UFO in Red Dead Redemption 2

First, you will need to go to this house in New Hanover.

You will notice Skeletons (loot everything).

You have to inspect a letter on the table.

Notice it says 2 AM during "half moon".

After that, exit the house and go to the horse.

Hold the right digit button to open the satchel.

And then tab to kit (L1 or R1).

Press X on watches and X again to equip.

After that, hold L1 and Press R1 to tab to items.

You can use the right analog and R2 to select the watch.

Release L1 only to see the watch face.

You can now see the time.

You will need to hold L1, R1 tab to items again.

Right analog to bottom and R2 to camp.

Release only L1 to camp.

Then press triangle button and choose night.

After that, you have to go back to the house.

Go inside the house when it is 1AM.

Notice the green glow.

You need to wait until 2 AM.

At exactly 2 AM, a UFO will appear.

You need to select camera to take pictures.

Exit house and UFO files away.

Pictures are in a social club.

After that, get back on the horse.

And go to Mount Shann.

This is the location where UFO will return.

Wait until 2 AM.

Need a full moon or wait 2000 years?

You need to go to the highest peak.