We’ve covered a lot of incredible stuff, but this week we’re talking about the weirdest objects in space: BLACK HOLES. Stellar mass black holes form when a very massive star dies, and its core collapses. The core has to be more than about 2.8 times the Sun’s mass to form a black hole. Black holes come in different sizes, but for all of them, the escape velocity is greater than the speed of light, so nothing can escape, not matter or light. They don’t wander the Universe gobbling everything down around them; their gravity is only really intense very close to them. Tides near a stellar mass black hole will spaghettify you, and time slows down when you get near a black hole — not that this helps much if you’re falling in.
A new age of space exploration, and exploitation, is dawning. But surprisingly, some of the boldest efforts at putting humans into space are now those of private companies started by a handful of maverick billionaire businessmen. Brian Cox gains exclusive access behind the scenes at Virgin Galactic, Blue Origin and Spaceport America, exploring what is really happening in privately financed space flight right now. From space tourism to asteroid mining, and even dreams of colonies on Mars, these new masters of the universe refuse to limit their imaginations. But are private companies led by Jeff Bezos, Sir Richard Branson and Elon Musk really going to be able to pull this off? How will they overcome the technical challenges to achieve it? And is it really a good idea, or just a fool's errand? Cox meets key players in the story - Bezos, founder of Blue Origin as well as Amazon, and Sir Richard Branson, founder of Virgin Galactic. He wants to find out how entrepreneurs - and engineers - really plan to overcome the daunting challenges of human space travel. It certainly hasn't been easy so far. Jeff Bezos has sold a further billion dollars of Amazon stock this year to fund Blue Origin. Branson has been working on Galactic for more than a decade. Lives have been lost. And some companies have already all but given up. But real progress has been made too. The origins of the new space boom, the X-prize in 2004, proved that reusable space craft could be built by private enterprise. Now the challenge is to work out how to run reliable, safe, affordable services that will show a return on the massive financial investments. Sixteen years since Dennis Tito became the first civilian in space, Cox explores the hardware and companies that are aiming to make daily tourist flights to space. Beyond mass space travel, and even space mining and manufacturing, the dream of Elon Musk and others is true space exploration. His company, SpaceX, already delivers supplies to the International Space Station, and their next step is delivering astronauts too. But their true ambition is to ensure the survival of the human race by crossing our solar system and colonizing Mars in the next decade. Could commercial spaceflight companies eventually make us a space-faring civilization?
2017 • Astronomy
How do astronomers make sense out of the vastness of space? How do they study things so far away? Today Phil talks about distances, going back to early astronomy. Ancient Greeks were able to find the size of the Earth, and from that the distance to and the sizes of the Moon and Sun. Once the Earth/Sun distance was found, parallax was used to find the distance to nearby stars, and that was bootstrapped using brightness to determine the distances to much farther stars.
The dream of sending humans to Mars is closer than ever before. In fact, many scientists think that the first person to set foot on the Red Planet is alive today. But where should the first explorers visit when they get there? Horizon has gathered the world's leading experts on Mars and asked them where would they go if they got the chance - and what would they need to survive? Using incredible real images and data, Horizon brings these Martian landmarks to life - from vast plains to towering volcanoes, from deep valleys to hidden underground caverns. This film also shows where to land, where to live and even where to hunt for traces of extraterrestrial life.
Join the members of the historic Rosetta mission through the years as they launch, wait and then deploy the lander onto the comet 67P/Churyumov–Gerasimenko. Experience the dramatic highs and lows of the first mission to land a probe on a comet in space.
2017 • Astronomy