The Real Discovery of Neptune

Have you ever read the story of the discovery of Neptune? It truly is a triumph of science and mathematics, and part of the reason it is my favourite planet (a hard choice to make).  The story goes like this: It all starts with the discovery of Uranus in 1781 by William Herschel.  This was the first ever discovery of a planet, as the Earth and the five visible planets have been known of since the dawn of history. Thanks to Isaac Newton working out the laws of gravitation and the mechanics of the solar system, mathematicians could easily calculate the properties...

The Galilean Moons

In the year 1610, it was commonly believed that the Earth was the center of the Universe, that all bodies rotated around the perfect planet, placed by god with the heavens around it.  Galileo Galilei dealt a major blow to this idea, by using an early telescope to improve his vision and look up at some surprising dots. These dots formed a line that went straight through the bright planet Jupiter.  As Galileo looked again and again, night after night, he noticed that they not only persisted, they moved.  Their motion was predictable, and Galileo realized that they were orbiting Jupiter, just...

Juno July

As Canadians start up Canada day celebrations and Americans get ready for their independence day, the world of space exploration holds its breath and hopes for a good result.  On July 4th, the Juno spacecraft will arrive at Jupiter after a five year long journey.  NASA continued its recent theme of producing movie-trailer-like videos to promote the mission. Although I love the imagery and the design of the trailer, it feels cheesy to me.  Maybe it’s because I find movie trailers cheesy in general, and this is trying to appeal to the general public.  Though regardless of how I feel,...

Mars in the Spotlight

On May 22nd, Mars will be at opposition.  It’s the astronomical term for when Mars and the Sun are on opposite sides of the Earth.  This makes the face of Mars fully illuminated from Earth, and also brings the Earth to it’s closest approach of Mars, at 75 Million Km.  Hubble images the red planet to celebrate the occasion. So get your telescopes out and be ready to take some pictures, because Mars is smiling! Mars will rise in the East at sunset, since they are on opposite sides of the Earth.  It will appear bright with a rusty hue, and...

Europa Chemistry

I always get giddy when talking about Europa, as many astronomers do.  It’s one of the most fascinating places in our solar system when it comes to the search for life.  It has lots of water, likely contained in a subsurface ocean.  It’s heated though a gravitational tug of war with Jupiter and the other Galilean moons.  And, as of recently, it has a chemical production system that matches Earth’s. I wonder what goes on beneath the thick ice of Europa.  Is there an ecosystem filled with alien life down there?  Life in Earth’s oceans feels very alien, but creatures from...

The How and Why of Planet Nine

It hasn’t been found yet – let me make that clear.  But with evidence that it should exist, astronomers are looking more closely at the proposed planet nine and how it might have formed, and how it could have ended up in such a distant orbit. When you start to think about how a planet ten times the mass of Earth could have ended up more than ten times as far from the Sun as Neptune, a few scenarios pop into mind: It was formed in the inner solar system, where interactions with gas giants or another star pulled it out It formed...

Three Nearby Earths

As the search for planets in the galaxy continues, there are two places to focus on: Distant stars with potential large planets, and nearby stars with potential small planets. If we are able to find Earth-like planets orbiting nearby stars, they will be prime targets for future generations to explore. Astronomers have just announced the discovery of three new planets orbiting a star only 40 light years from Earth.  The star is a very small red dwarf, only slightly larger than Jupiter, and even though it’s close to Earth, it can’t be seen with the naked eye or even with a large...

Comet or Asteroid?

What is the difference between a comet and an asteroid? The typical response is that an asteroid is rocky and a comet is icy/gassy.  Further than this, asteroids typically orbit closer to the Sun than Neptune, and comets orbit beyond this loose dividing line.  But as with everything in nature, there are often exceptions to the rule. C/2014 S3 PANSTAARS is classified as a weakly active comet, originating in the Oort cloud with an orbital period of 860 years.  As it approached the Sun, astronomers noticed that it was lacking the characteristic comet tail, resulting from the blast of solar radiation upon approach to the...

Mercury Surprises

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...

Tug-Of-War Magnetism

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...