Final answer:
The distress radio signal is the most urgent call for help in emergency situations. It is broadcasted on multiple channels or frequencies and can be picked up by radio telescopes and communication devices.
Step-by-step explanation:
Distress Radio Signal:
The distress radio signal is the most urgent call for help in emergency situations. It is used to indicate that immediate assistance is required due to a life-threatening situation or critical circumstances. When a distress signal is transmitted, it is broadcasted on multiple channels or frequencies to increase the chances of being received. These signals are usually picked up by radio telescopes or other communication devices.
Example: A common distress signal used at sea is the SOS signal, which consists of three short signals, followed by three long signals, and then three short signals again.