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...
When were the planets discovered? Uranus and Neptune were definitely not found until modern science began, since a telescope was required to see them. The other five planets were not actually discovered per se. Since they are visible to human eyes, they have been observed since prehistoric times, and we see examples of cultures across the ancient world who observed them. The five visible planets are Mercury, Venus, Mars, Jupiter, and Saturn. Starting this weekend, you can see them all across one part of the sky, a visual alignment that hasn’t occurred since 2005. Planets are so-named because of the Greek...
Every time a comet slowly approaches the inner solar system, astronomers get excited. We are hopeless romantics, wishing the new comet will brighten enough to be labeled the next ‘comet of the century.’ Yet we have had our hearts broken before, more often than not. The most recent fizzled comet was nearly two years ago with the burn up of comet ISON as it passed close to the Sun. It made for a spectacular view for SOHO and SDO looking at the Sun, but for the rest of us it was just another heartbreak. But once again we have hope; A...
More than two-thirds of stars are not solitary like our Sun. They are binary systems, meaning they contain two stars that orbit each other about their common centre of gravity. Stars like our Sun are much more rare, and we are not sure what the difference in formation is between binary and solitary systems. Binary systems are much more useful from a scientific perspective, as we can study their orbital period and separation to infer a wide range of properties such as masses and distances. A special class of stars, called RR Lyrae variable stars, have puzzled astronomers for years...
The Milky Way Galaxy has about 26 associated satellite galaxies, which is strange to imagine, since we think of a galaxy as a massive collection of Billions of stars. The dwarf galaxies are not easily visible since they are small, so they tend to blend in with the background of Milky Way stars that are much closer. You might also notice from the above image that the dwarf galaxies are distant, lying beyond the 100,000 light year scope of our large spiral home. Most of them likely originated in the turmoil of protogalaxy collisions that occurred billions of years...
For Christmas I was given a green 200 mW laser! A couple of AAA batteries later and the laser can point out any star or object in the night sky, with the beam clearly visible the entire way up to infinity. Its the epitome of an Astronomer’s toolkit, at least in my eyes, and it got me thinking about all the amazing things you can see in the sky right now. It also makes me feel like I’m brandishing a light saber, and sadly it’s about as close as I’ll ever get. First off, Venus is back in the evening...
I thought Hurricanes had powerful winds. The strongest wind ever recorded was a gust up to 400 Kph near a tropical cyclone in Australia. But Earthbound wind has nothing on Galactic wind. Around the time when our ancestors were just learning to walk upright, the core of the Milky Way Galaxy unleashed a blast of gasses and material at 2 Million Kph. Millions of years later, we see the aftermath of this eruption as two massive bubbles of material blown out above and below the galactic centre, at least 30,000 Light Years tall! The lobes were discovered by the...
