A long time ago, in a galaxy far far away…. Two black holes, with masses 29 and 35 times the mass of the Sun, merged to form an even bigger black hole. The merger resulted in three entire suns worth of matter converted to pure energy in the form of gravitational waves. The waves travelled a billion light years before a tiny meat-filled species on a pale blue dot in space figured how to see them. Thanks to the smartest one that species had seen in a century, they knew that black holes might merge, and that they would produce these waves if...
Today, the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) is expected to announce a monumental discovery that is 100 years in the making. Theorized by Einstein’s general relativity in 1915, gravitational waves are ripples in space-time, similar to sound waves, but much tinier. The search has been ongoing for decades, with no results. Until now. LIGO has the most sensitive gravitational wave detector ever conceived – in two interferometer facilities in Livingston, Louisiana and Hanford, Washington. They use a laser split along two axes to give an in-phase beam. If gravitational waves along one of the axes affect the beam, it...
I’ve covered a few ‘hidden galaxy’ stories lately, from the ultra high resolution see-through of Andromeda, to dark dust in front of M81 and M82. Now, hundreds of new hidden galaxies have been revealed by a team of astronomers who are looking straight through the Milky Way for the first time ever, shedding light on the structure of new galaxy clusters and the enigmatic pull of the ‘great attractor.’ The Earth is not stationary in space. It orbits the Sun, which in turn orbits the Milky Way galaxy, which then moves through the Universe as part of a galaxy cluster. ...
If you listen to an astronomer talk about a supernova, you’ll probably hear something along the lines of ‘A massive explosion of a massive star that is bright enough to outshine an entire galaxy.’ You can imagine how bright it might be, but it doesn’t really give you enough context to get the wow factor from it. Carl Sagan always said ‘When you make the finding yourself – even if you’re the last person on Earth to see the light – you’ll never forget it.’ Now you, dear reader, have the chance to make the discovery yourself. A series of images of galaxy...
Big stars tend to stick together. They all require incredibly dense regions in which to form, but once they do, they do a great job of blowing away and ionizing any other gas and dust in the vicinity. This is why nebulas in distant galaxies are great tracers of massive star formation. The bigger and hotter the star, the more UV light it produces, the more it ionized a gas cloud, the more we see gorgeous nebula. So it’s no surprise that when I look at the nebula below, I can guess that the central stars are huge, outweighing our...
Gamma rays are the most powerful form of electromagnetic radiation in the universe. With wavelengths as small at atoms, they usually result from the most powerful interactions known, such as the collision of two particles, or the release of energy from the accretion disk of a black hole. But there is another potential source of gamma rays that has not yet been confirmed: Dark Matter. The leading candidate for dark matter is the theorized Weakly Interacting Massive Particle (WIMP), though it is not as wimpy as its namesake suggests, making up 5 times as much mass as the visible matter...
Welcome to a new series of posts that will characterize 1000 amazing facts about the Universe. There is so much out there that we have yet to learn, and every day, astronomers across the globe are using their research to reveal the deepest secrets of the cosmos. This series will look at the strangest, coolest, most exciting facts that we have discovered in hundreds of years of modern science. Fact #5:When you see an aurora in the sky, it is a sign that you are being protected by the Earth and not being blasted with solar radiation. The Sun; A...
A few days ago I wrote about a galaxy that was tough to see because of Milky Way field stars. But our galaxy is far more than just a bunch of stars smattered about. There is also a huge amount of gas and dust with varying temperatures. Some of the hotter and more illuminated gas and dust are what make nebulae so lovely in space. But the cold gas and dark dust that is just out floating in the cold interstellar medium? That stuff gets in the way. A normal image of interacting galaxies M81 and M82 would try to hide the...
Remember the big picture of Andromeda that showed 100 Million stars? That image resulted in a ton of new galaxy discoveries. Most of these new galaxies were once hidden beyond the Andromeda galaxy, but with the super high resolution image, astronomers and the public were able to look straight through and see far more distant objects. Most images of galaxies have what we call ‘field stars’ in them. These are some of the 400 Billion stars of the Milky Way that are far closer than the galaxy we are imaging. For this reason, galaxy images tend to look very cluttered...
There are many types of objects in space that just can’t be seen with visible light, and many more that have very different features when observed across the electromagnetic spectrum. A prime example of the former is a molecular cloud. Cold, incredibly huge, and full of low density Hydrogen, these clouds are the raw material for star forming galaxies. If stars begin to form within them, they can be seen as gorgeous nebulae, but when alone in the darkness of space we need to look for the dim signature of radio waves they emit. The Smith cloud, named after it’s...
