67P is a comet located around 500 billion kilometers away from the Earth. Discovered in 1969 and named after its discoverers Churyumov-Gerasimenko, 67P has a position in between the orbits of Earth and Jupiter. It revolves with a speed of 140 thousand kilometers per hour and completes a tour around the sun approximately every 6.5 years. It rotates around its axis every 12.4 hours. It is a small comet, with just a 1.9 kilometers radius (25 km3). Its distance to the Sun is nearly 3300 times that of what is between the Earth and Sun. Though it might seem far away, if we take the diameter of our solar system as roughly 2 light years, comet 67P does not seem to be so distant.
In 1993, the European Space Agency (ESA) prepared a project to investigate 67P; the launch of a satellite named Rosetta was planned for the year 2003. However, due to an explosion of a rocket (Ariane 5) in 2002 right after its launch, Rosetta's launch was delayed until 2004. Very sophisticated calculations were completed to make the orbit of Rosetta intersect with 67P. This was done by utilizing the gravities of both Earth and Mars.
A spacecraft called Philae was included with the Rosetta satellite. This device was to be separated from the satellite and land on the comet. Philae was also equipped with instruments that could carry out 10 different analyses. One of these was a drill with an approximately 30 cm probe enabling it to collect specimens by boring into the comet's soil. These soil specimens would be analyzed via some of Philae's devices to determine the composition of the comet. Another mounted instrument would send radio waves directly into the center of the comet and these signals would be analyzed by the Rosetta and tell us about the comet's center and core.
The comet was estimated to have a planar and cylindrical structure; however, when its photograph was taken at a close distance, it was seen to have a duck-like shape. This situation made it very difficult for Philae to land. Despite that, Rosetta entered the orbit of the comet in August 2014. Three months of surveys were conducted and photographs were taken, generating information to locate a landing spot for the Philae craft. After assessment of this data, a decision was made on where to land.
The landing took three attempts. Philae sent a signal to Rosetta five hours after its detachment and the satellite itself relayed that signal to Earth. Then, it made a soft landing. However, the landing zone was away from the initially planned spot and deprived Philae of solar rays, which would charge its batteries. It was running out of energy. Nonetheless the module operated for nearly 57 hours before running out of power and was able to send analysis information regarding the soil it collected with the drill. This was the result of 10 years of planning, 10 years of travel, and 1.6 billion dollars spent.
Are there minerals on comets?
Philae is actually hoped to be a start for "asteroid mining." In other terms, it is an effort to obtain precious minerals, which are about to diminish on Earth, from asteroids. According to the report published by the US Geological Survey in 2006, the Titanium (Ti) reserves on Earth will run out within 34 years. Titanium is mainly utilized by heavy industries, especially in plane and spacecraft manufacturing. Today the situation is also critical for other rare earth metals, primarily platinum (Pt), europium (Eu), and palladium (Pd) which are consumed in the production of smart phones, tablets, PCs, and weapons. For instance, in tablets, europium (Eu) is used; in touch screens, indium (In) is used; and for headphones, neodymium (Nd) is used. For these reasons, it is anticipated that countries with space technology will increase their efforts to obtain these types of precious elements via asteroid mining in space. The firm Planetary Resources is a pioneer for this enterprise.
There is also hope that Philae gathered new information which pertain to the creation of the solar system – and even the whole universe. Asteroids are the oldest heavenly masses in the solar system, and as such can provide data in terms of planet formation. Discoveries of major geological clues to the Earth's past are expected. Furthermore, the report sent by Philae enabled a reinvestigation of the issue as to whether there are different elements in space than on Earth or not. No new elements were discovered during the study. In other words, it is proved one more time that space does not contain different elements than are already found on Earth.
No new element found
These type of studies have been completed in the past; no new elements were found during the analysis of the rocks brought to Earth on board the US spacecraft Eagle from the moon; and analysis of the soil brought from Mars by the Phoenix Mars Lander in 2008 also showed no new elements. Lastly, every meteor collected has been analyzed, and none have had any new elements. The carbon testing conducted on these samples, each a constituent of the outer space, has also confirmed that the solar system is approximately 4.5 billion years old.
What does space dust tell us?
Every year, an average of 15 million tons of space dust lands on Earth. The laboratory analysis of these microscopic particles means a lot for science.
As the result of studies carried out with electron microscopes and uranium testing, scientists have never encountered any element other than the 92 found on Earth. These analyses also confirm the age of the solar system.
All this dust raises the question: where does it come from? Dr. Loretta Dunne from Cardiff University said: "The origin of cosmic dust is, in fact, the basic question of the origin of our planet and others. Effectively, we live on a very large collection of cosmic dust grains and yet, until now, we have not been sure where cosmic dust is made."
As we explore stars, comets, and meteorites, and reflect about the vast space, we remain fascinated by the size and order of the universe. Finding the same materials in everything we have discovered confirms the one singular source of all existence, from every point of view.
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