If you've seen an email, or heard from your friends, about how incredibly bright Mars will be on August 27th... it's a hoax.
Snopes has the entire history of the event. I've corrected 3 people now on the subject already this year. If you see this in the wild, send them to the Snopes site.
Smokey the Bear Says - "Only you can prevent wild hoaxes from spreading on the internet."