ESA and Athens Observatory investigate meteoroid risks – What Lunar flashes reveal

How unsafe tin meteoroids — the objects that origin meteors, commonly known arsenic shooting stars — become? Although these tiny bodies usually pain up arsenic soon arsenic they participate Earth’s atmosphere, this is not the lawsuit extracurricular of it. When they collide astatine precocious speeds with different objects successful space, the consequences tin often beryllium catastrophic. A probe programme tally by the European Space Agency (ESA) and the National Observatory of Athens (NOA) is studying these impacts to fortify planetary defense.

The NELIOTA task (Near-Earth entity Lunar Impacts and Optical TrAnsients) has been underway since 2015 and has conscionable entered its 3rd phase. Its extremity passim each phases is to survey meteoroids — objects ranging successful size from a fewer millimeters to respective centimeters — which question astatine highly precocious speeds, from 15 to 60 kilometers per second. Their kinetic vigor is truthful large that they tin pierce metallic and truthful airs superior risks to artificial satellites and aboriginal lunar bases.

The Moon serves arsenic a earthy laboratory for this program. Because meteoroid speeds cannot beryllium reproduced successful terrestrial laboratories, the Moon — which has nary ambiance to shield it, meaning each meteoroids onslaught its aboveground — is the perfect investigating ground.

“We whitethorn beryllium studying the flashes created by impacts connected the Moon, but yet we privation to recognize what happens erstwhile objects of this size onslaught artificial satellites. There are present respective 1000 satellites orbiting Earth. Also, since humanity plans to physique lunar bases, it is important for america to cognize the consequences of specified impacts,” explains Dr. Alexios Liakos, probe subordinate astatine the Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing (IAASARS) of the National Observatory of Athens, and the technological pb of the program.

Since the programme began, 193 afloat confirmed flashes from impacts connected the Moon’s aboveground person been recorded, on with an further 103 campaigner events. By analyzing these flashes, scientists tin estimation the wide and radius of the impacting bodies, the size of the craters they make connected the Moon, and — for the archetypal clip — the temperatures produced by the impacts. For the 193 confirmed flashes, it was recovered that successful astir cases the impacting objects had a wide of little than 200 grams and a radius of astir 1–3 centimeters.

“Mass unneurotic with velocity gives america kinetic energy, which allows america to recognize the imaginable harm specified an entity could origin if it struck thing human-made — specified arsenic a spacecraft, an artificial satellite, oregon infrastructure connected the Moon. Also, the temperatures that make wrong tenths oregon hundredths of a second, reaching 3,000–4,000°C, assistance america prime materials for abstraction missions that tin withstand these abrupt somesthesia spikes,” Dr. Liakos notes.

The program’s 3rd phase, funded by Horizon Europe, began successful the summertime and volition past 3 years. A period ago, the squad resumed observations, and during the archetypal 4 nights they detected 5 imaginable lunar flashes, though lone 1 was afloat confirmed — the 193rd since the program’s inception.

The task is based astatine the Kryoneri Observatory successful Corinthia, Greece, wherever a 1.2-meter scope — the largest successful the satellite dedicated to observing the Moon — uses 2 precocious integer cameras to seizure images of the Moon astatine 30 frames per 2nd successful 2 antithetic wavelengths. This allows researchers to estimation the somesthesia of the flashes. An automated bundle strategy past analyzes the images to observe imaginable interaction flashes.

The programme volition effect successful the improvement of an open-access lunar interaction flash database, inviting the broader technological assemblage to contribute.

In summation to the ground-based NELIOTA observations, ESA is backing the LUMIO abstraction mission, successful which a tiny CubeSat outer volition beryllium launched successful precocious 2026 and sent to the Moon’s acold broadside to grounds lunar flashes. Dr. Alexios Liakos and Dr. Alkistis Bonanos — probe manager astatine IAASARS/NOA and erstwhile technological pb of NELIOTA — are participating successful the ngo arsenic technological advisors.