Aftermath of biggest ever explosion to be seen on lunar surface: Images reveal the latest giant crater to appear on the moon
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Incredible before and after images have revealed a fresh lunar scar created by the biggest explosion ever recorded on the moon's surface.
The moon is pelted with cosmic debris all the time, but this relatively recent crater was created by an object the size of a small boulder.
Scientists watched the object explode as it hit the surface in Mare Imbrium creating a flash of light 10 times as bright as anything ever recorded on the moon before.
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Incredible before (left) and after (right) images reveal a fresh lunar scar created by the biggest ever explosion recorded on the moon surface. Slide the middle bar to see how the moon's surface changed after impact
When a meteoroid strikes the moon, a large portion of the impact energy goes into heat and excavating a crater.
However, part of it also goes into generating visible light, which results in a brilliant flash at the point of impact.
The images reveal intricate details of the resulting impact crater and could help scientists learn more about how craters form.
The brightest flash occurred on March 17, 2013 with coordinates 20.6°N, 336.1°E.
The team predicted the crater's size based on the energy, and then eagerly awaited Lunar Reconnaissance Orbiter Camera;s next pass over the location to confirm their calculations.
Being able to get observations before, during and after the impact is a valuable opportunity to understand impact events better.
Four different mages of a crater formed on the moon, March 17, 2013; each scene is 1837ft (560 metres) wide. The brightest flash occurred on March 17, 2013 with coordinates 20.6°N, 336.1°E
Comparing the actual size of the crater to the brightness of the flash helps validate impact models.
The crater itself is small, measuring 61.7ft (18.8 metres) in diameter, but its influence is large; debris excavated by the sudden release of energy flew for hundreds of metres.
More than 200 related surface changes up to 19 miles (30km) away were noted.
Not only did the LROC images reveal intricate details of ejecta distribution, but they also offered a valuable opportunity to study the structure of the top meter of the regolith.
Regolith is a term that refers to a soil that is lacking organic material.
The soil on the moon is formed slowly over time as micrometeorites impact the surface and slowly grind rocks into a fine powder.
As the fresh soil grains sit on the surface, they are exposed to radiation and slowly become darker and redder.
This is largely caused by a reduction of iron in minerals to iron metal – reverse of rusting that happens on Earth.
This slow change in reflectance and colour is generally referred to as space weathering; fresh soil is referred to as immature, and weathered soil is mature.
Several surprises were revealed in the before and after image pairs around the new crater.
Conventional thought predicted that the new crater should be surrounded by a high reflectance ejecta with some patchy debris spreading out two or three diameters.
'The high reflectance was there, but three other zones were discovered,' said Mark Robinson, a professor in ASU's School of Earth and Space Exploration and LROC's principal investigator.
'At the edge of the high reflectance ejecta was a low reflectance zone, then, beyond that, another high reflectance zone, and beyond that, another low reflectance zone.'
It's not easy to find new impact craters because most of them are very small. The only way to really do this is to have a before image and an after image to compare.
With the help of the automated tool, the team has identified 225 new impact craters ranging in size from 4.9ft to 140ft (91.5 meters to 43 metres) and over 25,000 small changes known as 'splotches'.
Using data from the Lunar Reconnaisance Orbiter's Lend tool (artist's impression pictured), Nasa scientists discovered the crater itself is small, measuring 61.7ft (18.8 metres) in diameter, but its influence is large; debris excavated by the sudden release of energy flew for hundreds of metres
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