Impossible Astronaut Day

Impossible Astronaut Day is an unofficial fan-created holiday celebrated annually on April 23. It honors the premiere of the Doctor Who episode titled “The Impossible Astronaut,” which aired on April 23, 2011. This episode marked the beginning of the sixth season of the modern Doctor Who series and introduced significant plot developments that captivated fans worldwide.​

Origin of the Holiday

The episode “The Impossible Astronaut” features the Eleventh Doctor, portrayed by Matt Smith, and his companions Amy Pond, Rory Williams, and River Song. In this story, the characters encounter a mysterious astronaut and face the enigmatic alien species known as the Silence. To remember encounters with the Silence—creatures that are instantly forgotten once out of sight—the characters mark tally lines on their skin. This distinctive visual became iconic among fans.​

Following the episode’s airing, fans began commemorating the date by drawing tally marks on themselves, sharing photos online, and rewatching the episode. Over time, April 23 became known as Impossible Astronaut Day within the Doctor Who community.​

How Fans Celebrate Impossible Astronaut Day

Fans, often referred to as “Whovians,” celebrate Impossible Astronaut Day in various creative ways:​

• Tally Mark Tradition
  Drawing tally marks on their arms or faces to emulate the characters’ method of tracking encounters with the Silence.​
• Episode Rewatch
  Hosting watch parties or personal viewings of “The Impossible Astronaut” and its follow-up episode, “Day of the Moon.”​
• Cosplay and Dress-Up
  Dressing as favorite characters from the series, including the Doctor, companions, or the Silence.​
• Creative Endeavors
  Engaging in fan art, writing, or crafting projects inspired by the episode.​
• Themed Activities
  Organizing trivia nights, creating themed meals (like the Doctor’s favorite fish fingers and custard), or visiting filming locations if accessible.​

Impossible Astronaut Day Dates Table