That Cool Goresat Picture We Have all Waited For
DSCOVR Shows Moon Crossing Face of Earth (Video)
“A NASA camera aboard the Deep Space Climate Observatory (DSCOVR) satellite captured a unique view of the moon as it moved in front of the sunlit side of Earth last month. The series of test images shows the fully illuminated “dark side” of the moon that is never visible from Earth. The images were captured by NASA’s Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope on the DSCOVR satellite orbiting 1 million miles from Earth. From its position between the sun and Earth, DSCOVR conducts its primary mission of real-time solar wind monitoring for the National Oceanic and Atmospheric Administration (NOAA).”
Yeahhhh, I was hoping you had this up here once I saw it show up on Google News somewhere else. That is so cool. I’ll make a somewhat smaller animated gif version.
Is there some kind of optical illusions going on here?
I would think that since the the moon is closer to the camera than the earth, that the moon would appear larger as compared to the earth do to foreshortening do to distance.
The moon looks to be I/6th the size of earth (actual size)
Something seems out of perspective here?
How far is the camera from the moon as compared to the distance from the moon to the earth?
Is the camera magnified?
The DSCOVR probe is at the Earth-Sun L1 point, which is about a Million miles away from the Earth, towards the Sun. Distance from the Earth to the Moon is ~240,000 miles. That makes the Moon still ~760,000 miles away, so it isn’t close enough to the probe to make it appear larger than the Earth.
Ok good info – and it doesn’t make the Moon appear a whole lot bigger proportionally than it should since both are pretty far from DSCOVR, and not like the Moon is halfway or something.
The Moon appears roughly 45% larger relative to the Earth from GoreSat, then if they were side by side.
Good to know
The Moon would have an angular diameter at that distance (3/4 million miles) of 0.16 degrees.
The Earth has an angular diameter at its distance (1 million miles) of 0.45 degrees.
Or, an Earth – Moon ratio of 2.8 which is exactly as it appears in the image.
If the Moon were side by side with the Earth, the ratio would be greater around 4
Yes
I agree
What I didn’t realize is that the moon is so small!
Very cool to see!
very roughly, the Earth is 8000 miles in diameter and the Moon 2000 miles in diameter (4 to 1). Only Pluto/Charon has a ratio smaller (2 to 1).
The rest are WAY WAY greater.
Might account for the melted ice on Pluto.
Side by side view. They actually would be separated by 30 earth diameters;
(CLICK ON IMAGE TO EXPAND)
http://i.ytimg.com/vi/FjCKw…
Here is an image from the surface of Mars of the Earth with the small and dark Moon. it is a bit misleading because it is not the separation you would see with the naked eye. It is a magnified view of the horizon:
(CLICK ON IMAGE TO EXPAND)
http://static.ddmcdn.com/gi…
It’s actually a pretty solid size, a little bigger than I expected I guess, but it is closer to the camera, not sure by how much, lol
240,000 miles
Take out a ruler and see the 2.8:1 ratio
Moon sure looks dead compared to earth.
Would it ever be possible to spin the moon so that is could have 24 hours days?
Maybe have space elevators tied to orbiting asteroids with nuclear drivers on the asteroids to keeps the momentum going?
Nope. Way too much energy involved in trying to do something like that. Plus the now-rotating Moon will simply continue to exchange tidal energy with the Earth, actually slowing down both the Moon and the Earth’s rotation. It would eventually become tidally locked again and the Earth would have a longer day.
In addition to Hug Doug’s comments, the Moon is quite asymmetrical. The tidal effects on the Earth of a spin faster than its current 29 day rotation might be rather large and unlikely to be net positive for us.
Is there a link that always has the latest pic?
Is there a twitter account that only posts the latest pic (every couple hours) that I can follow?
Last I heard, apparently there will be a daily image posted with a 12 to 36 hour delay on a webpage to be set up in September.
When’s the next solar eclipse? *looks info up*
Partial eclipse across Antarctica September 13.
Next total eclipse is March 8/9, 2016.
That’ll be a sight to see.
http://www.timeanddate.com/…
Make your reservations now, Doug. I have.
It would be fun to be an eclipse-chaser! But I’ll just have to wait for the eclipse that will cross North America on Aug. 21, 2017
That’s the one I was talking about, actually. Got my dates goofed up.
I was kind of wondering that too. The Moon is almost totally lit here, but the shadow is a bit off. Would you be able to see a dark spot on Earth from this distance? I think it would be large enough, but not sure if it would contrast enough to make it out. It would be sweet to see the Moon and it’s shadow on the Earth too!
Keep in mind that DSCOVR may not be in position to see the Moon during these eclipses (since it is in a halo orbit around L1, it only crosses the orbit of the Moon twice a year), but it certainly will see the shadow of the Moon on the Earth. Eclipses have been observed from space stations.
http://www.astronomy.ohio-s…
http://i.ytimg.com/vi/BXGWC…
Ok, now that’s what I need to see next from DSCOVR 🙂
there should soon be a video with the front face of the moon as it passes behind the earth.
There are some trajectories that pass inward of the Earth.
Ya know.. this might have bad repercussions. The dust on the Moon is as dark as charcoal. The full Moon farside seen in the video is much darker than the shiny Earth. I fear this will feed the confusing term “Dark Side of the Moon” 🙁
It’s not that confusing, it’s a nice poetic term for the lunar far side. Actually its brighter on the far side, as there are several dark maria on the near side. I think it appears darker in this image because the camera is ~3x further away from the Moon than we on the Earth are. Could also be due to camera settings.
The lunar albedo is 1/3 the Earth’s. In this image the Moon is a quarter million miles closer to the camera than the Earth (and the same distance closer to the Sun). Because the exposure of the camera is set for the brightness of the Earth, the actual relative dullness of the Moon is emphasized.
I understand the poetic use of “dark” as the mysterious and unknown, but what I fear is that the poetic will be confused with the literal based upon the dimness of the image.
Prescient
Radiance is radiance no matter how far the target.
Joe, I was actually answering two points at once.I was putting a number on H.D.s lunar distance and separately pointing out the lower albedo. I wasn’t relating them. I oversaved a period and a capital.
Just sounded like you were saying the brightness (radiance) of an extended object depends on the viewer’s distance from it. It doesn’t. The observable radiance depends only on the object’s distance from the radiating source, unless it’s collimated, and its reflectance, And the Earth and Moon are darn near at 1 AU no matter the phase.
Now on rereading and your reply I see you were referring to the camera dynamic range setting not some distance vs radiance idea.
There really would be no big change in relative radiances if the Moon were on the far side of the Earth (ignoring the difference in Moon near and far side reflectance), still about 1 AU to the Sun. And the changing camera-to-target distance is a non-factor as I mentioned. Cheers.
Do you mean people attacking Gore and/or climate science?
What is the link?
Possibly due to the nutjobs declaring this is fake. There’s already a bunch of people on facebook dribbling the usual nonsense.
Behold: https://www.facebook.com/sp…
what are the links?
Unreal! If there was no description that this came from DSCOVR, I would have thought it was a composite of Photoshopped photos and made into a gif. It gives perspective of size of moon compared to earth, but shows how close it is (actually it is long distance but in galactic scale it’s a walk to the local store), you can feel how the moon pulls the oceans towards it.
The presence of the moon and the effect on tides is part of my daily ritual.
As a denizen of beautiful Naples, Florida, I take advantage by running a couple miles each day on the beach. A handy iPhone app called ‘Tides’ shows me where the tide will be so that I can find a strip of hard sand.
Far back in the last century my wife and I were bicycling/meadow-camping across Ireland. When in Galway we saw an elaborate tent camp set up way out on the sandy flats from the shore. In about 3 hours those hapless hikers were going to be on a scenic cruise of the Atlantic.
Sometimes it helps to understand the Universe and its Rules.
In dealing with Nature there are no rewards and punishments, only consequences.
I have an app called iCTides that also runs on the Apple Watch — very handy!
Yeah it looks like a video game, or a person messing around in some celestial software.
Welp, that’s my new desktop!
Nothing nefarious. Sometimes we simply don’t have the person-power to moderate all the comments that come in after hours on the most popular videos. FWIW, so far no one seems to by trying to use it as a platform to attack the former Vice President. Plenty of people attacking NASA for supposedly faking it, of course.