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...
Whether you’re looking for an excuse to eat dessert or just love mathematics, March 14th is a good day for geeks, nerds, and the rest of the world too. The third month and the fourteenth day, 3.14, is known as Pi day, after the simplest and most ubiquitous constant in nature (no disrespect to c, e, g, or h). Defined as the ratio of a circle’s circumference and it’s diameter, Pi is an irrational number, meaning there is no end to its digits. Most people know 3.14159, but some people have memorized hundreds more digits. Mathematicians armed with supercomputers have calculated Pi to...
Every time we see amazing photos of galaxies or planetary disks, we can see most of the detail since we see them face on. But since the orientation of spiral galaxies in the universe is random, there are a plethora of galaxies ignored by image processors since we just can’t see much of the detail. We can still learn from edge-on spiral galaxies, just not as much as we can from those that are face on. We can see some fascinating dust lanes in the image above, and a ton of detail considering the view, but we don’t know what...
It takes a long time for things to change in the Universe. Time takes on an entirely different role when it comes to the lives of planets, stars, and galaxies. A million years in the life of a star or planet is the equivalent of a single day in the life of a human being. Human lifetimes come and go while stars and planets stay pretty much the same. However, just like human lives, where many days can build up to an important event, millions of years of lead-up can produce some incredible changes to a planet or star. New...
We know that the giant bright light in the sky that keeps us warm is so much more than we can see. A star, like countless others in the sky, close enough to outshine all of them. The Sun is a dynamic object, endlessly churning and burping plasma beyond it’s boundaries into the solar system and beyond. NASA spacecraft and ground-based telescopes have been keeping eyes on the Sun for years to characterize its 11-year magnetic cycle. And every so often they have a front-row seat to the massive blasts that just can’t be seen with human eyes. The first...
When we see the Earth’s only Moon up in the sky, we often think about how small it is. It’s only about 1/4 the diameter of the Earth, and at a distance of 384,000 Km, it looks small in the sky. But often size is entirely a matter of perspective. What we compare something to, that’s what determines it’s size. When the Moon is high in the sky we easily compare it to the size of the window we are looking through, or to a nearby tree, or our outstretched hand. All of this can make the Moon seem pretty tiny....
Baryonic matter, which is everything we are made of and everything we can see in the universe, is not a lot of stuff. I mean to a tiny Earthling, it’s a heck of a lot, but if you put it all together it only makes up about 5% of the total Mass-Energy in the Universe. If you’ve ever seen the Millennium simulation, it highlights the fact that both baryonic and dark matter are organized into filaments of mass, with the baryonic matter at the densest points, ie the galaxies. What lies between these dense nodes and filaments are vast empty...
On the outskirts of the Milky Way galaxy, its two major satellites can be seen, the large and small clouds of Magellan. Both considered irregular galaxies, they are more like swarms of stars, similar to gnats here on Earth. But even though they lack structure, they are still alive. The large magellanic cloud contains the single largest active star forming region in the entire local group of galaxies. This is the Tarantula Nebula. In the core of the tarantula, huge supernova shockwaves blast gas and dust, triggering star formation while forming dense filaments away from the center. Along the entire...
After falling continuously for an entire year, Scott Kelly is ready to hit the ground. With the goal of studying the long-term effects of microgravity on humans, his year is space has been something to keep an eye on. Always in good spirits, he is probably excited to come home, albeit apprehensive due to the dangers of returning to gravity after such a long time. Next Tuesday, March 1st, he will experience significant forces once again as he undocks from the ISS and is ferried home by the Soyuz capsule. Like wearing a weighted suit, coming home will be an...
