Greetings Physics Brainiacs, Please advise about the planetary / solar / lunar relationship I've developed in my sci-fi novel. It should be believable and devoid of issues with gravity. The protagonist wakes up on another world. The reader knows only what she does: the day is 44 hours in length, gravity matches Earth's, the planet has similar rotation (ie, sun rises east). What she sees: • A desert planet, no plant life • Towering mountain ranges, rugged impact craters • No sign of water: no ice, no clouds, no dry lake beds • Intense, deep blue sky (not dark or black: she's inside a gargantuan, invisible, climate-controlled enclosure) • Large sun--almost twice Earth's sun • Giant moon** ** Unsure if there would be gravity issues with this moon: It shows four days straight, filling 15-20% of the sky. It's almost daylight on those nights. Every time the moon appears in the daytime sky, it causes a full solar eclipse. I think this scenario will work if it's a giant gas object with a small, rapidly-spinning core. Would it nevertheless cause the planet's gravity to vary? If so, would a second moon or asteroid belt on the opposite side of the planet in the same lunar orbit create some kind of equalizing gravitational pull? The moonlight plays a critical role in a large segment of the book, so whatever I can do to support it is key. Thank you.