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,...
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...
In the post-Voyager era of deep space flight, spacecraft propulsion designs feel like science fiction. Instead of using rockets and a thermonuclear generator to produce heat, we have things like solar sails, laser sails, and ion propulsion. These all take advantage of the vastness of space to create a slow-but-continuous acceleration that can get spacecraft moving at incredible speeds. Of course, even at incredible speeds it will still take decades to reach other stars, but compared to Voyager, it’s a step in the right direction. If you want to get to the outer solar system quickly, try the Heliopause Electrostatic...
There are eight planets in the Solar System. This statement makes a lot of people angry for several different reasons. The obvious group to respond with anger is the ‘people for Pluto,’ who have an unwavering dedication to the little planet that could. It’s scientifically recognized as a dwarf Planet, and is still one step up from a Kuiper Belt Object (KBO), so it’s doing well. Far beyond Pluto, in the outer recesses of our Solar system, you may have heard of a potential Super-Earth-sized Planet recently theorized by Konstantin Batygin and Mike Brown. This is the other reason people would...
Have you ever seen the North star, Polaris? It’s decently bright and very close to the North celestial pole. Lining up with the rotation axis of the Earth, the North celestial pole is the point in the sky that never moves, day or night. If you know how to find Polaris, it becomes easy to find the cardinal directions and navigate by the stars. And finding it simply requires finding the big dipper, a bright and easily recognizable object. The same rules apply in the southern hemisphere. But even though there is no southern star, there is another fantastic object in the South that can guide you to the...
I feel like I’ve been covering a lot of stories on magnetic fields over the past few months. Fields around the Earth, the Sun, Mars, Jupiter’s Moons, and exoplanets are just some of the places in the universe where we are looking at magnetic field behaviour. The intention is to use our understanding of magnetism to figure out what is inside these worlds, and how they interact with their space environment. You would expect us to understand the Earth’s magnetic field and interior very well, after all, we are stuck here. But it turns out it’s very difficult to study the interior of...
One of my first books on Astronomy was about the planets. It had a collection of pictures from the first missions to each of the worlds in our solar system. Seeing those photos, the planets felt so alien, so different, and the perspective was like something out a 1950s science fiction comic. But now, with modern advancements in imaging technology and rocketry, we can send heavier instruments to distant worlds, and see them in high definition. It changes the perspective and makes the world seem more familiar than alien, more livable and real. Take a look at the first picture...
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...
Since diving into astrophotography last year, I’ve discovered that I love the concept of time-lapse, and not just with respect to astronomy. It’s amazing to see the changes that can occur over long periods of time, and time-lapse photography is a way to record the changes and see how they unfold. In astronomy the best time-lapses give you a sense of the Earth’s motion through space, show satellites zipping overhead, and show aurora dance along with weather patterns. Large amounts of time with slow incremental changes produce incredible results when it comes to time lapses. Science communication is about how to...
One of the most surprising and intriguing finds during the decade-long Cassini mission has been the discovery of geysers on the Moon Enceladus. Originally spotted in 2005, scientists have spent the last decade trying to understand how they work. And now they finally have a working model. How does an eruption on a frigid Moon last so long? Eruptions on Earth are not long-lived, and if they are, they are very spread out. For Enceladus to have a ton of localized geysers in the South polar region, you need some pretty specific scenarios. Aside from the fact that a constant stream of material could clog...
