Utric. Flying Objects

Barry Meyers-Rice (barry@as.arizona.edu)
Tue, 14 Jun 94 09:48:45 MST

Last night I keyed out another newly flowering plant in the collection.
This one turned out to be _U.bifida_, a small yellow flowered beastie. I
was not looking forward to keying this plant because I could tell it was
from section _Oligocista_, which has 37 species! And about half of those
are yellow flowered. It took a few hours of careful checking to make

>worthwhile amount. I've tried collecting some off the roof of the house from
>the gutters but I did not use this water since it looked a little brownish.
>Would this water be safe for the plants despite its coloration?

I agree with the other posting that this is potentially hazardous water.
I used to collect rainwater from the greenhouse (I installed a system of
gutters) but even though I used no materials like tar on the roof, windblown
contaminants decreased the quality of the water. I've switched to RO (Reverse
Osmosis) water since then.

>plants. I seriously doubt any stage of the life cycle of any VFT could
>survive the temperaturea attained by an asteroid passing into our atmosphere
>now or in the ancient past. Even seeds cannot tolerate temperatures such
>as these.


Actually a somewhat subtle point here. Planetesimal bodies approximately
the same distance from the sun as is the Earth are at an equilibrium
temperature of about 0 Celsius (freezing). An object on re-entry experiences
huge amounts of wind resistance (because of huge relative velocities) and
this heats the planetesimal. Small objects will be completely vaporised (we
all know this is the cause of meteors aka falling stars aka shooting stars).
The cores of larger objects will make it to the Earth. It is thought that for
these larger objects, much of the wind resistance will not heat the body,
so much as explosively remove its outer layers by ablading them. The core
could remain quite chilly. It is quite reasonable that a dormant life inside
some appropriately sized planetesimal could survive re-entry---assuming
of course that it could survive a few billion years of vacuum. But a life
form adapted to vacuum life would probably be pretty unhappy to find itself
in the dense and corrosive atmosphere found on the surface of the Earth!
Enough said, back to CP.