On the golden record that accompanies the Voyager spacecraft, there is a map showing the location of Earth. It’s not a road map that you might pull out when navigating a city, but a 3D map showing the location of a star, the Sun, in a populous galaxy. But just how would this map work? And more importantly, what are the map markers? If you notice the lines at the bottom left of the golden record image, they all intersect at a common center point. This is the Sun, and the lines extend out showing relative distances to the nearest...
As I’ve said before, the most powerful, most energetic, most intense processes happen in the center. The gravitational center of the Earth, the Sun, and the galaxy are all places where temperature, pressure, and interactions of matter and energy are pushed to their limits. When you look up to the sky it’s easy to see the Milky Way (unless you live in an urban center). Do you ever wonder where the middle of it is? Where that supermassive black hole lies? Astronomers know where it is, but you need infrared cameras to see it past the thick dust that blocks...
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...
We know that galaxies like our Milky Way are far more massive than we can see. The dark matter in the Milky Way makes up 90% of it’s total mass. Another way of saying this is the Mass to Light ratio, comparing the total mass inferred by the rotation speed of the galaxy to the total mass of stars in the galaxy. This ratio, M/L, for the Milky Way, is about 10. But for a galaxy cluster, the M/L ratio is more like 100. Galaxy clusters are not just dense collections of stars and massive galaxies, they are also immense...
In the early universe, there was a huge amount of swirling matter and light that didn’t really have much structure. Compared to today’s much more regular dotting of galaxy clusters and superclusters, the early universe was all over the place. But as will all things, there had to be a first. a first star, a first galaxy, and even a first galaxy cluster. The massive cluster of galaxies known as IDCS J1426.5+3508 is the most distant massive galaxy cluster ever discovered, and it has some interesting properties that point to how it formed and evolved so quickly. One such property is...
If you actually had the ability to see X-Rays, the world around you would look pretty boring. Actually it would be invisible, since nothing around you gives off X-rays. You might be able to see an imaging device if you live or work near a medical office, but that’s about it. If you looked at the night sky, you would see many interesting sources of X-Ray light, mostly from active black holes in our own galaxy and beyond. Recently a high-resolution scan of the Andromeda Galaxy revealed a plethora of sources, showing where black holes and neutron stars are feeding...
The only reason we can see black holes in the universe is because some of them swallow up gas and dust. This heats up material that is spinning rapidly around the black hole as it falls in (called an accretion disk), and produces massive jets of material due to conservation of angular momentum that can be seen across the universe. The energy released in the jets and the energy given off in the accretion disk are proportional to how much gas and dust is being consumed by the black hole. More matter = more food = more energy released. But...
One of the greatest scientific discoveries of all time came with the invention of the spectroscope by Joseph Von Fraunhofer in 1814. It enabled us to look out at the universe and realize that the same basic building blocks that made you and I and all other life, were the same things that make up everything else in the cosmos. The tiny atoms in our bodies all started out at the center of a massive star billions of years ago. So naturally, when we talk about the odds of life forming elsewhere, we have to include a study of where...
The only way we can understand the cosmos is to find new and innovative ways to interpret the light we capture from it. Using the largest and most technologically advanced telescopes in the world, we peer deeper into space, further back in time, and see photons that have spent eons travelling to Earth. If we can get rid of all of the other light from closer objects, and zero in on this distant light, we can begin to understand what was present at the beginning. Using data from deep sky surveys conducted by the Hubble Space Telescope (HST), astronomers from...
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...
