Category: Science

Ah, Mars. My favourite of the inner planets, because it is so close (astronomically speaking) but yet it is mostly a mystery to us, and it has such an interesting past. And this is exactly what we are going to talk about today.

Scientists think that once upon a time, a long time ago, Mars was once much like Earth. It had an atmosphere, it had water (in fact, they think the northern hemisphere was mostly covered whilst the southern was mostly land! Imagine a planet where all the northern hemisphere was water and all the southern was land, how cool would that be?) and, like Earth, to this day it still has seasons, weather and everything!

So, what happened?

A writer friend of mine asked if she could barrage me with astrophysics questions for a story she was writing. Of course, I said “fire away!” I will always help out a fellow writer! Her first question was “What is the Snow line?” (Which is also known as the Frost Line). The answer is pretty interesting, so I thought I would share it with you guys!

But before that, just in case you are unaware, I will cover a related topic: The Habitable Zone. From here, the Frost Line will make more sense.

Every star in our known universe has an area a specific distance from the star where water can exist as liquid, solid and a gas. This varies from star to star as it depends on the star itself: the size of the star, how hot the star is and which stage of life the star is currently in. This area is known as the “Habitable” zone, or the “Goldilocks Zone”, named because the planet is not too far away from the star, and not too close, but the perfect distance away for the only known prerequisite for life as we know it: Liquid water. Earth, very obviously, is in this zone, and no other planet is. Sort of.

Ah, Christmas. The joyous time of year where families come together and celebrate the birth of Christ.

As we approach Christmas, I recently went to a Church service with the family and the story of Jesus was told, including the Wise Men that followed the Star of Bethlehem to find the baby Jesus. As an astrophysicist, I have often wondered about the Star of Bethlehem, and what it could have been. Was it an astronomical event, or was it a sign from God?  So, as always, I did some research.

Everybody knows the story of the Star of Bethlehem. When Christ was born, three wise men were guided by a bright star in the sky, which led them to the stable in which Jesus was born. They saw the star, and deemed it a sign, followed it and found their savior resting directly under the star.

I have always wondered “Was it actually a really bright star, or was it something else entirely?”