Artemis 2 launch - humans return to the Moon after 54 years

[.Scott]

Artemis, twin of Apollo.
Fitting name for the second series of manned moon missions.

And she personified the Moon. But Artemis was the older of the twins.

 

[PeterDonis]

Did the rocket speed up when moon's gravity became stronger than earth's?

I'm not sure I would expect it to, because the trajectory it's following is so far from the Moon, as compared with the Apollo missions. I haven't run the numbers, but I suspect the Moon's force is just curving the trajectory, not speeding it up.

 

[Charles Link]

I did find from one article in a google that the expected speed at closest approach would be 3,139 m.p.h. I am lead to believe the website that showed no increase all day and a decrease to below 1,000 m.p.h. was inaccurate.

Edit: I found a video on Facebook that may offer at least a partial explanation: The rocket passes the moon to the left of the moon and then loops to the right when it is behind it, with the moon moving right to left. The 3,139 number might be the speed relative to the moon. I estimate the moon's right to left speed at about 2,000 m.p.h. Edit: With a google I see the moon moves about 2,288 m.p.h. in its orbit around the earth.

Meanwhile an acceleration of the rocket to the right will create a velocity component to the right that adds as a vector to the forward velocity component (relative to earth) and may not affect the speed w.r.t. the earth all that much.

 

[Jonathan Scott]

The area brightness of an object does not depend on distance.

True of course, and presumably relevant in this case, but to avoid confusion this needs to be accompanied by the important point that if the angular size of an individual object (such as a star) is smaller than the sensor or eye resolution then the apparent brightness is decreased accordingly (which is presumably the main factor limiting the number of stars which we can see with the naked eye).