A team of geologists has been exploring the caves beneath the table mountains of Venezuela, where new lifeforms may have been quietly developing for millions of years. Journalist Lars Abromeit describes the expedition into the unknown.

In August, a group of scientists announced that people deserve their own new epoch in official geologic time, like the Holocene or the Paleogene. Welcome to the Anthropocene!

Humans are off to live on Mars. At least, that’s the case journalist Stephen Petranek makes in his TED Book, “How We’ll Live on Mars.” According to Petranek, the move is no less than an “essential back-up plan for humanity.” Here, he shares just some of the factors those who make the first trip will have to manage.

History professor Yuval Noah Harari, author of “Sapiens: A Brief History of Mankind,” explains why humans have dominated Earth. The reason’s not what you might expect.

Human beings have made enormous changes to Earth, reshaping it, developing it and generally altering it so much that in many cases its pre-human condition has become unrecognizable. In this far-ranging conversation, ecologist Erle Ellis and landscape architect Bradley Cantrell discuss what this means for ecology and architecture … and how we might think about protecting our planet.

And you think your commute is bad. On November 12, 2014, the Philae probe finally landed on a comet some 10 years after it left Earth. Fred Jansen, who manages the mission for the European Space Agency, remembers some of the key moments that led up to the landing.

Aerospace engineer Jeremy Kasdin explains how two new NASA reports hold promise for those hoping to detect habitable planets orbiting nearby stars — and might even see the launch of the “starshade” occulter.