We visited the moon half a century ago and have not been back since. During this time, we have thrown robotic spaceships over our solar system and learned something about distant worlds. In the meantime, scientists are still thinking about the rocky visitor of our night sky.
The Apollo Missions helped us to solve many of the mysteries of the moon, but there are many more unanswered questions – and even a few that came back as a result of that Samples were created Apollo astronauts.
"There have been numerous scientific questions in part of the Apollo evidence," Roger Launius, former NASA chief historian, told Space.com. "There are a number of things that can be gained by going back, such as collecting additional material and collecting new data."
As NASA prepares to send astronauts to the Moon again by 2024 the United States Government issued mixed communications to the Moon upcoming mission. Scientists affirm that the moon still holds many secrets that we need to explore.
"We have many great questions," says Sarah Noble, the next generation Apollonian sample analysis program executive at NASA's Washington headquarters, Space.com said. "What has happened in the last ten years is that we have put a lot of things into orbit around the moon, giving us a global picture ." We know where we are going need to answer these questions now, "Noble added.
Nearly 40 years after the return from the moon, water was found in rock samples returned from the Apollo 15 mission radically new area of lunar research because it suggested that water may have existed on the Moon since its formation.
Having water on the moon is crucial for future space exploration because it could be used for drinking water and rocket fuel  "For 40 years, we thought the samples were completely dry," Noble said. "We now understand that there is a water cycle, but we do not understand how it works." What not yet, but we have the tools to crack it now.
"From my perspective We have all sorts of instruments that did not exist before," said Paul Hayne, assistant professor at the Department of Astrophysical and Planetary Sciences at the University of Colorado, Space.com.
Hayne added that the instruments have since become so miniaturized that they now easily fit in spacecraft.
Apart from water, recent findings also suggest that ice is on the moon . A study from 2018 confirmed that there were frozen substances at the bottom of the north and south poles of the moon.
"The one [question] that interests me very much is the question of the ice and the poles," said Hayne. "We want to know how much [ice there is] and where and collect new data to investigate this."
To detect the ice on the lunar surface, Hayne said that there are new tools such as infrared instruments detecting the chemical fingerprint of ice, thermal imaging cameras, and other exothermic tools.
Samples of basalt rocks or solidified molten lava returned by the Apollo missions were mostly old, but according to Noble, some were as young as a billion years old. (Scientists believe that the moon itself is 4.51 billion years old.)
Scientists know that volcanic eruptions have occurred on the lunar surface, but are not sure when and on which timeline these outbreaks occurred the moon took place to be volcanically active.
"There are still some questions about how active the moon is today – this is a kind of hot area," Hayne said.
He added that he did not know when these volcanic eruptions stopped, we also do not know what caused them – whether they were triggered by a huge impact on the moon or whether the moon is radioactive ,
Recent research has shown that it is lunar rocks rich in radioactive material such as uranium, and an article from 2014 in Nature suggested that heat-generating elements such as uranium, thorium and potassium cause that the lunar surface expands and contracts as it gets hotter and cooler. The cracks on the surface caused by this process would have allowed the lava to flow through them.
Hayne suggests that scientists must revise their models of the volcanic activity of the Moon, as most of them believe that he is no longer active a long time ago, which may not be true – some scholars believe that the Moon still tectonic is active .
It is also discussed how old our moon is, with an age of 4.5 billion years to much younger 150 to 200 million years.
According to Noble, scientists have attempted to appreciate the age of the moon by analyzing the moon rocks returned by Apollo and by trying to date when the craters formed on the lunar surface, but so far there has been no consensus.
"This is one of the big questions we want to answer." Noble said.
However, Noble added that it was not just about determining the age of the moon, but about finding out the age of other rocky bodies in the solar system like Mercury or Mars.
Once we know the age of the moon, we can estimate the age of other planets by comparing the number of craters between the Moon and Mars or Venus. The more craters on the surface, the older the rocky body is.
When we gather as much information as possible from the moon, we can finally better understand other planetary objects in our solar system that we wish to explore in the future.
"The moon can help us to understand how we can live and work on another body, for example when we go to Mars," she said.
In the midst of a continuing debate over whether we return to the moon lunar scientists reaffirm that it is absolutely necessary for future space exploration to do so and learn more about our own planet.
"As a lunar scientist, I am very excited about science we can do on the moon," said Noble. "Our current plan is to hit the moon so we can move on and hit Mars."
Hayne agreed. "We still have so much to learn about the moon, which not only informs us about other planets in the solar system, but also about the earth itself," he said.
"After all, it's exciting," added Hayne. "It inspires people, there is no substitute for having boots on the ground."