Observers who watched the full eclipse of the moon in January spotted a rare event, a short-term flash as a meteorite hit the surface of the moon. Spanish astronomers now think that the space rock collided with the moon at 61,000 kilometers per hour, digging a crater of 10 to 15 meters. Prof. Jose Maria Madedo of the University of Huelva and Dr. Jose L. Ortiz of the Institute of Astrophysics of Andalusia, publish their results in a new paper in the Monthly notifications by the Royal Astronomical Society.
Total lunar eclipses occur when the moon is completely moving in the shadow of the Earth. The moon takes a red color – the result of a scattered sunlight broken through the Earth's atmosphere-but is much darker than the normal one. These spectacular events are regularly observed by astronomers and the general public.
The latest eclipse of the moon occurred on January 21, 2019, with observers in North and South America and Western Europe enjoying the best view. At 0441 GMT, immediately after the entire eclipse phase, a flash appeared on the Moon's surface. Widespread reports from amateur astronomers pinpointed the flash – attributed to the impact of the meteorite – was light enough to be seen with the naked eye.
Madiedo and Ortiz are working on the Moon's Detection and Analysis System (MIDAS), using eight telescopes south of Spain to monitor the surface of the moon. The impact block lasted 0.28 seconds and was first captured during the eclipse of the Moon, despite numerous previous attempts.
"Something inside me has told me that this time will be a time," said Madiode, who was impressed when he watched the event because it was brighter than most of the events that were regularly discovered by the research.
Unlike Earth, the moon has no atmosphere to protect it, and even small rocks can hit its surface. As these influences take place at huge speeds, the rocks are currently evaporating at the point of impact, creating an expanded outflow of residues whose luster can be detected by our planet as short-lived lashes.
MIDAS telescopes have monitored the impact of flash on multiple wavelengths (different light colors), improving the analysis of the event. Madiedo and Ortiz conclude that the entrance rock had a mass of 45 kilograms, measured from 30 to 60 centimeters wide, and struck a surface of 61,000 kilometers per hour. The place of influence is close to the crater Lagrange X, near the western and southwestern part of the lunar limb.
Both scientists estimate the impact energy equivalent to 1.5 tons of TNT, enough to create a crater up to 15 meters, or about the size of two double-decker buses side by side. It is estimated that the ejected remains reached a peak temperature of 5400 degrees Celsius, approximately the same as the surface of the Sun.
Madedo commented: "It would be impossible to reproduce these high-speed collisions in a laboratory on Earth. Observation strikes are a great way to test our ideas of what happens when a meteorite collides with the moon."
The team plans to continue to monitor the impact of the meteorite on the Moon's surface, and not only to understand the risk it represents to astronauts, who should return to the moon in the next decade.
MIDAS videos recorded the moment of impact.
Materials provided by Royal Astronomical Society. Note: The content can be edited for style and length.