In 2014, comet C/2013 A1, known as sliding spring, came within 140,000 Km of the planet Mars. This is a bit more than a third of the distance from the Earth to the Moon. Comets are small, so gravitationally this interaction was insignificant, but from an electromagnetic point of view, things were shaken up big time! Comets are small, relatively speaking. A typical comet is a few kilometers across, about the size of a big city. But with sunlight melting ices and liberating gases and dust from the comet’s interior, the part of the comet we see in the sky,...
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...
I’ve spent the last couple of days as a zombie due to the time change, but now that I feel like myself, I’ve got some catch-up posts to do. The first one has to do with today’s APOD. Can you spot the phoenix shape? It doesn’t mean anything special, it’s just the way our brains see the patterns of light from this gorgeous aurora in Iceland. Ionization of atmospheric gases from charged solar particles doesn’t sound as glamorous as ‘phoenix aurora,’ but I still appreciate the scientific beauty of it. Human beings are excellent at pattern recognition, and so we...
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...
Can we grow crops on the Moon? How about Mars? If you saw the movie “The Martian,” it seems you could grow potatoes on Mars with a supply of water, oxygen, and some fertilizer, but without these necessities (soil nutrients, water, oxygen) they just wouldn’t last. If we eventually want to colonize places like the Moon and Mars, finding a way to live off the land is a must. The sunshine will help, but can we really grow crops on alien soil? As it turns out, Earth scientists have been working on this problem, by simulating the soils of the...
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...
