Liquid Water on Mars

TL;DR

NASA has discovered evidence of flowing liquid water on the surface of Mars, known as recurring slope lineae (RSL). These RSLs are caused by hydrated perchlorate salts, which raises new questions about the source of the water and the possibility of life on Mars.

Transcript

Hello and welcome to this Special Edition of SciShow News. Today, NASA announced that there is...occasionally...flowing, liquid water on the surface of Mars. Or, at least, liquid hydrated perchlorate salts that flow down steep slopes in the warmest Martian months. When they do this, the martian dust gets dark, a darkness we can see, and that was fi... Read More

Key Insights

• 💦 Liquid water is present on Mars in the form of recurring slope lineae (RSL).
• 🥶 The RSLs are caused by hydrated perchlorate salts, which lower the freezing point and evaporation pressure of water.
• 💦 The source of the water on Mars is still unknown, with potential theories including water-lovings salts in the atmosphere or super-salty sub-surface aquifers.
• 🤨 The discovery of liquid water on Mars raises new questions about the possibility of life on the planet.
• 🛟 The extreme salinity and corrosiveness of the Martian brine make it challenging for life as we know it to survive.
• 🛟 Protecting these areas on Mars from contamination by Earth bacteria is crucial for preserving potential Martian ecosystems.
• 💦 Further research is needed to understand the hydrology and geology of Mars and the implications of the presence of liquid water.

Questions & Answers

Q: How did scientists confirm that the recurring slope lineae (RSL) on Mars are caused by flowing water?

Scientists used the HiRISE camera on the Mars Reconnaissance Orbiter to identify the RSLs, but it required a spectrometer to determine the composition of the streaks. The spectrometer revealed that hydrated perchlorate salts are deposited inside the RSLs, confirming the presence of flowing water.

Q: What is the significance of the hydrated perchlorate salts in relation to the RSLs?

Hydrated perchlorate salts, such as calcium perchlorate, are abundant on Mars and have the ability to attract and hold water from the environment. These salts create a stable brine that lowers water's freezing point and evaporation pressure, allowing it to flow on the Martian surface and potentially exist underground.

Q: Could the presence of flowing liquid water on Mars indicate the possibility of life?

While the discovery of liquid water is an exciting development, the extreme salinity and corrosiveness of the Martian brine make it challenging for life as we know it to survive. However, scientists consider these areas to be potential places to search for life on Mars and continue to study the hydrology and geology of the planet.

Q: Why should these areas on Mars be protected from future missions?

Discussions have already begun about the need to protect these areas from contamination by Earth bacteria. If Earth-based bacteria were to colonize Mars, it would interfere with the study of potential Martian life and could potentially destroy any existing ecosystem on the planet.

Summary & Key Takeaways

• NASA has confirmed the existence of recurring slope lineae (RSL), which are dark streaks on the Martian surface that appear to be caused by flowing liquid water.

• The RSLs are formed by hydrated perchlorate salts, which lower the freezing point and evaporation pressure of water, allowing it to exist on the surface and potentially underground on Mars.

• The source of the water and the exact nature of the Martian mud is still unknown, but researchers are investigating the possibility of water-lovings salts in the atmosphere or super-salty sub-surface aquifers as potential sources.