NASA is not in charge of astronomy world wide. It’s not even an astronomical organization. They do send some space telescopes into orbit, and they provide some funding that goes towards asteroid detection. But they are one of many space agencies. As for astronomers, there are thousands of professional astronomers and probably millions of amateurs with powerful telescopes.

There is nothing to be scared of. The whole thing is made up. By gullible people who don’t understand even the most basic ideas in astronomy, or hoaxers, or the like.

For the reasons why astronomers, if they have even heard of it, immediately dismiss it as BS, see

• Nibiru Bullshit Tester - How to check if they know anything about astronomy
• Debunked: Nibiru will hit Earth on [Insert Date here]
• Debunked: NASA do all the asteroid tracking and hide information about Nibiru