A long time ago in a galaxy far, far away…. Not just the star wars intro, but a true statement if you’re an astronomer. You see, once we start to look deep in space at the more distant objects in the universe, we are actually looking deep in time as well. It all begins with a light year. A light year is not a measure of time, it’s a measure of distance. When you turn on the light in a dark room, the light appears to fill the room instantly. But it actually takes a small amount of time, as light has...
Every year, as the Earth revolves around the Sun, we pass an imaginary line directly from the Sun to Saturn. The Sun is on one side of us and Saturn is on the other. When two bodies are on opposite sides of the Earth like this we call it opposition. Saturn’s opposition for the year was on May 23rd, and even though it has been a few days, you can still see Saturn up pretty much all night. Along with opposition, we can clearly see the rings, but Saturn does wobble on a 29.5 year cycle, meaning there are times...
Auroras on Earth are caused by the ionization of atoms high in the atmosphere near the north and south magnetic poles. The solar wind flies toward the Earth and this harmful radiation is blocked and funnelled by our magnetic field, creating harmless, beautiful glows that remind us how close we came to total destruction, but were saved by our planet. Do other planets have auroras? Certainly! Jupiter and Saturn do, and even moons like Ganymede can have auroral activity. It really depends on the magnetic field. So how does a planet like Mars, with no magnetic field, have auroras? This...
It sounds like something out of a science fiction novel. The incredible and rare dark star cluster, hiding the evil super villain’s headquarters. A dark star cluster is something I would imagine as a spooky, eerie type of place where everything you see changes when you enter its space. Science fiction aside, a dark star cluster is real, and it’s a new type of cluster that is similar to the mighty dense globular clusters that orbit most galaxies. Globular clusters orbit in a halo of space around the centres of galaxies, and though our Milky Way harbours 150 of them,...
The Dawn space craft has finally begun its science phase after settling into a 13,500 Km orbit around the dark dwarf planet Ceres. It took some manoeuvring to get it in the right spot, but now it has begun mapping the surface as it slowly orbits once every two weeks. A lovely mosaic image from the space craft is the latest jaw-dropping picture of the former asteroid. Like a great shot of the Lunar terminator, by seeing the shadows created by the light from the Sun, we can get a sense of depth of the heavy craters on the surface....
The first exoplanet ever discovered was 51 Pegasi b in 1995. It kicked marked the slow beginning of what would soon become the ‘exoplanet gold rush.’ It meant that for the first time, we had the technological capacity to discover new worlds, and science fiction soon became science fact. 51 Pegasi b was also a very strange planet. A massive Jupiter sized world orbiting very close to its home star. On one hand it was this characteristic that made it much easier to detect. On the other, it showed us that we did not understand planetary system formation as well...
After yesterday’s post about some data that has caused us to rethink a theory, I wanted to follow it up today with an even bigger bit of data that could substantially change an even bigger theory. Dark energy was discovered as a large-scale repulsive force in the universe that is responsible for the acceleration of its expansion. It was discovered by looking at type 1a supernovae in distant galaxies. since the supernovae all explode with the same mass limit, they appear to all have the same intrinsic luminosity. If we know how bright they actually are, we can compare them...
Yesterday I posted some of my own photos of the Moon and Mars in conjunction from the night before. Last night I went out again knowing that there was another planetary conjunction in the works. The Moon was now with Venus. People on the internet and in person were asking me “Mars? I thought the Moon was near Venus,” and “Venus? I thought the Moon was near Mars.” It really speaks to the fact that most people don’t realize how quickly the sky changes from the point of view of an Earthbound observer. So what happened between the Mars-Moon and...
The science of Astronomy goes far beyond what humans can see with our eyes. The visible part of the spectrum has taught us so much, but when we look at all photons across the spectrum of light, we find exponentially more powerful methods for discovering the mysteries of the universe. Radio waves, yes the same ones that bring you music in your car, are found throughout the universe in very interesting environments. Radio waves often trace the most powerful objects in the universe, such as super-massive black holes, quasars, and other types of active galactic nuclei. Humans see visible light...
Even I was blown away when I saw this image a friend sent me. Gravitational lensing is a rare occurrence, and a supernova is a rare occurrence, so to see a supernova in a gravitationally lensed galaxy deep within the universe is exceptional. So exceptional that it was spotted for the first time ever in a Hubble image of the distant universe. That dot in the image is a single supernova in a very distant galaxy, split into four images by the gravitational lensing of the galaxy cluster in front of it. But there is also a secondary lensing effect from...
