jueves, 23 de octubre de 2014

About Halloween

Next Friday is Halloween. Perhaps you don't know that Halloween's origin is astronomical. Since the fifth century B.C. Halloween has been celebrated as a cross-quarter day, a day halfway between an equinox and a solstice. Nowadays, Halloween modern celebration retains historic roots in dressing up to scare away the spirit of the dead. This is the reason why lot of people wear fancy dresses that day.
And if we look at the sky with big telescopes we can see pictures like this one I show you below. The stars seems to be dressed up there. Can you see in this picture a witch head? Her eye, nose, mouth and chin? Sure. This is the reason why this cloud is known as the Witch Head Nebula.
But please, come back to the Earth.Will you be wearing a Halloween costume next Friday? We would  like to know. Please, write a comment. 
By the way, we are learning about Astronomy in our clases now. So, why don't you dress your favourite planet, moon, comet, galaxy or nebula up as a Halloween monster? I will put in this blog the best drawings.
Have a Happy Halloween.

The Witch Head Nebula (APOD, NASA)

viernes, 17 de octubre de 2014

Can you see any planet in your constellation?

In our last class, we were talking about the Solar System and its bodies: planets, satellites, comets and asteroids. As I told you, ancient Greek gave the planets this name as they noticed how these bodies travel through the night sky. So, if you look at the sky night after night it is possible that you recognize a planet as a small point of light that changes its position between constellations (see the picture below). Every one of you have chosen your constellation and we are going to learn lots of things about them, about their galaxies, nebulae... But, what about planets? Is possible to see planets in every constellation? Could you see any planet in your constellation?  Those are our first questions.
But if you think that you can see planets only in some constellations... Which ones are these constellations? And why you can watch planets only in those regions of the sky? 
They are not easy questions, but I am sure that all of you are very clever. Please, send your answers as a comment. You will have extra points.
And here you have a picture from APOD. It's Saturn moving through the sky from August 2005 to September 2008.

Three years of Saturn. Nasa APOD, Peter Wienerroither