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...
A few days ago I wrote about a galaxy that was tough to see because of Milky Way field stars. But our galaxy is far more than just a bunch of stars smattered about. There is also a huge amount of gas and dust with varying temperatures. Some of the hotter and more illuminated gas and dust are what make nebulae so lovely in space. But the cold gas and dark dust that is just out floating in the cold interstellar medium? That stuff gets in the way. A normal image of interacting galaxies M81 and M82 would try to hide the...
