But I'll get back to this...
Let's go back to the start of a remarkable day at ESO's Paranal Observatory.
We started with a drive from the Very Large Telescope site (at Paranal mountain itself) to a nearby peak called Cerro Armazones.
It is here that the European Extremely Large Telescope (E-ELT) will be built.
Artist's impression from ESO (note cars in bottom corner!)
The drive was cross country and on pretty rough roads.
It was a bumpy ride
But we made it to the 3064m summit.
The summit is currently dotted with a few scientific instruments so astronomers have a good record of weather and atmospheric conditions at the peak.
This summit will eventually be blown away to make a nice flat platform for the monstrous E-ELT.
Me at the summit marker
On the way back down we stopped an a nice piece of "Martian landscape" and at that moment the Moon popped over the horizon.
My travelling companion, astrophotographer Pete Lawrence, was beside himself and started snapping away.
Pete and the Moon
He even lay in the desert dust in search of that perfect picture.
Back at Paranal itself, I was very fortunate to be given access to the the "delay lines" under the telescopes.
A lucky peek in the delay lines
I will visit this later in videos about interferometry, but essentially this pristine and precise tunnel is where light is sent to bounce back and forth like planes in a holding pattern!
It was very impressive and real highlight of the trip so far.
Next it was to the adjacent VISTA telescope, on a small sub-peak next to Paranal.
This is like a wide-angle lens telescope, imaging a larger tract of the sky.
We then returned to the main telescope platform, in the shadow of the huge VLT telescopes, for sunset.
Pete was hoping to capture the elusive green flash which can be seen as the sun dips below the horizon.
It is a challenging target and success is not guaranteed.
I filmed the whole process in what I think will be a very interesting and exciting video.
And to slightly ruin the ending, we were rewarded with an extraordinary green flash.
It was clearly visible to the naked eye and Pete captured this image (which is hot from his camera and not yet processed in any way!)
Still glowing with success, and with the stars and Milky Way appearing, we started taking a few night images.
Then another treat. One of the four VLT telescopes, UT4, is equipped with a laser to create a "artificial star" in the upper atmosphere.
It only is used occasionally and in short bursts.
But for reasons unknown to us, it was switched on for an extended period.
It felt like about 20 minutes.
Pete and I scurried about, taking as many pictures as we could.
Imagine if I actually knew what I was doing?
Fire the laser (the Moon also in shot!)
Finally the laser was extinguished and we happily made our way back down the mountain.
As a I type we are considering another adventure into the night for more photography.
Then tomorrow we start a very long drive to the the dramatic and high altitude ALMA observatory.
All the videos from the trip will eventually appear at Deep Sky Videos and Sixty Symbols.
Chile Diary - Day Four
Chile Diary - Day Five
Chile Diary - Day Six