Halloween is an amazing chance for people to be someone (or something) they have always wanted to be. To step outside of their norm and live their life as an alter ego, if only for one night. This is why so many people have crazy Halloween stories, and why the ‘holiday’ captivates us so much. With humanity’s excellent pattern recognition skills, we tend to see spooky things in space, where if you would just turn the picture 90 degrees, it probably would look like some other item from human experience, and not be spooky after all. Here are a few...
It’s hard to do experiments in space. It costs a boatload of money, takes years of preparation, and even then we can’t get much further than low-Earth orbit. But there is a cheaper alternative to understanding the universe. We can perform experiments on Earth to simulate what happens far beyond our own planet. That’s just what scientists did at the Vertical Gun Range at NASA’s Ames Research Center in California. They found that Ceres is likely a mish-mash of celestial bodies from several billion years of bombardment. Until March of this year, when the Dawn spacecraft entered orbit of the...
Around 470 Million years ago, two asteroids collided in the asteroid belt between the planets Mars and Jupiter. This sent fragments everywhere, and millions of years later these fragments moved into the inner solar system, many of which struck the Earth as meteorites. Recently, in Jämtland county, Sweden, a team of geophysicists has identified a pair of impact craters that were formed at the same time, likely from two separate impactors. One of the craters is a massive 7.5 Km across, while the other is smaller at 700 meters. This is the first time a double impactor has been scientifically confirmed on Earth....
Categorizing objects in the universe can be difficult. The fiasco with Pluto over the last decade is more than proof of that. We generally look to location and then to size as the two main methods for classifying the stuff that permeates the cosmos. Galaxies contain stars, which host orbiting planets, which host orbiting moons; While asteroids fly in between planets and icy comets are wander through the outskirts of star systems. But what about the in-between objects? Often we find strange things in strange places. There are moons in our solar system that are larger than planets. What would...
The true story of why Pluto isn’t a planet goes back further than you would think. It has a lot to do with our understanding of science at the time, and a lot more to do with surprising luck. I made this video a couple of days ago for the Khan Academy Talent Search. I hope you enjoy it. It will be interesting as we move into better telescope technologies that allow us to see further into the depths of the solar system and the universe. What strange mysteries will we find?
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...
We have found evidence of ancient impacts all across the Earth, from the famous Chixulub crater in Mexico to the Sudbury Basin a little bit closer to my home. From Space the remains look nothing like craters, millions of years of sediment and growth hide the massive regions from obvious detection, but signs remain of these massive events, even after millions of years. This week, what is possibly the largest impact crater basin ever discovered has been found in central Australia. And it is thought to originate from the breakup of a massive 400 Km asteroid into two pieces that...
Today is the day that the Dawn Mission completes a long 7.5 year long journey that has taken it past the orbit of Mars and into the asteroid belt, studying the second largest asteroid Vesta before heading toward the dwarf planet Ceres, where it has now injected itself into orbit, as of 7:39 am EST. This marks the first time in history a spacecraft has seen a dwarf planet up close, and with New Horizons passing Pluto in July, Dawn won the race in an astronomical photo finish. The Story So Far Launching on September 27th, 2007, Dawn orbited the Sun and...
With the MESSENGER probe set to crash into Mercury this month, it’s nice to look back on some of the finest data that it gathered during its tenure orbiting the smallest planet of the solar system. The image shows the Caloris Basin, the largest impact basin on Mercury and one of the largest in the solar system. The result of a massive asteroid impact during the early days of the solar system, the 1,500 Km wide crater was filled with lava aeons ago when Mercury was geologically active (seen in orange). Large impacts have punctured the surface of the basin since...
Enjoy this great little video about an asteroid hit as viewed by a dinosaur on ancient Earth. The one in the video is 10Km wide and it’s the size of the one that killed the dinosaurs at the end of the Cretaceous-Paleogene period 66 Million Years ago. For reference, the Asteroid BL86 that passed by us this week was 300Km wide, a true killer! Sadly there’s no explosion, but hey, if we were able to see it we would be instantly vapourized so we wouldn’t be watching it anyway.
