At the time, the researchers said that studying this underground pool of water could yield insights on the past and present chances for life on Mars. However, scientists had many more questions than answers about the origin, composition and longevity of this lake and its water.
In the new study, to learn more about this hidden water, researchers used the MARSIS radar sounder instrument on board the European Space Agency’s Mars Express spacecraft to scan a 155-by-185 mile (250-by-300 km) area surrounding the suspected underground lake. The scientists analyzed this radar data with techniques previously used to detect lakes under glaciers in Antarctica.
The scientists confirmed the liquid nature of the previously observed lake, narrowing down its dimensions to about 12 by 18 miles (20 by 30 km) in size. They cannot say how deep this lake extends, as the radio waves from MARSIS cannot penetrate salty water, study co-author Elena Pettinelli, a geophysicist at Roma Tre University in Rome, told Space.com.
Moreover, Pettinelli and her colleagues identified three other lakes on the order of 6 by 6 miles (10 by 10 km) in size. Strips of dry rock separate these smaller patches of water from the main lake, the scientists said.
The researchers suggested these lakes are extraordinarily salty. High brine content would keep their water liquid despite the extremely cold conditions at the base of the glaciers at Mars’ south pole, the scientists noted.
Although Martian polar ice may be melting a little due to warm noontime temperatures, the scientists do not think it likely that such ongoing processes formed these lakes. Instead, the scientists think this saltwater may be the remnants of a larger body of water now lost from the surface, and may be millions or even billions of years old, Pettinelli said.
Scientists have considered the possibility that geothermal activity might have melted polar ice to form the underground lakes, but that explanation was plausible when there was only one such body of water. Forming several lakes this way might require a huge geothermal anomaly. “I don’t think it is physically possible, given what we know,” Pettinelli said.
Instead, these lakes may have formed due to a warmer global climate in the Martian past, Pettinelli said. “This is a complex system of water, not just a single pond,” she said. “It suggests that the conditions that created these lakes might have been more spread across the region, that there might be other systems like this around.”
All in all, if these lakes “are remnants of water that was once on the surface, it certainly may have been a good habitat to harbor life, extinct or living,” Pettinelli said. But the ideal mission to study such potential life would need to drill 0.9 miles (1.5 km) into the ice, which isn’t possible with available technology, she said. “Still, maybe one day a mission to the Martian poles may sample the surface there to see if we can find interesting information,” Pettinelli said.
In the future, the scientists would like to look for similar networks of lakes elsewhere at the south pole, and maybe at the north pole as well, Pettinelli said.
The scientists detailed their findings online today (Sept. 28) in the journal Nature Astronomy.
Follow Charles Q. Choi on Twitter @cqchoi. Follow us on Twitter @livescience and on Facebook.
Two flights to Abbotsford have each had a recent COVID-19 exposure, according to the B.C. Centre for Disease Control (CDC).
The agency indicates on its website that the flights involved were WestJet flight 637 from Calgary to Abbotsford on Wednesday, Oct. 14 (rows nine to 15) and Swoop flight 107 from Hamilton to Abbotsford on Monday, Oct. 19 (rows 20 to 26).
The CDC advises that anyone who was on these flights should self-monitor for symptoms for 14 days.
Passengers on domestic flights are not required to self-isolate, but those who have travelled outside of Canada are required to self-isolate for 14 days upon their arrival.
Passengers seated on a plane with a case of COVID-19 that was later identified are no longer directly notified of their potential exposure. Instead, anyone who has travelled is asked to monitor the CDC website.
Passengers seated in the affected rows are considered to be at higher risk of exposure due to their proximity to the case.
At least she didn’t have to wait in line. A US astronaut cast her ballot from the International Space Station on Thursday, making her voice heard in the presidential election despite being 408km above the Earth.
“From the International Space Station: I voted today,” crew member Kate Rubins, who began a six-month stint aboard the orbiting station last week, said on Nasa’s Twitter account.
The post featured a photo of Rubins, her hair floating in the zero-gravity environment, in front of an enclosure with a sign that reads “ISS voting booth”.
Rubins and Nasa described the process as a form of absentee voting. A secure electronic ballot generated by a clerk’s office in Harris County, home of Nasa’s Johnson Space Center in Houston, Texas, was sent up via email to the ISS. Rubins filled out the ballot in the email and it was downlinked and delivered back to the clerk’s office.
Rubins had cast her vote from the ISS during the 2016 election as well. “We consider it an honour to be able to vote from space,” she said in a video before she and two Russian cosmonauts launched from the Baikonur cosmodrome in Kazakhstan on October 14.
Privacy & Cookies Policy
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.