Alien Day 2017. Image via Airwolfhound/Flickr

Just in time for Alien Day, a new book on unidentified flying objects (UFOs) has settled the bet for where to head if you’re interested in spotting one for yourself — and no, it’s not Nevada’s Area 51 or Roswell, New Mexico. According to findings reported in "UFO Sightings Desk Reference: United States of America 2001-2015," California sees more UFOs than any other U.S. state.

Don’t live in California? Don’t worry. The book found that UFO sightings are being reported all over the United States. Co-written by UFO experts Cheryl Costa and Linda Miller Costa, the book examines more than 100,000 eyewitness accounts throughout the first 15 years of the 21st century.

"Since 1969 the government has claimed no interest in the subject, and the press and media either ignore or ridicule any mention of UFOs," reads its synopsis. "Yet citizen scientists and non-governmental organizations have continued to this day the research into this important subject: this book seeks to make the hardest data available accessible to the general public, as well as other UFO researchers."

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Many of the reported UFO sightings can be explained, the authors told the New York Times, but not all of them. "We found that UFOs were sighted in every county in the United States. Every county had at least one sighting sometime in the past 15 years," Cheryl Costa told CBS.

CBS reported that Northern California, in particular, saw 569 sightings alone, while Alameda County and San Francisco trailed close behind with 518 and 327 reported sightings, respectively. However, it’s worth noting that the report is not per capita, and California remains the state with the highest population by a margin of well over 10 million people.

"Most people were very sincere about what they reported; about what they think they saw," Costa told CBS. "They weren’t jerking us around. But we understand the only proof some people are going to accept is a space ship cracked up in the mall parking lot."

"UFO Sightings Desk Reference: United States of America 2001-2015" was released March 24 and is available for purchase on Amazon.