Max Planck Institute for Chemistry

Max Planck Institute for Chemistry

In the atmosphere, everything has to do with everything else – and all of it has to do with chemistry. Scientists at the Max Planck Institute for Chemistry in Mainz therefore study topics such as how ozone or organic substances produced by plants affect the climate. Or the role played by aerosols, tiny airborne particles, in the formation of clouds and rainfall. Generally, the scientists focus on the study of the chemical – and physical – processes in the Earth system, and particularly in the interplay between the atmosphere, oceans, land and biosphere. In so doing, they measure data across the globe, conduct lab tests and construct models of the systems under examination. Another topic of interest is geochemistry: using the chemical characteristics in rocks and sea water, the scientists study the past and present-day processes in the Earth system, for instance, from a climate perspective.

Contact

Hahn-Meitner-Weg 1
55128 Mainz
Phone: +49 6131 305-0
Fax: +49 6131 305-1309

PhD opportunities

This institute has an International Max Planck Research School (IMPRS):
Max Planck Graduate School (MPGS) at MPI for Chemistry

The Max Planck Graduate Center (MPGC), which is managed in cooperation with the Johannes Gutenberg University Mainz, constitutes a framework for diverse dissertation topics supervised at several of the University’s established faculties. The MPGC thus constitutes a virtual interdisciplinary faculty with its own regulations for the award of doctoral degrees.

Reducing manure and fertilizers decreases atmospheric fine particles
A decrease of agricultural ammonia emissions avoids mortality attributable to air pollution more
The myth of the pristine Amazon rainforest
Indigenous inhabitants shaped the rainforest by domesticating tree species in pre-Columbian times more
Amazon rain helps make more rain
In the Amazon region, downdrafts bring aerosol particles from higher altitudes to the atmospheric layer where clouds form. more
Suspense in the movie theatre air

Suspense in the movie theatre air

Forschungsmeldung May 12, 2016
Cinemagoers' exhaled breath reveals the scene that is playing more
Climate-exodus expected in the Middle East and North Africa
Part of the Middle East and North Africa may become uninhabitable due to climate change more
The effect of bacterial ice nuclei

The effect of bacterial ice nuclei

Forschungsmeldung April 23, 2016
Bacteria induce the formation of ice crystals by changing the order and dynamics of surface water molecules more
Why nerve cells die

Why nerve cells die

Forschungsmeldung January 12, 2016
Protein aggregates in cytoplasm interfere with important transport routes more
Elemental metamorphosis

Elemental metamorphosis

Forschungsmeldung December 17, 2015
With very high pressure chemical elements could be examined under new aspects more
More deaths due to air pollution

More deaths due to air pollution

Forschungsmeldung September 16, 2015
Air pollution could claim 6.6 million lives by 2050 more
Protection for Brazilian wetlands

Protection for Brazilian wetlands

Forschungsmeldung September 13, 2015
A study involving Max Planck researchers creates the basis for new regulations more
Middle East: The atmospheric signs of the crises

Middle East: The atmospheric signs of the crises

Forschungsmeldung August 19, 2015
A study shows how armed conflicts, political and economic crises and also environmental legislation impacts air quality in the Middle East. more
Superconductivity: No resistance at record temperatures
Hydrogen sulfide loses its electrical resistance under high pressure at minus 70 degrees Celsius more
<p>New source of greenhouse gases discovered</p>

New source of greenhouse gases discovered

Forschungsmeldung July 14, 2015
Lichens, mosses and cyanobacteria produce large amounts of nitrous oxide more
At least 40,000 tree species in the tropical forests
Study surprises with new numbers: forests of the Indo-Pacific region are as rich in species as the tropics in America more
High tech at a lofty height

High tech at a lofty height

Forschungsmeldung December 11, 2014
A 325-metre-high climate research tower is being built in the Amazon rainforest more
Each grain is different

Each grain is different

Forschungsmeldung August 14, 2014
The interstellar dust particles from the Stardust mission show great variations in their elemental composition and structure more
At the methane source of plants

At the methane source of plants

Forschungsmeldung June 25, 2014
Plants produce greenhouse gas from the amino acid methionine more
Terror bird was frightening but harmless

Terror bird was frightening but harmless

Forschungsmeldung September 10, 2013
The prehistoric bird Gastornis was probably not a bird of prey but a herbivore more
Sulfate aerosols cool climate less than assumed

Sulfate aerosols cool climate less than assumed

Forschungsmeldung May 14, 2013
Life span of cloud-forming sulfate particles in the air is shorter than assumed due to a sulfur dioxide oxidation pathway which has been neglected in climate models so far more
Methane source discovered in the underbrush

Methane source discovered in the underbrush

Forschungsmeldung September 05, 2012
Greenhouse gas is also released by fungi more
More carbon dioxide leads to less clouds

More carbon dioxide leads to less clouds

Forschungsmeldung September 03, 2012
A new feedback mechanism operating between vegetation and cloud formation could enhance the climate change more
How salt in the rainforest becomes clouds

How salt in the rainforest becomes clouds

Forschungsmeldung August 30, 2012
Potassium salts from fungi and plants initiate the formation of aerosol particles upon which moisture from the air condenses more
Increase of air pollution

Increase of air pollution

Forschungsmeldung August 01, 2012
Atmospheric model calculates changes in air quality for a large portion of the world’s population over the coming decades more
Wallflowers of the Earth system

Wallflowers of the Earth system

Forschungsmeldung June 01, 2012
Algae, lichens, and mosses take up huge amounts of carbon dioxide and nitrogen from the atmosphere and thus also influence the climate more
Methane on Mars is not an indication for life

Methane on Mars is not an indication for life

Forschungsmeldung May 31, 2012
Intense UV radiation on the red planet releases methane from organic materials which meteorites transport onto its surface more
Probability of contamination from severe nuclear reactor accidents is higher than expected
Western Europe has the worldwide highest risk of radioactive contamination caused by major reactor accidents more
Glass sponge as a living climate archive

Glass sponge as a living climate archive

Forschungsmeldung April 04, 2012
An 11,000 year-old deep-sea sponge provides a record of past environmental changes in the sea more
Catalyser for clean rainforest air

Catalyser for clean rainforest air

Forschungsmeldung February 29, 2012
Plant odour isoprene buffers atmospheric self-cleaning capacity more
The chemistry of exploding stars

The chemistry of exploding stars

Forschungsmeldung January 19, 2012
Meteorite contains evidence of formation of sulfur molecules derived from the ejecta of a supernova explosion more
Megacity emissions sensed from space

Megacity emissions sensed from space

Forschungsmeldung October 05, 2011
The emissions of nitrogen oxides can be determined from satellite measurements of the pollution levels by using a mathematical trick more
Breathless in the Megacity

Breathless in the Megacity

Forschungsmeldung September 22, 2011
Together with an Indian Partner Group of the Max Planck Institute for Chemistry in Mainz, Bhola Ram Gurjar is analyzing the pollution in Indian megacities and how badly it is affecting the health of city dwellers. more
Nitrogen in the soil cleans the air

Nitrogen in the soil cleans the air

Forschungsmeldung August 19, 2011
Nitrogen-containing soil is a source of hydroxyl radicals that remove pollutants from the atmosphere more
Deep recycling in the Earth faster than thought

Deep recycling in the Earth faster than thought

Forschungsmeldung August 10, 2011
Sunken ocean crust resurfaces from Earth’s mantle after only 500 million years more
The hidden danger of oxygen

The hidden danger of oxygen

Forschungsmeldung February 17, 2011
Long-lived reactive oxygen intermediates that develop on particles in the atmosphere could explain why more and more people are suffering from allergies more
Atmosphere cleans itself more efficiently than previously thought
Concentration of pollutant-degrading hydroxyl radicals in the air remains stable worldwide more
Max Planck research protects the Amazon rainforest

Max Planck research protects the Amazon rainforest

Forschungsmeldung December 15, 2010
Extensive inventory forms basis for legislation governing when trees in the Brazilian rainforests can be logged more
The Amazon rainforest - a cloud factory

The Amazon rainforest - a cloud factory

Forschungsmeldung September 20, 2010
Scientists demonstrate that atmospheric aerosols above the Amazon rainforest are mainly produced by biological sources and are able to draw conclusions about the mechanisms of this ecosystem more
Dust which makes clouds grow<br />

Dust which makes clouds grow

Forschungsmeldung February 23, 2010

Aerosols are the salt in our climate soup. Step by step climate researchers find out the manyfold ways, in which the tiny particles in the atmosphere affect the formation of clouds and precipitation.

more
Moderate quantities of dirt make more rain

Moderate quantities of dirt make more rain

Forschungsmeldung September 09, 2008
An international team of scientists sums up the current effects of aerosols on precipitation more
Looking at methane sources in the right light

Looking at methane sources in the right light

Forschungsmeldung May 27, 2008
UV radiation and rising temperatures increase methane emissions from plants more
The Treasure in Meteorites

The Treasure in Meteorites

Forschungsmeldung May 10, 2006
American-German research team finds interstellar organic materials in meteorites more
New Software for Modelling Earth Systems

New Software for Modelling Earth Systems

Forschungsmeldung November 17, 2005
2005 Billing Prize for scientific computation goes to the Max Planck Institute for Chemistry's "Modular Earth Submodel System (MESSy)" more
What actually influences air pollution over the Indian Ocean?
Scientists from the Max Planck Institute for Chemistry detect substantial pollution of the atmosphere during periods between summer or winter monsoons more
Increasing Ozone over the Atlantic Ocean

Increasing Ozone over the Atlantic Ocean

Forschungsmeldung May 13, 2004
Max Planck Scientists discovered that ozone smog is increasingly a global problem more
&quot;Smoking&quot; Rain Clouds over the Amazon

"Smoking" Rain Clouds over the Amazon

Forschungsmeldung February 27, 2004
Forest fires in the Amazon rainforest intensify turbulence in the weather and could have global impact, report German Max Planck scientists more
Astonishing discovery over the Amazon rainforest

Astonishing discovery over the Amazon rainforest

Forschungsmeldung February 25, 2004
International research team has discovered huge amounts of unexpected organic aerosols over the South-American tropical rain forests more
The fiery face of the Arctic deep

The fiery face of the Arctic deep

Forschungsmeldung July 18, 2003
Results from a German-American Arctic expedition to the Gakkel Ridge have implications for the understanding of the generation of new seafloor more

Hot Air in the Orient

4/2016 Environment & Climate

The Middle East and North Africa are currently being rocked by armed conflicts and political crises. But even if these were to be resolved, many people there will likely be forced to leave their homes in the coming decades. Jos Lelieveld, Director at the Max Planck Institute for Chemistry in Mainz, and his colleagues are predicting that the region will see dramatic climate change and an increase in air pollution, including airborne desert dust.

Tracing the Noxious Five

3/2013 Environment & Climate
In many regions of the world, air pollution is set to worsen in the decades to come. Jos Lelieveld and his colleagues at the Max Planck Institute for Chemistry in Mainz forecast where this will happen. Their studies of atmospheric chemistry also uncover the unexpected effects of some substances.

Greenhouse Gas from the Garden

2/2013 Environment & Climate
It is commonly thought that methane forms either chemically, at high pressure or temperature, or as a product of microbial activity. But there are also other ways. Junior scientists working with Frank Keppler from the Max Planck Institute for Chemistry in Mainz discovered unexpected sources of methane: plants, fungi, soil – and even meteorites.
The Kaiser Wilhelm Institute for Chemistry opened its doors in Berlin-Dahlem 100 years ago. Just three years later, it produced its first Nobel laureate: Richard Willstätter had worked out the structure of chlorophyll. However, the research facility, later reborn as the Max Planck Institute for Chemistry in Mainz, became world-famous through the discovery of nuclear fission.

Elemental Metamorphosis

MPR 4/2012 Physics & Astronomy
The inside of planets, stellar shells and numerous other uncomfortable spots in space have one thing in common: matter there is under extreme pressure of several million atmospheres. Mikhail Eremets and his colleagues produce such cosmic pressures in their lab at the Max Planck Institute for Chemistry in Mainz – and they do so in surprisingly simple experiments. They are researching which unique transformations gases, but also metals, undergo under these conditions.
The setting in which researchers at the Max Planck Institute for Chemistry study which substances plants exchange with their environment is artificial, yet still as natural as possible. Nina Knothe, who works at the Mainz-based institute, is preparing such an experiment at the Max Planck Society’s sub-institute in Manaus, in the Brazilian Amazon rainforest, by checking the lighting conditions in a cuvette covered with an airtight film.
Megacities offer the enticing prospect of employment and the benefits of an urban infrastructure – but they also expose their inhabitants to high levels of air pollution. Together with an Indian Partner Group of the Max Planck Institute for Chemistry in Mainz, Bhola Ram Gurjar is analyzing this pollution and how badly it is affecting the health of city dwellers.
When the astronauts of the Apollo 11 mission returned to Earth, they had almost 22 kilograms of rock from the surface of the moon in their baggage. Josef Zähringer from the Max Planck Institute for Nuclear Physics in Heidelberg was one of the first researchers allowed to analyze the material in the US. Two months later, Heinrich Wänke’s team at the Max Planck Institute for Chemistry in Mainz also received a grain.
No, the sky is not falling, but it does occasionally rain down cosmic chunks. And these are an enrichment for research.
Researchers embarked on board a research vessel to investigate the gas emissions of phytoplankton.
The Amazon region cleans the atmosphere, keeps the global atmospheric cycle running and stores water on a grand scale. These are just three reasons why the Max Planck Society main-
tains a branch in Manaus, in the heart of the Amazon region.
Once a year, atmospheric chemists travel by train from Moscow to Vladivostok and collect data on the concentration of surface-level climate-relevant trace gases.
No job offers available

Radicals in the dark: NO3 and the nighttime chemistry of the troposphere

2017 Crowley, John; Lelieveld, Jos
Chemistry Climate Research Earth Sciences
Atmospheric chemistry does not stop at sunset but continues via the formation and reactions of the NO3 radical. Whilst this dark chemistry is distinct from that during the day, the day-night systems are strongly coupled. Understanding the present composition of the troposphere and the ability to predict the impact of increasing anthropogenic emissions in the future require detailed understanding of the multifarious gas-phase and heterogeneous processes, both night and day. more

Beijing winter haze and its formation mechanism

2016 Cheng, Yafang; Su, Hang; Pöschl, Ulrich
Chemistry Climate Research Earth Sciences
Extreme haze episodes shrouded Beijing during the winter of 2013, causing major environmental and health problems. We show that the severe winter haze was driven by stable synoptic meteorological conditions rather than by an abrupt change of emissions; the fast build-up of PM2.5 in Beijing was mainly controlled by the atmospheric transport; and the production of secondary aerosols is enhanced during the haze periods. This enhancement cannot be explained by the weakened photochemistry suggesting a missing source of PM2.5, which is likely the heterogeneous reaction. more

Fire and smoke: observed with satellite eyes

2015 Kaiser, Johannes W.; Heil, Angelika
Chemistry Climate Research Earth Sciences
Scientists at the Max Planck Institute for Chemistry develop methodologies for the estimation of emissions from forest, savannah and other vegetation fires from satellite observations. The EU-funded, open access Copernicus Atmosphere Monitoring Service calculates global daily biomass burning emissions with these methodologies, and their impact on the global atmospheric composition and the European air quality every day. The calculations are also used for the monitoring of global climate change. more

Glass sponges – a new paleoclimate archive

2014 Jochum, Klaus Peter; Andreae, Meinrat O.
Chemistry Climate Research Earth Sciences
Scientists of the Max Planck Institute for Chemistry in Mainz have investigated up to 2.70 m long giant spicules of the deep-sea glass sponge Monorhaphis chuni by new microanalytical techniques. They showed that the lifespan of these biogenic silica structures can be up to 13,000 years. Giant spicules therefore offer a unique opportunity to record changes of past oceanic and climatic conditions. more

Air quality in the Anthropocene

2014 Lelieveld, Jos; Pozzer, Andrea
Chemistry Climate Research Earth Sciences
Calculations using a global Earth chemistry model show that about 80 % of the population worldwide is exposed to fine particulate matter concentrations that are higher than the guideline concentration by the World Health Organization (10 µg/m3) and 35 % to more than 25 µg/m3 (EU Directive). Presently, gaseous and particulate air pollution causes about 3.4 million premature deaths per year. In the coming decades air pollution and related public health impacts are projected to increase particularly rapidly in South and East Asia and in the Middle East. more

Fungi – a recently discovered source of methane

2013 Lenhart, Katharina; Keppler, Frank
Climate Research Ecology Microbiology
Large amounts of methane are produced in the biosphere and released into the atmosphere. The junior research group ORCAS at the Max Planck Institute for Chemistry explores new sources of methane in the environment and describes the underlying formation mechanisms. Fungi are an important component of terrestrial biological communities. Just recently, the researchers showed that fungi also release methane in their metabolism. But it is still unknown to what extent this new source of methane contributes to the methane balance of terrestrial ecosystems. more

Landuse and drylands – spatio-temporal measurements of biogenic nitric oxide emissions from soils

2013 Mamtimin, Buhalqem; Behrendt, Thomas; Badawy, Maowad; Qi, Yue; Meixner, Franz X.
Chemistry Climate Research Microbiology
The biogenic emission of nitric oxide (NO) from natural and agriculturally managed soils of the terrestrial drylands is largely unknown, but of high importance for the local and regional air chemistry. The basic spatio-temporal scales of NO-emission ranges from a few cm2 to km2, and from some minutes to months. A full suite of experimental methods (laboratory incubation of soil samples to remote sensing) is applied to cover these scales for overlapping quantification of the unknown NO-emissions. more

CARIBIC, a flying observatory for efficient exploration of global atmospheric chemistry

2012 Brenninkmeijer, Carl A. M.
Chemistry Climate Research
The Earth’s atmosphere is a complex system with a multitude of physical and chemical processes. To better understand this system a wide range of gases present at very low concentrations must be measured. This not only means the use of a range of measurement equipment. To track chemical changes in the atmosphere, long term, regular measurements on a global scale are needed. The Max Planck Institute for Chemistry has in cooperation with Lufthansa Airlines developed a unique measurement container which carries out measurements on a monthly basis as airfreight during long range flights. more

Studies on the role of vegetation exchanging nitrogen dioxide with the atmosphere

2012 Kesselmeier, Jürgen
Chemistry Climate Research Plant Research
The exchange of nitrogen dioxide (NO2) between vegetation and the atmosphere was studied with six tree species under controlled laboratory conditions. Additionally, two tree species were investigated under field conditions. Uptake was found to be strongly correlated with plant stomatal aperture (conductance). Upon stomatal closure uptake was decreasing to zero. Uptake rates exhibited a linear dependency with the ambient NO2 concentration. The data contradict the existence of a compensation point for natural ecosystems and underline the role of vegetation as a sink for this trace gas. more

The photochemical production of ozone in the troposphere

2011 Fischer, Horst; Bozem, Heiko; Lelieveld, Jos
Chemistry Climate Research
Ozone plays an important and multi-facetted role in the chemistry of the troposphere. Depending on the concentration of nitrogen oxides it can be photochemically produced or destroyed. The net ozone tendency is the residue of large production and destruction terms. State-of-the-art airborne measurements of trace gases over South America and Europe allow a direct determination of the gross ozone tendencies. more

Global monitoring of volcanic emissions with satellite instruments

2011 Wagner, Thomas; Hörmann, Christoph; Penning de Vries, Marloes; Sihler, Holger
Chemistry Climate Research Earth Sciences
Volcanoes have a large impact on life on earth. Besides their direct influence they are also important for atmospheric chemistry and climate. Since several years, satellite observations provide a completely new view on volcanic emissions of gases and aerosols. Current retrieval methods are sensitive enough to allow even the observation of emissions from weak eruptions or continuous outgasing. In this article we provide an overview on the current status of satellite remote sensing of volcanic emissions. Also a case study on the eruption of the Sarychev Peak in June 2009 is presented. more
An increasing number of people are living in the growing cities of this world. This results in a rapid growth of the fraction of anthropogenic emissions of pollutants from such megacities. For a detailed investigation of the particulate and gaseous substances in the atmosphere in such a city and in its vicinity, extensive measurements were performed in the metropolitan area of Paris. The study of the transformation and aging processes of such species was done using modern instrumentation in a ground measurement station, on a research aircraft, and on a mobile laboratory for aerosol research. more

The air above the green lung rainforest

2010 Andreae, Meinrat O.; Trebs, Ivonne; Meixner, Franz X.; Kesselmeier, Jürgen; Pöschl, Ulrich
Chemistry Climate Research
The exchange of reactive trace gases and aerosol particles between biosphere and atmosphere contributes substantially to chemical and physical processes in the atmosphere. Recent investigations provide insight into the interplay of reactive nitrogen compounds, volatile organics and aerosol formation. The results underline the major importance of the Amazonian rainforest for the global climate and the Earth system. more

Cosmic dust in the laboratory

2009 Hoppe, Peter
Astronomy
Cosmic dust is the carrier of a variety of astrophysical information. With mass spectrometric methods it is possible to study cosmic dust in the laboratory. Stardust, which is found in small quantities in meteorites and comets, provides detailed insights into the physics of the parent stars and in physical and chemical processes in the interstellar medium. Studies of cometary dust, which was recently collected and returned to Earth with the “Stardust” space probe, make it possible to reconstruct important aspects of the history of Solar System formation. more
Over most of the Earth´s surface the atmosphere is in direct contact with the ocean. Therefore, gas exchange at this interface has an enormous potential to influence global atmospheric chemistry. As part of the European project “OOMPH” researchers from the MPI for Chemistry crossed the “roaring forties” of the South Atlantic on board a research vessel and encountered a giant phytoplankton bloom which forms there every summer. An investigation of such pristine regions gives important clues about how the atmosphere functions in the absence of man-made pollution. more

MPI databases for earth and environmental scientists from all over the world

2008 Jochum, Klaus Peter; Sarbas, Bärbel
Chemistry Earth Sciences
Scientists of the Max-Planck-Institute for Chemistry have developed two geochemical databases, GEOROC and GeoReM, which are used by earth and environmental scientists from all over the world. The public databases are available online and contain tens of thousands published chemical analyses of geological and environmental samples as well as of nearly all (1600) international reference materials. more
With the launch of the satellite instrument ‘GOME’ in April 1995 it became possible for the first time to measure the distribution of several surface-near trace gases. In the derived ‘trace gas-worldmaps’ various emission sources can be identified and quantified. By comparison with numerical simulations it is possible to test and improve the budgets of atmospheric pollutants and greenhouse gases. more

Small particles with large effects on climate and health

2007 Pöschl, Ulrich
Chemistry Climate Research Medicine Microbiology
Aerosols are of central importance for atmospheric chemistry and physics, the biosphere, climate, and public health. The airborne particles influence the Earth’s energy balance, the cycling of water and trace gases, as well as the reproduction and diseases of biological organisms. Current investigations elucidate the relevant properties and mechanisms, especially for biogenic components. more
The junior research group has been examining several aspects of tropical tropospheric chemistry using two 3D models. Here an overview of the results is given, focusing particularly on two central activities of the group: 1) the outflow of pollutants from southern Asia and the factors controlling pollution over the Indian Ocean; 2) the role of deep convection in tropospheric chemistry, especially in the tropics, and its treatment in cloud-resolving and global models. more

Aerosol mass spectrometry – analysis of traffic related particle emissions

2006 Schneider, Johannes; Drewnick, Frank
Chemistry Earth Sciences
Novel in-situ mass spectrometric techniques offer new possibilities for the investigation of traffic related particle emissions. Measurements performed on an engine test facility showed that ultrafine particles (<100 nm) in diesel exhaust consist of freshly nucleated compounds as sulfuric acid and organics, which have been emitted as gaseous substances. Since it was found that the formation efficiency of these nucleation particles is strongly dependent on the fuel sulfur content, it was concluded that sulfuric acid plays a major role in this process. Measurements of mass concentrations and size distributions of various aerosol compounds in the vicinity of a German motorway and in New York City showed the various influences of traffic emissions on the composition of ambient aerosol in the different size ranges at different times. more

Anatomy of a mantle plume

2005 Hofmann, Albrecht W.; Sobolev, Alexander; Abouchami, Wafa; Galer, Stephen J.
Researchers of the Geochemistry Department developed a new model of melt production in a mantle plume to explain the enormous magma production of Hawaiian volcanoes. They also showed that the Hawaiian mantle plume is compositionally not purely concentric, but consists of two isotopically different halves. more

Synthesis of Polymeric Nitrogen

2005 Eremets, Mikhail I.; Gavriliuk, Alexander G.; Trojan, Ivan A.; Boehler, Reinhard
We report on an allotropic form of nitrogen where the atoms are connected with single covalent bonds, similar to carbon atoms in diamond. Nitrogen under ambient conditions consists of molecules where two atoms are strongly triple-bonded. The new substance was synthesized directly from molecular nitrogen at temperatures above 2,000 K and pressure above 110 GPa (ca. 1.1 million atmospheres) using a laser-heated diamond cell. From X-ray and Raman scattering we have identified this as the long-sought-after polymeric nitrogen with the theoretically predicted cubic gauche structure (cg-N). This cubic phase has not been observed previously in any element. The new phase is a stiff substance with bulk modulus ≥300 GPa, characteristic of strong covalent solids. This polymeric nitrogen is metastable, and contrasts with previously reported amorphous non-molecular nitrogen, which most likely is a mixture of small clusters of non-molecular phases. The cg-N represents a new class of single-bonded nitrogen materials with unique properties such as energy capacity: more than 5 times that of the energetically most powerful materials. more
The two NASA rovers "Spirit" and "Opportunity" are currently successfully exploring their landing sites Gusev crater and Meridiani Planum on Mars. On board are two Alpha-Particle-X-ray-Spectrometers (APXS), which determine in-situ the chemical and mineralogical composition of rocks and soils. The chemistry of the analyzed surfaces clearly provides evidence for a water-rich past on planet Mars. The volcanic rocks at Gusev crater are covered by a rind and are penetrated by veins that are enriched in elements, e.g., sulfur, chlorine and bromine, which occur as anions in water. The chemistry of the old rocks at the Columbia Hills is altered to such an extent that their indigenous composition is difficult to deduce. The Meridiani Planum landing site exhibits bedrocks which consist of sulfates of up to 40 percent by weight. They were possibly deposited under conditions similar to those encountered presently in desert areas of the Earth. more