Since it entered Saturnian orbit on July 1st, 2004, the Cassini spacecraft has changed our view of Saturn and its moons. It is a dynamic gas giant with unique and fascinating moons that have their own characteristics that make them seem more like small, rocky, planets than moons of a gas giant. Cassini has been delivering amazing science for over a decade, and it’s next journey lies in a polar orbit of Saturn, where it will dive through Saturn’s rings, giving the most detailed and close up views of the tiny ice particles that compose them. Before this journey, Cassini...
A couple of days ago, the still-active Cassini spacecraft orbiting around Saturn performed a flyby of the small Moon Hyperion, taking high resolution photos of the surface, and showing the sponge-like surface of the moon in a different light. Hyperion is a moderate 250 kilometers wide, yet it doesn’t tug very hard on Cassini. Performing measurements of its surface gravity, Cassini has shown that the moon is mostly empty space, similar to a pumice stone on Earth. The odd shapes of the craters are thought to be a result of this. When an impactor hits Hyperion, it blows the material...
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...
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...
No, he isn’t a zombie. He’s a long dead scientific pioneer. He discovered Saturn’s moon of Titan and was the first to suggest that Saturn’s odd ‘blob’ shape could be explained by rings around the planet. He was a pioneer of optics and developed a telescope with two lenses, more powerful than Galileos. He also characterized the motion of an ideal mathematical pendulum (with a massless cord and a length longer than its swing), and invented the pendulum clock as a method of keeping time. He had a few other contributions to astronomy, including the observation of individual stars in...
About a year ago I had an idea for a music video. I wanted to take a concept in science and put it to music, making it funny, catchy, memorable, and educational. I wrote out the majority of the lyrics but left it alone for a few months, until I connected with the right friend. My good friend Bob Wegner is a very talented guitarist and audio engineer, and as we spoke about the idea he wanted to be the guy to record it. We spent an afternoon doing the vocals and guitars, and he cleaned it up and made...
How do we measure the rotation speed of a planet? Exactly as you would expect. Watch the surface, look for markable features, and time how long it takes until those features pass the same point again in the future. But how can we possibly nail down this information when the planet has little to no visible surface features. Gas giant planets are great examples of this. Jupiter is a bit easier since it has plenty of storms and separated cloud layers along the planet’s rotation axis, but the other three are much tougher. Aside from hard-to-spot features, gas giants also...
It’s difficult to determine the history of the Solar System. The planets have been in their current orbits for Billions of years, and any signs of prior activity or configuration has to come from leftover geologies of smaller, rocky worlds. It makes it especially difficult when the Billions of interloper asteroids and comets throughout history have to be accounted for, adding to the already complex task. But if there is one thing humanity has going for us it’s the ability to theorize, model, simulate, and test scenarios here on Earth. We can try new ideas and see if they match...
With all the talk of the large geomagnetic storm of the past few days, it’s important to understand that other worlds have beautiful auroral activity as well. Being on Earth and seeing the gorgeous displays that result from our magnetic field protecting us from harmful solar radiation, the best views come from Earth. But there are several other places in our own solar system that have aurora. Jupiter has a massive magnetic field, and its gigantic aurora are visible here. Jupiter’s moon Ganymede is the only moon in the solar system that has auroral activity. Saturn has its own, discovered...
