar species where the father carries his young in pouches and then gives birth. It also features warring giant salamanders over a metre long and show-off newts that offer displays just like underwater birds of paradise.

Once they were dreaded and thought to be dragons eating the sun--but modern science has dispelled mythology and we now look forward to total Solar Eclipses as one of the most spectacular phenomena in the heavens. Explore the complex movements of Earth, Moon and Sun that produce these unusual events and hear details why we may be the only intelligent beings in the known Universe to witness eclipses like we see on Earth. Man-made eclipses also figure into the science in the form of instruments called "coronagraphs." They blot out the sun and reveal its corona, uncovering secrets which, while enlightening, also warn of a disaster that could make our advanced technology crash and burn. Finally, travel into deep space, where the tiny eclipses caused by planets circling distant stars is now beginning to reveal hundreds more stars where "exoplanets" exist... perhaps even those in habitable zones like the Earth.

Led by Prince William, founder of The Earthshot Prize and featuring Sir David Attenborough and other members of the Earthshot Prize Council, the series looks past the problems we face and onto the solutions that promise to deliver us all a sustainable world in which both nature and humanity can thrive.
In the first episode, David Attenborough introduces us to inspiring people with solutions to help restore nature, and reveals the three finalists of the first ever Earthshot Prize for Nature.

Within the earth, right beneath our feet, are strange and sometimes deadly secrets. Earthquakes, tsunamis, and volcanic eruptions are just some of the phenomena that are driven by hidden forces deep inside our planet. With the latest sensors and surface scans, a virtual X-Ray of the earth can be generated for study.
In the first episode, we will explore how a vast fault 80 miles off the Pacific Northwest coast. With pressure building for over 300 years, a slip would result in a megaquake and tsunami that will devastate the region threatening 15 million people.

Sagan discusses comets and asteroids as planetary impactors, giving recent examples of the Tunguska event and a lunar impact described by Canterbury monks in 1178. It moves to a description of the environment of Venus, from the previous fantastic theories of people such as Immanuel Velikovsky to the information gained by the Venera landers and its implications for Earth's greenhouse effect. The Cosmos Update highlights the connection to global warming.