The Benac Orbit, Kepler’s Follow On
Once Kepler finds the other Earths, it time to listen to their radio stations!
So here is the next big thing: Craters as huge satellite dishes for antenna feeds orbiting above them.
Think Arecibo, but a bagillion times bigger, and instead of that little white thing hanging on cables with winches you have a satellite flying above the dish.
Ceres, you big ball of radio wave reflective ice and rock, this is what you–and your equatorial craters–were made for! Orbital parameters copy write. (But if you must know: www.twitter.com/johnbenac)
6 Responses to “The Benac Orbit, Kepler’s Follow On”
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Darnell Clayton on March 17th, 2009
Heh! That is a very interesting view of Ceres! I always saw it as a launching pad for mining the asteroid belt (since we assume it has water within it, which could make it “livable”).
Perhaps it could also serve as a communications hub as well.
Phillip Huggan on August 30th, 2009
I had a sketchy idea a while back that you use a farside Lunar Impact Crater for radio astronomy. This is already analyzed but uses an expensive and currently impossible “tarp” across the crater. I was thinking a “Peace Symbol” of three strips of “vitrified” Lunar soil could be created from crater rim to interior (I thought lenses NASA knows a microwave rover)…
It was pointed out, not very conclusively, the crater curvature isn’t homogenous or shaped right to make this work. If that is true long radiowaves are picky, wouldn’t the roughness of Ceres’s surface ruin this concept? Or does all the water overcome this? Or was a satellite team member BS-ing me and radiowave aren’t picky?
As an aside if you are doing a google search about why a cloud satellite named CERES was cancelled/postponed, it is really hard when there is an asteroid and another satellite mission with the same name. Lots of 5 letter words out there.
John Benac on August 31st, 2009
Well, a dish is “smooth” as far as the electromagnetic radiation is concerned as long as the disturbances are smaller than half the wavelength that you are using the dish for.
Also, a rough crater that has only 10 percent of it’s surface reflecting back toward the feed but is 200 times bigger than a conventional dish will still get you more photons, which is what it all comes down to in the end.
So a rough crater on Ceres, with it’s topography understood, can be a dish when raytracing, space time adaptive processing (STAP), and interferometry is used with an array of feed elements whose geometry is also known.
Phillip Huggan on August 31st, 2009
Right. Space time adaptive processing….
John Benac on September 1st, 2009
I would explain it, but Google does a better job. Basically, If I take a reading at 1 second and a reading at 2 seconds in a different location, I combine the readings as if I had twice the measurement instruments. If what you are looking at doesn’t change with time, then this works.
So if you combine the readings of a satellite as it passes over the crater and combine them all, it would be as if you has a linear array of antennas that were as long as the path that the satellite flew on. At least that is my understanding of the technology.