Panel Session Saturday 11:00 AM
How could you connect to interplanetary probes? Block spam from the asteroid belt? (And does Mars really want our women?)
Peter Olson (M), Larry Pfeffer, Linda Fuhrman
Subtopics:
The Laws of Physics as they apply to interplanetary communication:
Speed of light determines transmission delays (you won't be using Instant Messaging to talk to anyone very much further away than the Moon):
The Moon -- 2.5 seconds round-trip delay
Mars -- 8.7 minutes at closest, 42 minutes at furthest
Jupiter -- 70 minutes to 102 minutes
Saturn -- 2 hours 22 minutes to 2 hours 55 minutes
Pluto -- about 8 hours right now; 14 hours max (in about 120 years)
It takes power to send a signal; the inverse square law applies, so if you are sending to somewhere 10 times as far away, you need 100 times as much transmitter power. This is one of the reasons we need relay satellites in orbit around the planets.
The planets move around: for instance about once a year Jupiter is on the opposite side of the Sun from Earth, so the radio frequency noise from the Sun drowns out the signal even when Jupiter is not entirely eclipsed.