To See Ourselves as Others See Us

 

The Mighty Mark 1 - a place of pilgrimage

On the day of named-storm Eunice in 2022, I managed to keep my appointment with MikeGarrett, Sir Bernard Lovell chair of Astrophysics at University of Manchester and Director of Jodrell Bank Centre for Astrophysics. Jodrell Bank, with its famous Mark 1 Telescope - made out of bits of battleships! - a name to conjure with. Many visits as a boy there; a place of pilgrimage during the Apollo program. Keeping just ahead of the storm on the M6, we were inside the Alan Turing Institute when it finally hit, and it was ‘knock-you-off-your-feet’ strong when we exited 2 hours later. It was great to meet a Radioastronomy and SETI group and to present the AMiTe idea. Lots of discussion, suggestions for references and encouragement to think further about observational consequences.

While Mike’s JBCA group of 190 people have wide ranging (multi light-year!) research interests including active galaxy nuclei and giant arrays (running  e-MERLIN, the UK's radio astronomy network), they are also active in the Search for Extraterrestrial Intelligence (SETI), and Mike is currently vice-chair of the IAAs SETI Permanent Committee.

So it’s quite fun to keep tabs on his publications. Here’s one that was publicised only in the last week: What would aliens learn if they observed the Earth? This claims to be the first proper study of the Earth’s Technosignature in 50 years and takes into account all modern human sources of radiation. We currently emit a whopping 4GW of radio noise, just from mobile phone transmission. The team has analysed databases of transmitters and considered the radiation pattern, and the potential for detection at nearby stars. These were limited to nearby systems, including Alpha Centauri, out to a maximum of 8 light-years. The conclusion:

“We worked out that an alien civilisation near these locations would, however, need much better telescopes than we have to detect the Earth’s mobile radio leakage. But that would be quite probable, given most technical civilisations are expected to be much more advanced than we are.”

It would be lovely to think that the closest stars have anciently wise civilisations, just waiting for the ‘youngsters’ (us, a mere 4.5bn years after the Earth cooled) to grow up and invent smartphones. Life may be ubiquitous (C’mon NASAPerseverance) but there again, it’s been a long, hard road here. And despite the best (breeding) efforts of Elon Musk, human numbers may start to decline as early as 2050. If the closest extant technical civilisation may be “outside theMilky Way and therefore forever inaccessible” (Brian Cox musing) then we’re going to need a pretty big ‘scope on the Cheshire Plain to detect that.

But maybe there would be a chance to detect ‘we’re here’ signals from an AMiTe point. I’m still to write up the next version of the paper with suggestions from meeting Mike, but there are some clues in the 'Brian Cox' post. Happy listening!

Picture credit: Unesco