This is the epic story of the stars, and how discovering their tale has transformed our own understanding of the universe. Once we thought the sun and stars were gods and giants. Now we know, in a way, our instincts were right. The stars do all have their own characters, histories and role in the cosmos. Not least, they played a vital part in creating us. There are old, bloated red giants, capable of gobbling up planets in their orbit; explosive deaths - supernovae - that forge the building blocks of life; and black holes, the most mysterious stellar tombstones. And, of course, stars in their prime, like our own sun. Leading astronomers reveal how the grandest drama on tonight is the one playing above our heads.
In order to understand how we study the universe, we need to talk a little bit about light. Light is a form of energy. Its wavelength tells us its energy and color. Spectroscopy allows us to analyze those colors and determine an object’s temperature, density, spin, motion, and chemical composition.
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
Today Phil explains that YES, there are other planets out there and astonomers have a lot of methods for detecting them. Nearly 2000 have been found so far. The most successful method is using transits, where a planet physically passes in front of its parent star, producing a measurable dip in the star’s light. Another is to measuring the Doppler shift in a star’s light due to reflexive motion as the planet orbits. Exoplanets appear to orbit nearly every kind of star, and we’ve even found planets that are the same size as Earth. We think there may be many billions of Earth-like planets in our galaxy.