Today we are talking about the life -- and death -- of stars. Low mass stars live a long time, fusing all their hydrogen into helium over a trillion years. More massive stars like the Sun live shorter lives. They fuse hydrogen into helium, and eventually helium into carbon (and also some oxygen and neon). When this happens they expand, get brighter, and cool off, becoming red giants. They lose most of their mass, exposing their cores, and then cool off over many billions of years.
This year we said goodbye to one of our most intrepid planetary explorers, the Opportunity rover. Take a look back at its storied 15-year mission on Mars, and how it revolutionized our understanding of not just the red planet, but our solar system at large.
Artificial selection is one example, eyes another, of the well-documented and inescapable process of evolution--change in a population of species over time--by natural selection. These are some of the things that molecules do.
For two years BBC cameras have followed, Dr Sheperd Doeleman of the Smithsonian Astrophysical Observatory and the work of the Event Horizon Telescope project team, a collective of the top scientific minds from around the world. The project combines radio observatories and telescope facilities from around the world to make up a virtual telescope with a diameter spanning the entire planet. This mega-telescope’s ultimate mission is to capture the first image ever of a black hole. Although the concept of black holes has been long assumed to be fact, the Event Horizon Telescope’s success would definitively prove the existence of this scientific phenomena for the first time – and provide clear visual evidence. The programme brings viewers into the laboratories, behind the computer screens and beside the telescopes of what may prove to be one of the great astrophysical achievements in human history.
2019 • Astronomy