Bedrock

In geology, bedrock is solid rock that lies under loose material within the crust of Earth or another terrestrial planet.

Cepheid Variables are the Bedrock of the Cosmic Distance Ladder. Astronomers are Trying to Understand them Better

Search for Ancient Life: NASA’s Perseverance Mars Rover Investigates Intriguing Martian Bedrock

NASA's Perseverance Mars rover hunts tantalizing bedrock that could hide evidence of life

Trees Drill into Deep Bedrock for Water Surprisingly Often

Water in Bedrock Is Sustaining Trees Across Country – Long-Held Assumptions About Where Trees Get Their Water Overturned