Credit: ESA/Hubble and NASA; Acknowledgement: Judy Schmidt
Despite being less famous than their elliptical and spiral galactic cousins, irregular dwarf galaxies, such as the one captured in this NASA/ESA Hubble Space Telescope image, are actually one of the most common types of galaxy in the universe. Known as UGC 4459, this dwarf galaxy is located 11 million light-years away in constellation of Ursa Major (The Great Bear), a constellation that is also home to the Pinwheel Galaxy (M101), the Owl Nebula (M97), Messier 81, Messier 82 and several other galaxies all part of the M81 group.
UGC 4459’s diffused and disorganized appearance is characteristic of an irregular dwarf galaxy...
The amazing stereo view combines 2 images from the Ralph/Multispectral Visible Imaging Camera (MVIC) taken about 14 minutes apart on July 14, 2015. The first was taken when New Horizons was 16,000 miles away from Pluto, the second when the spacecraft was 10,000 miles away. Best resolution is approximately 1,000 feet Credits: NASA/JHUAPL/SwRI
One of the strangest landforms spotted by NASA’s New Horizons spacecraft when it flew past Pluto last July was the “bladed” terrain just east of Tombaugh Regio, the informal name given to Pluto’s large heart-shaped surface feature.
The blades are the dominant feature of a broad area informally named Tartarus Dorsa. They align from north to south, reach hundreds of feet high and are typically spaced a few miles apart...
Schematic representation of the four stages of CaSO4 formation.
A new explanation of how gypsum forms may change the way we process this important building material, as well as allow us to interpret past water availability on other planets such as Mars. Gypsum (CaSO. 4· 2H2O) is an economically important mineral, extensively used as the commercial construction material Plaster of Paris, with a global production of ~100 billion kg per year. It is a ubiquitous mineral on the Earth’s surface, and is also found on the surface of Mars. Despite its importance, until now we have not understood how gypsum grows from ions in solutions.
The formation of gypsum, from concentrated aqueous solutions of calcium sulfate, was thought to be a simple, single-step process. However, a group of European geochemists has now shown that gypsum forms through a complex 4-step process: the understanding of this process opens the way to more energy efficient production of plaster.
The multinational team examined the process using in situ and time resolved synchrotron-based X-ray scattering at Diamond Light Source (Harwell, UK), and identified and quantified each of the 4 steps of the formation process, highlighting specially that the initial moments in the reaction chain are of particular importance, because they determine the final properties of gypsum. In this 1st step, tiny sub-3 nm elongated particles form the primary building blocks (bricks). In subsequent steps these bricks aggregate, self-assemble and rearrange themselves, and finally transform to gypsum crystals.
“Importantly, we envisage that it is possible to alter this pathway by specifically targeting individual stages. For example we could arrest the reaction at the first stage when only nano-bricks are formed, and thus directly synthesise a highly reactive precursor to Plaster of Paris” said Dr. Thomas Stawsky. Since plaster is normally produced by the energy-intensive heating of gypsum, such an approach would drastically reduce the cost of production, and significantly decrease the carbon footprint of the industry.
“We know that gypsum is naturally found on Mars, so applying our current finding will also help us understand and predict the hydrological conditions at the time of gypsum formation on other planets,” said Professor Liane G. Benning. http://www.eurekalert.org/pub_releases/2016-04/eaog-sdh032916.php
This images shows sediment-filled craters on Mars (top) in different stages of erosion compared with results of a crater model in a wind tunnel experiment (bottom). Warm colors reflect high elevation, and cool colors low elevation. Credit: Mackenzie Day
New research has found that wind carved massive mounds of more than a mile high on Mars over billions of years. Their location helps pin down when water on the Red Planet dried up during a global climate change event. The findings show the importance of wind in shaping the Martian landscape, a force that, on Earth, is overpowered by other processes.
“On Mars there are no plate-tectonics, and there’s no liquid water, so you don’t have anything to overprint that signature and over billions of years you get these mounds, which speaks to how mu...
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