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What happened to the water on Mars? · Gil I Am

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  Speaker 1: What happened to all of the water on Mars. NASA
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  Speaker 1: finally knows what happened to all the water on Mars.
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  Speaker 1: New findings from NASA missions uncover Mars water loss over
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  Speaker 1: billions of years and provide clues about its ancient atmosphere
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  Speaker 1: and climate. Mars, once a planet teeming with vast amounts
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  Speaker 1: of water, is now a dry, desolate landscape. The evidence
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  Speaker 1: for this transformation lies in the planet's surface features, which
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  Speaker 1: suggests that water once flowed freely. Over the past three
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  Speaker 1: billion years, some of that water has seeped deep underground.
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  Speaker 1: But what happened to the rest? This question has puzzled
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  Speaker 1: scientists for years. Thanks to NASA's Hubble Space Telescope and
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  Speaker 1: the Mars Atmosphere and Volatile Evolution MAVEN missions, were now
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  Speaker 1: closer than ever to unraveling this mystery. John Clark, a
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  Speaker 1: researcher at Boston University's Center for Space Physics, leads a
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  Speaker 1: team of scientists working to solve this puzzle. According to Clark,
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  Speaker 1: water on Mars had only two potential fates. It could
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  Speaker 1: freeze into the ground, or its molecules could break apart,
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  Speaker 1: with the resulting atoms escaping into space. To understand how
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  Speaker 1: much water there was and what happened to it, we
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  Speaker 1: need to understand how the atoms escape into space, Clark explains.
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  Speaker 1: By analyzing data from Hubble and Maven, Clark and his
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  Speaker 1: team have been able to track the current rate at
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  Speaker 1: which hydrogen atoms are escaping from Mars's atmosphere. Using this data,
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  Speaker 1: they have extrapolated backward to map the planet's water loss
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  Speaker 1: over time, offering a clearer picture of what Mars was
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  Speaker 1: like during its wetter warmer past. On Mars, sunlight breaks
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  Speaker 1: apart water molecules in the atmosphere into hydrogen and oxygen atoms.
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  Speaker 1: This process, known as photodissociation, releases two types of hydrogen,
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  Speaker 1: regular hydrogen and a heavier isotope called deuterium. Deuterium contains
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  Speaker 1: a neutron in its nucleus, giving it twice the mass
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  Speaker 1: of normal hydrogen. Due to this increased mass, deuterium escapes
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  Speaker 1: mars atmosphere more slowly than hydrogen. Over time, more hydrogen
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  Speaker 1: escapes than deuterium, leading to a higher ratio of deuterium
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  Speaker 1: to hydrogen in the atmosphere. Measuring this ratio allows scientists
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  Speaker 1: to estimate how much water was once present. On the
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  Speaker 1: red planet. By studying the current escape rates of these atoms,
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  Speaker 1: they can also learn about the processes that have infl
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  Speaker 1: luenced water loss over the last four billion years. While
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  Speaker 1: the Maven spacecraft provides most of the data used in
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  Speaker 1: this research, it isn't sensitive enough to detect uterium throughout
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  Speaker 1: the entire Martian year. Mars follows an elliptical orbit around
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  Speaker 1: the Sun, which means it swings far from the Sun
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  Speaker 1: during its long winter. As a result, deuterium emissions become
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  Speaker 1: too faint for Maven to measure during this period. To
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  Speaker 1: fill in the gaps, Clark's team turned to Hubble, which
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  Speaker 1: has been observing Mars since nineteen ninety one, well before
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  Speaker 1: Maven's twenty fourteen arrival. By combining data from both missions,
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  Speaker 1: they were able to construct a complete annual cycle of
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  Speaker 1: hydrogen and deuterium escape rates for three Martian years, each
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  Speaker 1: equivalent to six hundred and eighty seven Earth days. This
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  Speaker 1: collaboration between Hubble and Maven gave scientists the first comprehensive
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  Speaker 1: view of hydrogen atoms escaping into space from Mars. These
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  Speaker 1: findings help explain what happened to Mars water and provide
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  Speaker 1: clues about the planet's ancient climate. Mars's atmosphere is far
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  Speaker 1: more dynamic than previously thought, Clark notes. In recent years,
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  Speaker 1: scientists have found that Mars has an annual cycle that
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  Speaker 1: is much more more dynamic than people expected ten or
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  Speaker 1: fifteen years ago. The atmosphere heats up and cools down rapidly,
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  Speaker 1: sometimes in just a matter of hours. This turbulence is
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  Speaker 1: influenced by mars distance from the Sun, which varies by
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  Speaker 1: up to forty percent over the course of a Martian year.
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  Speaker 1: This new understanding of Mars's atmosphere has led to two
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  Speaker 1: major discoveries. First, when the planet is closer to the Sun,
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  Speaker 1: water molecules rise through the atmosphere much more rapidly than expected,
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  Speaker 1: releasing hydrogen and deuterium at high altitudes. Second, the rapid
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  Speaker 1: fluctuations in hydrogen and deuterium escape rates suggest that these
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  Speaker 1: atoms need additional energy to escape Mars's gravity. At normal
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  Speaker 1: atmospheric temperatures, only a small fraction of atoms has enough
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  Speaker 1: energy to escape, but when Mars is close to the Sun,
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  Speaker 1: the water molecules in its atmosphere absorb energy, which allows
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  Speaker 1: more atoms to escape into space. In addition, solar wind
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  Speaker 1: protons and sunlight driven chemical extra energy, causing more atoms
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  Speaker 1: to break free from Mars's atmosphere. This explains why the
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  Speaker 1: escape rates of hydrogen and deuterium vary so much throughout
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  Speaker 1: the Martian year. The study of mars water history is
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  Speaker 1: critical for understanding not only the red planet, but also
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  Speaker 1: other Earth sized planets in distant star systems. Astronomers have
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  Speaker 1: discovered many such planets, but their distance from Earth makes
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  Speaker 1: them difficult to study in detail. Mars, along with Earth
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  Speaker 1: and Venus, resides in or near the habitable zone of
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  Speaker 1: our Solar system where liquid water could exist. However, each
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  Speaker 1: of these planets has evolved under vastly different conditions, providing
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  Speaker 1: scientists with natural laboratories for studying how planets inhabitable zones
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  Speaker 1: can change over time. By examining Mars past, scientists hope
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  Speaker 1: to gain insights into the conditions that allow liquid water
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  Speaker 1: and potentially life to exist on distant planets. Clark's work,
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  Speaker 1: along with the data from Hubble and Maven, is helping
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  Speaker 1: to piece together the puzzle of water loss on Mars,
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  Speaker 1: a crucial step toward understanding the history of water in
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  Speaker 1: our Solar System and beyond. These findings were published in
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  Speaker 1: Science Advances, a journal by the American Association for the
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  Speaker 1: advance of Science. The MAVEN Mission Mars Atmosphere and Volatile Evolution,
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  Speaker 1: launched by NASA in twenty thirteen, was designed to study
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  Speaker 1: the upper atmosphere of Mars. Its primary goals were to
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  Speaker 1: understand how Mars lost its atmosphere over time and to
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  Speaker 1: investigate the history of Martian climate change. Scientists aimed to
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  Speaker 1: learn more about why Mars, which likely had a thicker
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  Speaker 1: atmosphere and liquid water in the past, became the cold
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  Speaker 1: and arid planet it is today. Understanding atmospheric loss, MAVEN
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  Speaker 1: aimed to determine how much of mars atmosphere has been
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  Speaker 1: lost to space over time, focusing particularly on the roll
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  Speaker 1: of the solar wind and solar storms. Study the current
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  Speaker 1: state of the Martian atmosphere. The mission sought to understand
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  Speaker 1: how the remaining atmosphere behaves today, including how it interacts
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  Speaker 1: with solar winds and radiation. Investigate ancient water loss. Scientists
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  Speaker 1: wanted to determine how the loss of atmospheric gases like
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  Speaker 1: hydrogen and oxygen contributed to the disappearance of liquid water
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  Speaker 1: from the Martian surface extreme atmospheric erosion. One of Maven's
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  Speaker 1: first big results was discovering that the erosion of Mars's
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  Speaker 1: atmosphere increases significantly during solar storms. The team studied how
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  Speaker 1: the solar wind, a stream of charged particles continually streaming
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  Speaker 1: from the Sun and solar storms, continually strip away mars atmosphere,
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  Speaker 1: and how this process played a key role in altering
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  Speaker 1: the Martian climate from a potentially habitable planet to today's cold,
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  Speaker 1: arid planet. Sputtering to space to better understand how Mars
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  Speaker 1: lost much of its atmosphere, Maven measured isotopes of argon
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  Speaker 1: gas in the upper Martian atmosphere. Argon is a noble gas,
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  Speaker 1: meaning it rarely reacts with other constituents in the Martian atmosphere.
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  Speaker 1: The only way it can be removed is by atmospheric sputtering,
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  Speaker 1: a process where ions crash into the Martian atmosphere at
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  Speaker 1: high enough speeds that they knocked gas molecules out of
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  Speaker 1: the atmosphere. When the Maven team analyzed argon isotopes in
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  Speaker 1: the upper atmosphere, they were able to estimate that roughly
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  Speaker 1: sixty five percent of the argon originally present had been
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  Speaker 1: lost through sputtering over the planet's history. A new type
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  Speaker 1: of aurora. Mavin has discovered several types of auroras that
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  Speaker 1: flare up when energetic particles plunge into the atmosphere, bombarding
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  Speaker 1: gases and making them glow. The MAVN team showed that protons,
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  Speaker 1: rather than electrons, create auroras at Mars. On Earth, proton
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  Speaker 1: auroras only occur in very small regions near the poles,
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  Speaker 1: whereas at Mars they can happen everywhere. Martian dust storm.
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  Speaker 1: In twenty eighteen, a runaway series of dust storms created
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  Speaker 1: a dust cloud so large that it enveloped the planet.
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  Speaker 1: The MAVON team studied how this global dust storm affected
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  Speaker 1: mars upper atmosphere to understand how these events affect how
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  Speaker 1: the escape of water to space. It confirmed that heating
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  Speaker 1: from dust storms can loft water molecules far higher into
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  Speaker 1: the atmosphere than usual, leading to a sudden surge in
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  Speaker 1: water lost to space. Map of Martian winds. MAVON researchers
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  Speaker 1: created the first map of wind circulation in the upper
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  Speaker 1: atmosphere of Mars. The new map is helping scientists better
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  Speaker 1: understand the Martian climate, including how terrain on the planet's
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  Speaker 1: surface is disturbing high altitude wind currents. The results provide
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  Speaker 1: insight into how the dynamics of the upper Martian atmosphere
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  Speaker 1: have influenced the red planet's climate evolution in the past
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  Speaker 1: and present. Twisted tail Mars has an invisible magnetic tail
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  Speaker 1: that is twisted by its interaction with the solar wind.
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  Speaker 1: Although models predicted that magnetic reconnection causes Mars's magnetotail to twist,
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  Speaker 1: it wasn't until Maven arrived that scientists could confirm that
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  Speaker 1: the predictions were correct. The process that creates the twisted
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  Speaker 1: tail could also allow some of Mars's already thin atmosphere
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  Speaker 1: to escape to space. Mapping electric currents researchers use Maven
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  Speaker 1: data to create a map of electric current systems in
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  Speaker 1: the Martian atmosphere. These form when solar wind ions and
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  Speaker 1: electrons smash into the planet's induced magnetic field, causing the
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  Speaker 1: particles to flow apart. The resulting electric currents, which drape
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  Speaker 1: around the planet, play a fundamental role in the atmospheric
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  Speaker 1: loss that transform Mars from a world that could have
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  Speaker 1: supported life to an inhospitable desert. Disappearing solar wind Maven
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  Speaker 1: recently observed the unexpected disappearance of the solar wind. This
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  Speaker 1: was caused by a type of solar event so powerful
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  Speaker 1: that it created a void in its wake as it
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  Speaker 1: traveled across the Solar System. Maven's measurements showed that when
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  Speaker 1: it reached Mars, the solar wind density dropped significantly. This
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  Speaker 1: disappearance of the solar wind allowed the Martian atmosphere and
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  Speaker 1: magnetosphere to balloon out by thousands of kilometers. Ultraviolet views
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  Speaker 1: of the Red planet. MAVEN captured stunning views of Mars
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  Speaker 1: in two ultraviolet images taken at different points along the
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  Speaker 1: red planet's orbit around the Sun. By viewing the planet
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  Speaker 1: in ultraviolet wavelengths, scientists gained insight into the Martian atmosphere
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  Speaker 1: and view surface features in remarkable ways. Mars response to
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  Speaker 1: solar storms. In May twenty twenty four, a series of
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  Speaker 1: solar events triggered a torrent of energetic particles that quickly
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  Speaker 1: traveled to Mars. Many of NASA's Mars missions, including MAVEN,
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  Speaker 1: observed this celestial event and captured images of glowing auroras
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  Speaker 1: over the planet. MAVEN continues to provide valuable data that
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  Speaker 1: helps scientists unravel Mars past and better understand its atmospheric
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  Speaker 1: process today. These findings also aid future missions in exploring
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  Speaker 1: the potential for human habitation on the planet.