Atmospheric Spectral Shift

Why does the Sun seem red near the horizon? Why does the Moon do the same?  We know the Moon isn’t actually changing colour, and the Sun isn’t either.  So what is happening to the light? The first thing to note about the image above is that the size of the Moon doesn’t change, showing that the well-known ‘Moon Illusion,’ where the Moon appears larger near the horizon, is just that – an illusion.  The second is of course the gradual change in hue as the Moon rises. The reason for the colour shift really has nothing to do with the Moon...

A Beacon in the Dark

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...

Dark Matter is Complicated

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...

Very Long Exposure Photography

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...

Holiday Lights Make Cities Visibly Brighter from Space

With the extra lights shining in cities across the world at this time of year, we are outputting a significant number of photons into Space.  So many that Satellites in orbit have been able to see the difference.  In the maps below, the areas in green are locations where the brightness has increased by as much as 50%. Being able to see the difference from Space is amazing.  The maps also exist for Caribbean nations, where much of the population celebrates Christmas. Now I’m not avoiding any one particular holiday in my use of the phrase ‘holiday lights,’ because it turns...