CMYK46 is correct those UFOs are renderings and can't be used. There are many UFOs that are photos on sites like Flickr (see this forum post on how to search on Flickr: http://www.pxleyes.com/forum/viewtopic.php?f=5&t=5644).

I can give you two links which I know are safe to use, this one on Wikipedia: https://en.wikipedia.org/wiki/File:Moonbeam_UFO.JPG and this one on DeviantArt: https://absurdwordpreferred.deviantart.com/art/Flying-Saucer-160295379 I've checked both and I know they are safe to use, the Wikipedia image is in Public Domain and the one on DeviantArt I verified to be a photo of a scale model. You can find more as I mentioned, if you aren't sure if the ones you find are okay just send me a PM and I'll check them for you.

It's an easy fix but make the correction as soon as you can to avoid a warning from the Contest Moderator.

UFOs are renders.

5.6. 3D Renders or Illustrations as Source:
Using other people's 3D renders or illustrations (even with permission and no matter in which form they are offered) creates a false impression of your artwork. So 3D renders or illustrations can not be used as sources, unless they are entirely created by yourself. Only acceptable non-illustration brushes and clip art may be used, but you need to mention them as a source too. Don't use an image that has been altered by the source owner nor an entire work created by someone else.

Nice job. 3rd place on your 1st entry. Not bad.

Good one !

I really enjoyed this Photoshop. It's an awesome concept and made my eyes wander. The faults I see are the overall tone should have been much warmer due to the light source being a setting sun (things are much more orangy at sunset right?). The power plant for example fits in as far as temperature is concerned but right next to it the skyline is really "cool" (bluer) in temperature so they conflict. Also when you have a back lit scene like that, you would see some of the sun's light reflecting off the left side of some of the individual buildings that are getting hit by the sun's light, as well as the right side of the mountains, and perhaps some of top of the arm/hand. This can be achieved via a Brushing Layer, or multiple ones that are "clipped" to the buildings, hand/arm, and even the mountain. Generally you would use an Overlay, Soft or Hard Light, or Screen Layers, but there are a few more you can use. Then just brush some gold/yellow/orange color for your light, varying the brightness and opacity of the brush as needed. The green part on the arm has too much light on the top "half" which does not concur with the back-lit light source (the "back side" of the arm should be more shadowy and less lit up). As for the power plant, it's backwards. The shadowy side should be on the right due to the sun being on its left. If you need some help with this, feel free to PM me.

I wanna live there!

Thank you

Author, sources 1 & 3 are the same, please fix this.