Although clouds had little effect on my observations at the end of last night, sunrise on March 30 shows rapidly increasing sky cover that soon fills the sky over the with torn clouds. I copy my data to a backup hard drive and go to sleep around 8 AM.
I wake up near 11. My observatory dorm room is dark, but my body knows it is not night. I have a thousand things to think and worry about. Worse still, the wind is howling around the dorm. Especially since the instrument failure last night, I really need data tonight. That wind could stop it. If the wind is too strong, above about forty-five miles per hour, we will not even be allowed to open the dome.
I have slept only three hours. I desperately need more sleep, but the wind is in my soul. My body tenses up with every gust. I pray for sleep. I try to lie still and relax, to give my up anxiety to God. I tell myself what is obvious: that worry is destructive; that if anxiety about bad weather keeps me awake, I will not be able to observe as efficiently even if I have good weather. Worse still, I do not expect to sleep at all tomorrow: I have to travel by car, airplane, and bus to
I have fought this battle many times at other observatories, and have seldom won it. I usually cannot go back to sleep once I have woken up in the daytime. There is too much to think about, and my over-active mind does not let me sleep. The effects of sleep deprivation accumulate from night to night: at the end of week-long observing runs I have sometimes been almost delirious.
Not today. Sometime after noon, my prayers are answered, and I sleep well. I sleep through the hours when the afternoon calibrations are taken, but with this telescope that does not matter: the daytime staff take a flawless set of calibration images without me. I wake up in time for dinner, and go to the door of my room.
This is the moment of truth. There is no sound of wind now, but last time I saw the sky it was hopelessly cloudy. The tiny, blurry window near my toilet looks blue, but that doesn’t mean much. I pray for good weather for the thousandth time. I take a deep breath, and I open the door.
Blue and clear. Clear from the Andean peaks in the east down to the west horizon, where a sheet of clouds far below us always shrouds the
Except that the seeing is slightly poorer, this night is everything I hoped last night would be. DECam performs perfectly. So does the telescope.
Far into the night, I use the third workstation to check an image, and I see something strange. The now-familiar starfield is there, but several bright parallel streaks span the entire image. This is so unusual that even the telescope operator is surprised. “What is that?” he asked, looking over from his own workstation.
I am wrestling with the same problem myself, but I have come up with a guess. “I think it is an airplane,” I say. We are both staring closely at the monitor now. The steady lights of a commercial airliner would make the streaks we see, but airliners also have flashing lights. If it is an airliner, why don’t we see them? I realize suddenly that there are three or four extremely bright stars in this image that are not in any of the others. The new stars lie at regularly spaced intervals along the streaks. “See,” I say to the telescope operator, “these are flashes.” We are both amused and pleased. The streaks and starbursts affect only a small fraction of the image area: they will not hurt my science. And now we are some of the first people in the world to have observed an airliner through a 4 meter telescope.
Dawn comes. I squeeze the last dregs out of the night as before, and then hurry to finish backing up my data before I need to catch my ride back to the town of