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...
Massive star clusters can pop into existence in a matter of a few million years, a very short period of time on astronomical time scales. They consist of hundreds or thousands of massive, bright, hot stars that will live relatively short lives of a few hundred millions of years. Using the Atacama Large Millimeter/Submillimeter Array (ALMA), astronomers have discovered a vanishingly rare molecular cloud of highly dense gas, containing no stars. It is poised to become a massive star cluster, and we found it in its infancy. “We may be witnessing one of the most ancient and extreme modes of...
The deeper we peer through the cosmos, the more we are looking into the distant past. Light from other galaxies takes millions of years to reach us, and so when that light has finally arrived at Earth, it is millions of years old, a snapshot in time of the distant galaxy. The furthest we can see is so far back in the history of the universe, that galaxies haven’t even formed yet. As we look at the large-scale structure of the Universe, we see it filled with a cosmic web of galaxy clusters, containing tens of thousands of galaxies each....
The Hubble Space telescope produced the finest Astronomical images in a generation, but Hubble’s time in the limelight has ended, and now it’s time for a new generation of both space- and ground-based telescopes to take over with their own jaw-dropping images and revolutionary science. Recently the Atacama Large Millimeter Array (ALMA) has taken the leap and used its full power to take an astonishing image of the protoplanetary disk of the young star HL Tau. This image is of a very young star, only about a million years old (Which is really young compared to the 4.5 billions year old...
