Categories
astronomy Physics

Earth as seen from the moon

In this video we can see the earth rise from the moon. It was taken about 10 years ago by the Japanese space agency JAXA (not NASA) from their lunar orbiter SELENE. The spacecraft orbited the moon for about a year before it was deliberately crashed in to the moon surface.

There are people who believe that the Earth is a flat disk and not a sphere. It is incredible I know. Apart from interpreting certain scriptures to support their claim it would seem that they have to also claim that all space agencies have faked all images of the earth since man’s quest into space began.

They also claim that there are no satellites (no GPS constellations), that there cannot be an International Space Station (ISS) in orbit and that man has never left the earth.

So they claim that this spacecraft could not have observed the spherical planet from the moon because no such craft ever left the planet. But the Japanese did send a spacecraft as have other nations. This one shows beautifully the jewel among the stars and it doesn’t look flat to me.

Recommended Reading

  1. THE EARTH IS NOT FLAT AND HANGS UPON NOTHING!
  2. A FLAT EARTH AND OTHER NONSENSE by Robert Carter and Jonathan Sarfati
  3. THE FLAT-EARTH MYTH AND CREATIONISM by Jerry Bergman

6/2/2020 Comment from a flat-earther: Haha you’re all comedians, but can’t see the reality that it is a fake video or believe that NASA could lie! Think about it. Where is the sun’s position, how bright should the moon be but isn’t, and seeing the earth seems to be in full light why is the background dark? When we are in day, the sky is blue. Perhaps someone has an answer.

My response: Number one, this video was not produced by NASA but by JAXA the Japanese space agency. I have had interactions with scientist colleagues from JAXA and find them to be a reputable organisation.

Number two: There is no atmosphere on the moon. Thus there are no molecules to scatter sunlight. You learn that in high-school. Hence the sky is black. On earth we see a blue sky because of scattered sunlight. Blue light (shorter wavelengths than red light) is scattered in all directions by the molecules of air in Earth’s atmosphere. Blue is scattered more than other colours because of its shorter wavelengths. As a result when we look at the sky we preferentially see the blue light component of sunlight which contains all the colours of the spectrum.

Then the automatic gain control on the camera on board the spacecraft reduces the aperture of the camera because of the high albedo of the moon. High albedo means high reflectivity. The moon reflects a little more than 10% of the sunlight hitting its surface. The moon’s surface has about 1/3rd the albedo of the earth’s surface. The reduction of the camera aperture means less light entering the camera so not to saturate the CCD module. Hence the moon surface does not look so bright, and note stars are not so easily seen in the black sky because the camera aperture is reduced.