APOD: Earthset from Orion (2024 Nov 20)

[APOD Robot]

Earthset from Orion

Explanation: Eight billion people are about to disappear in this snapshot from space taken on 2022 November 21. On the sixth day of the Artemis I mission, their home world is setting behind the Moon's bright edge as viewed by an external camera on the outbound Orion spacecraft. Orion was headed for a powered flyby that took it to within 130 kilometers of the lunar surface. Velocity gained in the flyby maneuver was used to reach a distant retrograde orbit around the Moon. That orbit is considered distant because it's another 92,000 kilometers beyond the Moon, and retrograde because the spacecraft orbited in the opposite direction of the Moon's orbit around planet Earth. Orion entered its distant retrograde orbit on November 25. Swinging around the Moon, Orion reached a maximum distance (just over 400,000 kilometers) from Earth on November 28, exceeding a record set by Apollo 13 for most distant spacecraft designed for human space exploration. The Artemis II mission, carrying 4 astronauts around the moon and back again, is scheduled to launch no earlier than September 2025.

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[RocketRon]

Looks like a dime falling down out of reach !
An iconic pic for the future ?

I have always wondered how NASA organises the navigation for these events.
What do they do for reference points/waypoints for celestial navigation in 3-D. ??
Are there any online 3-D navigation explainers ?

Merely pointing the nose towards the Moon would not quite achieve what is required.
When the whole plot is swirling around, almost independently of each other.
Planning that 130 km flyover would require near pinpoint precision, all along the way..
Must require some serious computer time ?
Calculating rocket burn times must be a very precise business also.
(Ask that Tesla that missed Mars - by a long way !).
??

[raschumacher]

Why is the resolution of the Moon's surface much worse than the image of Orion? Something to do with the dynamic range of the camera?

[Ann]

Since I am the self-appointed Color Commentator, I note that the only spot of color in this image is the (rather pale) bluish color of the Earth.

Earthset from Orion. Image Credit: NASA, Artemis 1

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I note that the sunlit face of the Moon is not very much darker than the sunlit face of the Earth. But parts of the Orion spacecraft are much brighter than the Moon (and the Earth). I guess it goes to show that the albedo (reflectivity) of the Earth is perhaps not as high as some of us might imagine. The Moon, of course, is really dark.

(Speaking of color, I think I remember that one of the astronauts that landed on the Moon found a spot on the Moon which was bright orange. I guess that must have been a rare outcrop of some sort of iron oxide compound, similar to whatever it is that gives Mars its reddish color.)

A final note: The Earth that we see in this APOD seems to present a gibbous phase to whoever took the picture that is today's APOD.

Ann

[johnnydeep]

Why is the resolution of the Moon's surface much worse than the image of Orion? Something to do with the dynamic range of the camera?

Not sure, but this image seems to be a still (or even a screen grab) from the first second of this video:

https://www.flickr.com/photos/nasa2expl ... 303788800/

[Guest]

Why is the resolution of the Moon's surface much worse than the image of Orion? Something to do with the dynamic range of the camera?

I think it’s because the shuttle is closer than the moon. Visually it looks like they’re the same distance but pretty sure the moon couldn’t fit in the frame like that if it was the same distance away as the ship

[RockatRon]

It sez the camera is externally on the Orion, so its definitely way closer than the moon. !

That is a strange contrast in colour and contrast....

[RocketRon]

No comments/knowledge/expertise on celestial navigation ??