Even if was not going to pass by earth- do you think anything would be published?
If it was 20 years ago you would not know until the shadow of the beastie was darkening our skyies. However in the world we live in now with Facebook and Twitter and Youtube and Wikileaks the shelf life of that secret would be measured in milliseconds. Someone on the inside would inform their wife or parents or kids and Social Media would have it around the world within minutes.