Equivalent to the explosion of about 3 tons of explosives: the remains of the SpaceX rocket will crash on the moon

The object that will make its way to the lunar soil is the used upper stage of the Falcon 9 rocket, which was launched from the Kennedy Space Center in Florida on January 15, 2025. The rocket carried two private spacecraft destined to land on the moon, Blue Ghost of the American company Fairplay and Resilience of the Japanese company Aspace. After the spacecraft separated from it, the upper stage remained in a high and unstable orbit outside the lunar orbit.

The length of the rocket stage is about 12 meters, its diameter is about 4 meters and its estimated weight is about 4 tons. The energy that will be released at the moment of the collision is expected to be similar to the explosion of about 3 tons of TNT type explosive material. It is not an explosive charge or a planned explosion, but the transformation of the tremendous energy of movement into heat, shock waves, crushing of the rocket and the ejection of large amounts of lunar soil.

The initial flash is expected to last less than a second. The scientists estimate that it will be relatively weak, partly because the rocket will hit a lighted area of ​​the moon and the light reflected from the surface could hide it. Even an ordinary home telescope will not necessarily be able to capture the moment itself, and certainly it will not be possible to see it with the naked eye.

On the other hand, the researchers’ main interest is not in the flash but in the cloud that will form immediately after it. The collision is expected to throw dust, rock fragments and metal fragments high above the ground. Because the moon’s gravity is six times weaker than Earth’s and it has no atmosphere or wind, the particles may remain in the air for many minutes before falling back to the surface.

Computer simulations released ahead of the event suggest that the central dust curtain may reach a height of 15 to 20 kilometers. A narrower jet of fast particles may, in the optimistic scenario, rise to a height of 75 to 100 kilometers. Since the impact site is near the edge of the visible disk of the moon, it is possible that part of the dust cloud will protrude beyond the bright edge and be seen against the background of the dark space.

The best viewing conditions are expected in the eastern parts of the United States and Canada and large areas of South America, where the event will occur during the hours of darkness and the moon will be above the horizon. The researchers emphasize that even there there is no certainty that the cloud will be seen. Its exact brightness depends on the angle of impact, the composition of the ground, the direction in which the rocket will move at the last moment and the size of the dust grains that will be blown.

Professional astronomers plan to use high-speed cameras attached to telescopes, which will take many pictures every second. Amateur astronomers with appropriate equipment were also called to try to document the event. The observation should continue even after the moment of the collision, since it is precisely the development of the dust cloud in the following minutes that may be the most obvious and scientifically important part.

The impact is expected to dig a crater with a diameter of about 20 to 30 meters and a depth of about 5 meters. A crater this size is too small to be seen from Earth, but spacecraft orbiting the Moon will be able to photograph it. NASA’s lunar probe and the South Korean spacecraft Denori are planned to compare images taken before the event with images obtained after it. Denori is expected to pass within a few kilometers of the rocket stage about two minutes before impact.

This would be the second known time that a remnant of a rocket has accidentally crashed into the moon. In March 2022, a rocket body attributed to a Chinese mission hit the far side of the moon and created a double crater. Since the impact occurred on the side not visible from Earth, it was not recorded in real time and was later discovered in satellite images.

Intentional impacts of aircraft and rocket remnants on the moon have occurred in the past as part of scientific experiments. During the Apollo program, NASA smashed rocket stages and parts of the lunar lander to create seismic waves that were measured using instruments left by the astronauts. In 2009, the Elcross spacecraft crashed near the South Pole as part of a search for water ice, and its impact sent up a cloud of material that was tested by scientific instruments.

This time the collision was not planned, and according to space experts, it could have been prevented by changing the trajectory of the rocket stage after launch and moving it to a stable orbit around the sun. The current event does not endanger people or equipment, but it illustrates the increasing difficulty of waste management in the space between the Earth and the Moon.

The fear is expected to become more significant in the coming years, when the number of spacecraft, landers and satellites around the moon will increase. The United States, China and commercial companies are planning manned missions and the establishment of long-term infrastructure on the surface of the moon. Particles thrown out in a similar collision could travel hundreds of kilometers, damage equipment, contaminate research areas or endanger astronauts who are outside a protected structure. The measurements that will be collected on Wednesday will be used by the researchers to examine the distribution of the fragments and to prepare for future impacts.