Date: June 14, 2012
Title: Encore: The Changing Universe
Podcaster: Jesse Rogerson
Links: Jesse’s website
This podcast originally aired on November 1st, 2010
http://365daysofastronomy.org/2010/11/01/november-1st-the-changing-universe/
Description: We sometimes forget how much is happening in our universe, but there’s a lot. Starting from our solar system, I highlight a few examples of just how much is happening in our skies, and in the universe.
Bio: I am a graduate student in the physics and astronomy department at York University in Toronto Canada. I study the gaseous regions that surround galaxies at high redshift, but am I also very interested in science public outreach. I like to take as many opportunities as possible to tell people about science. For example I volunteer on a weekly radio show “Live at YorkU”, where myself and others discuss recent astronomy news. I also play hockey and ultimate frisbee.
Today’s Sponsor: “This episode of 365 days of astronomy was sponsored by iTelescope.net – Expanding your horizons in astronomy today. The premier on-demand telescope network, at dark sky sites in Spain, New Mexico and Siding Spring, Australia.”
Transcript:
Hello, my name is Jesse Rogerson and I am a graduate student in the department of physics and astronomy at York University in Toronto, Canada. By day I study the gaseous regions that surround galaxies very far away from our own Milky Way. By night I participate in the public outreach efforts at the York University Observatory. Through my experiences in the observatory I’ve learned that there things about the universe I take for granted. Specifically how much it’s changing.
When people look up at the sky they see a big black thing with a bunch of little points of light shining down. Everyone knows the stars and they’ve had their place in stories and legends over the years. Many people can point out the Big Dipper and Orion, maybe find the north star or even Cassiopeia. But what is usually lost in translation is just how much is happening up there. If you spend a few minutes looking at the sky on a clear night, you’ll find that the stars aren’t actually constant, they twinkle and this is due to the turbulent atmosphere above our heads that we look through as we observe the stars. Maybe youÕll see a few shooting stars which occur when small dust particles from space enter our atmosphere and burn up. If you spend a few hours watching the sky then you’ll notice the slow crawl from east to west generated by the spinning of our Earth on its axis. If you watch the sky for a week, you would notice the movement of the moon through sky as it travels through various constellations in its month-long orbit around Earth. If you watch the sky for a month you may start to notice the planets in our solar system slowly changing their positions in the sky. What I think we can forget is the sky above is far more busy than we may realize, but it’s all about perspective.
Cassini, the joint NASA/ESA robotic spacecraft currently orbiting Saturn, has provided unparalleled detailed analysis of the Saturnian system including a recent study on Saturn’s Aurorae. Just like on Earth, Saturn supports massive aurora (or “northern lights” as we describe them in the northern hemisphere) and these aurora span distances much larger than our little planet. The features are generated in the same way as on Earth: charged particles moving at incredible speeds that were thrown from the Sun fall down the magnetic fields lines on Saturn, when they hit the atmosphere they deposit their energy and generate amazing light shows.
The solar system is a very busy place, there is a lot happening in our little corner of the galaxy. We have observed that Venus has massive polar hurricane systems. Spirit and Opportunity on Mars have caught dust devils or tornadoes on camera, kicking up Mars dust as they make their way across the mars landscape. JupiterÕs great red spot is a massive storm cell that has been active for at least the last 400 years. The Hubble Space Telescope has recently observed a collision of two asteroids in the belt between mars and jupiter. The collision generated massive amounts of debris. There are hundreds of thousands of asteroids flying through our solar system that we know of, and probably many more.
We also find there are many comets orbiting our sun. Comets are very interesting because they perfectly represent the changing universe. These objects formed out in the cold reaches of the solar system. Out there they are hard to see but when they travel in towards the Sun, they are heated and grow large tails of gas and dust. The comet is still the same object, but the warmth of the Sun will change its features. And we canÕt forget our Sun! The sun is a constantly bubbling ball of plasma with massive magnetic fields. It can release Coronal Mass Ejections: a wave of charged particles ejected out into space that can sometimes disrupt our satellites and power stations.
WhatÕs amazing about all these examples is that we haven’t even left our solar system yet! The myriad of things happening in the Universe outside our solar system is even more astounding than those happening within. For instance, the Orion Nebula, found at the tip of the sword in the constellation Orion is home to a stellar nursery. The bright gas is being heated by the birth of many new stars. This nebula is very close to us in galactic terms, representing one of the most active regions in our area. Our galaxy also houses a black hole at its centre. Many stars orbit this black hole, and anything that falls into it, including light, will never come out.
Moving outside of our galaxy, we have two small dwarf galaxies orbiting the Milky Way named the Large and Small Magellanic Clouds. These objects are gravitationally bound to us, orbiting us in much the same way we orbit the sun. One of the nearest neighbours to the Milky Way is the Andromeda galaxy. Andromeda is a galaxy very similar to ours and has had a fixed location on our sky for as long as the history books have been written. That galaxy is actually on a collision course with our own. Each galaxy out there is moving through space and the interact gravitationally with anything that comes in their path.
Moving to the an even larger picture, the universe ITSELF is expanding! Space is getting bigger, and has been consistently expanding since the dawn of its existence. From what we can tell, it seems the universe will continue to expand, stretching all the galaxies, stars, planets, and us along with it.
If you take a picture of your friend from 100 meters away, you may only get their face in one pixel of your camera. If you take an image from 50 meters, you might be able to see different shades of colour. From 10 meters, you would see facial features, and from 10 centimeters away you may get more detail than you asked for. We should all look at the universe from 1 meter away. There is far more detail in our skies than we tend to realize, and the amazing thing about this is that you don’t need a telescope to appreciate this. All you need are your eyes and a thermos full of hot chocolate.
So next time you are taking a quick glance at the night sky, stop and think for a minute that there is more there than just pretty white lights up there. The universe is a teeming and bubbling pot of natural forces constantly churning up activity. Stars are constantly being born and dying, planets continually orbit their stars, galaxies are rushing through space. It’s all there, you just may not realize it. But again, it’s all about perspective.
Thanks for listening to my podcast, I’d like to thank everyone who makes 365 Days of Astronomy possible, including the listeners. Once again, my name is Jesse Rogerson. Have a great day.
End of podcast:
365 Days of Astronomy
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