Doug's Darkworld

Ah, SETI. The search for extra-terrestrial intelligence, a topic near and dear to my heart. One of the very first books I saved up for and bought as a teenager was one of the first, if not the first, SETI books. So this is a topic I’ve given a lot of thought to. So have a lot of people, SETI has been an ongoing area of scientific enquiry for decades, the first papers were published in 1959. I was born in 1957,  just about when scientists were starting to seriously consider the topic. Heck, the space age started less than three months after I was born, is it any wonder I am fascinated with everything to do with space?

Okies, moving right along. So scientists have been searching for alien signals for decades. And sadly despite amazing advances in our ability to “listen” to vast numbers of radio frequencies and locations, so far, nada. Well, almost nada, but that’s a topic for another post. That’s been the main focus of SETI, trying to listen for alien radio signals. There’s been a few other ideas too, one of which was to look for alien probes that have visited or are even orbiting Earth. And one of the most obvious places to look is … the Lagrangian points.

What are the Lagrangian Points? They are helpfully illustrated above in the diagram of the Sun and Earth, but the same applies to any two bodies, like the Earth and the Moon. The Lagrangian points, or L points (L1-L5,) are basically stable points in any two body system. IE an object in or orbiting an L point will pretty much stay there forever. Or more realistically, will be able to remain there with a very modest expenditure of fuel. Humans in fact have a number of spaced based instruments parked in and around various L points. In other words, one of these points would be a very obvious place for aliens to park an Earth observing probe. And in fact they have been searched with deep space radar by scientists looking for anything that might be lurking there, natural or unnatural. There’s clouds of asteroids in some of the L points around Jupiter and a few other outer planets, but except for some dust, there’s nothing in Earth’s L points.

Well, it occurs to me that aliens who are watching us might want to remain undetected. There’s any number of perfectly plausible reasons they might want to remain unobserved. For one, as we try to observe wildlife undetected, so might they want to observe us. Plus it would be really annoying to fly a probe all the way to Earth, and then have the comparatively stone age natives find it and break it. It would certainly be easy enough to make a probe that was hard to see, paint it black and we’d have to basically run into it to see it. And the use of microwave radiation (radar) to scan for matter is a pretty obvious application, and we already have the technology to build stuff that is hard to see on radar. So it wouldn’t be particularly difficult for advanced aliens to hide a probe from radar, visible light, and heck, maybe any number of possible scanning mechanisms using some type of radiation.

So assuming aliens had such a probe parked nearby, and it was shielded from various types of scanning devices such as radar, how the hell could we spot it? Well, how about occultation? Occultation is when an object passes between an observer and a distant object. For example when the Moon passes in front of a planet or a star. A slight variation on this is a transit, that’s when the object passing between the observer and the  distant object is smaller than the distant object. Like when Mercury or Venus passes in front of the Sun. We already have space telescopes so sensitive that they can measure the minuscule drop in light from stars light years away when planets orbiting those stars transit them, this is how we are detecting all sorts of planets around nearby stars.  So it  seems to me that this is off-the-shelf technology, how hard could it be to point a telescope at  star that was about to pass behind a likely probe location in an L point and see if some “invisible” object occults the star as the probe briefly passes in front of it?

Honestly, I don’t know enough about astrophysics and math to even guess. I’m pretty sure the occasional star briefly winking would hardly ever be noticed on Earth, and even if it was it would be dismissed. So I think it’s possible that humans could have overlooked these sorts of proposed occultations. There are many astronomical discoveries where  it has turned out after the fact that they were  photographed years or decades before the official discovery, and no one noticed. And in my Internet searches and SETI readings I haven’t found any indication that anyone ever thought to use occultations to look for alien probes parked in L points.

So that’s my idea, maybe its original, maybe not. I publish it here in the hopes that some readers with more knowledge in the field can assess if it’s a good idea, or if it’s one of those ideas that not only doesn’t get off the runway, it explodes in the hanger. And I also publish it here so that I can get credit if it is a new idea, I’d be annoyed if I mentioned it to some astronomer in a  bar, and a week later she achieved fame and fortune by being the first person to discover an alien artifact. Heck, maybe it’s such a good idea that the MIB will try to stop it from getting passed on.  In fact I think I hear a wheelchair outside my door right now, wtf?