the description which will give you digital privacy for a little more than two dollars per month a NUMBER_TOKEN-day money-back guarantee and will even throw in two extra months for free so it's a simple way to stay safe out there now coming back to our alien transmission if we can't decipher its meaning all is not lost the very fact that the signal is a laser or narrow beam transmission would immediately reveal it to be artificial thus establishing that we are not alone yet more at the source of that signal is a piece of alien technology in our own backyard something that we could visit salvage and potentially reverse engineer some might question the wisdom and procedures here might it be dangerous to visit the probe could we trigger some kind of hostile violent reaction how would the usa respond to china visiting and even recovering the probe before they do all of this is a great photo for science fiction but in this video we're going to try and stay focused just on the science questions and leave the politics aside one scientific question we can address is where this probe might plausibly be which in turn can give us some guidance as to where we should be looking for them remember that if this probe intends to image the earth at high resolution then it really helps to be as close as possible a low earth orbit or leo is ideal for observing the surface but it is already intensively monitored using a variety of techniques such as electro optical passive radio and active radar the us space surveillance catalog includes over NUMBER_TOKEN NUMBER_TOKEN orbiting objects as of NUMBER_TOKEN with sizes down to NUMBER_TOKEN centimeters of course an alien satellite could be simply smaller than this and thus undetected so far however a NUMBER_TOKEN centimeter size low earth orbit telescope would be limited to a spatial resolution of NUMBER_TOKEN meters which is really barely tolerable if you're trying to resolve the behavior of individual people on the surface perhaps this could be remedied with a network of interferometric centimeter-sized probes or even smaller but a low earth orbit is fundamentally problematic as such orbits are simply not long-term stable in particular atmospheric drag gradually de-orbits such objects over a time scale of decades to centuries anything below NUMBER_TOKEN NUMBER_TOKEN kilometers altitude will need periodic thruster adjustments to raise its orbit such a system is possible don't get me wrong but clearly there are also several reasons why a low earth orbit lurker is challenged by both our extensive monitoring of that region and the unnecessarily complicated mission profile that such a probe would have to have going further out we might next look to the moon a probe that landed on the moon would of course be perfectly stable from a gravitational perspective as well as undisturbed by atmospheric erosion weathering or geological activity however much like low earth orbit almost every part of the moon has now been extensively photographed and catalogued with orbiters over the last few decades for example the lunar reconnaissance orbiter imaged the moon's surface at a spatial resolution of NUMBER_TOKEN meters so if there was a NUMBER_TOKEN meter sized alien telescope on the lunar surface so it's hiding just beneath the resolution of our existing maps it would itself have the ability to image the earth's surface at a resolution of about three meters in visible light so again not enough to see the inhabitants here too then we can say that our existing data already starts to put pressure on the idea of a useful alien telescope on the moon obviously beneath the lunar surface anything is possible but that would now sacrifice the ability to image the earth in visible light in his paper james benford
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