Are we able to communicate with other planets?
No
Why not?
we don't have the right tools to receive their messages
Will we ever?
Yes
When?
By 2025
Who thinks that?
Seth Shostak
Who is he?
astronomer
Does he believe in alien intelligent life?
Yes
Do others believe that?
Yes
Who else?
Alexandra Barnett
Who is that?
astronomer
What do they think?
intelligent life exists somewhere in the universe
What makes them so sure?
The first reason is time
What about time?
the universe is about 12 billion years old
Why does that matter?
This is long enough for other planets to have intelligent life
What's another reason?
size--the universe is huge
How big?
at least 100 billion galaxies
Why does that matter?
our galaxy, the Milky Way, has at least 100 billion stars
Why is that important?
Some planets going around these stars might be similar to Earth
How would we know if there was life?
powerful telescopes allow scientists to discover smaller planets
Has earth already been visited by aliens?
"Probably not,"
Why not?
It's a long way away