A lunar farside low radio frequency array for dark ages

by spekcular • 5 years ago

90 10 5 years ago

I know that this has nothing to do with anything, but every time I see a word document I just want to scratch my eyes out. I mean, it seems to have gotten much better since the last time I used it, but still, jeeez...

Of course that doesn't say anything about the content of the paper, but I don't have any real opinion on that, just childish excitement about the idea. :)

tapia• 5 years ago

I totally feel you...

surgeryres• 5 years ago

Fascinating.

They mention in the paper that the Dark Ages power spectrum would require a 100,000 dipole antenna array, seems like we are far from that.

Full disclosure brain fart - dark side of the moon still gets sun light (duh, right?), this basic fact had me scratching my head with regards to power source for an embarrassing amount of time.

tooltower• 5 years ago

Some scientists prefer the term Far Side because of this :)

vkreso• 5 years ago

One of two components of phase 1 implementation of the SKA[1], the SKA1-LOW in Australia, will host around 130,000 dipole antennas[2] when finished with construction starting soon.

[1] https://en.m.wikipedia.org/wiki/Square_Kilometre_Array

[2] https://www.skatelescope.org/key-documents/

mordymoop• 5 years ago

From the title my first thought was that this would be about hiding a low-power radio broadcasting station on the far side of the moon to help people reboot civilization after a dark age.

amai• 5 years ago

Me too. It sounded like an idea from Isaac Asimovs Foundation Series.

jcims• 5 years ago

Current terrestrial radio astronomy is severely handicapped below ~30MHz because of the effects of the ionosphere. It reflects/absorbs long wavelength RF.

This would be an amazing new capability. I am curious where all of the network bandwidth will be coming from.

ck2• 5 years ago

Drop a pack of 128 automated rovers with the antennas and let them crawl out to their designated grid

Which brings up the thought that someday hundreds of years from now someone is going to install GPS on the moon (and mars) and ruin radio silence

I wonder how they precisely position things on the moon now.

shagie• 5 years ago

Moon orbiters have the difficulty that there "mascons" (mass concentrations) on the moon that make its gravitational field very lumpy. https://en.wikipedia.org/wiki/Mass_concentration_(astronomy)...

That makes an orbital GPS difficult.

Lunar mascons alter the local gravity above and around them sufficiently that low and uncorrected satellite orbits around the Moon are unstable on a timescale of months or years. The small perturbations in the orbits accumulate and eventually distort the orbit enough that the satellite impacts the surface.
Because of its mascons, the Moon has only four "frozen orbit" inclination zones where a lunar satellite can stay in a low orbit indefinitely. Lunar subsatellites were released on two of the last three Apollo manned lunar landing missions in 1971 and 1972; the subsatellite PFS-2 released from Apollo 16 was expected to stay in orbit for one and a half years, but lasted only 35 days before crashing into the lunar surface. It was only in 2001 that the mascons were mapped and the frozen orbits were discovered.
... At that time, one of NASA's highest priority "tiger team" projects was to explain why the Lunar Orbiter spacecraft being used to test the accuracy of Project Apollo navigation were experiencing errors in predicted position of ten times the mission specification (2 kilometers instead of 200 meters).

You could still do things with atomic clocks on tops of mountains - but it is unlikely that we'll ever see something like StarLink or GPS on the moon.

I suspect they do the positioning today via a really good map.

https://moon.nasa.gov/resources/87/high-resolution-topograph...

NASA's Lunar Reconnaissance Orbiter science team released the highest resolution near-global topographic map of the Moon ever created to date. This topographic map shows the surface shape and features over nearly the entire moon with a pixel scale close to 328 feet.

https://www.lpi.usra.edu/planetary_news/2020/05/26/the-most-...

The geologic map makes use of LRO Lunar Orbiter Laser Altimeter data with 100-meter resolution for the polar regions and Kaguya terrain camera data with 60-meter resolution for the equatorial regions. This global map, combined with future high-resolution maps of local regions on the Moon, can be used to prioritize potential landing areas for robotic and crewed spacecraft.

To download it - https://astrogeology.usgs.gov/search/map/Moon/Geology/Unifie...

A lunar farside low radio frequency array for dark ages

Related Stories