cubinator

I will be able to give a try at the value of the distance later on, but for now I can say that Mars is definitely farther away than the Moon.

So will astronauts egress Orion after it's already on the boat?

It's probably gotten all covered in dust, what with getting left alone all that time. Better go sweep some of it up.

Learning is cool, having to get jobs isn't.

You will have to wait patiently, as I need to write a report on a far less exciting experiment for a week first.

Thanks greatly @Starshot! I hope you get some sleep at some point!

I have my reappearance times! First Appearance 04:09:27.7 UTC Fully Detached 04:10:06.8 UTC What an amazing experience! I'm definitely going to go watch Mars for a little while longer, because I can see an amazing amount of detail!

Thanks so much for the observation @K^2!

Mars occlusion from Minnesota: 1st Contact 03:03:10.7 UTC 2nd Contact 03:03:58.0 UTC This is 1 minute later, and slightly longer lasting than Stellarium predicted. Perhaps I should make sure my location is set precisely.

I set up my telescope and I haven't been able to spot k Tauri in the Moon's glare. I think that star's not going to be much help. I think the calculation should still be possible with timing of just Mars and parallax across Earth's surface, if we use the known distance to the Moon and Moon's angular velocity. It most likely won't be as accurate, but it might be good enough. We can know the Moon's angular velocity across the celestial sphere from its period, as well as the Moon's angular size, and because we're effectively measuring Mars' angular velocity against the Moon we can find Mars' angular velocity against the celestial sphere. We just need to take a guess at the timing of Mars' occultation on different parts of Earth based on the distance to the Moon and figure out the difference with what we observe.

That's a good idea, I may have to try that.

I also suggest using an online service like https://time.is/ or https://www.time.gov/ to verify the accuracy of your clock.

There may be a few ways I could make this work with fewer observations, but all of these measurements can be helpful. The time it takes Mars to 'set' and 'rise' should be around 30 seconds, so I think if we are measuring a difference which should be a few seconds we might just get something. I think the rotation of Earth might actually help us out a little here too, by increasing the distance between our first observations by a little bit. You should have the Moon about 20 degrees up at disappearance, and rising. Thanks so much! That would be fantastic! As for the timing measurements, I am thinking of recording myself calling out times on my phone, because I won't be able to reliably hit a stopwatch button on the screen while I'm looking through the telescope. I'll call out the time of day at some point in the recording so I get a basis for the other timings.

A more perfect opportunity is unlikely to come by chance, and it's a rare experience to begin with, but I can't make you do it. I know the value of sleep too. Alright, maybe you can let me know an hour or two in advance whether you think you'll be able to make the measurements. If you can catch the emergences but not the disappearances that would be just as helpful.

I did a similar experiment a few years ago with fellow forum user @LaydeeDem where we used parallax to measure distance to the Moon. We got a pretty good estimate of its distance, and this time it's not necessary to take an image like we did last time, just to record the timing between certain events. I think the parallax of the Moon will be irrelevant for the Mars experiment calculations because we are only using the Moon's angular velocity across the sky as a basis for other timing measurements that give us Mars's position against the background stars.

Original message: On the night of Wednesday, December 7th/Morning of Thursday December 8th, Earth's Moon passed directly in front of Mars for observers in the highlighted areas of this graph. The event coincided with the opposition of Mars, when it should (theoretically!) be at its closest point to Earth. Using the difference in timing of the event at different locations around the Earth, it should be possible to calculate the distance to Mars using parallax. Thanks to the effort of a few of our forum members, timing data was gathered from three distant points across the world! California: Mars Disappearance: Halfway ~18:34:54.3 PST = ~02:34:54.3 UTC Fully Set 18:35:18.4 PST = 02:35:18.4 UTC Mars Appearance: Halfway ~19:35:39.5 PST = ~03:35:39.5 UTC Fully Risen 19:36:02.6 PST = 03:36:02.6 UTC Minnesota: Mars Disappearance: Beginning 03:03:10.7 UTC Fully Set 03:03:58.0 UTC Mars Appearance: Beginning 04:09:27.7 UTC Fully Risen 04:10:06.8 UTC Derbyshire: Mars Disappearance: Beginning 04:57:02:82 UTC Fully Set: --- Mars Appearance: First Seen 05:57:11:09 UTC Fully Risen 05:57:36:71 UTC Thanks to @K^2 and @Starshot for participating and providing this data! I will not get around to the math on this right away because of other obligations, but I will probably have some results to post here by the end of the year!

What happens on Gateway if there is a solar flare?

"...From a certain point of view."

However, Snoopy was not intended to carry humans to the distance it achieved, whereas Orion was.

Amazing to be able to see the far side like that, and just in general to watch live.

That rocket was just as pretty as Shuttle. Sad to see those SSMEs go.

I agree. I'd love to see the GSE separations from this angle.

Radar problem for the range, now... we can't catch a break.

Sounds like they've stopped the leak!

I know but I will be tired in class tomorrow