Gedanke Experimentieren #1

Okay, it appears I goofed and provided far too little information when I first posted this, so let's start again.

90377 Sedna is a real object. It's a recently discovered planetoid roughly 1,000 miles in diameter (+/- 300), in a highly elliptical orbit that's believed to enclose the entire solar system and take roughly 12,000 years (+/- 500) to complete. The aphelion is believed to be in the neighborhood of 900 AU (+/- 50) or about 5 light days out, while the perihelion is expected to be in the neighborhood 76 AU out, or roughly twice the distance to Pluto. We've gotten a good look at 90377 Sedna through the Hubble, and at this time we know five interesting things about it:

1. It's as red as Mars.
   
2. It's rotating slowly.
   
3. It has a surface temperature of about -400 F.
   
4. It's coming this way and expected to hit perihelion in 2075 or 2076.
   
5. It was named for Sedna, the Innuit goddess of the ocean, who is believed to live in the coldest and most remote depths of the ocean and be the mother of all the great beasts of the sea.
   

Props to BoysMom for being the only one who looked up this easily found information. As for the rest of you, here's the challenge:

What if 90377 Sedna is discovered to be, not a natural object, but an artificial object, clearly made by some human or other intelligence. In one paragraph, synopsize your story about this discovery and what happens immediately afterwards.

Have fun!