I’m going to come right out and ask the burning question: Is Pluto a Planet? No. At least under the current definition. So the question becomes “Should Pluto be a planet?” That answer is a bit more complicated. Let’s look at the history. Discovered by Clyde Tombaugh in 1930, Pluto was initially considered the ninth planet of our Solar System. It was part of an intense search that follows back all the way to the discovery of Uranus and the orbital calculations that led to the discovery of Neptune. Even after Neptune’s discovery, gravitational perturbations pointed to a ninth planet,...
Alliteration is accessible to all! Okay I’m done. Start some science! Really done this time. Today’s double post covers the smallest of stars, still larger than most planets, and the only weather Mercury will ever have. Humans are naturally interested in the extremes, the biggest, smallest, fastest, hottest, coldest, and every other characteristic outlier. With stars, being so huge and powerful, we are often more interested in the largest, hottest, and most energetic. Though on the opposite end of the spectrum, Cambridge University astronomers have discovered the smallest star in the known universe. The star, a red dwarf, has the...
Last week, while looking at some of the best images from the Cassini spacecraft, I commented on the fact that the smooth rings of Saturn are small, varied chunks of ice and rock when you get down to the smaller scales. Reflecting on that this morning, I was thinking about how observing objects in our universe at smaller scales gives new insight into the variety and complexity of natural phenomena. Not long after, I came across a story of a new interesting object in our own Solar System. A new binary asteroid was discovered. This in itself isn’t too different...
As I was watching the grand finale of Cassini and listening to the mission team talk about the accomplishments of the mission, I learned a little bit about propellors. Not your typical airplane propellor, but the name used to describe this fascinating feature in Saturn’s rings. Seeing Saturn’s rings from afar, or even relatively close with Cassini, we see the rings as perfect. How do we end up with strange features and imperfections like this one? Looking elsewhere in the rings, we can find clues. The first clue is the namesake of the mission itself. The Cassini spacecraft was named for...
I remember vividly my first astronomy class in university. Winter 2004, only months before the Cassini spacecraft was set to arrive at Saturn after a seven year journey. On several occasions in that class we talked about what we might see when Cassini reached it’s destination. The first dedicated mission to the jewel of the solar system, originally conceived right after the voyager flyby in 1982, would give us a chance to study more than just a planet, but an entire system of interaction between a planet and it’s moons. Beyond that, it included the Huygens probe, to land at...
You’d think I would have learned my lesson by now. Every time I think I’ve seen it all, that I’ve seen every strange phenomenon in space, every unique planet, moon, star, galaxy, every variation, I’m proven wrong. I expect that the order has been established and everything newly discovered will fall into a category with no more unique variation. But here we are again. The close up view of Pan. Pan was photographed only a few days ago by the Cassini spacecraft as it carries out the final months of it’s mission to Saturn. It was revealed to be a...
Like lighthouse beacons in a dark ocean, stars act as tiny islands in the vast universe. Producing light at the atomic level from the powerful release of energy through fusion, they are the engines that drive the formation of new elements. But in the darkness there are plenty of other hidden objects that are cold and give off little to no light. Yet many of them are easily seen. Here’s Why! The first thing to think about is infrared light, the radiation given off by warm objects. Large planets and brown dwarf stars are very bright in infrared, much brighter...
On May 22nd, Mars will be at opposition. It’s the astronomical term for when Mars and the Sun are on opposite sides of the Earth. This makes the face of Mars fully illuminated from Earth, and also brings the Earth to it’s closest approach of Mars, at 75 Million Km. Hubble images the red planet to celebrate the occasion. So get your telescopes out and be ready to take some pictures, because Mars is smiling! Mars will rise in the East at sunset, since they are on opposite sides of the Earth. It will appear bright with a rusty hue, and...
It hasn’t been found yet – let me make that clear. But with evidence that it should exist, astronomers are looking more closely at the proposed planet nine and how it might have formed, and how it could have ended up in such a distant orbit. When you start to think about how a planet ten times the mass of Earth could have ended up more than ten times as far from the Sun as Neptune, a few scenarios pop into mind: It was formed in the inner solar system, where interactions with gas giants or another star pulled it out It formed...
Even after a decade of interloping among the Saturnian system, the Cassini spacecraft is still doing great science. It helps that there are lots of places to visit, since Saturn has 62 moons and the largest ring system of the gas giants. Arguably the best science has come from Saturn’s largest moon Titan, second largest moon in the solar system (behind Ganymede) and the only moon known to have an atmosphere. Since Cassini has been in orbit around Saturn and it’s system of moons, it’s been revealed that over 1.6 million square kilometers of Titan’s surface are covered in liquid...
