Occurring March 17, it was the biggest explosion in the 8-year history of NASA’s Lunar Impact Monitoring program that shoots continual video of the moon through 14-inch telescopes on Earth. NASA announced the event on May 17 after an analyst noticed the strike on a digital video. Scientists estimate the meteor weighed 88 pounds, was about 16 inches wide, and hit the moon at 56,000 miles per hour.
Steve Roy, Marshall Space Flight Center
An artist’s rendering of a small but powerful meteor strike on the moon.
In this Q&A Smithsonian Geophysicist Bruce Campbell, of the Air and Space Museum’s Center for Earth and Planetary Studies, answers a few questions about the explosion and the geologic processes that shape the moon’s surface. For years Campbell has been using radio telescopes to see through the moon’s thick layer of dust and debris and create a detailed radar map of the moon’s ancient bedrock topography.Q: Can the crater caused by this impact be seen from Earth?
Campbell: There is erosion on the moon which is coming from the exact process that caused this new crater. Think about it, that new 20-meter crater obliterated all the little craters that were in that spot before it. And it threw out dust that covered up and smoothed out other areas.
But even when fresh bedrock from beneath the dust is exposed by very large meteorite strikes, these new rocks are eventually broken down by the little bits of space dust zipping in and striking the moon day in and day out. In general, these tiny particles are traveling extremely fast. Most hit the ground at 2 kilometers per second or more. Even a particle of dust that’s moving at several kilometers per second will break a pretty good chunk off a rock on the ground.
Undetectable from Earth, these little particles are the dominant erosive effect on the moon…on a cosmic time scale these particles are just raining in. This crater is just part of that endless process of the soil gradually building up and rocks on the surface being broken down and craters being smoothed out. If you look at the pictures, the moon’s features are very rounded with gentle slopes; there are almost no sharp-edged hills on the moon.
Alison Mitchell | Newswise
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Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
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Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
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Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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