A spacecraft left behind by US astronauts on the lunar surface could be causing small tremors known as moonquakes, according to a new study.Researchers revealed the previously unknown form of seismic activity on the moon for the first time through an analysis of Apollo-era data using modern algorithms.Massive temperature swings that occur on the moon can cause human-made structures to expand and contract in a way that produces these vibrations, the report suggests. The lunar surface is an extreme environment, oscillating between minus 208 degrees Fahrenheit (minus 133 degrees Celsius) in the dark and 250 degrees Fahrenheit (121 degrees Celsius) in direct sun, according to a news release about the study.
