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The Night Shift

February 19, 2004

by Peter Backus, Observing Programs Manager

It seems like an anachronism.  We have a high-tech search system that practically runs itself, but we have a person on duty to keep a written log.  Every few minutes, the observer carefully copies numbers from a computer screen into a notebook.  The screen displays numbers from a computer file that is archived.  So why do we have a Ph.D. copy data thats already in the computer?  Its not to maintain full employment of astronomers.

Our search system and its software are relatively new.  We dont yet trust it to make the right decision every time.  So, forcing someone to check every result right away gives us confidence that the observations are reliable.  When we do catch the occasional error, it is reported right away and usually fixed within hours. 

Then there are the surprises.  For example, there are power glitches.  Although our systems are protected by uninterruptible power supplies, there is something in the observatory frequency reference system that isnt.  When the power drops, we have to manually reset some components that are locked to the observatory reference.

Perhaps the most important function of the observer is to observe, i.e., to notice things, subtle things, that the computers were not programmed to see.  We found some internal signals in the Arecibo electronics because someone noticed that a signal seen at one frequency looked suspiciously like a signal at a completely different frequency.

As the errors and surprises become less frequent, we become more confident in the system.  Thats important for our next observing venue, the Allen Telescope Array.  When its completed, we plan to observe with the ATA seven days a week, 24 hours a day.  We simply cant afford to have personnel watching over the system all of the time.  It has to be able to observe on its own and only call for human intervention when necessary.

So, here I am at three in the morning, hunched over a notebook copying numbers.  It is not the most exciting job Ive ever had.  But at least once an hour, the computer commands the telescope to point to a new star.  Since it typically takes five minutes for the telescope to slew, I get a chance to walk around and stretch.  I usually walk outside and watch the azimuth arm and the Gregorian Dome swing slowly into position.  The view from the front of the control building is spectacular.  Beyond the giant antenna I see the Southern Cross and near it, the bright star Alpha Centauri, a twin to our Sun only a little more than four light years away.  Perhaps this isnt such a bad job after all.  I guess its time to get back to the log book.