In fact, intelligent beings could be trying to communicate with us now, but we may not have the right ... to receive their ....
tools, messages
15
The ... between planets is too great. Despite this, intelligent beings might eventually contact us using other methods such as ...
distance, radio signals
15
In the past, it was difficult to ... signs of intelligent life in the universe.
search for
20
Nowadays, powerful telescopes ... scientists to identify many more small planets —the size of ... or Earth —in other solar systems.
allows, Mars
25
Shostak and Barnett think intelligent life exists on other planets because of two reasons. The first reason is ..., and the second reason is ... .
1. time (They believe the universe is 12 nillion years old. This is too long to have only 1 planet that has intelligent life). 2. size (The universe is huge)
20
Seth Shostak and Alexandra Barnett are ... . They believe intelligent life exists somewhere in the ... .
astronomers, universe
10
Is there intelligent life on other planets? For years, scientists said "No". But today, this is ...
changing
15
Within the next 20 years, we could make ... with other life forms in our universe
