Scientists hypothesize that the moon is over 4.51 billion years old, formed soon after earth’s creation. Yet it’s physique and texture have remained a mystery for thousands of years, leading to much speculation and myths throughout history. To this day, much of the moon’s geography is still a mystery but scientists have managed to uncover some of its unique traits.
Moon craters or lunar craters are simply bowl-shaped depressions or pits on the surface of Earth’s moon. They were mostly caused by the impact due to volcanism and cratering.
How are impact craters formed from collisions?
Impact craters are formed when certain objects collide with the surface, resulting in a deep circular hole or depression known as impact craters. These extra-terrestrial objects are in most instances either meteors or asteroids. In order to form craters, these objects must be moving at extremely high speeds; more than thousands of miles per hour! Since these objects are moving through space so fast, that upon hitting the surface (i,e. of the moon) they instantly vaporize, leaving behind depressions.
Why do the impacts on the moon stay?
On July 20, 1969, Neil Armstrong placed his left foot on the moon for the first time, during the Apollo 11 mission. It is recorded as the first time in history for anyone to have set foot on the moon. However, surprisingly as of now, years later the footprint still exist and will for millions of years! This brings_____ the question, how is such a feat possible? This feat/phenomena occurred because of the moon’s unique atmosphere/geography that enables any impression on the moon’s surface (regardless of its size) to permanently stay on the moon.
Although, both the Earth and the moon have been repeatedly hit with impact over their billions of years of shared history, the moon has faced far more permanent impact.
Unlike the earth, all craters that result because of collusion the impact craters on the moon last. This is because unlike the moon, over the Earth’s billions of years of history it’s features have constantly changed and adapted. This is due to a variety of reasons, including but not limited to the existent life on earth that aids the process of erosion, washing away and fading any remnants/evidence of the collision. Apart from this, Earth’s atmosphere and tectonics (or shifting of tectonic plates) aid in smoothing its landscape from the impact craters. Lastly, the active volcanic activities (ie.explosions) on earth cover depressions by the spread of lava in volcanic explosions. Hence, Earth’s surface contains very few craters, though similar to the moon it has had its fair share of collisions.
In contrast, the moon possesses no known life on its surface and has no atmosphere. As a result, it has no weather. The lack of weather or life on the moon results in the inability to erode. Apart from this, the moon has no tectonic plates and therefore cannot rely upon tectonics to remove imprints or change its features. Lastly, the moon has no active volcanoes, in fact, scientists report that the last active volcano was 3 billion years ago! Therefore, unlike Earth, the moon has no means to remove the imprint of craters on its surface. Therefore, any impression on the moon will almost certainly remain there forever.
What are the different types of craters?
Scientists have largely categorized craters into four different types including; complex craters, multi-ring basins, irregular craters, degraded craters. An example of a more specific crater is the “impact basin”.
Complex craters are large-sized craters with intricate and complicated characteristics and traits, such as terraces, central peaks, and multiple rings.
Multi-ring basins are large craters with a basin-like deep depression that typically consists as much as 5 to 6 rings of ‘mountain chains’. In addition, it usually includes a main basin/crater rim.
Irregular Craters are craters that form irregular shapes instead of a standard circle. This can also include multiple craters which were formed simultaneously. These also include ‘oblong craters’ which are formed when the impact is created by hitting the surface at a short/low distance.
Degraded Craters are craters that have been changed from their original form due to erosion. This can happen by any means including lava flows (the last of which happened on the moon billions of years ago!).
Lastly, Impact Basins are craters that are longer than 185 miles (300 kilometers) wide in diameter. Records show that the largest ‘impact basin’ on the moon is 1550 miles (2500 kilometers) wide and deeper than 7 miles (12 kilometers)!
The Moon’s Seas, Maria
The Sea of Nectar, the Sea of Serenity, the Known Sea; the Lake of Time and Lake of Luxury; the Marsh of Rot, Bay of Roughness and Ocean of Storms are all intriguing names of lunar seas.
In fact, these lunar seas were formed about 3.8 million years ago! And yet, they don’t have a single drop of water on them. How is this possible?
When asteroids bombarded the moon, they left behind many craters. During this time, the moon’s interior was still molten due to its relatively young age. Thus, the lava within the moon would consequently, often erupt exposing it to the surface of the moon. Though now, all volcanic activities on the moon are dormant, this was not the case 3.8 million years ago. This lava flowed over the surface of the moon, falling into its many depressions. These basins of lava were named the moon’s seas or “Maria” by early astronomers who mistakenly thought these were bodies of water. To this day the name remains, reminding us of the moon’s mysterious nature.
It was only after humans explored the moon that they uncovered it’s many hidden features and mysteries. Perhaps now it suffices to say that our fascination or obsession with it is over. But it’s a gift to us will never go away, our curiosity over its mysterious nature compelled us to go further motivating us to discover more.
Haniyah is an aspiring writer and science lover. She was raised in California and recently moved to Pakistan. She is currently studying her ‘O’ levels in Lahore. She is an avid fan of literature and loves to read. She is passionate about horseriding and spends her free time painting and horseriding. She is interested in robotics and has mentored a robotics team. Additionally, she has taken part in many robotics competitions, both international and local