Looking for Proplyds
|On-line Resources||Resources Needed|
Your first task is to carefully view the Hubble Space Telescope Movie of the Orion region. The movie begins with a wide-angle, low resolution view of the region below Orion's belt and goes to higher and higher resolution. Guess what this movie is supposed to be showing? Provide several possibilities.
Part II - Viewing Proplyds with HST
The Hubble Space Telescope has captured high resolution images of the area just under Orion's belt (large image). Carefully look and see if you can find areas that might be dust disks around stars where planets might just be beginning to form.
How many proplyds can you
find in this image?
|What makes a proplyd different
in appearance than a star?
One clue is that stars appear round in these pictures whereas protoplanetary disks, or proplyds (PRO-p-lid-s), often appear to be elliptical. Another help is to use image processing software (like NIH Image or ImagePC) and magnify & change color tables in this pict or tif image to get a better look.
Part III - Searching for Extra-Solar Planets
The only evidence of extra-solar planetary systems directly observed was seen in the Orion star forming region. By looking for "stellar wobbles," astronomers can indirectly discover planets. The general idea is to look for small doppler shifts as a star wobbles in response to the orbital motion of circling planets. Today, astronomers know of a number of other planetary systems around other stars (current list).
of these planets are in a region called the ecozone, at that distance
from a star where water, necessary for life as we know it, is stable.
In an eco-zone, water is neither too hot nor too cold (on Venus, water
would boil away , and on Mars freeze, because of the distances of these
planets to our Sun). The chart below shows newly discovered planets
that seem to exist in the eco-zone (big chart).
Using the Public Broadcasting System (PBS) WWW site on "hunting for alien worlds," see if you can find the locations of these extra-solar planetary systems in tonight's sky. Create a "cheat sheet" to use outside tonight!
The sun, the earth, and the rest of the solar system formed from a nebular cloud of dust and gas 4.6 billion years ago. The early earth was very different from the planet we live on today.