Our Moon is Not So Special Afterall!

The foremost theory of the formation of our Moon is the giant impact model where most likely a "Mars-sized" body impacted the early Earth, causing the release of dust that originated from the Earth's surface into space. This dust later slowly accreted to form the Moon as we know it. Our moon was first thought of as the only satellite that formed from a giant impact on the planet it is orbiting. Recent evidence suggests that Phobos, one of Mars' moons may be the cause of a similar giant impact of Mars!

Such a conclusion was derived from measurements originating from the European Space Agency's (ESA) Mars Express and NASA's Mars Global Surveyor missions. Mar's two moons, Phobos and Deimos have always been under scrutiny due to their questionable origins. Mars does not have the gravity capable of capturing asteroids from the asteroid belt, yet these two moons with asteroid like appearances are orbiting Mars. The alternative scenario is that both moons reaccreted after a major impact similar to our moon's giant impact theory .

(Mars Express, ESA, http://news.softpedia.com/newsImage/MARSIS-Probes-the-Ionosphere-2.jpg/)

(Mars Global Surveyor, NASA, http://mars.jpl.nasa.gov/technology/orbiters/orbiters01.html)

Observations have shown that the type of minerals that compose these two moons are very similar to the minerals found on Mars' surface as well. Not to mention it is also observed that these two moons have a high porosity, in which 25-45 percent of for example, Phobos' interior is most likely made up voids within sponge like structures. Because of this high porosity, scientists believe that an asteroid with such high porosity would not survive being captured by Mars as the gravity from Mars would rip the asteroid into dust. Instead this high porosity suggests re-accretion where the largest blocks of mass re-accreted first while smaller debris re-accreted by themselves and due to the low gravity of these moons, when these different sized blocks came together, these gaps were never filled in. Thus this supports the theory that Phobos was caused by a giant impact theory.

(A picture of Phobos from the Mars Express, http://www.universetoday.com/wp-content/uploads/2011/10/Phobos_MarsExpress1.png)

To test this theory, the Russian Space Agency have came up with "a bold mission to Mars." They are sending the Phobos-Grunt interplanetary spacecraft, the first of its kind, from Earth to Mars, and back to Earth! Phobos-Grunt will not just attempt the first landing on Phobos, it will also be the first to return soil samples from that moon as well, which hopefully may help scientists understand the formation or the origin of Phobos and Deimons. The spacecraft will also be carrying the Yinghou-1 Mars Orbiter, a mini-satellite built by China (and is also the first probe China has ever sent to Mars). Yinghou-1 is a 110kg satellite that will study Mars' magnetic field, gravity field, and surface environment for a year after jettisoning off Phobos-Grunt when the spacecraft is near Mars' orbit.  This is also the first time research is done by "two spacecrafts simultaneously."

(A Russian mission poster for Phobos-Grunt, http://www.universetoday.com/wp-content/uploads/2011/10/fobos_00.jpg)

(The entire spacecraft while en-route to Mars, http://www.universetoday.com/wp-content/uploads/2011/10/general_annotated_1.jpg)

(Phobos-Grunt after landing, http://www.universetoday.com/wp-content/uploads/2011/10/spacecraft2_gb.png)

(Shows the return vehicle launching off Phobos-Grunt, http://www.universetoday.com/wp-content/uploads/2011/10/elements_spacecraft21.png)

What's so exciting is about this Russian spacecraft is its audacious plan to return 200grams of soil samples from Phobos for analysis. It is predicted that only the top part of the entire spacecraft (the return vehicle from the picture above) will return by August 2014. The entire Phobos-Grunt spacecraft is equipped with two robotic arms, and 15 scientific instruments which includes lasers, spectrometers, cameras, and even a microscope. The launch date for Phobos-Grunt is not set, but should be sometime at around November 7th, 2011. Hopefully the Russian Space Agency will set a suitable time before November 25th, because the launch window for Mars is from November 5th to November 25th. Without managing to finish this spacecraft within this window of opportunity, the Russian Space Agency will be forced to wait for years for Mars' orbit to be in an opportune location for another Earth and Mars close proximity launch.

(The mission scenario of Phobos-Grunt, http://www.universetoday.com/wp-content/uploads/2011/10/mission_2011_gb1.png)

If this mission goes successfully, scientists will acquire the first soil specimen from the region of Mars. Not to mention, this mission may also encourage the use of mini-satellites as it shows that by piggybacking on other larger spacecrafts, flight launches and costs are very minimal for such satellites. The Phobos-Grunt and Curiosity not only show that robotic technology has increased substantially over the last few decades, but it also brings in the question of NASA's development of manned flights to Mars and if such decisions are cost effective, and not to mention reasonable when robotic interplanetary flights can do so much already. If we have the technology to bring back soil specimens from Mars' moons and perhaps Mars itself, is there a need for us to send manned flights to Mars? I do hope NASA's decision to do so is more based on the pursuit of scientific knowledge than merely showing off that they are still ahead of the space race. With that said, I do support the NASA's funding in developing interplanetary transportation as there is no doubt benefits for mankind for developing such technologies!