"And that was Venus. Nothing but nothing- except it scared me."
You should always trust your instinct about a certain situation. In the story, Arthur's feelings towards Venus foreshadow the terrible things that happen to him during the story.
I estimated the wind speeds on Venus to be over 600 miles per hour.
"It was like circling a haunted house in the middle of deep space."
Suspense is defined as a state or feeling of excited or anxious uncertainty about what may happen. This creates suspense because the reader is scared for the characters and what may happen next, and why Arthur feels this way.
This scene represents suspense because the reader doesn't know what is happening to Arthur or why it's happening. They don't know why his hands are turning red, therefore the reader has to conclude through suspense.
"The flesh where the red spots had appeared was hot, feverish, and the flesh was soft and gelid like the flesh of an apple gone rotten."
After Arthur got back from Venus, Arthur discovered something very strange was happening to him. He had something inside of him; and the eyes of it were on his hand. He saw a different, messed up, side of reality. This is suspenseful because the reader doesn't know what Arthur and the monster will do after this.
"I had looked into my own face and seen a monster."
"When the boy passed, raising one hand in his usual non-committal salute."
Don't talk to strangers, even if you think they are portrayed as kind. In the story, the boy was always nice to Arthur. At the end, Arthur kills the boy.
Someone may look one way, but actually be another way. The boy trusted Arthur because he seemed nice, but Arthur choked him to death.
"...what he thought when the hands made that sudden, flailing gesture in the air, just before his head burst."