The Sedna fallacy (was How does one find an Oort cloud body?)

--- In spacesettlers@yahoogroups.com, "brooksn" wrote:
> astronomers using the detection methods that found Sedna and other deep small bodies

Sedna isn't small compared to typical theorized Oort cloud bodies. It's about 1,000 km in diameter. Try 1 km.

Also, we know Sedna is larger than typical Oort cloud bodies, because if there were a trillion Sedna-sized bodies (e21 kg), they would together mass (e33 kg) more than the sun (e30 kg).

Sedna isn't deep compared to typical theorized Oort cloud bodies. It's less than 100 AU from the sun. Try 200,000 AU.

> we've gone from zero extrasolar planets 20 years ago to 891 today

Those were found by transit observation, and other detection methods that don't work on Oort cloud bodies:
http://en.wikipedia.org/wiki/Extrasolar_planet#Detection_methods

There are no Oort cloud transits to observe. As I said:

> > even if you were only one AU away from one, you still wouldn't be able to see it, because it would be cloaked in pitch blackness.

"Radial velocity or Doppler method"

...Doesn't apply to Oort bodies because of too little mass.

"Transit Timing Variation (TTV)"

...Doesn't apply because they are too small and too distant from any stars.

"Gravitational microlensing"

...Doesn't apply because their masses are too low.

"Astrometry"

...Doesn't apply because their masses are too low.

"Pulsar timing"

...Doesn't apply because they don't orbit a pulsar.

"Circumstellar disks"

...Don't apply because they are too small and too distant from any stars.