Saturns moon as spotted through Cassini

Here I am comparing an older image of Saturn's ice moon Tethys to an more recent image as captured through the spacecraft Cassini. As we can see the two images are hard to distinguish, but believe it or not, the one on the left was shot in 1988! as the other was shot in 2005. Why am I comparing these two images when it looks like the two are the same? Well they are the same, and they are different. The larger image was shot in a larger resolution and at a much closer distance. This is significant because during Cassini's mission, we were able to get a picture of the moon in the sunlight and by zooming in (which I cannot find, but I know it is there.) we see  two very small moons Telesto and Calypso locked in orbit around Tethys. So why is this image so interesting, exactly?

The point of this is to talk about how much astronomy has changed within the last 20 years. The smaller image was shot while on earth and the other in space! This changes the distance between the light source and the receiving medium. This changes the focal distance and leads to better resolution within our cameras and telescopes. Think of the equation d = (f_1)^-1 + (f_2)^-2 which means that if we have a smaller distance we would need a larger focal length. This basically means, the closer we are, the larger the image. And that is exactly what we see here.

Post Holiday Festivities

http://www.jpl.nasa.gov/news/news.php?feature=4745

On Halloween of 2015, NASA scientists tracked a flyby of asteroid 2015 TB145 with several observatories. The purpose of viewing this asteroid would be to test several new capabilities to obtain radar images with two-meter resolution for the first time and to see new levels of detail. This means that if we can have better resolution of the asteroid. We will be able to have better resolution of the stellar bodies in our solar system and have even more capabilities to measure stars from farther distances. This would mean we will be able to explore our universe with a much better perspective.

(the focal length equation is d = (f_1)^-1 +(f_2)^-1)

Arecibo Observatory

Today's blog will be regarding the Arecibo Observatory which is located in Arecibo, Puerto Rico. (https://en.wikipedia.org/wiki/Arecibo_Observatory) Unlike a traditional telescope that we think about such as the mirror type telescope used by Galileo; this telescope is a radio telescope. It is  used to detect radio-frequency radiation emitted by extraterrestrial sources. Much like a concave mirror, the waves are reflected from the sides and concentrated (and received) in the middle of the telescope where the receiver is. This is to amplify the signal. So why would this type of telescope would be worthwhile to invest in and use on practical scales? This radio telescope as stated earlier, detects radio-frequency radiation, which allows us to analyze and determine the composition of the light of the stars that we are measuring. We can actually measure the type of material the star is composed of just by measuring the wavelengths of the measured waves.