The observation of neutral hydrogen (HI) line emissions from within our home galaxy (the 'Milky Way') is a medium level difficulty project for the citizen scientist radio astronomer. The detection of HI line emissions outside our galaxy presents an additional level of difficulty.
The project described here is designed to determine whether extra-galactic neutral hydrogen (HI) line emissions from nearby galaxies can be detected using a small 3 metre diameter TVRO-style mesh dish.
In years gone past detection of any hydrogen line emissions were out of reach of the citizen scientist as a quote from one of the author's reference books states (circa 1975)...
"Unfortunately for amateurs, this 21 cm equipment is either too elaborate or too expensive for the average household budget. Until microwave equipment becomes available at a much lower cost, there is little point in pursuing the idea any further"
Fortunately for today's citizen scientist radio astronomer, that time has well and truly arrived.
It could be argued that HI observations are second only to the detection of pulsars in terms of difficulty for the citizen scientist radio astronomer with 'backyard level' systems.
The detection of extra-galactic neutral hydrogen is, in general, a significantly harder task than detecting neutral hydrogen line within our own galaxy - and thus provides an interesting challenge.