the lunar environment

The moon is a celestial body that orbits our planet, Earth. The moon is also known as the Earth's most permanent natural satellite. It is the smallest of the solar system's natural satellites, ranking fifth in dimension. As compared to the size of the planets it orbits, it is the largest of the planetary satellites (relative). It is also ranked second among the densest satellites, behind only Jupiter's Lo moon. The atmosphere surrounding the moon is known as the Lunar environment, and it is marked by very harsh weather patterns and variations. For instance, the temperatures of the moon’s surface can fall to as low as 70 Kelvins in the dark, and its surface can heat up to up to 230 kelvins. Despite the fact that the lunar environment is entirely a vacuum, sparse amounts of water vapor have been discovered around it possibly due to sublimation. A discussion of the lunar environment focusing on the solar wind, cosmic rays, meteorites and gravity are presented in this discussion.

Solar wind

The solar wind refers to a stream of highly charged particles emitted from the sun’s upper atmosphere. This stream of wind that the sun emits periodically is known as the plasma. The plasma mainly consists of protons, electrons and several alpha particles with thermal densities in the range of 1.5keV to 10keV. The flow of the wind through the solar system also creates a bubble in the solar system’s interstellar medium which is likened to plasma but with less density.

The flow of these two winds in the lunar environment leads to an interaction between the two mediums creating a shock front called the Heliopause. The Heliopause then leads to the formation of Galactic Cosmic Rays (GCR) barrier. Furthermore, the vast steady streams of heat ions existing along the magnetic field lines also flows outwards from the environment’s solar corona whose temperatures hit up to one million Kelvin. It is this complex combination of the magnetic fields and ionized gasses that lead to plasma.

However, since the moon does not have a global magnetic field, it often creates a solid dielectric barrier to the rapidly moving and dense solar wind. The magnetic fields generated by the moving plasma pass through the moon. As they do so, they often impact the moon’s surface thereby rapidly getting buried in the moon’s surface grains. This movement of plasma around the moon and the ensuing magnetic field it creates leads to the creation of a void behind the moon. The vacuum created contains a combination of both the high spend moving solar wind as well as the low speed moving solar wind.

The solar wind moving at a low speed often travels outwards from the sun at speeds close to 400 km/sec whereas the faster solar wind often moves out of the lunar environment’s solar coronal holes twice as fast as the low-speed solar wind. The ions in this environment also contain ionized nuclei from several substances. Nevertheless, the electrons and protons form the largest proportion of these ions. All these ions form part of the solar wind gasses that often move around the surface layers of the environment’s lunar grains. More research indicates that at a distance of more that the radii of the sun, this solar wind moves at supersonic speeds up to 750,000 m/s though at the termination shock, it is not supersonic.







Cosmic rays

The cosmic rays collectively known as the Galactic Cosmic Rays (GCRs) are highly charged atomic nuclear particles that have been stripped of their surrounding electrons as they move through the galaxy at very high speeds. Besides atomic nuclei, they also contain several electrons, protons, and very ionized light nuclei. They normally enter the milky way galaxy from other outside galaxies. At the time they enter the milky way galaxy, they have had their speeds accelerated within more than millions of years back. Furthermore, at the time they enter the milky way galaxy, they are believed to have traveled several times across the galaxy while trapped by the galactic magnetic fields. Research also indicates that the GCRs have now been accelerated to speeds close to that of light by their supernova remnants. As these cosmic rays traverse the thin interstellar space, they often interact leading to the emission of gamma rays. It is through studying the gamma rays that it is possible to know that the milky way and the several other galaxies where they pass. However, although they have enormous energies, these energies are still very low to penetrate the atmosphere surrounding the Earth. As a result, they end up striking the moon instead.

As is the case with most ionizing radiation, these cosmic rays can cause enormous damage to the DNA structure leading to increased risk of cancer, eye cataracts, several neurological orders and other mortalities that may not be related to cancer. Although it is suggested that material shielding can be useful in combating the effects of these rays, it can only stop rays in a certain energy range and level. In fact, this material shielding can even exacerbate the problem because it can easily lead to an increase in secondary radiation. Consequently, the best-known shielding strategy for combating the GCRs and their effects is the use of structural shielding technic combined with very hydrogenated materials like plastic or water.

Meteorites

Meteorites are solid pieces of debris often falling from objects like moving comets, asteroids and other meteoroid bodies that originate from the outer space but survive the passage through the atmosphere and impact the Earth’s planet. As the meteorites enter the Earth’s atmosphere, several factors like pressure, friction and complex chemical reactions with the gasses in the atmosphere cause it to heat up thereby radiating energy. After their energy has been emitted, the meteorites form meteors that later become fireballs referred to as shooting stars.

The brightest of the meteors are called bolides and are capable of creating a crater if they survive atmospheric entry. Research indicates that most of the impactors on the Moon, mostly consisting of meteorites are capable of producing spray ejecta or some crater. The layer of the lunar surface, known as the regolith has been formed following geologic years of impact. Several pieces of the regolith have been fractured, eroded and smashed by these impacts. For that reason, the regolith has been hugely gardened and mixed by these impacts.

The micrometeoroid impacts, the most frequent impacts by far, often vaporize the individual grains and in the end, deposit the residue to the nearby grains. Similarly, they have the ability to weld several individual grains to fragile agglutinates. The unilluminated moon is routinely and regularly being monitored at the MSFC suing a special video camera attached to the telescope and as a result, over 100 flashes arising from impact have been recorded in the past 30 months. These impacts are known to be larger than those caused by the micrometeoroids. Although the meteoroids can impact the lunar surface, there is little risk to astronauts of a direct hit. As for the habitat, the risk can be calculated precisely together with the best strategies to combat them.



Lunar Gravity

Gravity refers to that force that attracts tends to attract all the physical objects towards each other. An individual’s weight on the moon is often a function of the gravity of the moon. Since the mass of the moon is almost 1.2% that of the Earth, the gravity of the moon is also much less than that of the Earth. The gravitational influence of the moon is responsible for several body tides, ocean ties and slight increases in the length of the day. The gravity on the moon is 1/6 g on its lunar surface making its acceleration due to gravity 1.625 m/s2. This gravity is 16.6% of the surface of the Earth. Furthermore, the escape velocity on the moon is 2.37 km/ s2.

The astronauts that have gone and stepped on the surface of the moon report that its surface is easier to walk on than working in a weightlessness environment. However, the low gravity on the moon and its intricate design environment are not fully explored. The most notable feature of the gravitational field of the moon is the presence of the mascons. The mascons are gravity anomalies that are large and positive but associated with series of giant impact basins on the moon’s surface.