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...
Dark matter could be almost anything. With little data other than how much total dark matter mass exists, we can’t decode much about what individual chunks of dark matter might be made of. I’ve talked before about Massive Compact Halo Objects (MACHOs) and Weakly Interacting Massive Particles (WIMPs), but these are just two possibilities. Other theorists have talked about Modified Newtonian Gravity (MNG), where gravity may work differently on the grand scale than it does on our small Earth scales. Or perhaps it’s something I haven’t seen before. Maybe what we call dark matter is just a large population of ancient black holes....
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...
Not to be confused with Canadian Gum Hubba-Bubba, Hubble has released a great birthday image for it’s 26th birthday. I’m a few days late to celebrate, but it’s still a beautiful image. Known as NGC 7653, the Bubble nebula is 8,000 light years distant in the constellation of Cassiopeia. The reason for this natural bubble shape is that the star just left of center in the image is ionizing a surrounding cloud of Hydrogen with it’s powerful stellar wind. As electrons and protons recombine at the edges of the bubble, they release an infrared photon that can be clearly seen...
A direct consequence of Einstein’s theory of general relativity, and an observational way to prove it, is gravitational lensing. It requires a powerful gravitational source to work, such as a galaxy or cluster of galaxies. It works in a similar way to a lens of glass, where rays of light are bent toward a single source, increasing the brightness. In this case, instead of glass, the bending of the rays is due to the curvature of space. Light rays coming from the source would otherwise miss Earth, but instead are bent toward us when there is a massive object in front of it. It’s...
There are eight planets in the Solar System. This statement makes a lot of people angry for several different reasons. The obvious group to respond with anger is the ‘people for Pluto,’ who have an unwavering dedication to the little planet that could. It’s scientifically recognized as a dwarf Planet, and is still one step up from a Kuiper Belt Object (KBO), so it’s doing well. Far beyond Pluto, in the outer recesses of our Solar system, you may have heard of a potential Super-Earth-sized Planet recently theorized by Konstantin Batygin and Mike Brown. This is the other reason people would...
As I’ve said before, the most powerful, most energetic, most intense processes happen in the center. The gravitational center of the Earth, the Sun, and the galaxy are all places where temperature, pressure, and interactions of matter and energy are pushed to their limits. When you look up to the sky it’s easy to see the Milky Way (unless you live in an urban center). Do you ever wonder where the middle of it is? Where that supermassive black hole lies? Astronomers know where it is, but you need infrared cameras to see it past the thick dust that blocks...
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...
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...
When you think of a nebula forming stars, it’s hard to imagine how large it is. Most nebulae form hundreds or even thousands of stars before being blown away by the young stellar winds. Pockets of a nebula collapse into dense regions that will eventually become stars with surrounding planetary systems. There are places in the galaxy we can look and actually see it happening. Pictured above, the beautiful ‘running chicken’ nebula, as strangely named as it is, is in the later stages of it’s star forming life. Many bright young stars have formed and their intense radiation is now...
