NASA’s Curiosity rover is using a new experiment to better understand the history of the Martian atmosphere by analyzing xenon.
While NASA’s Curiosity rover concluded its detailed examination of the rock layers of the “Pahrump Hills” in Gale Crater on Mars this winter, some members of the rover team were busy analyzing the Martian atmosphere for xenon, a heavy noble gas.
The Five Most Abundant Gases in the Martian Atmosphere
Curiosity’s Sample Analysis at Mars (SAM) experiment analyzed xenon in the planet’s atmosphere. Since noble gases are chemically inert and do not react with other substances in the air or on the ground, they are excellent tracers of the history of the atmosphere. Xenon is present in the Martian atmosphere at a challengingly low quantity and can be directly measured only with on-site experiments such as SAM.
“Xenon is a fundamental measurement to make on a planet such as Mars or Venus, since it provides essential information to understand the early history of these planets and why they turned out so differently from Earth,” said Melissa Trainer, one of the scientists analyzing the SAM data.
A planetary atmosphere is made up of different gases, which are in turn made up of variants of the same chemical element called isotopes. When a planet loses its atmosphere, that process can affect the ratios of remaining isotopes.
Measuring xenon tells us more about the history of the loss of the Martian atmosphere. The special characteristics of xenon – it exists naturally in nine different isotopes, ranging in atomic mass from 124 (with 70 neutrons per atom) to 136 (with 82 neutrons per atom) – allows us to learn more about the process by which the layers of atmosphere were stripped off of Mars than using measurements of other gases.
A process removing gas from the top of the atmosphere removes lighter isotopes more readily than heavier ones leaving a ratio higher in heavier isotopes than it was originally.
NASA’s Curiosity Mars rover can be seen at the “Pahrump Hills” area of Gale Crater
The SAM measurement of the ratios of the nine xenon isotopes traces a very early period in the history of Mars when a vigorous atmospheric escape process was pulling away even the heavy xenon gas. The lighter isotopes were escaping just a bit faster than the heavy isotopes.
Those escapes affected the ratio of isotopes in the atmosphere left behind, and the ratios today are a signature retained in the atmosphere for billions of years. This signature was first inferred several decades ago from isotope measurements on small amounts of Martian atmospheric gas trapped in rocks from Mars that made their way to Earth as meteorites.
“We are seeing a remarkably close match of the in-situ data to that from bits of atmosphere captured in some of the Martian meteorites,” said SAM Deputy Principal Investigator Pan Conrad.
SAM previously measured the ratio of two isotopes of a different noble gas, argon. The results pointed to continuous loss over time of much of the original atmosphere of Mars.
The xenon experiment required months of careful testing at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, using a close copy of the SAM instrument enclosed in a chamber that simulates the Mars environment. This testing was led by Goddard’s Charles Malespin, who developed and optimized the sequence of instructions for SAM to carry out on Mars.
“I’m gratified that we were able to successfully execute this run on Mars and demonstrate this new capability for Curiosity,” said Malespin.
NASA’s Mars Science Laboratory Project is using Curiosity to determine if life was possible on Mars and study major changes in Martian environmental conditions. NASA studies Mars to learn more about our own planet, and in preparation for future human missions to Mars. NASA’s Jet Propulsion Laboratory in Pasadena, California, a division of Caltech, manages the project for NASA’s Science Mission Directorate in Washington.
8 ft 1 tall Sultan Kösen from Turkey is a rare specimen – the tallest over 8 ft tall man alive on planet Earth today according to the Guinness World Records.
Sultan currently also holds the record for largest hands 28.5 cm (11.22 in) from the wrist to the tip of the middle finger and the second largest feet – his left foot measuring 36.5 cm (1 ft 2 in) and right foot measuring 35.5 cm (1 ft 1.98 in).
Guinness World Records has come across only about ten people above 8 ft over the past 20 years but Sultan is the only such person alive today.
Born on 10 December 1982, Sultan was like an average child till the age of 10, even the other members of his family, including his parents and four siblings were ‘normal’ in terms of size.
But suddenly Sultan started growing uncontrollably fast due to a condition called “pituitary gigantism” which accounts for over-production of growth hormone and its spread from the pituitary gland in the brain. This invariably leads to large hands, thickening of the bones and painful joints. Due to his extreme size, Sultan had to face many ups and downs in life. Because of his gigantic height Sultan couldn’t finish school, could never find fitting clothes or shoes and found it extremely hard to fit into a regular-size car.
On the other hand because of his height he was found to be good at changing bulbs or hanging curtains.
Sultan Kösen today is recognized everywhere around the globe because of his extraordinary height and invited to star in a number of Hollywood movies.