That's an interesting question. According to what we know now, nothing can travel faster than the speed of light. Even traveling in our own solar system would take many years, and we don't think there's any life in our solar system except what comes from Earth. But what about getting messages from other planets? Those messages could have been sent thousands of years ago.
When we want to make predictions in science, we take what we know, then make assumptions about what we don't know. Dr. Frank Drake of the National Radio Astronomy Observatory in Green Bank, West Virginia came up with an equation to answer that question in 1961. I got this information from
The Drake equation takes into account:
The rate of formation of suitable stars (stars such as our Sun).
The fraction of those stars with planets.
(Current evidence indicates that planetary systems may be common for stars like the Sun).
The number of Earth-like worlds per planetary system.
The fraction of those Earth-like planets where life actually develops.
The fraction of life sites where intelligence develops.
The fraction of communicative planets (those on which electromagnetic communications technology develops).
The "lifetime" of communicating civilizations.
Dr. Drake used this equation to predict that there were 10,000 civilizations in our galaxy that could potentially communicate with us. You can go to this site and plug in your own estimates to see what probability you predict.
Will any contact us in the next 100 years? No one knows, but it would be amazing. What do you think other life would be like? What questions would you want to ask them?
Nobody knows. We don't currently know how easy or difficult it is for life to originate in the first place; it would appear to be fairly easy, if life on Earth is four billion years old, but much less easy if life on Earth is only three and one half billion. Current astronomical observations seem to imply that habitable planets around other stars are fairly common, but we don't know how common and we don't know how far life usually gets. Life on Earth was all essentially microbial until about a billion years ago, so that's much of its history that it was microscopic and not very noticeable, since the oxygen levels in the atmosphere were also very low until about then, too. As a result, we may have a hard time finding life, even if it's there - we would have to physically GO to another star and have a look. I think it highly unlikely that we will be undertaking any interstellar travel within the next hundred years, for a variety of problems, both physical and socio- economic.
Although finding life on another star within the next century is very unlikely, finding life on Mars within the next century is quite likely. Because of the dynamics of within-solar system objects, in particular blasting of meteorites off of planets from impacts; it is highly likely that once life exists on one world in the solar system, other worlds will get colonized via meteorites. There is some credible suggestion that life on Earth may have originated on Mars, and got here this way; if life on Earth originated here on Earth, then it is less likely that Mars got colonized but I would not say unlikely. However, this simply means that microbes have been undertaking interplanetary travel long before we have, and it would all be one common origin of life. A separate origin of life is much less likely to find, unless by chance it happened on Mars as well as Earth, and we have no way of gauging the probabilities of that.