Alien Contact Unlikely For Another 1,500 Years, Says Study (msn.com)

An anonymous reader writes: Astronomers at Cornell University predict based off estimates that alien contact is unlikely for another 1,500 years. MSN reports: "According to the astronomers, signals from Earth would need to reach half of all the solar systems in the Milky Way in order to be picked up by an intelligent life form. Given that signals from TV and radio were first sent into space as a byproduct of broadcasting 80 years ago, it will take around 1,500 more years for aliens to receive, decode and respond to the signals." A co-author of the paper who will present it at the American Astronomical Society's meeting on June 16, Evan Solomonides, said, "We haven't heard from aliens yet, as space is a big place -- but that doesn't mean no one is out there. It's possible to hear any time at all, but it becomes likely we will have heard around 1,500 years from now. Until then, it is possible that we appear to be alone -- even if we are not. But if we stop listening or looking, we may miss the signals. So we should keep looking." Stephen Hawking and Russian entrepreneur Yuri Milner announced a $100 million research program in April to send robotic probes the size of postage stamps to nearby stars within a generation.

Comments

Re:Twenty five thousand light years

[Zak3056]

In 25,000 years, you'd reach far less than half. I don't feel like trying to do the math, but suffice to say that a circle centered on Sol with a 25,000 LY radius contains more like 25% of the stars in the milky way (if that).

Easy : a few AU less than a few ly

[aepervius]

More or less since the first signal we blasted out for tv and radio where omni-directional , count about 1/r^2 decay in intensity. A few hundred AU at most a few light year (e.g. we are almost not detectable if we had a SETI outpost placed on our nearest neighbors). Basically what our SETI is trying to detect , is intentional unidirectional powerful "we are here" signal sent by an ET civ, like we did in direction of Gliese or M13. There is a nice table with all signals including TV and maximum range : http://www.faqs.org/faqs/astro... scroll to "Table 1 Detection ranges" for assumption and detection range. Basically the only signals ET could detect beyond 10 LY, is our own intentional signals sent from various folk in the last 4 decades, and those maximum are around a few hours duration top.