In the APOD photo from May 14th, it is easy to imagine the rocket launching far away into the galactic disk. Sadly the rocket can’t traverse the thousands of light years to reach the distant stars, and is restricted to orbiting the Earth. Another beautiful part of this image is the technique involved in producing it. It required combining two exposures. The first, with low sensitivity to capture the orange rocket trail of the Falcon 9. The second with high sensitivity and a longer exposure time to capture the faint light of the Milky Way galaxy beyond. The result is...
Have you ever seen a picture of a comet or asteroid in the sky against a background of stars? Here let me show you. Can you spot the asteroid? Okay I confess there is no asteroid in the image above, but if there was you’d believe me because an asteroid in this image would be indistinguishable from the stars. They are all points of light, so how can you tell them apart? There’s something that separates asteroids, comets, planets, and all other solar system objects from background stars in an image. When you’re driving in a car and you look to the...
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...
The best ever image of a Cometary Globule has been released by the European Southern Observatory (ESO) from the Very Large Telescope (VLT) in the Atacama desert in Chile. It looks a lot like a nebula right? In actuality a cometary globule is a very specific type of nebula. It’s very faint, and it’s formation is a matter of debate among the astronomical community. A cometary globule is small, containing the mass of a few suns worth of material. Compare this to a typical nebula, which has enough material to form thousands or even hundreds of thousands of stars. The...
