From the mission that saw Pluto for the first time to the Mars rovers, a new breed of explorers are risking their careers, and even their lives, to lead humanity to worlds we have never seen and tackle the mysteries of life itself.
Voyager has had a profound effect on our knowledge of the cosmos. Its mission was supposed to last five years but remains ongoing, fundamentally changing our understanding of the solar system. Featuring contributions from key scientists, we’ll explore what’s been achieved and what happens next.
2016 • Astronomy
Description of the two Voyager probes sent for interstellar travel. Tyson ends the series by emphasizing Sagan's message on the human condition in the vastness of the cosmos & to encourage viewers to continue to explore and discover the undiscovered.
What would happen if the sun took out our electrical power grid for an entire year? It may sound like the plot of a sci-fi movie, but this doomsday scenario could actually happen. Despite its calm appearance, the sun is a violent place, constantly releasing huge masses of energy known as coronal mass ejections. These storms have hit the earth before. The last big one struck more than 150 years ago in the Victorian era taking out worldwide telegraph service. The impact of a similar storm would be far more destructive in our modern age of hyper-connected telecommunication and total reliance on electricity and electronics. Fortunately scientists and engineers are building the world's largest solar telescope and launching the first ever spacecraft to fly to the sun to help us predict these potentially devastating events - and prepare for them.
2017 • Astronomy
Now that we’re done with the planets, asteroid belt, and comets, we’re heading to the outskirts of the solar system. Out past Neptune are vast reservoirs of icy bodies that can become comets if they get poked into the inner solar system. The Kuiper Belt is a donut shape aligned with the plane of the solar system; the scattered disk is more eccentric and is the source of short period comets; and the Oort Cloud which surrounds the solar system out to great distances is the source of long-period comets. These bodies all probably formed closer into the Sun, and got flung out to the solar system’s suburbs by gravitational interactions with the outer planets.
Today on Crash Course Astronomy, Phil explains comets. Comets are chunks of ice and rock that orbit the Sun. When they get near the Sun the ice turns into gas, forming the long tail, and also releases dust that forms a different tail. We’ve visited comets up close and found them to be lumpy, with vents in the surface that release the gas as ice sublimates. Eons ago, comets (and asteroids) may have brought a lot of water to Earth -- as well as the ingredients for life.