What's wrong with a part of the rocket colliding with the moon?

In January 2022,

the prediction that 'a part of the rocket launched in 2015 by SpaceX led by Mr. Elon Musk will collide with the surface of the moon on March 4, 2022' was announced and became a hot topic. David Rothery , a professor of planetary earth sciences at the Open University in the United Kingdom, explains the question, 'What are the concerns of a rocket crashing on the moon?'

Moon: crashing rocket will create new crater – here's what we should worry about

On February 11, 2015, SpaceX launched the US National Oceanic and Atmospheric Administration (NOAA) space weather observation satellite ' Deep Space Climate Observatory (DSCOVR) ' using the 'Falcon 9 ' rocket, which boasts a large share in the launch of artificial satellites. rice field. At this time, a non-reusable second stage rocket booster was left in outer space as originally planned, but it is predicted that this booster will collide with the moon on March 4, 2022 after many years. It is set up.

Prediction that SpaceX rocket will be out of control and collide with the moon-GIGAZINE

by Michael Seeley

The rocket booster, which was separated in February 2015, is about 14 meters long and weighs about 4 tons, and is floating in outer space under the influence of the gravity of not only the earth but also the moon and the sun. According to calculations by Bill Gray, who develops software for tracking near-Earth objects, the booster will collide with the other side of the moon at 12:25:58 (Coordinated Universal Time) on March 4, 2022. The speed at the time of the collision is a whopping 2.6 kilometers per second, and the craters generated by the collision are expected to be about 19 meters in diameter.

There have been angry voices about the incident on social media, but Rosalie points out that most concerns don't really have much of an impact. For example, when a part of a rocket crashes on the moon, 'It is definitely more environmentally friendly to fall on the moon than to burn out and become metal oxide particles scattered in the earth's atmosphere when re-entry into the atmosphere. 'Rosary said.

Regarding the concern that new craters will be created on the moon, he pointed out that 'the moon has no atmosphere to protect itself from the debris floating in space, so the number of naturally occurring craters is constantly increasing.' NASA's ' Lunar Impact Monitoring ' project has discovered hundreds of small collisions over the past decade, and it is not uncommon for new craters to be created.

In addition, there have been multiple cases of man-made objects colliding with the moon in the past. In the Apollo program , 11 experiments were conducted in which explosives and unnecessary rocket boosters collided with the lunar surface and the moonquake was observed with a seismograph installed on the lunar surface. In 2009, in the mission of NASA's unmanned spacecraft LCROSS , the upper rocket Centaur and the main body collided with the polar crater to artificially create a crater.

'I'm not worried about another crater being created on the moon,' Rosalie said. 'The moon already has 500 million craters over 10 meters in diameter.' More worrisome is that it contaminates the moon with 'living microbes and molecules that can be mistaken for evidence of life.'

Most countries are enrolled in planetary protection protocols to minimize biological pollution from Earth to another planet, or from another planet to the Earth. The purpose of the protocol is both ethical and scientific, ethically not to endanger the ecosystems of other planets, and scientifically to prevent pollution from interfering with planetary research.

The biggest violation of the planetary protection protocol so far is the case where 'thousands of bear beetles' were stored dry in the Israeli lunar explorer that collided with the moon in 2019. Tardigrades are known to be able to revive even when exposed to vacuum, and are believed to be scattered near the crash site even at the time of writing the article.

It was discovered that thousands of tardigrades were on the lunar probe that crashed on the surface of the moon, and there is a possibility that it will breed on the surface of the moon.

Compared to the case of a spacecraft carrying tardigrades, Falcon 9 is not sterile at the time of launch, but seven years have passed since its launch, and the risk of biological contamination is considerably reduced. Still, the more objects we send to the Moon, the harder it is to comply with planetary protection protocols, Rosalie said.

in Science, Posted by log1h_ik