![](https://webarchive.library.unt.edu/eot2008/20090305080604im_/http://astrobiology.nasa.gov/img/_placehold/placehold-ask.jpg)
![Ask an Astrobiologist](https://webarchive.library.unt.edu/eot2008/20090305080604im_/http://astrobiology.nasa.gov/img/text/ask-an-astrobiologist.gif)
"Is it true that scientists at NASA are looking for life on the moons of Jupiter?"
-
Question
How come we have not been visited by intellegent life if it does exist? Is it because they cannot travel faster than the speed of light?
The fact that nothing can travel faster than the speed of light may be the reason we are not being visited; it is so much easier to just communicate by electromagnetic waves! Electromagnetic signals (radio or optical) are by far the most economical way to bridge the distances between the stars, so that is how SETI approaches the problem of searching for extraterrestrial intelligence. Your question is really a restatement of what is called the "Fermi Paradox". A good source for this topic is the book by Stephen Webb called "If the Universe Is Teeming with Aliens... Where Is Everybody? Fifty Solutions to Fermi's Paradox and the Problem of Extraterrestrial Life --". David Morrison
NAI Senior Scientist
November 14, 2006
![FAQ](https://webarchive.library.unt.edu/eot2008/20090305080604im_/http://astrobiology.nasa.gov/img/text/hd_faq.gif)
- How frequently are questions answered?
- I asked a question but there was no answer?
- Who is the Astrobiologist answering these questions?
- Will I get an email when my question is answered?
- What college courses should I take to become an astrobiologist?
- How can I get a job as an astrobiologist at NASA?
- Have aliens visited Earth? Are UFOs real?
- Is there a planet or brown dwarf called Nibiru or Eris that is approaching the Earth and threatening our planet with widespread destruction?
- Is it true that the Sun will be in the center of the Milky Way Galaxy in December 2012 and that this will cause a pole shift and massive destruction.
- Has NASA discovered life on other worlds?
- Astrobiology Career Path Suggestions