DENVER -- A week and half after he showed Denver reporters his alleged proof that aliens exist, Jeff Peckman is taking his story to David Letterman.

David Letterman's Web site lists his guests for Tuesday night as Mark Wahlberg, UFO Expert Jeff Peckman and Alanis Morissette.

Peckman wants the city of Denver to create an 18-member extraterrestrial affairs commission. He pitched the idea to city staff in May.

The goal of the commission, according to Peckman, would be to collect information and inform people how to peacefully co-exist with aliens.

Then he invited reporters to see a video that he said was absolute proof that extraterrestrial beings exist on earth. He wouldn't release the video to the public, but did release a still picture.

Just last Friday, David Letterman's top 10 listed the Top Ten Signs Your Neighbor Is an Alien. According to the Web site, the top five were:

5. In the class photo, his kids are the ones with the tentacles

4. When a rerun of "Mork & Mindy" is on, he sneers, "That guy's not from Ork"

3. Says, "We had a great weekend on Venus -- I mean, Vegas"

2. He drives a 2011 Toyota Corolla

1. He's bald, gray and creepy, but he's not Dick Cheney