Having trouble viewing this email? | View it in your browser   The object was discovered as part of astronomy’s ongoing hunt for unknown dwarf planets and Planet X, aka "Planet Nine," an as yet undiscovered world that could have a mass about 10 times that of Earth. FOR MORE ON THIS STORY, GO TO:   USATODAY.COM       You are currently subscribed to this newsletter with the address: newsletter@newslettercollector.com. To UNSUBSCRIBE please click here.     Manage Subscriptions | Help | Advertise | Home Delivery | Privacy Policy - Your California Privacy Rights     © 2017 USA TODAY, a division of Gannett Satellite Information Network, LLC. 7950 Jones Branch Drive, McLean, VA 22108