X-ray Diffraction Used by Curiosiy

As we talk about space and the chemistry of foreign bodies millions of miles from Earth, it seems silly not to discuss one of the most important aspects regarding the analysis of such data; the retrieval of samples. Presently there are probes traveling through space gathering data and sending it back to Earth, such as the New Horizons Probe, which was launched by NASA in 2006 and is expected to pass Pluto in July 2015, as well as rovers on Mars, such as the Mars Opportunity Rover, which was launched in 2003 and has already trekked 20 miles.

Mars Opportunity Rover

Currently, there is a new rover on Mars, called the Curiosity Rover. It was this rover that created so much hype as it descended successfully onto the Martian surface on August 6th. This rover is set apart from previous rovers for its sophisticated on board sample analysis system. Through such instruments, it is possible for the rover to send important data back to Earth. One of the most important equipment on Curiosity is a spectrometer called the Chemistry and Mineralogy instrument, or Chemin for short. It is about the size of a laptop computer inside a carrying case and it measures the abundances of various minerals of Mars, which are indicative of environmental conditions that existed when they formed. 

As the gif demonstrates, Chemin performs X-ray diffraction measurements. It fires thin beams of X-rays through powdered material gathered by Curiosity. Some of the X-rays get absorbed by the atoms in the sample and then re-emitted at energies that are specifically characteristic of the particular atoms present in the sample. X-rays can also bounce away at a certain angle that corresponds to the internal crystalline structure of the sample. Measuring this angle which which the X-rays are diffracted into the detector can identify the minerals.

The image above is the X-ray diffraction results produced by Chemin which is sent back to Earth. The diffraction signals are the rings that represent the fingerprint of the minerals. The rings provides information on both what minerals are present as well as how abundant they are. 

And Chemin is only one piece of equipment on the Curiosity Rover. There are also cameras, radiation detectors, environmental sensors, and atmospheric sensors. Weighing one ton, more than any other rover made, the Curiosity Rover truly deserves the name Mars Science Laboratory. 

The Significance of Saturn to Past Civilizations

When we think about the planets, we think of these massive extraterrestrial objects that just happen to be in our solar system, revolving around the sun just like the Earth does. These planets have an atmosphere of their own, are made up of different materials, can be ridiculously far away, and some possibly have the means to support life. But to people years and years ago, the planets meant so much more. These planets were so magnificent in their structure and so far away because they were not simple objects in the skies. The planets we commonly see in a textbook were to them the Gods that control the universe and everything in it.

Zeus in his fight with Cronus. 

In Greek mythology, Saturn is the all powerful being Cronus, who was the father of Zeus (Jupiter). Cronus was the head of the throne over all the other Gods in the universe. However, to prevent being dethroned, Cronus ate his children. Zeus ends up overpowering Cronus, puts him in chains, and banishes him completely.


In Egyptian mythology, the story plays out a little differently. Saturn was the God Osiris. Osiris is murdered and completely dismembered by his brother Seth. Osiris' wife Isis (who was Jupiter) is able to collect all of the dispersed parts, and puts them into a swathing. Osiris' body is restored and he is brought back to life, becoming the king of the Underworld. Isis conceives a baby with Osiris named Horus, who fights Seth to avenge his father's death. 

The standoff between Horus and Seth 

In both of these situations, Saturn is portrayed as an amazing God who ends up losing his power forever. Saturn is then put into the shadow of another being like Jupiter. Maybe when civilizations saw Saturn, they were captivated by its rings and named it to be the almighty God instead of other planets. Maybe when past civilizations were around, they were easily able to see Saturn, but as years went by, Jupiter became the more common sight. Regardless of the reason, the beliefs of these cultures show how amazing these objects in the sky were to them, and how prevalent they were to their daily lives.