Ancient Dust Falling onto Mar’s Atmosphere from Oort Cloud Comet Contains Metal Ions

Artist’s concept of Comet Siding Spring approaching Mars, shown with NASA’s orbiters preparing to make science observations of this unique encounter. Image Credit: NASA/JPL
Artist’s concept of Comet Siding Spring approaching Mars, shown with NASA’s orbiters preparing to make science observations of this unique encounter.
Image Credit: NASA/JPL

Comet Siding Spring sprinkles ancient metallic dust onto Mars atmosphere 

Space news (November 23, 2014) Comet Siding Spring seeds Mars with ancient metallic dust –

NASA and European space scientists recently observed a large comet flying past a planet for the first time. On October 19, 2014, three spacecraft, two American and one European, observed and gathered data as Comet Siding Spring flew past Mars. You can watch a YouTube video here of the artists rendering of the flyby.

Comet C/2013 A1 Siding Spring arrived from a very distant region of the solar system called the Oort Cloud. At around 2:27 p.m. EDT, this traveler from the outer regions of the solar system was only about 87,000 miles (139,500 kilometers) from the Red Planet. It was at this time the comet was observed by three spacecraft as it deposited ancient debris on its atmosphere. This is the first direct measurement of dust from an Oort Cloud comet and an opportunity scientists and astronomers have been waiting for.

Five images of comet C/2013 A1 Siding Spring taken within a 35-minute period as it passed near Mars on Oct. 19, 2014, provide information about the size of the comet's nucleus. These observations by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter suggest that the nucleus is smaller than 1.2 miles (2 kilometers) across.
Five images of comet C/2013 A1 Siding Spring taken within a 35-minute period as it passed near Mars on Oct. 19, 2014, provide information about the size of the comet’s nucleus. These observations by the High-Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter suggest that the nucleus is smaller than 1.2 miles (2 kilometers) across.

Oort Cloud comets are thought to be leftover material from the birth of the solar system. Space scientists have an opportunity to test the present theory on the evolution of the solar system and possibly life on Earth. Theories persist that the ingredients of life could have been deposited on Mars in the distant past and then this life traveled to Earth and took root. The data collected during this encounter between Comet C/2013 A1 Siding Spring and Mars could help determine if this is possible.

Space scientists gathered information on the comet’s nucleus and the effects of the comet’s passage on the Martian atmosphere. The data was collected using NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) and Mars Reconnaissance Orbiter (MRO) spacecraft, in conjunction with radar instruments on the European Space Agency’s (ESA’s) Mars Express.

These three plots are spectrograms showing the intensity of radar echo in the Martian far-northern ionosphere at three different times on Oct. 19 and 20, 2014. The middle plot reveals effects attributed to dust from a comet that passed near Mars that day. The data are from the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS), an instrument on the European Space Agency's Mars Express orbiter.
These three plots are spectrograms showing the intensity of radar echo in the Martian
far-northern ionosphere at three different times on Oct. 19 and 20, 2014. The middle plot reveals effects attributed to dust from a comet that passed near Mars that day. The data are from the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS), an instrument on the European Space Agency’s Mars Express orbiter.

Data collected indicates comet debris containing sodium, iron and magnesium metal ions, along with at least five others, fell on the atmosphere of Mars as the comet flew past the planet. Readings indicate this added a temporary layer of strong metal ions to the ionosphere of Mars. Planetary and atmospheric space scientists are now studying whether this could have resulted in the development of a similar layer in the atmosphere of a primordial Earth. They also want to take a look at the possibility the sprinkling of comet dust in the atmosphere of Mars could have long-term consequences for the planet.

“This historic event allowed us to observe the details of this fast-moving Oort Cloud comet in a way never before possible using our existing Mars missions,” said Jim Green, director of NASA’s Planetary Science Division at the agency’s Headquarters in Washington. “Observing the effects on Mars of the comet’s dust slamming into the upper atmosphere makes me very happy that we decided to put our spacecraft on the other side of Mars at the peak of the dust tail passage and out of harm’s way.”

NASA and European space scientists will now continue to monitor Mar’s atmosphere after the passage of Comet C/2013 A1 Siding Spring for continued and additional effects and developments. They also hope to get further opportunities in the future to observe Oort Cloud comets flying past planets within the solar system.

For more information on MAVEN, MRO or any of NASA’s missions to Mars go here.

You can learn more about the Mars Express spacecraft here.

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