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...
I love false-colour images. They reveal detail that you can’t see in real life, but they also highlight things in an artistic way. For me it’s an excellent marriage of art and science, and as a communicator it helps me get concepts across in an accessible way. So when I saw the APOD image of Saturn from earlier this week, I had to discuss it. Saturn never has looked this way, and it never will. The colours are vivid and unrealistic, but they show the differences in three distinct but close wavelengths of light on the electromagnetic spectrum. All of...
Looking at the universe in radio waves is a fascinating sight. For one, the radio sky is very weak; If you placed your cellphone on the Moon facing back at Earth, it would be brighter than all other radio sources in the entire sky by a factor of a million. But as with every other part of the electromagnetic spectrum, it has scientific value in studying the sky. Over the past decade, astronomers have been identifying several Fast Radio Bursts (FRB), short bursts of radio waves from different places in the universe that last for a few short seconds. These are...
You may have heard about the leaked rumour about the discovery of gravitational waves from earlier this week. It was from Lawrence Krauss, who is an amazing science communicator and author, as well as a darn good astrophysicist. My earlier rumor about LIGO has been confirmed by independent sources. Stay tuned! Gravitational waves may have been discovered!! Exciting. — Lawrence M. Krauss (@LKrauss1) January 11, 2016 It’s safe to say that as a guy with an inside scoop on a lot of the latest science news, this is something to get excited about. The ‘LIGO’ he is referring to stands...
Black holes are the most extreme phenomena known in the universe. They are the absolute limit of what gravity and space-time can be twisted into. It’s no surprise that some of the most massive and advanced telescopes in the world are tasked with studying their properties and how they interact with their environment. But maybe there’s a way for you and I to see what a black hole can do, and all we need is a moderate 8 inch telescope and our eyes! Even though black holes generally give off tons of radiation, we need to observe them in the...
We are reaching the point in our study of exoplanets, planets orbiting other stars, where the atmospheres of distant worlds are within the limits of our technology. Once we could barely see the wobble of a star, the telltale sign of an exoplanet, and now we can see reflected starlight and study a distant atmosphere. Now we can probe deeper questions, are atmospheres of exoplanets similar to solar system planets? What are they made of? Do other solar systems have the same raw materials as ours? Do they have what we believe to be the raw materials for life? A...
Is this a giant hole in space? I show a picture similar to this as I ask this question to students and audiences that I host in my planetarium. Most people answer that it is a black hole, or dark matter, or dark energy, or something strange like that. But the amazing thing is that it is actually a thick cloud of dust that is opaque, letting no visible light from the distant stars pass through. The funny thing is that the cloud is transparent in infrared light, but in the visible spectrum it highlights something interesting about the universe:...
How often does a star explode as a supernova in the Milky Way? With as many as 400 Billion stars, you would expect it to happen often But stars live a very long time, and most massive stars take anywhere from a few hundred million to a few billion years to reach maturity and explode. Putting all this together gives us a surprisingly human estimate. A supernova explodes in the Milky Way, on average, once every 50 years, or about once per human lifetime. We can still see remnants of great explosions that happened long ago, still expanding into the...
We know that solar systems form in a disk shape, with the star forming in the middle and any other rocks, presumably planets, form out from the center in whatever dust and gas remains. But what about the space between stars? Is it truly empty? And if there is something out there, how could we find it? How did it get there? For years, astronomers and chemists (believe it or not) have been trying to answer these questions and more. The specific problem is that when we take a spectrum of a distant star, we see a collection of 400...
The Sun, stars, nebulae, galaxies, planets; We can see them all from our lonely cosmic address, but not all is revealed in the light our eyes see. We need to look at the entire electromagnetic spectrum to understand the range of objects we see in the universe. Our closest star shows us how different it can look when you change the observed wavelength. In high energy ultraviolet and X-ray light we can see the most powerful sunspots emitting their bursts of radiation and the swirls of solar plasma releasing ultraviolet energy in all directions. We still have a few years...
