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,...
Have you ever read the story of the discovery of Neptune? It truly is a triumph of science and mathematics, and part of the reason it is my favourite planet (a hard choice to make). The story goes like this: It all starts with the discovery of Uranus in 1781 by William Herschel. This was the first ever discovery of a planet, as the Earth and the five visible planets have been known of since the dawn of history. Thanks to Isaac Newton working out the laws of gravitation and the mechanics of the solar system, mathematicians could easily calculate the properties...
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...
There are eight planets in the Solar System. This statement makes a lot of people angry for several different reasons. The obvious group to respond with anger is the ‘people for Pluto,’ who have an unwavering dedication to the little planet that could. It’s scientifically recognized as a dwarf Planet, and is still one step up from a Kuiper Belt Object (KBO), so it’s doing well. Far beyond Pluto, in the outer recesses of our Solar system, you may have heard of a potential Super-Earth-sized Planet recently theorized by Konstantin Batygin and Mike Brown. This is the other reason people would...
When were the planets discovered? Uranus and Neptune were definitely not found until modern science began, since a telescope was required to see them. The other five planets were not actually discovered per se. Since they are visible to human eyes, they have been observed since prehistoric times, and we see examples of cultures across the ancient world who observed them. The five visible planets are Mercury, Venus, Mars, Jupiter, and Saturn. Starting this weekend, you can see them all across one part of the sky, a visual alignment that hasn’t occurred since 2005. Planets are so-named because of the Greek...
What do other planetary systems look like? We have seen some where massive Jupiter-sized worlds orbit closer to their star than Mercury does to the Sun, baking them with radiation. Others have had multiple rocky planets within the Earth’s orbit distance. Some have planets similar to Earth in a variety of locations. But what about far away from the star? We never expected to find gas giants like Uranus and Neptune in the far reaches of our solar system. Are there planetary systems where planets live even farther away? Maybe there are planets that live in the empty darkness between stars,...
If you wanted to look at weather and climate patterns on the Earth, you would put a satellite in orbit and watch the planet for a long time, looking for changes in the cloud layers and measuring wind speeds, etc. It isn’t a stretch to think that we could do the same for another planet, especially since most of the planets in the solar system have atmospheres. Jupiter, being the largest and heaviest planet, also has immense wind speeds and beautiful vortex features, some of which are larger than the Earth. But in order to understand these features, we have...
A video released a couple of days ago is a brilliant short film about a group of friends who went in to the Nevada desert and built a scale model of the solar system to give us a perspective on how large space actually is. Filmmakers Alex Gorosh and Wylie Overstreet led the project, which featured footage of the production of the model as well as some interesting results. Watch right to the end, where some fabulous footage of the Apollo program is shown, along with some inspiring words from the few men who have seen the Earth from beyond...
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?
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...
