[meteorite-list] NASA's LRO Spacecraft Finds March 17, 2013 Impact Crater and More

[Ron Baalke]

http://www.nasa.gov/content/goddard/nasas-lro-spacecraft-finds-march-17-2013-impact-crater-and-more/

NASA's LRO Spacecraft Finds March 17, 2013 Impact Crater and More
March 17, 2015

NASA's Lunar Reconnaissance Orbiter (LRO) acquired images of the lunar 
surface before and after the largest recorded explosion occurred on the 
surface.

On March 17, 2013, an object the size of a small boulder hit the surface 
in Mare Imbrium and exploded in a flash of light nearly 10 times as bright 
as anything ever recorded before.

This bright flash was recorded by researchers at NASA's Marshall Space 
Flight Center in Huntsville with coordinates 20.6°N, 336.1°E. The Lunar 
Reconnaissance Camera (LROC) scientists were able to obtain observations 
before and after the impact. Comparing the actual size of the crater to 
the brightness of the flash helps validate impact models.

LROC's first set of post-impact flash images acquired on May 21, 2013 
by the Narrow Angle Camera (NAC) were targeted on the Marshall-reported 
coordinates and numerous small surface disturbances (“splotches”) were 
detected by comparing the pre- and post-flash images, but no new crater 
was found.

A second set of NAC images was acquired on July 1, 2013, showing three 
faint ray-like features and several chains of splotches and asymmetric 
splotches that generally pointed to a common area west of the Marshall 
coordinates. A NAC pair was targeted on that convergence point for July 
28, 2013; comparison of this third set of images with preexisting coverage 
revealed a new crater.

Before and After Images: 
[Images]
Caption: 
This image pairing shows a lunar impact crater created on March 17, 2013. 
The two images are from the LROC instrument aboard NASA's Lunar Reconnaissance 
Orbiter. The left image is from Feb. 12, 2012, and the right image is 
from July 28, 2013. The new crater is about 59 feet wide. Click and drag 
the slider bar to swipe between the two images.
Image Credit: 
NASA/Goddard Space Flight Center/Arizona State University

The crater itself is small, measuring 18.8 meters (61.7 feet) in diameter, 
but its influence large; debris excavated by the sudden release of energy 
flew for hundreds of meters. More than 200 related surficial changes up 
to 30 kilometers (19 miles) away were noted.

The results are published in the January 31 edition of the journal Icarus.

The March 17 impact crater is one of thousands of craters being mapped 
by the instrument. The LROC team is going back to images taken in the 
first year or two and comparing them to recent images. Called temporal 
pairs, these before/after images enable the search for a range of surface 
changes, including new impact craters, formed between the time the first 
and second image were acquired.

As of January 1, 2015, LROC has acquired about 10,000 before and after 
image pairs.

Launched on June 18, 2009, LRO has collected a treasure trove of data 
with its seven powerful instruments, making an invaluable contribution 
to our knowledge about the moon. LRO is managed by NASA's Goddard Space 
Flight Center in Greenbelt, Maryland, for the Science Mission Directorate 
at NASA Headquarters in Washington.

To download the visualizations of these impacts, visit:

http://svs.gsfc.nasa.gov/goto?4242

To read more about the March 17, 2013, impact crater, visit LROC's website:

http://lroc.sese.asu.edu/posts/770
 

Nicole Cassis
Arizona State University, Tempe

Nancy Neal Jones
NASA's Goddard Space Flight Center, Greenbelt, Maryland