Astronomy cast 1&2

Ep. 253: Rayleigh Scattering (Why is the Sky Blue?)
This astronomy cast was about why the sky is blue. The sky is blue due to an effect called Rayleigh Scattering. This effect is caused by gases and dust particles in the atmosphere that scatter a large amount of electromagnetic radiation. Red, yellow, and green get through pretty well, but blue becomes scattered and photons are directed all over the sky. All of the light photons of blue wavelength or shorter are scattered and leave the blue haze that is visible to everyone. It is techinically an absorbtion reabsorption process where the photons act like a ball and the particles like walls. The ball continues to bounce and there are so many balls that they create a visible screen of light. This visible screen happens to be the color blue because of the size of the particles of our atmosphere. The size of the particles has to be just the right size in order for this effect to be utilized. The probability of the light being blue was not any higher than any other color, however the way the planet has evolved has created a system where this is now the norm and will remain this way.
Ep 254: Reflection and Refraction
The way that vision essentially works is that photons are emitted from the sun and are sent towards every object on earth. The photons hit each and every object and they bounce and reflect. They reflect at different wavelengths depending on the material and different characteristics of objects. Green is just a type of material that can reflect light at a green wavelength. Green is really just an interpretation of the brain of wavelengths of light. Objects do not truly have color, its just the mind interpreting the information it recieves from cones and rods in the eyes that absorb photons passing into them. Different materials, dust, interstellar space, and many different factors cause light to be adjusted in terms of speed or constitution. These changes result in all different types of images being detected by your eyes and therefore your brain.

APOD 4.5

This is a picture of both the moon and Mercury. The two celestial objects rose in the early morning sky on April 19th. Last week, Mercury wandered far to the west of the sun. It was joined by the crescent moon only because it is the closest planet to the sun. The greatest angle created by this short distance, which is about 27 degrees is, allows the two to be seen together. The two objects managed to stay about 8 degrees apart from each other as they rose in the early morning sky. The images were taken about every 3 minutes and combined to create this image.

APOD 4.4

This is a picture of Antares, which is  a red super giant star that has gone through several stages of stellar evolution. Becoming a red giant takes a certain amount of mass, which is less than three solar masses. The star evolves and as it runs out of hydrogen to burn, it expands and evolves into a red giant. Antares is 850 times the diameter of our sun, 15 times more massive, and 10,000 times brighter. Antares is the brightest star in the constellation Scorpius and is clearly visible in the summer night sky from Florida.

APOD 4.3

This is a picture of the constellation monoceros and the Rossette Nebula that it resides in. NGC 2264 is a star forming region that has an array of light and stars that are visible through a telescope. The 2,700 light year away nebula as its reddened light due to a mixture of gases and dust as well as the emission nebula. The blue reflection nebula marks the region of the nebula where star formation is mostly occurring. The image covers an entire 3/4 of a degree which is about 1.5 moons.

APOD 4.2

This is a picture of the bright planet Venus. This picture was taken as Venus passed over the Pleiades and created the interesting light. This photo of the "seven sisters" was taken from Arizona and appear much less bright than Venus. The seven sisters are the stars that make up the Pleiades. The light distortion that is created is from the telescopic lens and not from the apparent "star crossing"

APOD 4.1

This is a picture of rocket trails left behind by one of NASA's recent missions. Five rockets were consecutively launched and left chemical tracers so that the high-altitude jet stream could push them around. This movement of the tracer would help the scientists better understand the high-altitude jet stream. The tracers were left in the ionosphere and were able to be captured in this picture from the shore of New Jersey facing south. The constellations of Saggitarius and Scorpius are visible, as well as the faint clouds of the milky way.