For most of the Earth's history, life consisted of the simplest organisms; but then something happened that would give rise to staggering diversity, and, ultimately, life as complex as that which we see today. Scientists are still struggling to figure out just what that was.
2015 • Nature
The expanding universe is a complicated place. During inflation the universe expanded faster than light, but that's something that actually happens all the time, it's happening right now. This doesn't violate Einstein's theory of relativity since nothing is moving through space faster than light, it's just that space itself is expanding such that far away objects are receding rapidly from each other. Common sense would dictate that objects moving away from us faster than light should be invisible, but they aren't. This is because light can travel from regions of space which are superluminal relative to us into regions that are subluminal. So our observable universe is bigger than our Hubble sphere - it's limited by the particle horizon, the distance light could travel to us since the beginning of time as we know it.
After 665 weightless days in space, NASA's most experienced astronaut, Peggy Whitson, smashes through the atmosphere on her last journey home to planet Earth. With unprecedented filming on board the ISS during Peggy's final mission and with the support of our other featured astronauts, we reveal how their time in space transforms their understanding of our planet's wonders, insights that will change our perspective, too. There is no place like home. Or is there? Just how strange is our rock, and is it really unique in the universe? Astronaut host – Peggy Whitson.
Scientists have started looking to the heavens and wondering what the weather might be like on other planets. Today, we are witnessing the birth of extra-terrestrial meteorology. They began with our solar system, sending spacecraft to explore its furthest reaches, and now the latest telescopes are enabling astronomers to study planets further afield. Our exploration of the universe is revealing alien worlds with gigantic storm systems that encircle entire planets, supersonic winds and extreme temperatures. On some planets, temperatures are so hot that the clouds and rain are believed to be made of liquid lava droplets, and on other planets it is thought to rain precious stones. We thought we had extreme weather on Earth, but it turns out that it is nothing compared to what's out there.
The first episode of Space Voyages looks at the Mars Curiosity Rover - an incredible 21st century machine. And it would never have been possible without the accomplishments of early NASA astronauts and engineers. Everything was new – rocket science, astronaut survival – even simply steering in space! This is the story of how both humans and robots laid the foundations for space exploration that continues today.