LOS ANGELES, April 23 (Xinhua) -- NASA's Mars InSight lander has measured and recorded for the first time ever a likely "marsquake," said a release of NASA on Tuesday.

The faint seismic signal, detected by the lander's Seismic Experiment for Interior Structure (SEIS) instrument, was recorded on April 6, the lander's 128th Martian day.

This is the first recorded trembling that appears to have come from inside the planet, as opposed to being caused by forces above the surface, such as wind, according to NASA.

Scientists still are examining the data to determine the exact cause of the signal.

"We've been collecting background noise up until now, but this first event officially kicks off a new field: Martian seismology!" said InSight Principal Investigator Bruce Banerdt of NASA's Jet Propulsion Laboratory in Pasadena, California.

The SEIS, which InSight placed on the planet's surface on Dec. 19 last year, will enable scientists to gather similar data about Mars. By studying the deep interior of Mars, they hope to learn how other rocky worlds, including Earth and the Moon, formed.