Even after a decade of interloping among the Saturnian system, the Cassini spacecraft is still doing great science. It helps that there are lots of places to visit, since Saturn has 62 moons and the largest ring system of the gas giants. Arguably the best science has come from Saturn’s largest moon Titan, second largest moon in the solar system (behind Ganymede) and the only moon known to have an atmosphere. Since Cassini has been in orbit around Saturn and it’s system of moons, it’s been revealed that over 1.6 million square kilometers of Titan’s surface are covered in liquid...
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...
Until the recent discovery of gravitational waves, the only ‘sense’ that astronomers had was vision. Granted our ‘vision’ with telescopes is far broader than human eyes, we still need to find ingenious ways to use the precious photons that rain down on Earth. One of the new ways astronomers are using light is to look at what we call a ‘light echo.’ In reality it’s a reflection of starlight. When a new star is forming, it is accompanied by a protoplanetary disk, which will eventually form all the planets of the system. Our own solar system went through this stage 4.5...
Not to be confused with Canadian Gum Hubba-Bubba, Hubble has released a great birthday image for it’s 26th birthday. I’m a few days late to celebrate, but it’s still a beautiful image. Known as NGC 7653, the Bubble nebula is 8,000 light years distant in the constellation of Cassiopeia. The reason for this natural bubble shape is that the star just left of center in the image is ionizing a surrounding cloud of Hydrogen with it’s powerful stellar wind. As electrons and protons recombine at the edges of the bubble, they release an infrared photon that can be clearly seen...
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...
Mice are a common laboratory animal for pre-human testing. Everything from drugs to medical treatments to surgeries have been tested on mice, and the effects of spaceflight are no exception. Animals such as Laika the dog and Rhesus monkey Albert 1 have had their own test flights, but mice offer an easy alternative when there’s not much extra room on a spacecraft. In a recent study, mice flown on the space shuttle Atlantis were shown to have developed early signs of liver disease. Could humans in space exhibit the same symptoms? “Prior to this study we really didn’t have much information...
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...
One of the most fascinating things happens whenever I show someone the planet Mercury in the sky. Their first reaction is to be surprised at how bright it is. Most people think of Mercury as a faraway planet, too close to the Sun to see at all. But in reality, Mercury is close to Earth, and when the angles are just right, it’s not hard to find. Mercury is 57 million kilometers from the Sun, more than a third of the way to Earth. We are also much closer to Mercury than we are to Jupiter and Saturn. When we see the...
