Astronomers telescopes are focused on a very small section of space, not the sky within Earth’s atmosphere.

 An astronomer responds  – By Ian Porritt.

Astronomy adviser for UFOCUS NZ Research Network.

Both professional, and a lot of serious amateur astronomers, are not sitting outside looking up at the night sky when they are working. They are inside a control room and their telescopes are focused on a very small section of space, not the sky within Earth’s atmosphere.

I’m an amateur astronomer and my setup is as follows:

•  My telescope is housed in a small observatory/dome next to my house, so I’m not actually looking through the telescope, but I’m taking photographic images of a small portion of space.
• The telescope, and the CCD camera attached to the back of it are controlled via a computer, which is in a separate control room a few meters away.
• I’m not in the dome with the telescope nor am I outside. I’m sitting in a nice warm control room with the lights on and multiple computer screens around me. It’s very cold outside in the middle of winter and the lights of the computer screens would interfere with the telescope (we want it nice and dark).
• As my control room is close to the observatory, I have blackout curtains on the windows and door of the control room so that the light from inside doesn’t interfere with the telescope.
• So I don’t even have a good view of the night sky from my control room. The only time I’m outside is to check on the weather or the observatory. On a good night I’m maybe outside for only a couple of minutes every hour.
• The area of space I’m looking at is extremely small – if you hold your thumb out in front of you at arm’s length, the area I’m looking at is smaller than your thumb nail.
• My exposures are in the order of minutes, with specialised equipment that locks onto a star and tracks the star as the Earth rotates.
• If a dark object was to pass in front of the telescope briefly it wouldn’t even register. A few seconds of dark would make no difference to the image at all.
• If the object is light and small it would appear as a streak of light (as is the case when satellites pass through the field of view – it just shows as a long line of light).
• If the object was very light or bright then it would just come up as a white over-exposed image, and I would discard it.
• Imagine taking an image of a moving object zoomed right in with a 1 second exposure on your camera, and how blurred it would be, now imagine how a 5 minute exposure will look with an extreme magnification.

So a UFO could land on the front lawn and I would miss it (as long as it was relatively silent), as I’ll often have the radio or TV on to keep me company. And as my control room windows and door are blacked out as well, I would not even be aware of any bright light outside.

So if there was something out there within our atmosphere, or even at reasonably close proximity, I would never know about it.