Like lighthouse beacons in a dark ocean, stars act as tiny islands in the vast universe. Producing light at the atomic level from the powerful release of energy through fusion, they are the engines that drive the formation of new elements. But in the darkness there are plenty of other hidden objects that are cold and give off little to no light. Yet many of them are easily seen. Here’s Why! The first thing to think about is infrared light, the radiation given off by warm objects. Large planets and brown dwarf stars are very bright in infrared, much brighter...
The first exoplanet ever discovered was 51 Pegasi b in 1995. It kicked marked the slow beginning of what would soon become the ‘exoplanet gold rush.’ It meant that for the first time, we had the technological capacity to discover new worlds, and science fiction soon became science fact. 51 Pegasi b was also a very strange planet. A massive Jupiter sized world orbiting very close to its home star. On one hand it was this characteristic that made it much easier to detect. On the other, it showed us that we did not understand planetary system formation as well...
Mercury, the smallest planet in the solar system, and closest to the Sun, is only a little bit bigger than Earth’s Moon. But the Moon is comparatively reflective object. Mercury is thought to be made of the same rock as the Moon, so what is the difference? Why do objects in our Solar system have different brightnesses? The key is in a property called albedo. It’s basically how much light an object reflects, measured as a fraction. For example, the Moon reflects 12% of the light the Sun shines on it, so it has an albedo of 0.12. The albedo...
