As warm as the temperatures have been recently, it may shock you to learn that today marks the Earth’s Aphelion, or its greatest distance from the Sun in its orbit. This may confuse those that think the Earth has seasons due to its proximity to the Sun. The seasons of Earth are actually due to the tilt of the Earth’s axis, and is a result of how much direct sunlight we receive at any given time of year. It’s one of my favourite trivia questions to ask kids in my planetarium shows, and have them guess when the Earth is...
On July 4th, for about an hour and twenty minutes, my heart stopped. This was the amount of time that New Horizons was quiet. No contact, no data, nothing but the lonely black of space. In this time, the craft did what it was programmed to do. It transferred control to its backup computer, which told the main computer to enter safe mode and suspend all non-essential functions. Then the backup computer attempted to re-establish contact with Earth, 5 Billion Kilometres away. Contact has been re-established with the craft and its backup computer has been transmitting telemetry data back to mission...
If you could see through the lens of a very powerful telescope, to an area of sky the size of a grain of sand held at arm’s length, a new universe would be revealed to you. For in that tiny patch of seemingly empty sky, there are thousands of galaxies visible, albeit with many hours of light collection. Observing the most distant of these galaxies, at the edge of the universe, allows us to estimate the number of Galaxies present in the distant past, when the universe was very young. As our observations improve, and our ability to simulate the conditions of the...
In the last few days, we have watched the intricate dance of Venus and Jupiter in the Western sky after sunset. They have tangoed and passed by one another and the world has watched as the best conjunction of the year has come and gone. Don’t forget that even though they appear close in the sky, Venus is actually closer to the Earth than it is to Jupiter. Jupiter is hundreds of millions of kilometers further away than Venus. Today’s APOD is a beautiful shot by Letian Wang combining the proximity of the two planets with the (much further East...
As is the case with any final approach to a new object, the early images, with their horrible resolution, pixelated appearance, and possibly false features due to processing, lead to significant speculation on what we will see as the craft approaches. It was the same a few months ago with Ceres. I personally love the blurry images. It’s a mystery waiting to be solved, and we see it unfold as we move ever closer to our destination. It also reminds me of the early days of the internet I grew up with, using a good old 28.8K modem and waiting 2...
I was downtown Toronto this morning, dressed in a suit and holding my umbrella to stay dry and navigate the city streets as they were soaked with rain. I was headed to the CBC building on John street to do an interview about the SpaceX CRS-7 mission that would launch an hour later. This would be a very important mission, the seventh of twelve ISS resupply missions contracted by NASA. It was also the third attempt at a secondary goal – landing the first stage launch vehicle, the Falcon 9 rocket, upright on an ocean platform, a feat that had...
How do we determine the size of the Universe? How do we know how far away the planets and stars are? How can we measure it without ever being there? The answer, as it always is in Astronomy, is light! More Photons = More Science! Here’s my video explaining the concepts of Parallax, spectroscopic parallax, and type 1a supernovae! Space is big, and although we can figure out how big it is, its another challenge all together to understand and comprehend its sheer size.
The true story of why Pluto isn’t a planet goes back further than you would think. It has a lot to do with our understanding of science at the time, and a lot more to do with surprising luck. I made this video a couple of days ago for the Khan Academy Talent Search. I hope you enjoy it. It will be interesting as we move into better telescope technologies that allow us to see further into the depths of the solar system and the universe. What strange mysteries will we find?
What is the brightest object in the sky? Why the Sun of course. Second brightest? The Moon. Most people are able to answer this question quite easily, but what is the third brightest? The fourth? Many people will confidently say Sirius, the brightest star in the sky, or Polaris the north star. The answer is that the planet Venus is third and the planet Jupiter is fourth. It shouldn’t be that surprising that planets hold these positions. They are much closer than the distant background of stars, and the human species has been observing them since the dawn of recorded...
The Moon has clearly seen some stuff. It’s visibly heavily cratered across it’s surface, which has remained unchanged since it’s surface solidified 4.2 Billion years ago. Think about that – the Moon has been the same, with the exception of cratering, for 4 Billion years. This is a stark contrast to the Earth, whose erosion and tectonic activity cause the crust to change on scales of a few hundred million years. Astronomers have worked hard to learn about the early solar system by looking at the Moon and its cratering patterns. Most of the visible craters on the Moon are...
