Extra Terrestial-ET

Yes, i do believe in extra-terrestrials. There are more than billion other planets and solar systems. So, there's a huge possibility that life may have evolved there, just like on earth. But, they must be very far away (min. 4 light years away), and so they can't reach us or we can't reach to them, even if we travel at the speed of light, if would take more than 4 years to reach.