The Circumnavigation of Mercury

[Andrew Linton]

Arrived at the Prime Meridian on the Equator.

So what I might do next is take a little excursion in my ship to measure the position of the terminator - I'm interested to see how far it has moved since I started the journey 14.8 days ago. At that time the 'dawn' terminator was at -110 degrees. Then I'll return to (0,0) to continue the drive, with my next milestone (kilometrestone, degreestone) at (0,10) which will be one third distance.

 

[Andrew Linton]

I observed the longitude of the terminator and found that it had moved, on account of the rotation and orbit of Mercury, to a longitude 17 degrees to the West; that's 1.14 degrees per day.

I'm currently at (0,0) and the 'dusk' terminator is at (0,53). IF, and it's a big IF, I continue to travel at an average of 7.5 degrees per day then let d be the number of days for me to reach the terminator. Then, I think this is right:

7.5d = 53 - 1.14d
8.64d = 53
d = 53/8.64
d = 6.14 days

In other words, in about a week I should be going into darkness.

 

[Andrew Linton]

Hehe I hope I will not disappoint...

Is your commander name the same as your forum name? I can send you a friend request and that will make finding each other a bit easier.

EDIT: ignore my question, apparently we're already friends

I just tried to add you as a friend on Discord; please could you check. I'm trying to coordinate a joint meetup with Just Bear Li who did some filming some days ago. Thanks.

 

[Jonas Treesong]

I just tried to add you as a friend on Discord; please could you check.

Accepted!

Not sure if I get any playtime this week though...

 

[Andrew Linton]

Accepted!

Not sure if I get any playtime this week though...

No worries, I'll be here for at least a month.

 

[Andrew Linton]

With Alec Turner on the way to (0,9). Fun driving with you Alec, and the scenery definitely needed more pink.

 

[Andrew Linton]

At (0,10), which is one third distance! Don't be fooled by the terminator in this image; it's not there, but more like at 52 degrees East.

 

[Alec Turner]

View attachment 183693Fun driving with you Alec, and the scenery definitely needed more pink.

You too, and Glad to oblige! Bravo on making the third (despite my attempts to distract you with ideas of driving to surprisingly distant crater mounds for photo shoots)

Video coming soonish.

 

[Andrew Linton]

Some people say the equator is an imaginary line, but no, it's real.

 

[Alec Turner]

 

[Alec Turner]

Some people say the equator is an imaginary line, but no, it's real.

View attachment 183710

I'm glad (sorry) that you're seeing those too. I haven't seen dark areas like that for a long time (I thought they'd been fixed). I've just recently switched to a 1440p monitor with a high refresh rate and I was slightly worried that that was somehow contributing to the effect because I ran into it a lot while following you (as you can see in the video).

 

[Zieman]

I'm glad (sorry) that you're seeing those too. I haven't seen dark areas like that for a long time (I thought they'd been fixed). I've just recently switched to a 1440p monitor with a high refresh rate and I was slightly worried that that was somehow contributing to the effect because I ran into it a lot while following you (as you can see in the video).

There are glitches in the matrix.

I also heard that many permanent POIs (like the 'All for germanium' tourist beacon) have gone AWOL.
I blame FCs.

 

[Alec Turner]

One more image grabbed from the video footage before I tidy up my hard drive a bit.

 

[Andrew Linton]

What a brilliant video, truly Oscar material! So glad you incorporated my more spectacular wipeouts. Mercury will be depleted in nickel and iron by the time I've finished, I have to make so many repairs.

 

[Andrew Linton]

Looking back at the westering Sol, I wondered how high it was in the sky. Oh, for a sextant right now.

...but, hold on, I have a sextant with me, or at least I can improvise one.

...by measuring the length of the shadow cast by the port thruster I can ask Pythagoras what the angle is to Sol.

It turns out to be 36 degrees, but I must add the 5 degrees that the SRV is pitched up, giving an altitude of 41 degrees above the horizon.

I feel sure this tells me something about the longitude of the terminator, but my schoolboy trigonometry isn't telling me.

 

[Alec Turner]

Looking back at the westering Sol, I wondered how high it was in the sky. Oh, for a sextant right now.

View attachment 183723

...but, hold on, I have a sextant with me, or at least I can improvise one.

View attachment 183724

...by measuring the length of the shadow cast by the port thruster I can ask Pythagoras what the angle is to Sol.

It turns out to be 36 degrees, but I must add the 5 degrees that the SRV is pitched up, giving an altitude of 41 degrees above the horizon.

I feel sure this tells me something about the longitude of the terminator, but my schoolboy trigonometry isn't telling me.

I have to ask ... are you aware of @Straha Yeagar's circumnavigation a couple of years ago and his incredibly successful experiments using shadows to measure the circumference of the planet he was on? Really extraordinary stuff!

meridian-a-planetary-circumnavigation

He too was constantly in need of a sextant.

 

[Andrew Linton]

I have to ask ... are you aware of @Straha Yeagar's circumnavigation a couple of years ago and his incredibly successful experiments using shadows to measure the circumference of the planet he was on? Really extraordinary stuff!

meridian-a-planetary-circumnavigation

He too was constantly in need of a sextant.

Thanks for that link, I'll study it carefully this evening (Earth evening not Mercury evening - I think it's mid-afternoon on Mercury where I am)

 

[Andrew Linton]

This was easier than I thought, and I didn't even have to sleep on it.

When I was at longitude +12, I observed Sol at 41 degrees above the horizon. That means that 41 degrees to the East, Sol was on the horizon and just setting. Therefore, the terminator was at 53 degrees East, which accords with my observation yesterday.

 

[Andrew Linton]

Arrived at (0,16)

I would have arrived sooner except the Mauve Adder stole 5km which I had to repeat - I'm sure I hit the same rock second time around, speaking of which, some of these mountains are beginning to look familiar. I think I've flown over mountain range number 5 several times now.

 

[Andrew Linton]

This modest pair of stars is usefully pointing the way Eastwards. I've named them Finger of the East.