How do Rainbows Form?

Sites Used: http://eo.ucar.edu/rainbows/ http://www.kodak.com/US/images/en/corp/membersGallery/wallpaper/1280_1024/RAINBOWS.JPG http://www.alanbauer.com/images/Weather/Rainbows%20over%20Case%20inlet-Vert.jpg

What is a Rainbow? A rainbow is one of the most spectacular lights shows observed on earth! It is sunlight spread out into its spectrum of colors and diverted to the eye of the observer by water droplets. The “bow” part of the word describes the fact that the rainbow is a group of nearly circular arcs of color all with a common center.

What Makes the Bow? Essentially a rainbow is formed by raindrops and light interacting! Rainbows appear not only in the sky, in air near us when there are water drops illuminated by the sun, like around fountains. It arises from the way in which rays of light act on raindrops and pass from them to our eyes. As a light beam enters the surface of a drop it is bent (refracted) a little, then at the point where it meets the wall it is reflected back in the other direction. As it exits the drop it is refracted (bent) again. The reflected light is diffuse and weaker except near the direction of this rainbow ray!

What Makes the Colors? A traditional rainbow is made up of 7 colors: Red, Orange, Yellow, Green, Blue, Indigo, and violet. But it is actually a whole continuum of colors from red to violet and even beyond colors that the eye can see! The Colors arise from two basic facts: 1.) sunlight is made of the whole range of colors that the eye can detect. The range of sunlight colors when combined looks white. 2.) Light of different colors is refracted by different amounts when it passes from one medium to another. When we see a rainbow and its band of colors we are looking at light refracted and reflected from many different rain drops!

Why is the Sky Blue?

Sites Used: http://www.sciencemadesimple.com/sky_blue.html http://pinker.wjh.harvard.edu/photos/cape_cod/images/blue%20sky%20sailboat.jpg http://hea-www.harvard.edu/~efortin/thesis/html/EMR_light.shtml

Light is... A kind of energy that radiates, or travels in waves. It is a small part of a larger range of vibrating electromagnetic fields, called the electromagnetic spectrum. Visible light is the part of the electromagnetic spectrum that our eyes can see. Light may look white, but it is actually a combination of colors! We can see the different colors of the spectrum by splitting the light with a prism. The spectrum is also visible when you see a rainbow in the sky!

Movement of Light! As light moves through the atmosphere, most longer wavelengths pass straight through. Little red, orange, or yellow light is affected by air. Much shorter wavelength light is absorbed by gas molecules. The absorbed blue light is then radiated in different directions. It is scattered all around the sky, so no matter where you look some of the scattered blue light reaches you and this is why the sky is blue!

What is a Shooting (falling) Star?

Sites Used: http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question12.html http://www.uweb.ucsb.edu/~lwingrove/shooting%20stars%202.gif

What Do You Mean it is Not a Star? The event known as a shooting or falling star has nothing at all to do with a star! The amazing streaks of light that can sometimes be seen in the night sky are caused by tiny bits of dust and rock called meteoroids falling into earth’s atmosphere and burning up. The short-lived trail of light the burning meteoroid produces is called a meteor.

Meteor Showers! At certain times of the year your are more likely to see great numbers of meteors. These events are called meteor showers and occur when the earth passes through debris that has been left from a comet as it orbits the sun.

Annual Meteor Showers! Name: Quadrantids April Lyrids Eta Aquarids Delta Aquarids Perseids Orionids Taurids Leonids Geminids When they Occur: January 1-6 April 19-24 May 1-8 July 15-August 15 July 25-August 18 October 16- 27 October 20-November 30 November 15-20 December 7-15