MI weekly selection #5

Venus as captured by Mariner 10 in early 1974 | Credit: Wikimedia Commons

When a standard kilogram is not a kilogram

Tens of micrograms worth of surface contamination have caused the international standard kilogram to gain weight, according to new research, causing concern that each country’s standard weight for a kilogram is now slightly different. The cylinder-shaped piece of metal is key for scientific experiments that require exact measurements, and a different weight could throw off research. The study suggests that ozone and ultraviolet light could clean the weights without damage.


Peter Cumpson and Naoko Sano (2013) Stability of reference masses V: UV/ozone treatment of gold and platinum surfaces Metrologia 50 27 DOI: 10.1088/0026-1394/50/1/27

Zinc-based tablets for eye-treatment from the times of the Roman republic

Ancient tablets found in a shipwreck off the Italian coast may have been used to treat sore eyes, scientists say. The medicine was mostly zinc-based, similar to modern day’s use of zinc for eye and skin treatments, and may be the world’s oldest medical treatment to be analyzed. The Relitto del Pozzino, the cargo ship that wrecked around 140 B.C., featured a bevy of medical supplies, though the well-preserved medicine was a rare find, said one expert.


Gianna Giachia, Pasquino Pallecchia, Antonella Romualdia, Erika Ribechinib, Jeannette Jacqueline Lucejkob, Maria Perla Colombinib, and Marta Mariotti Lippic (2013) Ingredients of a 2,000-y-old medicine revealed by chemical, mineralogical, and botanical investigations PNAS DOI: 10.1073/pnas.1216776110

Unexpected Earth mantle dynamics: peridotite liquefies as deep as 250 km

A group of geologists has discovered that small amounts of peridotite, a common mineral in Earth’s mantle, can liquify under intense pressure. The findings help explain characteristics of mantle rock deep beneath the oceanic crust.

Our Amazing Planet

Rajdeep Dasgupta, Ananya Mallik, Kyusei Tsuno, Anthony C. Withers, Greg Hirth & Marc M. Hirschmann (2013) Carbon-dioxide-rich silicate melt in the Earth’s upper mantle Nature 493, 211–215 DOI:10.1038/nature11731

A microbe that could survive in Mars

Researchers found that a common Earth bacteria is able to thrive in a Mars-like environment, a development that opens doors for the type of life forms believed to be able to survive on Mars.. Scientists will still need to see if the microbe, Serratia liquefaciens, can survive the harsher realities of the Martian environment, including ultraviolet radiation and fewer water sources.


Andrew C. Schuerger, Richard Ulrich, Bonnie J. Berry, and Wayne L. Nicholson. (2013) Growth of Serratia liquefaciens under 7 mbar, 0°C, and CO2-Enriched Anoxic Atmospheres Astrobiology doi:10.1089/ast.2011.0811.

Magnetic ropes in the atmosphere of Venus

Massive flux ropes discovered in Venus’ atmosphere have scientists rethinking what they know about the planet’s magnetic properties. The large lines of magnetic fields have been seen in other planets, including Earth, but the discovery on Venus is unique because the planet does not have a significant magnetic field.


T. L. Zhang1, W. Baumjohann, W. L. Teh, R. Nakamura, C. T. Russell, J. G. Luhmann, K. H. Glassmeier, E. Dubinin, H. Y. Wei, A. M. Du, Q. M. Lu, S. Wang, M. Balikhin (2012) Giant flux ropes observed in the magnetized ionosphere at Venus Geophysical Research Letters Volume 39, Issue 23, December 2012 DOI: 10.1029/2012GL054236

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