Alien Civilization and Earth's Signals

What has Earth been sending into space for about 100 years that could be detected by alien civilizations?

• Satellite images

• Radio and television signals

• Morse code messages

• Laser beams

Why do some scientists believe it's unwise to broadcast too much information about Earth into space?

• It might cause space pollution

• It could interfere with Earth's own communications

• Aliens could be hostile

• Aliens might not understand our signals

What can a prism reveal about white light?

• It contains infinite colors, including infrared and ultraviolet

• It is composed of only seven colors

• It is a single pure color

• It is invisible to the naked eye

How can an alien civilization deduce the presence of life on Earth?

• By analyzing shadows in the rainbow caused by atmospheric molecules

• By measuring Earth's temperature

• By observing Earth's rotation

• By detecting Earth's gravitational pull

What is the Earth's biosphere described as in the context of alien detection?

• A source of renewable energy

• A barrier against alien detection

• A planet-sized unintentional message

• A deliberate message to aliens