life on Mars

The possibility of life on Mars is a subject of interest in astrobiology due to the planet's proximity and similarities to Earth. To date, no conclusive evidence of past or present life has been found on Mars. Cumulative evidence suggests that during the ancient Noachian time period, the surface environment of Mars had liquid water and may have been habitable for microorganisms, but habitable conditions do not necessarily indicate life. Scientific investigations for potential life on Mars began in the 19th century and continue today with telescopes and robotic probes searching for water, chemical biosignatures in the soil and rocks at the planet's surface, and biomarker gases in the atmosphere.