The Moon has clearly seen some stuff. It’s visibly heavily cratered across it’s surface, which has remained unchanged since it’s surface solidified 4.2 Billion years ago. Think about that – the Moon has been the same, with the exception of cratering, for 4 Billion years. This is a stark contrast to the Earth, whose erosion and tectonic activity cause the crust to change on scales of a few hundred million years. Astronomers have worked hard to learn about the early solar system by looking at the Moon and its cratering patterns. Most of the visible craters on the Moon are...
Mercury, the smallest planet in the solar system, and closest to the Sun, is only a little bit bigger than Earth’s Moon. But the Moon is comparatively reflective object. Mercury is thought to be made of the same rock as the Moon, so what is the difference? Why do objects in our Solar system have different brightnesses? The key is in a property called albedo. It’s basically how much light an object reflects, measured as a fraction. For example, the Moon reflects 12% of the light the Sun shines on it, so it has an albedo of 0.12. The albedo...
As the Rosetta spacecraft remains in orbit around the comet 67P/Churyumov-Gerasimenko, the comet is slowly drifting toward its closest approach to the Sun, known as perihelion. As the comet moves closer to the Sun, intense sunlight liberates gases and dust in streams of material that form clearly visible streaks. The orbiter is able to sample some of the material liberated from the comet, and for the first time it has seen the tell-tale signature of Molecular Nitrogen. Nitrogen is abundant on Earth as a gas, constituting the majority of our atmosphere. It is also present in the atmospheres of Pluto and Neptune’s...
Comets are a lot like the Toronto Maple Leafs hockey team. They get you really excited early on, and just when your hopes are highest, they become a continual disappointment. Then you go through the same thing the next time around. More often than not, comets with great expectations fizzle or burn up. Here are my top five comet fizzles from recorded history. But comets, unlike the Leafs, can sometimes succeed. They can live up to expectations and become a beautiful night sky jewel. Hale-Bopp comes to mind from 1997, when it exceeded the expectations and became the comet of a...
Like piecing together a car accident, by looking at the results of a collision in space, we can use our knowledge of science to piece together the past and determine what happened to a high degree of accuracy. The velocity of a star, along with high powered computer simulations and statistical techniques, can help us determine where it once was. But since space is so vast, why do we care where stars have moved? The short answer is that there are so many stars out there that we don’t often care where individual stars have moved. Some exceptions are when...
This week there were just too many fantastic photo releases to pick just one and stick with it, so here are some of the great stories popping up with fantastic images to accompany them: Fine Detail From Rosetta on 67P This amazing shot from the Rosetta orbiter shows such incredible detail as comet 67P catches light from the sun. The shadows are what makes this image spectacular as you can see so many fine features. The other noteworthy part of the image is the bright streaks of material coming off the comet in the background. As the comet and the...
It seems that in recent years, asteroids have been flying past Earth with increasing frequency. Does it mean that more asteroids are coming around? Is it the beginning of the end? Will one of them hit us soon and doom us all? Probably not, but there’s always a chance. It’s almost certain that the reason we’ve been able to find so many new asteroids, and especially near-Earth asteroids, is because of the technology increase in Astronomy the past few years. New telescopes and tracking methods exist with the sole purpose of finding near-Earth asteroids, somewhat of an early warning system...
For Christmas I was given a green 200 mW laser! A couple of AAA batteries later and the laser can point out any star or object in the night sky, with the beam clearly visible the entire way up to infinity. Its the epitome of an Astronomer’s toolkit, at least in my eyes, and it got me thinking about all the amazing things you can see in the sky right now. It also makes me feel like I’m brandishing a light saber, and sadly it’s about as close as I’ll ever get. First off, Venus is back in the evening...
Have you ever wondered how they differ? The Asteroid Belt, shown above, consists of hundreds of thousands of rocks, with all kinds of different shapes, ranging in size from the Dwarf Planet Ceres at 950 Km in Diameter, down to small bits the size of dust particles. It lies between Mars and Jupiter. The Kuiper Belt (pronounced Kai-per) consists of Icy rocks, and it a major source of short-period Comets in the Solar system. Extending beyond the planet Neptune, Pluto was discovered to be one of the largest objects in the belt. The mysterious Oort cloud is a collection of...
One of the most important science goals of the Rosetta mission is to determine the conditions in the early solar system, as well as the element abundance and climate that led to the development of life on Earth. By studying a comet that has been isolated in Space for 4.5 Billion years, we can learn about the formation of the Solar System and the origin of the raw materials for life on Earth. The Earth was thought to be so warm when it formed that any water would have evaporated away into space. If so, where did our vast oceans come...
