Skip to main content

Mystery behind Mercury’s darkness solved


  • Mercury appears to be dark due to the abundance of carbon that originated deep below the surface of our solar system’s innermost planet, a new study has found.
  • The planet reflects much less sunlight than the Moon, on which surface darkness is controlled by the abundance of iron—rich minerals that are known to be rare on Mercury’s surface, researchers said.
  • Researchers led by Patrick Peplowski of the Johns Hopkins University in US have confirmed that a high abundance of carbon is present at Mercury’s surface.
  • They have also found that the carbon most likely originated deep below the surface in the form of a now-disrupted and buried ancient graphite-rich crust, some of which was later brought to the surface by impact processes after most of Mercury’s current crust had formed.
  • The researchers obtained data from NASA’s MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft, the first space mission designed to orbit Mercury.
  • “We used MESSENGER’s Neutron Spectrometer to spatially resolve the distribution of carbon and found that it is correlated with the darkest material on Mercury, and this material most likely originated deep in the crust,” said Larry Nittler, from Carnegie Institution of Washington.
  • “We used both neutrons and X-rays to confirm that the dark material is not enriched in iron, in contrast to the Moon where iron-rich minerals darken the surface,” said Nittler, who is also Deputy Principal Investigator of the MESSENGER mission.
  • MESSENGER obtained its data via many orbits on which the spacecraft passed lower than 100 km above the surface of the planet during its last year of operation.
  • Neutron Spectrometer measurements showed higher amounts of low-energy neutrons, a signature consistent with the presence of elevated carbon, coming from the surface when the spacecraft passed over concentrations of the darkest material.
  • Combining the neutron measurements with other MESSENGER datasets, including X-ray measurements and reflectance spectra, Scientists found that Mercury’s surface rocks are made up of as much as a few weight per cent graphitic carbon, much higher than on other planets.
  • Graphite has the best fit to the reflectance spectra, at visible wavelengths, and the likely conditions that produced the material, researchers said. When Mercury was very young, much of the planet was likely so hot that there was a global “ocean” of molten magma.
  • Scientists have suggested that as this magma ocean cooled, most minerals that solidified sank, except graphite, which would have been buoyant and floated to form the original crust of Mercury.

Comments

Popular posts from this blog

India’s challenge of securing the seas

Three recent events underline India’s efforts to highlight its growing maritime interests and ambitions in order to secure them unilaterally and in partnership with others. The first was the quiet release of the Indian Maritime Security Strategy (IMSS) titled  Ensuring Secure Seas   in October. The second was the holding of the combined senior commanders’ conference, with top officers from all three services, on board   INS Vikramaditya , the Indian Navy’s latest aircraft carrier and its largest platform, in December. The last and most recent was India’s hosting of its second International Fleet Review (IFR) at Visakhapatnam in early February. While the pomp and circumstance as well as the photo-ops of the IFR, which attracted naval vessels from 50 countries, predictably, created the biggest splash, its significance is best understood in tandem with the 185-page IMSS-2015. Although the document is simultaneously comprehensive, conservative and cautious, it conveys on...

Differences between Indus civilization & Vedic Culture

What were the Differences between Indus civilization & Vedic Culture? The Indus civilization and Vedic culture constitute two great corner stone's in the history of Indian culture and civilization. When we make a comparison between the two, we notice more differences than similarities. Our sources of information of the Harappan civilization are mainly archaeological, while the Vedic culture is mostly known from the literary sources - the Vedas. Differences: Harappans are said to have been the original inhabitants of India while the Aryans, the founders of Vedic culture, are believed to have come to India from Central Asia. The Harappan civilization was urban in nature as is evidenced by its town-planning, drainage system, and granary and so on. The Vedic culture was rural. There is almost complete absence of towns in the Rigvedic period. At best the Rigvedic Aryans lived in fortified places protected by mud walls; and these cannot be regarded as towns in the Harap...

India at 90th rank in terms of energy security, access: World Economic Forum

India  has been ranked at the  90th place in a list of 126 countries compiled by World Economic Forum (WEF) on the basis of their ability to deliver secure, affordable  and sustainable energy, which was topped by Switzerland . The latest  Global Energy Architecture Performance Index  Report, explored the energy architecture of 126 countries based on their ability to provide energy access across three dimensions of the "energy triangle" - affordability, environmental sustainability, security and access. The list was topped by Switzerland followed by Norway and Sweden in the second and third place, respectively. Others in the top 10 include France (4th), Denmark (5th), Austria (6th), Spain (7th), Colombia (8th), New Zealand (9th) and Uruguay (10th). Among the BRIC nations, Brazil was the top performer as it was ranked at the 25th place, followed by Russia (52nd), India (90th), China (94)y. Regarding India, the report noted that it is "facing a vast array o...