Life in the universe is a fascinating topic. The simplest question: Are we alone? It breeds so many deeper and more profound scientific questions, like “How many habitable planets are there?” “How likely is life to develop on any given planet?” and “How long can a civilization survive?” We can’t answer them definitively, but we can narrow it down. The Drake equation, shown above, was first developed by Frank Drake, the head of the Search for Extraterrestrial Intelligence (SETI), in 1961. He took the question of are we alone and made it quantifiable, in a probabilistic way. It lets us...
A supernova is the death blast of a giant star, far larger than our Sun. Massive stars go out with a bang, outshining entire galaxies, allowing us to see them across the universe. A supernova observed in 2013 occurred in a distant galaxy and took over 30 Million years to reach Earth, where the timing was perfect for us to observe and study it. And now that it’s been studied, the explosion was truly the death of a giant. The supernova, named 2013 ej, was discovered in June 2013 in the galaxy M74 in the constellation Pisces. It was the closest supernova...
The fact that we have found gravitational waves tells us that we have come a long way in terms of science and technology. We detected a perturbation in the fabric of space-time that was one one-thousandth the diameter of a proton. It’s insane to think about that level of precision. And yet we still can’t find Dark Matter, the stuff that is literally everywhere in the universe. Is it our problem? Or is dark matter just on a whole different level? By now, we know that dark matter isn’t some clump of stuff sitting out there in space. But that...
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,...
A direct consequence of Einstein’s theory of general relativity, and an observational way to prove it, is gravitational lensing. It requires a powerful gravitational source to work, such as a galaxy or cluster of galaxies. It works in a similar way to a lens of glass, where rays of light are bent toward a single source, increasing the brightness. In this case, instead of glass, the bending of the rays is due to the curvature of space. Light rays coming from the source would otherwise miss Earth, but instead are bent toward us when there is a massive object in front of it. It’s...
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...
Black holes form when a massive star runs out of fuel. Gravity causes the core to collapse down to an object so dense that light itself can not escape. In the Milky Way galaxy, there are expected to be over 100 Million black holes, though of course we can’t see them. The one we can see is the supermassive black hole Sag A*, lying deep within the core of the galaxy. But how did Sag A* form? Was it from the merger of many smaller black holes? Or is there some other process forming the most enigmatic objects in the...
There was a report about a month ago that a Fast Radio Burst (FRB) produced a repeating signal. This is big news because we really don’t know what causes FRBs, and once they have ended it can be difficult to trace their source. But a repeating signal means we can pinpoint their origin and potentially figure out their root cause. It’s no wonder the astronomical community was excited…and skeptical. Most of the FRBs that have been discovered were in archival data – data from past surveys that were given a closer look. Only a few have been seen in real-time, so when...
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...
