sci-universe:

Mars is now known as the planet who lost an ocean’s worth of water. According to new results published today, about 4 billion years ago a primitive ocean on Mars held more water than Earth’s Arctic Ocean. Above’s an artist’s impression showing how Mars may have looked.

An international team of scientists used European Southern Observatoy’s Very Large Telescope, along with instruments at the W. M. Keck Observatory and the NASA Infrared Telescope Facility, to monitor the atmosphere of the planet and map out the properties of the water in different parts of Mars’s atmosphere over a six-year period. read more here
illustration credit: ESO/M. Kornmesser/N. Risinger (skysurvey.org)