
NASA Camera Shows Moon Crossing Face of Earth for 2nd Time in a Year - dnetesn
http://www.nasa.gov/feature/goddard/2016/nasa-camera-shows-moon-crossing-face-of-earth-for-2nd-time-in-a-year
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Fry-kun
Awesome shots! Because of the particular angles & distances, it looks like the
moon is almost grinding against us! Of course, that's just an optical
illusion; the actual distance & proportions are more like
[https://en.wikipedia.org/wiki/Lunar_distance_(astronomy)#/me...](https://en.wikipedia.org/wiki/Lunar_distance_\(astronomy\)#/media/File:Earth-
Moon.png)

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sp332
The moon is about 1/4 as far away from earth as the camera is. The camera
always sees the sunny side of the earth - neat trick!
[http://epic.gsfc.nasa.gov/](http://epic.gsfc.nasa.gov/)

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danso
I hope people don't flag this because of its admittedly millennial-sounding
headline...I'm not a huge astronomy geek but was surprised at this particular
juxtaposition of two familiar entities. It almost looked Photoshopped. I was
also surprised that this kind of visual arrangement is unusual enough to
warrant an article, but that's because I'm clueless to where our satellites
are usually positioned in relation to the Earth and moon.

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sunseb
I agree. I'm not a crazy conspiracy theorist, but this looks photoshopped. The
clouds are not moving and the moon is not rotating at all :

[http://imgur.com/prywsJq](http://imgur.com/prywsJq)

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waterphone
The clouds absolutely are moving.

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sunseb
Yes maybe and the distance between the Earth and the Moon could explain why we
don't see the Moon rotation :

[https://en.wikipedia.org/wiki/Lunar_distance_(astronomy)#/me...](https://en.wikipedia.org/wiki/Lunar_distance_\(astronomy\)#/media/File:Earth-
Moon.png)

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SeriousM
Now it's official: no evil cooperation operates on the backside of the moon.

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david-given
Don't be silly! Evil corporations don't have farside moon bases!

No, this proves that there aren't any _space nazis_ on the far side of the
moon.

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dogma1138
FALSE: Everyone knows that the Nazi's aren't on the moon that was just a
diversion, they are in the hollow earth...

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sunseb
Just a quick dumb question : where are the satellites and the stars ?

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foota
"Since Earth is extremely bright in the darkness of space, EPIC has to take
very short exposure images (20-100 milliseconds). The much fainter stars are
not visible in the background as a result of the short exposure times." \-
[http://www.nesdis.noaa.gov/DSCOVR/](http://www.nesdis.noaa.gov/DSCOVR/)

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sunseb
Thanks ! It makes sense. :-)

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ams6110
There's another cool one here showing a solar eclipse.

[http://earthobservatory.nasa.gov/IOTD/view.php?id=87675&eocn...](http://earthobservatory.nasa.gov/IOTD/view.php?id=87675&eocn=home&eoci=iotd_image)

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magicbuzz
It's called "mooning", not "photobombing"

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gdubs
The history of the DSCOVR satellite is pretty interesting. Was pushed for by
Al Gore in the 90's -- unofficially known at the time as GoreSat -- but was
ultimately killed by the Bush administration. Obama's administration
resurrected the project, and now we have an amazing view of earth for science,
discovery, and some pretty neat pictures.

[https://en.m.wikipedia.org/wiki/Deep_Space_Climate_Observato...](https://en.m.wikipedia.org/wiki/Deep_Space_Climate_Observatory)

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drdoom
A few days ago, in a moment of 6-degrees of youtube, I came across a flat
earth video. Out of curisoity to see what their beef was, I watched one. It
was interesting. One of the claims was that _all_ of the earth images we have
are not actual photos or pictures per se, but rather, artists renditions (I
think they used a different term which I don't recall at the moment).
Apparently, this point was admitted to by NASA too. And they had pictures of
earth from space (taken and distributed by NASA) over the years where
continent sizes change drastically on the same circle. One of them even had
"sex" spelled in the clouds.

Watching this, it too looks like an artist rendition. Notice how the moon
moves in a straight line. And while the earth rotates around, the moon
doesn't. That is fine as we see only the same side/face of the moon but
remember: this is taken from far far away so, at that distance and angle, you
should be able to pick up a change in the moon's rotation as well. Here, we
don't.

Interesting indeed.

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quux
I know the moon has a low albedo (reflectivity) but it's easy to forget until
you see it compared to the earth like this.

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corndoge
Are there full size static images somewhere? I want to look at the photos but
the gif isn't doing it for me

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Andrenid
[http://svs.gsfc.nasa.gov/cgi-
bin/details.cgi?aid=11971](http://svs.gsfc.nasa.gov/cgi-
bin/details.cgi?aid=11971)

~~~
KwanEsq
This link is actually the first time this happened last August, not the second
event referred to in the subject article.

This page has static images of the current event:
[http://epic.gsfc.nasa.gov/galleries/lunar_transit_2016/](http://epic.gsfc.nasa.gov/galleries/lunar_transit_2016/)

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Eutow
I've never given it much thought but the first thing that hit me is that the
moon really is just a big 'ol rock up in the sky. These images have changed
the way I view the moon. Pretty neat.

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fma
Looks like the NASA satellite got mooned

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grimmdude
aaghhhhh

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grimmdude
Really, -4? Man, HN sucks

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milesokeefe
What value did your comment add?

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grimmdude
I value my comment at $5.25. How much do you value your comment?

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codesnik
If I understand correctly, satellite is directly between sun and earth (at
lagrange point L1?), and somewhere at the time of the shooting there was an
solar eclipse seen somewhere in Australia

Edit: nevermind, "The satellite is orbiting the Sun-Earth L1 point in a six-
month period, with a spacecraft-Earth-Sun angle varying from 4 to 15 degrees",
so it's not directly between.

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creshal
Yes, it's at the L1 point:
[https://upload.wikimedia.org/wikipedia/commons/a/a5/Lagrange...](https://upload.wikimedia.org/wikipedia/commons/a/a5/Lagrange_points_simple.svg)

No idea about the eclipse, though. There is none listed in NASA's eclipse
portal for July:
[http://eclipse.gsfc.nasa.gov/OH/OH2016.html](http://eclipse.gsfc.nasa.gov/OH/OH2016.html)

~~~
logfromblammo
Objects at Lagrange points L1 (between), L2 (small-body side), and L3 (large-
body side), either have to continually spend propellant to keep station or use
a Lissajous halo orbit around the point.

In space, the choice to use more fuel or less fuel requires little
consideration. So this satellite essentially scribes an elliptical ring around
the sun as viewed from Earth. If the Moon passed between the satellite and the
Earth, the Moon would appear from Earth to be 4-15 degrees away from the Sun,
which would just be an ordinary new moon, not an eclipsing new moon.

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amelius
What is that black triangle in the lower right of the image? And why is it
moving?

EDIT: Okay, never mind, I just realized these images were taken over the
course of several hours, so the triangle must be a movie-composition artifact,
caused by the camera not being fixed.

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chris_wot
Yeah, well - I think the moon is pretty good natured after astronauts walked
on its face.

Proof:
[https://m.youtube.com/watch?v=eM1hv9ileaA](https://m.youtube.com/watch?v=eM1hv9ileaA)

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ktRolster
wow, I didn't realize we had satellites up that high.

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sp332
It's actually orbiting the Earth and the Sun at the same angular rate. It will
make one orbit around the Earth per year. Normally, things that have smaller
orbits around the Sun move faster than the Earth. But if you start the
satellite's orbit near the Earth, the Earth's gravity will pull it back and
slow it down a bit. If you're very careful, you can get them to balance out so
the satellite orbits the Sun in one year instead of going faster.

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vain
How far away from earth is this satellite? Further away from the moon?

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haliou
Yes. In the article, it states the satelite is 1 million miles from Earth.
That's a bit more than 4 times the distance Earth-moon.

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okket
Original source at NASA (which, as usual, phys.org does not link to, they even
ripped the short movie from youtube)

[http://www.nasa.gov/feature/goddard/2016/nasa-camera-
shows-m...](http://www.nasa.gov/feature/goddard/2016/nasa-camera-shows-moon-
crossing-face-of-earth-for-2nd-time-in-a-year)

~~~
Trombone12
yeah, phys.org as a source always make me slightly suspicious, clocking in at
about the level of a university press release in terms of trustworthyness.

NASA's own press release at least specifies how unusual this event is, and the
answer is "a bit less unusual than new years"

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sizzzzlerz
That's no moon!

