NASA says that MESSENGER’s propellant runs out today, 30April, and then hits Mercury at eight ,750 mile per hour, or 3. 91 at kilometres per second. This ends its mission, which began in 2004 from Earth. It was designed to study the Sun’s closest planet. MESSENGER will crash into Mercury’s surface on Thursday, at mid-afternoon Eastern Time. Mission control won’t be able view exact position of collision as the spacecraft will strike Mercury with its face away from Earth. Prior to the MESSENGER mission (MErcury Surface Space ENvironment and Ranging Mission), scientists didn’t know anything about Mercury, the smallest planet in the solar system, despite its being our closest neighbour. The permanent shadows of Mercury’s surface allows ice to grow. Image: Nature. John Grunsfeld is the Associate Administrator for NASA Headquarters’ Science Mission Directorate in Washington. He said that while spacecraft operations are ending, we celebrate MESSENGER as much more than a successful mission. This is the start of a long journey to analyse the data and uncover all of the mysteries about Mercury.” The spacecraft traveled for over 6 1/2 years, before reaching Mercury’s orbit on March 2011.. The spacecraft’s primary mission was to orbit small Earth and gather data for one year. NASA says that the spacecraft was healthy and had enough fuel to carry on its mission. New questions and additional information raised by early discoveries led to two operations extensions. One of the most significant achievements of the MESSENGER missions was in 2012,, when convincing evidence was provided to Earth that Mercury contained plenty of frozen water in its permanent shadowed polar craters. This was also the year when planetary scientists began to understand the mechanisms by which the water and chemical building blocks of life on the outer planets. The dark layer covering most of the water-ice deposits is consistent with the idea that water and other organic compounds on the inner planets are derived from the outer solar systems. This could have been the catalyst for prebiotic chemical synthesizing, which ultimately led to the emergence of life on Earth. Artist’s rendering of the MESSENGER spacecraft orbiting Mercury. Image: Wikipedia. Sean Solomon is the principal investigator at Columbia University’s Lamont-Doherty Earth Observatory (Palisades), MESSENGER mission. He stated that the water stored in the ice floors in impact craters at Mercury poles was most likely delivered to the planet’s innermost by impacts from comets or volatile-rich asteroids. Those impacts likely also delivered dark organic material.” Several firsts Technological firsts The MESSENGER missions has a long list of impressive scientific discoveries. It also developed the ceramic sunshade, which shields electronics and instruments from the direct sunlight, which is extremely high due to Mercury’s close proximity to the Sun. NASA claims this technology will aid in planning future missions to the Solar System. Helene Winters is the Mission Project Manager for APL. She stated that the front of the sunshade experienced extreme temperatures 300deg Celsius deg Fahrenheit, while the rest of its components operated at room temperature degF. Scientists were surprised by the high levels of volatile elements found in Mercury. These are liquids that can evaporate quickly. Alexandra Witze, a nature author, quoted Sean Solomon as saying: “The biggest surprise was the large abundances of volatile elements. All the theories about Mercury’s formation predicted it would have a low level of volatile elements, similar to the Moon. Instead, however, we find ten-times the Earth’s average amount of sulphur. There is also sodium and potassium. We also see chlorophyll, which is one of the most volatile element that we can measure.” This means that we didn’t really understand how Mercury was made an iron-rich world. The process that drove out the volatile elements wasn’t one with high sustained temperatures. NASA Video – Mercury Formation – I doubt the last chapter is written.
