Query: There seems to be evidence for a link between solar activity and water levels.

Relevant passages:
Lakes on Mars <=SEP=> In summer 1965 , the first close-up pictures from Mars showed a cratered desert with no signs of water . However , over the decades , as more parts of the planet were imaged with better cameras on more sophisticated satellites , Mars showed evidence of past river valleys , lakes , and ice in glaciers and in the ground . It was discovered that the climate of Mars displays huge changes over geologic time because its axis is not stabilized by a large moon , as Earth 's is . Also , some researchers maintain that water could exist for periods of time due to geothermal effects or asteroid impacts .   Besides seeing features that were signs of past water , researchers found other types of evidence for past water . Minerals detected in many locations needed water to form . An instrument in the Mars Odyssey , an orbiting spacecraft , mapped the distribution of water in the near surface . When the Phoenix spacecraft fired its rockets to land in the far north , ice was exposed .   When water enters a large body of water , such as a lake , a delta may form . Many craters and other depressions on Mars show deltas that resemble those on Earth . In addition , if a lake lies in a depression , channels entering it will all stop at the same altitude . Such an arrangement is visible around places on Mars that are supposed to have contained large bodies of water -- including around a possible ocean in the North .   Lake formation has been proposed by various researchers for quite some time . One study found 205 possible closed-basin lakes in craters on Mars . The basins have an inlet valley that cuts the crater rim and flows into the basin , but they have no visible outlet valley . The total volume of the basins is equivalent to a depth of 1.2 meters spread evenly over the Martian surface . However , this amount is a small fraction of the current water ice stores on Mars . Another study found 210 open-basin lakes . These were lakes with both an inlet and an outlet ; hence water must have entered the basin , and reached the height of the outlet . Some of these lakes had volumes similar to Earth 's Caspian Sea , Black Sea , and Lake Baikal .   Moreover , some basins on Mars form part of long chains of lakes . The Naktong/Scamander/Mamers Valles lake-chain system is about 4500 km ( 2800 miles ) long , with a drainage area similar to that of the Missouri-Mississippi rivers . Another , the Samara/Himera Vallis system , is 1800 km long . Many of the long chains of lakes are found in the Margaritifer Sinus quadrangle .   Some of the lakes appear to have had a high volume as compared to their drainage area ; hence , it is believed that some of the water was groundwater . Further evidence is the existence of knobby material on the basin floors . These knobs can be formed when large amounts of water left the ground .   This article describes some of the places that could have held large lakes .

Ice age <=SEP=> An ice age is a period of long-term reduction in the temperature of Earth 's surface and atmosphere , resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers . Within a long-term ice age , individual pulses of cold climate are termed `` glacial periods '' ( or alternatively `` glacials '' or `` glaciations '' or colloquially as `` ice age '' ) , and intermittent warm periods are called `` interglacials '' . In the terminology of glaciology , ice age implies the presence of extensive ice sheets in both northern and southern hemispheres . By this definition , we are in an interglacial period -- the Holocene -- of the ice age . The ice age began 2.6 million years ago at the start of the Pleistocene epoch , because the Greenland , Arctic , and Antarctic ice sheets still exist .

Aeolis quadrangle <=SEP=> The Aeolis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey ( USGS ) Astrogeology Research Program . The Aeolis quadrangle is also referred to as MC-23 ( Mars Chart-23 ) .  The Aeolis quadrangle covers 180 ° to 225 ° W and 0 ° to 30 ° south on Mars , and contains parts of the regions Elysium Planitia and Terra Cimmeria . A small part of the Medusae Fossae Formation lies in this quadrangle .   The name refers to the name of a floating western island of Aiolos , the ruler of the winds . In Homer 's account , Odysseus received the west wind Zephyr here and kept it in bags , but the wind got out .   It is famous as the site of two spacecraft landings : the Spirit rover landing site in Gusev crater ( January 4 , 2004 ) , and the Curiosity rover in Gale Crater ( August 6 , 2012 ) .   A large , ancient river valley , called Ma'adim Vallis , enters at the south rim of Gusev Crater , so Gusev Crater was believed to be an ancient lake bed . However , it seems that a volcanic flow covered up the lakebed sediments . Apollinaris Patera , a large volcano , lies directly north of Gusev Crater .   Gale Crater , in the northwestern part of the Aeolis quadrangle , is of special interest to geologists because it contains a 2 -- 4 km ( 1.2 -- 2.5 mile ) high mound of layered sedimentary rocks , named `` Mount Sharp '' by NASA in honor of Robert P. Sharp ( 1911 -- 2004 ) , a planetary scientist of early Mars missions . More recently , on 16 May 2012 , `` Mount Sharp '' was officially named Aeolis Mons by the USGS and IAU .   Some regions in the Aeolis quadrangle show inverted relief . In these locations , a stream bed may be a raised feature , instead of a valley . The inverted former stream channels may be caused by the deposition of large rocks or due to cementation . In either case erosion would erode the surrounding land but leave the old channel as a raised ridge because the ridge will be more resistant to erosion   Yardangs are another feature found in this quadrangle They are generally visible as a series of parallel linear ridges , caused by the direction of the prevailing wind .

Gale (crater) <=SEP=> Gale is a crater , and probable dry lake on Mars near the northwestern part of the Aeolis quadrangle at . It is 154 km in diameter and estimated to be about 3.5-3 .8 billion years old . The crater was named after Walter Frederick Gale , an amateur astronomer from Sydney , Australia , who observed Mars in the late 19th century . Aeolis Mons is a mountain in the center of Gale and rises 5.5 km high . Aeolis Palus is the plain between the northern wall of Gale and the northern foothills of Aeolis Mons . Peace Vallis , a nearby outflow channel , ` flows ' down from the Gale crater hills to the Aeolis Palus below and seems to have been carved by flowing water .   The NASA Mars rover , Curiosity , of the Mars Science Laboratory ( MSL ) mission , landed in `` Yellowknife '' Quad 51 of Aeolis Palus in Gale at 05:32 UTC August 6 , 2012 . NASA named the landing location Bradbury Landing on August 22 , 2012 . Curiosity is exploring Aeolis Mons and surrounding areas .