The 32 Planets Malcolm Reed has set foot on, from Star Trek: Enterprise "Terra Prime"

"32!"
  "Hmm?"
"This is the thirty-second planet I've set foot on!"
  "248!"
                - Malcolm Reed and Phlox, after getting out of the shuttlepod on Mars. ("Terra Prime")

More or less since the Star Trek: Enterprise episode "Terra Prime" aired in 2005, I've intended to go back and count those up to see how many planets it is suggested that tactical officer Lt. Malcolm Reed set foot on off-screen. (Spoiler: It's 12.)

Note that other than Earth and Mars, these numbers are for my counting and while they may be in the right order, there may be some between those listed that didn't happen during episodes.

Season One (2151)
1. Earth  - Based on the phrasing, I'm counting Earth by default.
2. Rigel X ("Broken Bow")
3. Archer IV ("Strange New World")

Terra Nova Colony

4. Terra Nova ("Terra Nova")
5. P'Jem ("The Andorian Incident") - Note it's not 100% clear the planet's name is P'Jem.
6. Coridan ("Shadows of P'Jem")
7. Dakala ("Rogue Planet")
8. Symbiotic entity planet ("Vox Sola")
9. Torothan homeworld ("Desert Crossing")
10. Risa ("Two Days and Two Nights")

Season Two (2152)
11. Tessic's deuterium mining planet ("Marauders")
12. Gosis' homeworld ("The Communicator")
13. Xantoras ("The Breach")

Tied up on Risa

Season Three (When none of the planets are given names!) 
14. "Tulaw" (Trellium mine) ("The Xindi") - Unnamed in the episode, but named in a novel.
15. Loque'eque homeworld ("Extinction")
16. Xanthan homeworld ("Rajiin")
17. Xindi-Arboreal colony ("The Shipment")
18. Skagaran colony ("North Star")

Season Four (2155)
19. Vulcan ("The Forge")
...
32. Mars ("Terra Prime")

If Reed had set foot on 12 other planets - but not Earth's closest neighbor - I presume most or all of them have been during Enteprise's missions and not during his earlier Starfleet career.

Honorable Mention
Not planets, but worthy of mention among Reed's away mission exploits.

• Archer's comet ("Breaking the Ice") - I think it's suggested he and Mayweather are the first humans to set foot on a comet?
• Tandaran moon ("Detained")
• Rura Penthe (Klingon moon) ("Judgement")

We don't know much about Reed's Starfleet career before Enterprise, aside from his time with Section 31. By the 24th century, Venus did have facilities for Starfleet officers, so that's a possibility. Otherwise, I can't remember any other adventures that are implied to have occurred off screen like Star Trek: Voyager occasionally mentioned.

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