Researchers revealed this Friday in presenting initial scientific findings from the flyby, “A comet that zipped past Mars last month, dumped tons of dust into the planet’s atmosphere, providing a spectacular light show.”
A planetary scientist from University of Colorado, Nick Schneider, who was working on NASA’s Maven orbiter mission said that thousands of shooting stars — scraps of cometary dust burning up in the atmosphere — splashed across the Martian sky that night.
During NASA’s news conference, Dr. Schneider said, “It’s a very rare event in the entire history of humanity, and it would have been truly spectacular to the human eye.”
Robotic explorers limitations were highlighted, neither of NASA’s Martian rovers, Opportunity and Curiosity, successfully observed the shooting stars.
Dr. Schneider said, “We’ve got all these high-tech robots around, but I have to say, it might be the most sensitive scientific instrument of all to have a human lying outside with dark-adapted vision looking up at that sky.”
On 19th Oct, Opportunity was able to capture images of the comet, Siding Spring, as it passed within 87,000 miles of Mars. L. Green, director of NASA’s planetary sciences division, said, “Curiosity and Opportunity don’t capture movies. They just weren’t designed to be able to do that.”
Though, orbiting spacecraft vibrantly observed the effects of the dust. Maven Orbiter’s instruments, which unexpectedly arrived weeks before the comet, looked at the upper Martian atmosphere, and afterward, a very bright color of UV light appeared which was linked to magnesium. Other colors showed the presence of iron.
Dr. Schneider, the lead scientist for the Maven instrument that made those observations said, “These are not what you expect for atmospheric ingredients, but they are what you expect from comet dust.”
Another Maven instrument detected Sodium, nickel, manganese, potassium, zinc and chromium.
Magnesium is usually 10% by weight of comet dust, Dr. Schneider said, leading to an estimate of thousands of kilograms of dust showering on Mars in about an hour. If that material arrived in pieces the size of sand grains, “a meteor shower could be made,” he added.
A radar instrument fitted on the ESA’s Mars Express orbiter observed an additional layer of electrons in the atmosphere — the result of falling dust particles burning up. Donald A. Gurnett, a physics professor at the University of Iowa who is the lead investigator for the instrument said, “This is extremely unusual.”
Moreover, the researchers revealed that within just hours most of the changes in the Martian atmosphere dissipated.
The European Space Agency and NASA’s orbiters were positioned on the opposite side of Mars when the peak of comet dust arrived. Traveling at 126,000 miles per hour, even a small particle could have damaged or destroyed a spacecraft.
The observatory in Australia that first identified the comet in January 2013 and named it as ‘Comet Siding Spring’, which is evolved from the Oort Cloud — a ball of icy debris about a light-year away. Though, each year, numerous cloud comets fly through the inner solar system, by the time they are seen, there is not enough time to send a spacecraft to study them.
But the comets that have been studied up close, such as Halley’s Comet, are closer in and return to the inner solar system every few years or decades.
With Siding Spring and its close encounter with Mars — less than half the distance between Earth and the moon — the spacecraft was already there to conduct the first close-up observations of an Oort Cloud comet. The NASA’s Mars Reconnaissance Orbiter took the photographs that revealed — comet’s nucleus was smaller than the expected 1.2 miles, and it was rotating once every 8 hours.
In the meantime, the European Space Agency is concluding preparations for a high-risk, high-reward attempt to place a small lander on a comet next week.
Its Rosetta spacecraft arrived at Comet 67P/Churyumov-Gerasimenko in August. On Wednesday, a lander named Philae with a weight of 220-pound is going to detach from Rosetta for a period of seven-hours to the surface of the 2.5-mile-wide comet, tugged down by its gravitational pull.
Once Philae is on its way, it has no way to adjust its trajectory, and the mission managers admit the attempt could go skewed if the lander ends up on a boulder or in a hole. Andrea Accomazzo, the flight director said, “We have to be a bit lucky.”