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.

"At an altitude of 16,000 light-years, the 33 and 42 stars belonging to clusters Camargo 438 and Camargo 439, respectively, have an exceptional (if heavily obscured) outsider’s view of the Milky Way’s spiral design."- http://www.skyandtelescope.com/astronomy-news/new-stars-at-the-edge-of-the-milky-way-03052015/

Interestingly enough, many clusters of stars has been reported to have been spotted far above the galactic plane of the Milky Way. This is strange due to the fact that star formation tends to occur within the Galactic Plane of the galaxy and not above or below it. This leaves these clusters of stars with "an outsider's view of the Milky Way's spiral design." Possible explanations for the formations of these stars is that during supernova explosions within the early formation of the galaxy, gas clouds of hydrogen were emitted far outside of our plane. Given the ideal conditions would later condensed and form stars. Due to the young ages of these stars, it appears that they have only just recently condensed and this could be because they so happen to spiral perpendicular to the galactic disk of our galaxy.

http://www.space.com/24625-oldest-star-universe-discovery.html

Above is a link to an article about the oldest star in the known universe which is called SMSS J031300.362670839.3. What makes this start particularly interesting is due to its age and composition. This star is the oldest known star in the universe (from our perspective) because of how little mass it has. This shows to us that early stars may have been composed of lighter elements than modern generation stars meaning that they have less iron and more carbon. This is profoundly different from the current measurements of modern stars (especially of our own) and tell us the early development of our universe may have been different than what we had expected.