On Sun, 09 Dec 2018 23:28:59 -0000, danny burstein wrote:

In "Bruce Farquhar" writes:

Why are these not used on earth?

Do you really, really, want chunks of plutonium
or strontium 90i sitting around?

We do have nuclear power stations which can and do explode....

Well, since you ask:

[wiki]

In addition to spacecraft, the Soviet Union constructed
many unmanned lighthouses and navigation beacons
powered by RTGs.[5]
......
One RTG, the SNAP-19C, was lost near the top of Nanda
Devi mountain in India in 1965 when it was stored
in a rock formation near the top of the mountain
in the face of a snowstorm before it could be
installed to power a CIA remote automated station
collecting telemetry from the Chinese rocket testing facility.
=======
rest:
https://en.wikipedia.org/wiki/Radioi...tric_generator
On Sat, 08 Dec 2018 21:04:59 -0000, Brian Gaff
wrote:

I'm sure you know this but the Voyager spacecraft are using thermocouples
using the heat from decaying plutonium for power all the way out in the
cosmos. it may be reducing now but its been one heck of a long time.