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...
What is the difference between a comet and an asteroid? The typical response is that an asteroid is rocky and a comet is icy/gassy. Further than this, asteroids typically orbit closer to the Sun than Neptune, and comets orbit beyond this loose dividing line. But as with everything in nature, there are often exceptions to the rule. C/2014 S3 PANSTAARS is classified as a weakly active comet, originating in the Oort cloud with an orbital period of 860 years. As it approached the Sun, astronomers noticed that it was lacking the characteristic comet tail, resulting from the blast of solar radiation upon approach to the...
The closest star to the Earth, aside from the Sun, is Proxima Centauri, a small red dwarf star that is part of the Alpha Centauri system, roughly 4 light years away. If you don’t know light years, the distance is a staggering 37,800,000,000,000 Km. Beyond that our stellar neighbourhood fills in as you move 20 light years in any direction, and by 100 light years, there are dozens of stars around us. This gives a stellar density of about 0.14 stars per cubic parsec (a parsec is about 3.26 light years), pretty normal in terms of the number of stars in a given...
Hubble just discovered the newest moon in the solar system, a tiny rock orbiting the dwarf planet Makemake, far beyond the orbit of Neptune. The new moon is about 250 Km across, compared to the 1,400 Km wide Makemake. It orbits in approximately 12 days, and has an edge on orbit, making it difficult to spot. “Our preliminary estimates show that the moon’s orbit seems to be edge-on, and that means that often when you look at the system you are going to miss the moon because it gets lost in the bright glare of Makemake,” said Alex Parker of...
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...
Sadly no, this time we are NOT talking about Pluto. Astronomer Mike Brown from Caltech, heralded as the ‘man who killed planet Pluto’ has done some new work that might replace Pluto with a better fit for a true ninth planet, one that is ten times the mass of Earth. Now the only problem is finding it. But wait, if we haven’t seen it, how do we know it’s there? Well it certainly showcases the power of science, that an understanding of the true laws of nature can give us incredible predictive power. It started out as a ‘that’s strange’...
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,...
