The closest star to the Earth, aside from the Sun, is Proxima Centauri, a small red dwarf star that is part of the Alpha Centauri system, roughly 4 light years away. If you don’t know light years, the distance is a staggering 37,800,000,000,000 Km. Beyond that our stellar neighbourhood fills in as you move 20 light years in any direction, and by 100 light years, there are dozens of stars around us. This gives a stellar density of about 0.14 stars per cubic parsec (a parsec is about 3.26 light years), pretty normal in terms of the number of stars in a given...
When could the Moon possibly be brighter than the Sun? The Sun is much bigger, produces energy, and gives all the energy needed for life on Earth. But if you look at the sky in gamma rays, the highest energy photons on the electromagnetic spectrum, you’ll see the Moon more easily than the Sun. Why? The Moon is the brightest gamma ray source in the sky, because it has no atmosphere or magnetic field. Essentially it has no protection from the dangerous cosmic rays that are constantly zipping through space. When they hit the Earth’s atmosphere they create a cosmic...
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...
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...
As I’ve said before, the most powerful, most energetic, most intense processes happen in the center. The gravitational center of the Earth, the Sun, and the galaxy are all places where temperature, pressure, and interactions of matter and energy are pushed to their limits. When you look up to the sky it’s easy to see the Milky Way (unless you live in an urban center). Do you ever wonder where the middle of it is? Where that supermassive black hole lies? Astronomers know where it is, but you need infrared cameras to see it past the thick dust that blocks...
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...
NASA has been zeroing in on certain features of dwarf planet Ceres and looked at them in more detail. Here are the most surprising as well as what we know so far. There are a few other great videos in this playlist, but the first one gives a great summary of what has been seen so far. The most surprising and interesting feature of Ceres in my opinion has been the Occator crater. With the enigmatic bright spots that have been observed since the Dawn spacecraft approached Ceres, we are seeing them in finer detail than ever before, and we...
