With no equivalent in the Holocene or late Pleistocene sedimentary record, modern incised stream channel forms in the mid-Atlantic US south of Pleistocene ice margins represent a transient response to major changes in land use and anthropogenic base-level forcing that began centuries ago. Walter and Merritts (2008) documented late 17th-early 20th c.
The Long Wavelength Array (LWA) is a new multi-purpose radio telescope operating in the frequency range 5-88 MHz with many different operational modes.
Earth's surface chemistry is controlled, at the most fundamental level, by mass exchanges occurring between the surface environment and the lithosphere. Although this has been recognized for more than 100 years, it has generally been assumed that erosion and recycling are the dominant process signals in the surviving rock record, and that erosion and destruction is roughly in balance with rates of sedimentation.
What was Earth like when life arose on our planet? Sedimentary rocks provide records of ancient environments, but the ever-active Earth did not preserve its oldest sediments. However, our neighboring world, Mars, did. Of course, we do not know whether Mars had life, but the planet has an older and accessible sedimentary rock record that can tell us something about environments that could be analogous to those of early Earth. The evidence that Mars has sedimentary rocks was first published in December 2000.
Separation of small amounts of melt from the residual solid and migration of that melt from deep beneath a mid-ocean ridge to its eruption at Earth’s surface require a transition from porous to channelized flow in order to preserve chemical and radiogenic disequilibrium. Chemically isolated, high-permeability melt conduits in Earth’s upper mantle develop as a consequence of instabilities in the deformable, dissolvable porous media.
Much of modern wine making in the luxury segment of the wine industry would seem familiar to a winemaker of 100 years ago. Behind the familiar, though, are new methods that are aimed at consistently producing wines of the highest quality. The modern winemaker is surprisingly often a traditionalist with a solid understanding of soil science, plant physiology, biochemistry and chemistry.
Space research has long been limited by availability of platforms with which to conduct the scientific inquiry desired. In the case of space life sciences, that inquiry was initially driven by the desire to send humans into space (and have them survive), followed by interest in longer duration human space habitation, followed by a drive to understand what it will take to have humans inhabit other planets in our solar system for years or longer. At the same time, the availability o
I study meteorites in order to understand the processes that aided and guided the formation of small planetary bodies and planets in our solar system. One of the main themes of my research is to investigate, through isotopic analyses, raw materials that came together to form the solar system.
Size matters. In general as a spacecraft or instrument, the smaller you are, the less is the cost to get built, integrated, tested, and carried to your destination. People at JPL built the first smallsat, Explorer 1, but that was because that was all that Wernher von Braun’s U.S.
