A friend of mine, the active amateur astronomer Colin Henshaw, brought the following photograph to my attention. It appears to show the Moon rising over Mossel Bay in South Africa. Although it was passed off as a genuine image, for reasons which Colin pointed out, it is a fake.
If you study the Moon, it is how it appears to an observer in the Northern Hemisphere. If the photo was genuinely taken from Mossel Bay, then the Moon should be the way it appears in the Southern Hemisphere (upside down to viewers in the Northern Hemisphere). Furthermore, the Moon is only half a degree (one Moon’s width) above the horizon. If the image had been genuine the Moon would have a reddish colour because, when near the horizon, the Moon’s light travels a longer distance through the atmosphere, compared to when it is higher in the sky. As it travels a longer path, more of the shorter, bluer wavelengths of light are scattered away, leaving more of the longer, redder wavelengths. The Sun appears redder near the horizon for the same reason.
The Moon appears as a perfect circle whereas when it close to the horizon it appears flattened due to differential atmospheric refraction. To find out more about this effect click here
Finally, if you look carefully at the Moon’s reflection, it is not directly under the Moon, as it would be in a genuine image but is a little off to the left.
Although fake, the fakery was fairly subtle and the photo could easily mislead a non-astronomer as being genuine. I’ll now talk about a number of fake images which have been circulating in which the fakery is more blatant.
Full moon and Sun together
This has the caption “Moon and sun in the same line between two trees”.
Clearly the author knows nothing about astronomy! When there is a full moon, the Sun and the Moon are 180 degrees apart ( i.e. on opposite sides of the sky). When the Moon appears close to the Sun it can only appear as a very thin crescent.
Starting with a new moon, when the Moon appears close to the Sun in the sky and is not visible at all, the sunlit part of the Moon gets successively larger or waxes through to the crescent phase then to a half moon (also known as the first quarter) and finally to a full moon, at which point the whole of the sunlit side of the Moon is fully visible. After the full moon, the sunlit part then gets smaller or wanes back to a half moon (also known as the last quarter), then to a crescent and then finally back to a new moon again. On average this cycle lasts 29.531 days.
Hideaway – image of a sunset at the North Pole
This photo has been circulating widely on the internet since it first appeared back in 2006. It claims to show a picture of a sunset at the North Pole. The caption below has been attached to the image.
A scene you will probably never get to see in person. This is the sunset at the North Pole with the moon at its closest point, so take a moment and enjoy God at work at the North Pole. An amazing photo and not one easily duplicated.
In fact the image was computer generated by a German artist Inga Nielson The picture cannot be real for a number of reasons, the most obvious one being that the Sun and Moon are approximately the same apparent size when viewed from Earth!
Fake photo taken from the ISS
This photo was widely circulating on the Internet five years ago and claimed to be a photo of the Milky Way and an almost full moon taken from the International Space Station. In fact, the image is clearly faked for a number of reasons.
- The Moon is too big in comparison to the Milky Way.
- The relative brightness of the Milky Way and the Moon are completely wrong. The Milky Way is relatively faint and on Earth it is only possible to see it with the naked eye against a dark sky. The Moon is very bright, particularly at full moon. To show the Milky Way at the level of detail would require a long exposure, in which case the image would be saturated by the brightness of the Moon.
- The Milky Way is not curved
- The area below the Moon looks like a reflection of the Sun in an ocean, yet the Sun does not appear in the image. Looking at the position of the reflection, the Sun should be a little above where the Moon is positioned on the image.
In fact, the image was almost certainly produced by manipulating the following NASA image
Image credit NASA
The Aurora – not a fake image but can be misleading
Image credit NASA
This image is genuine, but it is a long exposure photograph. Many people who travel to higher latitudes, on aurora viewing trips, expect to see brilliant glowing lights like this with the naked eye and end up being disappointed. Aurora are faint flickering phenomena caused by electrically charged particles striking the Earth’s upper atmosphere. To see them you need to go to a dark location at a time when aurora are forecast. There are many space weather websites such as https://www.swpc.noaa.gov/products/aurora-30-minute-forecast which are useful. Even in such a location they will be, in general, fairly faint to the naked eye and not be as brilliant lights like those shown in the photo.