NASA linking / crawling my site?

I've just been looking over my site stats and its showing up that I've got 21 "91 hits" visits from NASA here is the id : gsod200613547d.ndc.nasa.gov

Any idea what this is?

 

was it a person or a bot?

 

seems to be a bot 150 visits so far

 

may be some lab kid learning scripting? or aliens?

 

These hits are being made by Nasa search bot that is NASA Search 1.0. If you so not want to receive hits from NASA, use following code:

User-agent: NASA Search 1.0
Disallow: /