# [The Oort Cloud](http://en.wikipedia.org/wiki/Oort_cloud)

The far edge of the Oort Cloud is believed to be [100,000 AU from the Sun](http://www.nasa.gov/sites/default/files/145944main_Kuiper.Belt.Lithograph.pdf). In fact, [Duncan et al. (1987)](http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1987AJ.....94.1330D&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf) created simulations that showed the inner edge of the Cloud to be at ~3,000 AU.

Given that 1 AU $\approx$ 8 light-minutes,
$$3,000\text{ AU}\times\frac{8\text{ light-minutes}}{\text{AU}}=24,000\text{ light-minutes}\gg1\text{ light-day}$$
Therefore, any signals - even from the *inner* edge of the Cloud - will not reach Earth for far more than one day, at which point the ship will be long gone.

Furthermore, any signals - even gamma-rays - should be reduced in strength, compared to signals from areas near any of the planets, the Sun, or the asteroid belt.