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...
As the search for planets in the galaxy continues, there are two places to focus on: Distant stars with potential large planets, and nearby stars with potential small planets. If we are able to find Earth-like planets orbiting nearby stars, they will be prime targets for future generations to explore. Astronomers have just announced the discovery of three new planets orbiting a star only 40 light years from Earth. The star is a very small red dwarf, only slightly larger than Jupiter, and even though it’s close to Earth, it can’t be seen with the naked eye or even with a large...
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...
One of the most fascinating things happens whenever I show someone the planet Mercury in the sky. Their first reaction is to be surprised at how bright it is. Most people think of Mercury as a faraway planet, too close to the Sun to see at all. But in reality, Mercury is close to Earth, and when the angles are just right, it’s not hard to find. Mercury is 57 million kilometers from the Sun, more than a third of the way to Earth. We are also much closer to Mercury than we are to Jupiter and Saturn. When we see the...
I feel like I’ve been covering a lot of stories on magnetic fields over the past few months. Fields around the Earth, the Sun, Mars, Jupiter’s Moons, and exoplanets are just some of the places in the universe where we are looking at magnetic field behaviour. The intention is to use our understanding of magnetism to figure out what is inside these worlds, and how they interact with their space environment. You would expect us to understand the Earth’s magnetic field and interior very well, after all, we are stuck here. But it turns out it’s very difficult to study the interior of...
Jupiter has aurora. It’s not surprising since it has a very powerful magnetic field. It’s only natural that the two largest structures in the solar system, the Sun’s solar wind influence (called the heliosphere) and Jupiter’s magnetosphere, should be constantly battling. But don’t expect to see Jupiter’s aurora through a backyard telescope. The result of this battle is far more energetic, producing an aurora invisible to the human eye, one made of X-rays. The Sun constantly blasts charged particles off into space in all directions, assaulting the planets, moons, and other solar system bodies. It is this blast of solar wind that gives...
I saw this pop up on Reddit yesterday, where user /u/bubbleweed posted a video to r/astronomy showing Jupiter with a clear sign of an impactor. It was independently observed in Austria at the exact same time. Notice that both videos show the exact same thing. In the reddit thread, users encourage the original poster to report it to the Planetary Virtual Observatory and Laboratory in hopes of getting follow up from the Hubble telescope. It is strikingly similar to a 2010 confirmed impact event. The ‘explosion’ of the potential impactor might make you think it’s fake, that it couldn’t explode because...
When we see the Earth’s only Moon up in the sky, we often think about how small it is. It’s only about 1/4 the diameter of the Earth, and at a distance of 384,000 Km, it looks small in the sky. But often size is entirely a matter of perspective. What we compare something to, that’s what determines it’s size. When the Moon is high in the sky we easily compare it to the size of the window we are looking through, or to a nearby tree, or our outstretched hand. All of this can make the Moon seem pretty tiny....
You’ve seen the planets, now let’s look at some of the best moons to visit in the solar system, ala the romanticized art deco style! Ceres is like a gas station for that long trip to Jupiter, treated as an icy rock that is not the best tourist destination. Enceladus is a lot like the spacefarer’s version of Yellowstone park, with the southern hemisphere geysers being the appeal. My two favourites are Titan and Europa. Titan’s colour scheme and view of Saturn are gorgeous, but the best part is the paddle boats in the hydrocarbon seas. The most interesting visit...
When it comes to science communication, the most important thing to keep in mind is the perspective of the layperson, what someone will see, think, or understand if they have no prior knowledge. When you have some expert knowledge in science it can be hard to put it aside, but imagining the thought-process of a beginner gives you valuable information about how you are communicating, and can make a huge difference in your effectiveness. Which is why I am always thrilled to see things that communicate real science, yet stimulate the imagination. NASA, being a publicly funded organization, has to...
