Have you seen a gorgeous red sky in the evening, just after sunset? If it’s cloudy, the effect becomes even more spectacular. The Sunlight reflects off the clouds and back down to the ground, creating the calm of twilight. Clouds only go so high, so as the Earth continues to turn and we go deeper into nighttime, the glow disappears. But sometimes it sticks around a bit longer. During a rocket launch at dusk, the exhaust trail from the rocket climbs into the upper atmosphere, far above cloud layers. It can reflect sunlight, with the shape of the particles refracting...
I’ve written many times about the power of looking at different wavelengths of light to study different properties of the universe. From a visualization standpoint, there are other techniques that give you additional power when imaging. More than just the wavelength of light you’re using to show the detail, you can choose the range of wavelengths to bring forward certain features while suppressing others. The aptly-named spaghetti nebula, shown above, is a great example of this. A supernova remnant that covers the constellations Taurus and Auriga, the nebula is very large in the sky, covering three full moons worth (love that unit...
Space seems dark to our weak human eyes. Most of the night sky is the blackness between stars. But in this darkness lies an endless number of photons, travelling in all different directions. These photos form background radiation, in three wavelengths in particular. You’ve likely heard of the Cosmic Microwave Background (CMB), it there is also a Cosmic Optical Background (COB) and a Cosmic Infrared Background (CIB). The COB is explained by the immense number of stars in the Universe. It’s a diffuse glow across the entire sky. The CMB is the leftover radiation from hot plasma that existed when the Universe...
Gamma rays are the most powerful form of electromagnetic radiation in the universe. With wavelengths as small at atoms, they usually result from the most powerful interactions known, such as the collision of two particles, or the release of energy from the accretion disk of a black hole. But there is another potential source of gamma rays that has not yet been confirmed: Dark Matter. The leading candidate for dark matter is the theorized Weakly Interacting Massive Particle (WIMP), though it is not as wimpy as its namesake suggests, making up 5 times as much mass as the visible matter...
We know that solar systems form in a disk shape, with the star forming in the middle and any other rocks, presumably planets, form out from the center in whatever dust and gas remains. But what about the space between stars? Is it truly empty? And if there is something out there, how could we find it? How did it get there? For years, astronomers and chemists (believe it or not) have been trying to answer these questions and more. The specific problem is that when we take a spectrum of a distant star, we see a collection of 400...
Lurking in the depths of a galaxy, hidden from human eyes, lie millions of monsters. They could swallow you up in an instant, sealing you off from the outside world and devouring you atom by atom. This sounds like your typical Hollywood monster movie, but with millions of black holes hidden throughout the galaxy, its more real than you might think. Supermassive black holes, the largest ones that reside at the centers of galaxies, are much easier to see. They are devouring gas and dust rapidly, resulting in bright emission across the electromagnetic spectrum, especially in x-rays. For many galaxies,...
