Planetary Nebulae

Some of the most gorgeous, ghostly, and variable objects in the universe are planetary nebulae.  They are all formed in a similar process, as a low-mass star (like our Sun) sheds it’s outer layers of gas and dust, heating them to a glow as they disperse over hundreds of millions of years.  A few Billion years from now, the Sun will undergo the same major state change.  When this happens, perhaps other species in the far future will gaze upon it and marvel at its beauty. One of the difficulties in studying a planetary nebula is measuring it’s distance from...

Dark Matter Domination

Dark matter is everywhere.  There is way more of it in the universe than the matter we are made of and interact with.  Yet for the sheer amount of it, we have no way of determining what exactly it is.  It’s as if we didn’t know what air was, and even though we could see it and breathe it, we couldn’t measure it.  The most tantalizing part about dark matter is that we can see the gravitational effect it has, and so we can determine how much of it there has to be.  Some places in the universe have more dark matter than...

“Without Gravity”

It always fascinates me to see videos and photographs from the International Space Station (ISS), how simple day to day activities are so altered because of the altered Physics of constant free fall in orbit around the Earth.  Many of the videos are showing what people call the ‘effects of zero gravity.’ This is actually not the case.  There is gravity in space.  Let’s take a closer look at the situation of an ISS astronaut. If we do the math (I do realize the term ‘do the math’ turns away a lot of people, so I will keep it short),...

Powerful New Method for Distances

Ask an astronomer what the hardest thing to do is in astronomy, and chances are they will say ‘measuring distance accurately.’  It is surprisingly difficult to take the light from stars we see and match them to a correct distance.  In the past we have used several different methods depending on how close a star is to us.  For the nearest stars we use parallax, which looks at the change in a star’s position as the Earth is on opposite sides of it’s orbit. All other methods rely on what we call the standard candle approach.  Let’s say you had...

Supernova Mystery Solved

Type 1a supernova explosions are used by Astronomers as a standard candle for measuring distances in Astronomy.  They all explode with the same intrinsic brightness, and so depending on their apparent magnitude, ie how bright they look, we can determine the distance to them. It’s like a 40 watt light bulb.  No matter how far away I move it, it’s still 40 watts, even though it looks dimmer if it’s further away.  However, a few months ago some research came forward about type 1a supernova explosions, hinting that there may actually be two or more distinct types with slightly different...

Precision and the Prime Meridian

The Prime Meridian is the imaginary line of zero longitude, the geographic starting point for any East-West degree measurement of any place on the Earth.  It was selected by an international delegation that convened in 1884 in Washington, DC.  It’s a North-South imaginary line that run right through the Airy transit circle at the Royal Observatory in Greenwich, England.  This is also where we get the measurement of Greenwich Mean Time (GMT). As our ability to measure position and time improves with the Global Positioning System (GPS), the precise position of the prime meridian has actually changed, moving 102 meters East...

Earth’s Twin Discovered!

Since the explosion of exoplanet science in the late 1990s, our entire understanding of the universe beyond our own solar system has changed.  We have confirmed over 1,000 planets orbiting other stars, with another 3500 waiting to be confirmed by subsequent observations.  As we search, our prime directive has always been to improve our technology to determine if other Earths exist, and to seek them out.  Every year we have added another discovery that brings us closer to finding a twin of the planet Earth in space.  Today we have come one step closer, and it is indeed a big step....

Hot Summer Days Mark The Earth’s Greatest Distance from the Sun

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...

New Horizons Loses Contact with Earth on Final Approach to Pluto

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...

Photos of the Epic Conjunction of 2015 Appear!

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...