Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.astronomy.com/magazine/ask-astro/2015/02/alien-airwaves
Äàòà èçìåíåíèÿ: Unknown
Äàòà èíäåêñèðîâàíèÿ: Sun Apr 10 11:05:21 2016
Êîäèðîâêà: ISO8859-5

Ïîèñêîâûå ñëîâà: optical telescope
The SETI Institute is after alien signals. Assuming another world is beaming a 1-million-watt radio signal in our direction, how far away can that source be before the signal is lost in intergalactic noise? | Astronomy.com
Tonight's Sky
Sun
ò??
ò??
Sun
Moon
ò??
ò??
Moon
ò??
ò??
Mercury
ò??
ò??
Mercury
ò??
Venus
ò??
ò??
Venus
ò??
Mars
ò??
ò??
Mars
ò??
Jupiter
ò??
ò??
Jupiter
ò??
Saturn
ò??
ò??
Saturn
ò??

Tonight's Sky ò?? Change location

OR

Searching...

Tonight's Sky ò?? Select location

Tonight's Sky ò?? Enter coordinates

ÒÀ '
ÒÀ '

The SETI Institute is after alien signals. Assuming another world is beaming a 1-million-watt radio signal in our direction, how far away can that source be before the signal is lost in intergalactic noise?

Don Schmidt, Oro Valley, Arizona
RELATED TOPICS: EXTRATERRESTRIALS
Spacebeacon
Many people assume that radio signals only can travel a limited distance before they are, like the Robinson family, lost in space. They believe there’s a range beyond which transmissions reach an intensity lower than background static and therefore become thoroughly undetectable.

Astronomy magazine subscribers can read the full answer for free. Just make sure you're registered with the website.

Already a subscriber? Register now!

Registration is FREE and takes only a few seconds to complete. If you are already registered on Astronomy.com, please log in below.
ADVERTISEMENT

FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter.

ADVERTISEMENT
ADVERTISEMENT
asy_gravitational_eguide

Click here to receive a FREE e-Guide exclusively from Astronomy magazine.

Find us on Facebook