Our world was rocked by last week’s announcement of good radar evidence for a liquid water “lake” under the Red Planet’s south pole.   Senior Editor Emily Lakdawalla introduces us to the story that is then taken up by two of host Mat Kaplan’s favorite Martians.  The Goddard Space Flight Center’s James Garvin headed NASA’s Mars exploration program, while NASA Ames astrobiologist Chris McKay co-founded the Mars Underground more than 35 years ago. Look up!  Mars is still close by, and the Perseid meteor shower is around the corner. Bruce Betts gives us the What’s Up lowdown. Learn more at:   http://www.planetary.org/multimedia/planetary-radio/show/2018/0801-2018-garvin-mckay-mars-lake.html