Possible Clues:

• ... Venus, __, Mars ..
• View for an astronaut
• It's not altogether clear that this was an element
• Witty response to ''Where are we?''
• Hide a broken heart
• Associated with works by Brian Aldiss
• Partly clear the ground
• Mud thrown at her
• Here we all are with the RA: soiled
• 18's ground that's not 12 24