Capital city of Mars by Nick Hvostik

Picture of the Day 15/7/2018 - "Opportunity: The Capital of the Corporate Republic of Mars" - cover art for Half Life 2 unfinished game mod "Badge of Blood" by concept artist Nick Hvostik from "Massive Black".

3D-printed home on Mars by SEArch+/Apis Cor

Picture of the Day 9/7/2018 - a 3D-printed home on Mars by SEArch+/Apis Cor team - one of the 10 finalists in phase 3 (virtual model stage) of NASA’s 3D-Printed Habitat Challenge.

City on Mars in a far future by Richard Bizley

Picture of the Day 5/7/2018 - Space art exhibition at a city on partly terraformed Mars in a far future by British painter Richard Bizley. More of his art here.

Boy on Mars messaging his dad (image from The Expanse season 3)

Picture of the Day 29/6/2018 - Alex receiving a video message from his son on Mars - image from episode 6, season 3 of The Expanse sci-fi TV series. Images of Mars from season 2 of the series here.

Elon future on Mars by Victor Hegger

Possible future on Mars inspired by Elon Musk - a drawing by Dutch comic artist Victor Hegger. More of his art here.

(Open link in new tab to view ⇩ in full resolution)

Terraforming Mars by Stefan Morrell, National Geographic

Gradual terraformation of Mars by concept artist Stefan Morrell from New Zealand. His picture was used to illustrate Robert Kunzig's article about terraforming Mars in National Geographic Magazine, February 2010 issue, and many more articles about colonization and terraformation of Mars since then.

Open image link in new tab to view images in full resolution

Close-up of the central section:

"Making Mars the new Earth" by Robert Kunzig, National Geographic Magazine, February 2010:

Occupy Mars - simulation game about Mars colonization

Occupy Mars is an upcoming (as of today: TBD 2018) highly technical open world simulation game about Mars colonization from Polish indie game developer Pyramid Games. In the game you will be able to "build and upgrade your base, discover new amazing regions, conduct mining operations, retrieve water and generate oxygen, grow crops, fix broken parts, learn how to survive on Mars!"

Here are some promo images, posters and a trailer from the developer. Note the SpaceX style spacesuit and ITS 2016 spaceship(s) near the base.

Domed city at night by Lorenz Hideyoshi Ruwwe

Picture of the Day 28/5/2018 - Domed city at night by German digital artist Lorenz Hideyoshi Ruwwe; part of cover image for Joseph Vasicek's eBook "Desert Stars".

Conference hall at Mars colony by Tarik Keskin

Picture of the Day 23/5/2018 - conference hall at Mars colony by Turkish digital artist Tarik Keskin. More of his art here.

(Open link in new tab to view ⇩ in full resolution)

Female astronaut in front of Mars base by Bryan Versteeg

Picture of the Day 21/5/2018 - Female astronaut in front of Mars base by Canadian concept artist Bryan Versteeg - a cover work for the Humans To Mars Report 2018 (by Explore Mars). More of his space art here.

(Open link in new tab to view ⇩ in full resolution)

Retro style Mars base by David A. Hardy

Picture of the Day 19/5/2018 - Retro style Mars base by classical space artist David A. Hardy. More of his Mars art here.

Mars - adventure awaits

Poster depicting adventurous life at human colony on Mars by digital artist Sam Taylor.

(Open link in new tab to view ⇩ in full resolution)

Human base in a Martian crater by Colin Geller

Picture of the Day 7/5/2018 - Human base in a Martian crater - concept art by Colin Geller for "Lazarus labs" exterior in DOOM (2016) computer game.

(Open link in new tab to view ⇩ in full resolution)

SpaceX Big Falcon Rocket approaching Mars; official design

Picture of the Day 23/4/2018 - SpaceX Big Falcon Rocket (BFR) spaceship (BFS) approaching Mars; official design presented by SpaceX's president & COO Gwynne Shotwell at TED 2018 conference. More images of BFR from her presentation here.

Full official schematics for BFR by Elon Musk at IAC 2017

Astronaut flying a drone near Martian base by Vanessa Reig

Picture of the Day 14/4/2018 - Female astronaut flying a drone near a human base on Mars by Vanessa Reig from Spain.

First plant on Mars by Samuel van der Hoeven

Picture of the Day 2/4/2018 - First naturally grown plant outside a greenhouse on Mars by Samuel van der Hoeven.
More of his art here.

(Open link in new tab to view ⇩ in full resolution)

Nuclear spaceship launching from Mars by William Black

Picture of the Day 23/3/2018 - Nuclear powered SSTO (single-stage-to-orbit) spaceship launching from Mars by William Black. More of his space concept art here.

Domed human colony on Mars from Surviving Mars game

Picture of the Day 20/3/2018 - human colony on Mars at night with several transparent domes from Mars city building game "Surviving Mars" by Paradox Interactive. The game was released on March 15 and this screenshot was made by gamer Ezilii.

(Open link in new tab to view ⇩ in full resolution)

Cultivating bamboo on Mars by Ludovic Celle

Picture of the Day 10/3/2018 - Cultivating bamboo trees in a greenhouse on Mars by French graphic artist Ludovic Celle.
More of his Mars art here.

Gremi Park in Poland that looks like human base on Mars

Gremi Park in southern Poland, located between Krakow and Katowice, is a development venue for AR and VR technologies (augmented reality and virtual reality). The futuristic complex which was originally built as a headquarters for Radio Mazyka Fakty station and later became a film studio looks a lot like human base on Mars with connected domes. Especially during the construction phase and colored appropriately :)