When could the Moon possibly be brighter than the Sun? The Sun is much bigger, produces energy, and gives all the energy needed for life on Earth. But if you look at the sky in gamma rays, the highest energy photons on the electromagnetic spectrum, you’ll see the Moon more easily than the Sun. Why? The Moon is the brightest gamma ray source in the sky, because it has no atmosphere or magnetic field. Essentially it has no protection from the dangerous cosmic rays that are constantly zipping through space. When they hit the Earth’s atmosphere they create a cosmic...
I love false-colour images. They reveal detail that you can’t see in real life, but they also highlight things in an artistic way. For me it’s an excellent marriage of art and science, and as a communicator it helps me get concepts across in an accessible way. So when I saw the APOD image of Saturn from earlier this week, I had to discuss it. Saturn never has looked this way, and it never will. The colours are vivid and unrealistic, but they show the differences in three distinct but close wavelengths of light on the electromagnetic spectrum. All of...
Gamma rays are the highest energy photons on the electromagnetic spectrum. Their wavelength is similar to the size of an atom, and when two of them collide they tend to produce a matter-antimatter particle pair. They represent energy high enough to synthesize the fundamental particles of matter, and are produced in the highest energy environments in the cosmos. The interchange of matter and energy works both ways, so one of the ways gamma rays are generated is through annihilation of a matter-antimatter particle pair. Looking back to the beginning of the universe it gives us the earliest ‘chicken or egg’...
If you ask someone what the craziest, most powerful, energetic, and enigmatic thing in the universe is, chances are they will say a black hole. After all, we know so little about them, we have never directly seen one, and we can see their influence across space and time. But there is apparently another notch on the crazy powerful cosmic object front. Like turning the volume knob to eleven, a binary system of supermassive black holes has been discovered in a nearby quasar. A quasar is an incredibly bright core of a distant galaxy, shining brighter than the entire galaxy...
The Sun, stars, nebulae, galaxies, planets; We can see them all from our lonely cosmic address, but not all is revealed in the light our eyes see. We need to look at the entire electromagnetic spectrum to understand the range of objects we see in the universe. Our closest star shows us how different it can look when you change the observed wavelength. In high energy ultraviolet and X-ray light we can see the most powerful sunspots emitting their bursts of radiation and the swirls of solar plasma releasing ultraviolet energy in all directions. We still have a few years...
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,...
