By Jennifer K. Bauer
While life changes around us, when we look into the night sky the Moon’s face is dependably the same. We see the same celestial spectacle our ancestors have laid eyes upon thousands of years.
For people of the future, maybe even the near future, the view could be different.
Since U.S. astronauts landed on the Moon 50 years ago, our scientific knowledge about nearest our orbiting neighbor has exponentially expanded, and with it our dreams of a future for humankind in space. To commemorate the first moon landing, Inland 360 asked University of Idaho physics experts some questions about the Moon, from common misconceptions to some of the latest scientific discoveries.
Gwen Barnes, an assistant research professor of physics, studies lunar geology and took part in the 2009 LCROSS NASA robotic Moon mission which confirmed the presence of water ice on the Moon. Associate Professor Matthew Hedman studies the outer solar system and dust in near-space around the Moon.
What are some common misconceptions about the moon?
That there is a dark side of the Moon, said Barnes.
“There is no dark side of the Moon. There is a far side of the Moon that we can never see from the Earth,” she explained.
The Moon receives the same amount of sunlight on each side but since the Moon is tidally locked to the Earth we only see one side from our viewpoint.
What’s a typical day and night on the moon like?
A full day on the Moon is about 27 Earth days.
Daytime on the moon lasts two weeks, followed by two weeks of night.
At the beginning of the week the sun rises. By the end of the first week it is straight ahead. Near the end of the second week it is setting, Barnes said.
In the following two week long lunar night, temperatures drop from highs of 253 degrees, to lows of 387 degrees below zero, according to NASA.
These extremes present special challenges to explorers.
“Designing a rover that can operate in both conditions is kind of tricky,” Barnes said.
How old is the Moon and where did it come from?
The Moon is nearly as old as the Earth, which formed 4.5 billion years ago.
“The going theory is that back in the early days of the solar system some object hit Earth,” said Hedman.
“Imagine an early Earth and think of something roughly the size of Mars crashing into it. The two things basically broke apart. Some of that material coagulated into Earth and some of it went into orbit to form the Moon. We know the Moon is at least 4 billion years old, thanks to the Apollo mission.”
The energy of that giant impact would have mostly melted the rock, said Barnes.
“The Moon was molten at some point and solidified to bare rock on the surface. Other lava flows later formed the mare (the moon’s large, dark basaltic plains).”
Evidence for the impact theory is fairly good, Barnes said.
“Certain chemical elemental ratios are absolutely identical to the Earth. Look at any other planet and the numbers are just vastly different.”
Why are scientists studying Moon dust?
“One reason people care about lunar dust is that it is a practical problem for working on the Moon. Dust on the Moon are tiny bits of rock that could coat equipment and could even pose a health risk to people,” Hedman said.
This lose layer is called regolith and on the moon it is tiny and sharp and covers almost everything.
Little chunks of rock are constantly flying about in space. When they reach Earth they burn up in our atmosphere, the phenomenon we call shooting stars.
“The Moon doesn’t have an atmosphere so even a tiny little speck of rock flying around in space can hit the ground and break the surface turning rock into pebbles and smaller pebbles,” Hedman said.
“We need to understand this stuff if you’re going to have things on the Moon because it’s going to affect how it operates.”
What are some of the latest scientific discoveries and unanswered questions about the Moon?
A high-resolution lunar reconnaissance orbiter camera has provided highly detailed images of the Moon’s surface. Some of these images show what could be caves or openings that appear to go down into empty lava tubes, Barnes said.
A network of caves could be a resource for human explorers who will be exposed to radiation and sickening solar flares on the Moon’s surface.
“A couple meters of rock is all it would take to protect you from those,” Barnes said.
The LCROSS mission determined that water ice is present on the Moon, likely delivered over solar system history by comets that carry water ice, Barnes said.
How much ice is there and how deeply it is buried are two questions scientists want to answer.
“Is there enough to support a colony, is it just a dusting, or would we have to import all our water from Earth, which would be really expensive?” Barnes said.
Could human development change the Moon’s appearance?
Space colonies, orbiting tourists, habitat domes and commercial mining operations are all things that have been discussed in relation to the Moon.
“If we build enough infrastructure up there at some point we’ll be able to see it from Earth,” Barnes said.
The Moon is full of iconic features. Many people see “the man in the moon.” Other cultures see different symbols. Giant mining operations could alter the Moon’s appearance and scientists’ ability to do work there.
“We should think about the effects of what we’re doing as well as just getting stuff done,” Barnes said.