Living on the Moon
by Anthony Bright-Paul
Temperatures on the moon are very hot in the daytime, about 100 degrees C.
At night, the lunar surface gets very cold, as cold as minus 173 degrees C.
This wide variation is because Earth’s moon has no atmosphere to hold in heat at night or prevent the surface from getting so hot during the day.
A single “day” on the moon lasts about 28 Earth days, meaning the lunar daytime is nearly two Earth weeks long.
First radio image of the moon taken with an ACA antenna. Left: Optical image taken with a digital camera. Right: Radio image at a wavelength of 2 mm taken with an ACA antenna. The optical image shows the sunlight reflected by the moon’s surface, whereas the radio image shows the physical temperature distribution of the moon. [ source >>]
On August 27th 2013, the hottest place on Earth is Palm Springs, where some dear friends of mine are living – I trust. The temperature has reached 134o Fahrenheit, which corresponds to 56.67oCentigrade. This is reckoned to be an all time record.
Just imagine then living on the Moon, where the daytime temperature can reach 123oC and the nighttime will drop to MINUS 153oC. 123oC is more than twice as hot as our hottest day recorded.
On the question of temperature I would like to quote an email that I received from Professor James A.Peden, 4.12.2011:
“Temperature” is based on a measure of the energy of molecular motion… and indeed, the temperature at the edge of our atmosphere is quite “hot” … because the molecules, albeit few in number, have a high kinetic energy … thus technically have a high “temperature”.
However, there are very few of them. Therefore the “heat content” is very small…. resulting in very few calories per unit volume. At sea level, there is a pretty good correlation between temperature and heat content: a kettle of boiling water has both a high temperature and high heat content.
But at the edge of space, with very few molecules per unit volume, you have the seemingly paradoxical condition of both high temperature and low heat content.
Ordinary thermometers work by transfer of heat energy from the surroundings to the thermometer.
At the edge of space, they simply don’t work because there aren’t enough surrounding air molecules to counter the natural cooling of an object by radiation. So, trying to measure the temperature via normal methods results in an erroneously low reading. We must remember that all bodies emit Infrared radiation and thus “cool” in the process. A thermometer may read quite low at very high altitudes not because the surroundings are“cold” but because the thermometer is losing heat by radiation and there aren’t enough surrounding “hot” air molecules to counter that cooling.
At the Kármán line … the so-called “edge of space” (about 100 km) there is in fact an abrupt rise in temperature… as solar radiation reacts with the few molecules still in that region, increasing their thermal energy, and thus raising their “temperature”.
Now the Moon like us on Earth is some 93million miles from the Sun, yet it is evidently both much hotter and much colder. Why is this? The answer lies in the sentence ‘There is no significant atmosphere on the moon.’
What does this at once tell us? At the edge of space on what is called the Harman line there are very few molecules – like Outer Space the Thermosphere is almost empty of matter, it is almost a vacuum. But the very few molecules that are there can be extremely hot. (Professor Peden gives no figure for the very good reasons stated in his email.)
The radiation from the Sun has already crossed some 91 – 95 million miles. From the top of the Thermosphere to the level of the sea is a mere 50 or 60 miles, a relatively tiny distance. How then is the surface of the Earth not also similarly hot? Why is the surface of the Earth not 100oC –123oC like the Moon?
The answer lies in the atmosphere, or rather the fact that we have an atmosphere. Without this atmosphere we should be as hot as the Moon by day and as cold as the Moon by night. In this way we can see that the gases of the atmosphere act as a filter, scattering and absorbing the radiation. In direct sunlight the gases of our atmosphere act as a huge coolant, without which life on earth would be impossible for either man or beast. Out of direct sunlight, as well as at night, those self same gases retain enough heat to prevent the temperature from dropping as low as on the Moon. Even the North and South Poles in the coldest part of their winters do not get as cold as the Moon. Airflows from warmer regions prevent the temperatures from dropping to the same low level as on the Moon.
If we take the lowest level of the atmosphere, which is the Troposphere, where all our weather occurs, we know that the warmest part is right at the surface. At 33,000 feet the temperature is circa Minus 55C. How does all this come about? How is I that we feel warm when sitting or working in the direct sunshine? How is it that cloud cover in the daytime will immediately reduce the effect of the sun?
Radiation has to encounter mass to produce warmth. If we sunbathe we are mass and will experience warmth, even sunburn. The Earth warms up and more importantly the seas and oceans warm. It is the oceans that play the largest part in warming the lower atmosphere, while the atmosphere does very little if anything to warm the oceans.
As the atmosphere warms the warmed air rises, and as it rises it cools. The cold gases cannot heat a warmer earth or oceans, which is the fundamental mistake of the Anthropogenic Global Warmers. The Sun’s radiation warms the Earth and the Earth warms the atmosphere, not the other way round.
The Greenhouse Gases play a major role in filtering the radiation of the Sun and thus keeping the Earth cool enough for mankind and the animal kingdom to live on. At night time the Greenhouse gases also inhibit heat loss, so they play a role both in keeping us cool and in keeping us warm, safe from the extreme fluctuations on the Moon. Water vapour in particular acts as a celestial thermostat.
The idea that Carbon Dioxide ‘causes’ Global Warming is thus seen to be fallacious. The Greenhouse gases do more to cool the Earth than keep it warm, since it is clear that the radiation from the Sun is far mightier than the radiation, infrared, emitted from the earth and oceans.
The idea that Greenhouse gases ‘cause’ warming is simply not true. Not even the most bigoted Alarmist would claim that these gases generate heat. Nor can they in any way add to the heat that is produced by the radiation for the Sun. Nor can a gas, Carbon Dioxide, trap heat. At most these gases can delay for a very short time the exit of that same said heat, and that would be only at night.
Any layman can learn and understand these principles – from which it is clear that there is no such thing as man-made Global Warming – there never has been and never can be. Far from Greenhouse Gases leading to Global Warming, precisely the opposite is true – without the Greenhouse gases we would all be fried to a cinder!
(Acknowledging also corrections and additional information from Hans Schreuder.)
PS How do astronauts survive the extreme temperatures on the moon?
How do the astronauts avoid freezing or boiling?
When anyone asks what “the temperature” is, your very first question should be “the temperature of WHAT?” When “it” gets up to 250 F, you have to know precisely what “it” is. In this case, “it” is the rocks and dust of the lunar surface. That is, the figures cited are lunar surface temperatures.
What we commonly think of as “temperature” in our environment is air temperature. So when you say, “Today it was 75 F in Los Angeles,” what you’re saying is that the air was 75 F. The hot pavement in the parking lot may have been 150 F. And the concrete floor of the bottom level of a parking garage may be 60 F. That is, each item in an environment doesn’t all come to the same temperature.
But more importantly, there’s no air on the Moon. So air temperature is meaningless. The surface may get very hot, but that doesn’t mean everything nearby will get that hot. How hot something gets in space depends largely on how much heat it absorbs from the sun. The lunar soil absorbs 85-90% of the solar energy (1300 watts max per square meter) that falls on it. So when the sun shines most directly on it it — lunar noon — it’s sucking up a lot of heat.
A space suit, on the other hand, absorbs only about 15% of the solar energy that falls on it. And the outer layers are heavily insulated from the inner layers. Aluminum absorbs only about 5% of the solar heat. Things made of aluminum don’t always heat up very much in space.
An astronaut’s boots touch the surface directly and so absorb heat from it. But again, insulation is the key. You can walk very easily in ordinary shoes across asphalt that’s 150 F or more without any ill effects. Your shoe soles get hot, but little of that heat conducts to your feet. Same with the astronauts. They had about an inch total of boot sole between them and the ground.
And the other key factor is that the Apollo missions landed in lunar morning. The sun was low in the sky. And just as surface temperatures on Earth take a while to warm up as the sun climbs, so do lunar surface temperatures. I computed once that the average lunar surface temperature during Apollo 11 was only about 30 F. The sun hadn’t risen very far yet.
Even at lunar noon, the hot part only goes down less than a meter. Dig more than a few centimeters below the surface, and you’ve got very cold rocks and dust. The sunlight never penetrates there, and heat conducts very poorly through the jumble of rocks and dust.
Keep in mind that +250 F and -300 F are the extremes. Most of the surface temperatures measured on the surface will lie somewhere in the middle of those. And it takes a long time for any object to change between those extremes. It’s not like you stand in full sun and then walk into the shadow of the spacecraft and your suit temperature immediately plummets to hundreds of degrees below zero. Heat transfer just doesn’t work that fast.