Remember last week when I was talking about the evidence for some ancient-but-astronomically-recent supernovae? It turns out there is other evidence! Evidence that has helped scientists narrow down the potential source locations. Data from the Cosmic Ray Isotope Spectrometer (CRIS), an instrument aboard NASA’s Advanced Composition Explorer (ACE) spacecraft, has helped us figure out where the recent supernovae might have come from. CRIS measures what we call cosmic rays, atomic nuclei that have been accelerated across the galaxy at close to the speed of light. CRIS has been around for a while, and through 17 years of cosmic ray observations,...
If a supernova were to go off somewhere in our galaxy, the minimum safe distance for Earthbound life would be about 50 light years. Any closer than that, and we would experience an intense blast of high energy radiation and an eventual shower of radioactive particles. It would be like nuclear bombs were set off all around the Earth, causing little destruction but a lot of radioactive fallout. Supernovae are incredibly powerful to be able to cause such damage at 50 light years, but even at larger distances, we can see evidence of their effects here on Earth. A team of...
Neutron stars are the most extreme objects in the universe that have been proven to exist. Black holes are very likely, but we’re still not 100% sure about them. A black hole is like a giant squid in the ocean. We’re pretty sure they exist, but nobody has caught one. The neutron star on the other hand is like a blue whale, everybody knows they exist, and they are massive, rare, and beautiful. Of course, once we know something exists, the next logical step is to figure out how it behaves, to characterize and generalize it, and to identify where it’s...
Data is fascinating. And what’s even more fascinating is that the laws of nature produce predictable patterns in data. For example, if you toss a coin 100 times and measure how many times heads comes up, you’ll get a number between zero and 100. If you repeat that experiment again and again and again, you’ll get different values each time, but usually the number will be around 50, and 50 will come up more than any other value if you repeat the experiment enough times. If you plot this data, with the # of heads in 100 coin tosses on...
Gold doesn’t come from your local jewelry store, and the Gold rush that occurred in the Yukon territory at the turn of the 20th century is not the source I’m talking about either. I want to take it further back, to the origins of gold the element. Similar to the origins of most other elements on the periodic table, it requires an immense amount of energy, such as the nuclear fusion that goes on within a star. But Gold can not be made by a star’s thermonuclear engine. Gold requires more energy, as does every other element heavier than Iron. So...
It’s always funny explaining astronomical time to a non-scientist. I often get the craziest looks when I mention a million years as being a ‘blip on the radar.’ Perhaps there is some immortal alien race out there who would understand how nothing much happens on the scale of the universe in a million years. To humanity and our ever-accelerating advancement, a million years is thrice the age of our entire species. But I guess Einstein was right when he said that ‘it’s all relative.’ This brings us to Saturn, a planet as ancient as the solar system. Moderately old in...
The most violent single event in the universe is the death of a massive star, a supernova. We have seen several different types, though the common element is a massive explosion, taking a star hiding amongst the background into an eruption that outshines it’s entire host galaxy. We have seen the brightness grow and fade over the duration of a supernova event, but we have never seen one just as it’s starting. Until now. Would you ever have thought that the Kepler space telescope, a planet hunter that continuously observes stars, could see supernovae? The key is in the words ‘continuously observed.’ By keeping...
Every time we see amazing photos of galaxies or planetary disks, we can see most of the detail since we see them face on. But since the orientation of spiral galaxies in the universe is random, there are a plethora of galaxies ignored by image processors since we just can’t see much of the detail. We can still learn from edge-on spiral galaxies, just not as much as we can from those that are face on. We can see some fascinating dust lanes in the image above, and a ton of detail considering the view, but we don’t know what...
We know that the giant bright light in the sky that keeps us warm is so much more than we can see. A star, like countless others in the sky, close enough to outshine all of them. The Sun is a dynamic object, endlessly churning and burping plasma beyond it’s boundaries into the solar system and beyond. NASA spacecraft and ground-based telescopes have been keeping eyes on the Sun for years to characterize its 11-year magnetic cycle. And every so often they have a front-row seat to the massive blasts that just can’t be seen with human eyes. The first...
Baryonic matter, which is everything we are made of and everything we can see in the universe, is not a lot of stuff. I mean to a tiny Earthling, it’s a heck of a lot, but if you put it all together it only makes up about 5% of the total Mass-Energy in the Universe. If you’ve ever seen the Millennium simulation, it highlights the fact that both baryonic and dark matter are organized into filaments of mass, with the baryonic matter at the densest points, ie the galaxies. What lies between these dense nodes and filaments are vast empty...
