Multiple spacecraft have identified some effects from the comet Siding Spring’s close call with Mars. Data from NASA’s MAVEN spacecraft and another NASA aircraft, in addition to a European spacecraft, indicate that the comet caused a meteor shower that deposited ionic debris into the planet’s atmosphere.
Siding Spring deposits ions
In a press release, officials from the University of Colorado at Boulder revealed the results of a study conducted by the MAVEN team, NASA’s Mars Reconnaissance Orbiter team and the European Space Agency’s Mars Express spacecraft team. The Siding Spring comet came from a far part of the solar system known as the Oort Cloud and passed by Mars on Oct. 19.
Researchers say that in that flyby, the comet caused a major meteor shower on Mars, adding a new layer of charged particles to the planet’s ionosphere. They say this is the first time they have ever observed a connection between a meteor shower that deposited ions into a planet’s atmosphere.
The comet’s flyby was a very close shave with Mars, as it passed within approximately 87,000 miles of the Red Planet, which is less than half the distance between our moon and Earth and less than a tenth the distance of any known comet passing by Earth.
How the comet flyby was studied
Scientists say that when the Siding Spring passed by Mars, it deposited dust that was vaporized high in the planet’s atmosphere, and the result was probably a major meteor shower. That dust caused temporary but significant changes to the upper part of the Martian atmosphere and perhaps long term changes as well.
NASA’s MAVEN spacecraft arrived at Mars not too long ago. It used a remote-sensing Imaging Ultraviolet Spectrograph to observe intense emissions from iron and magnesium atmospheres high in the Martian atmosphere following the meteor shower. Researchers say the shower was much more intense than any other meteor shower that has occurred on Earth in recorded history.
In addition, MAVEN sampled and enabled scientists to determine the composition of some of the dust that came from the comet and was vaporized in the planet’s atmosphere. These measurements were the first direct ones taken from a comet that originated from the Oort Cloud. Researchers called this a “one-in-a-lifetime event,” although some say it’s more like a once-in-a-million years event.