Gas Emissions From Comet ISON A Threat To Planet Earth?
By Sam Goodwin | Jul 24, 2013 02:28 AM EDT
Researchers using NASA's Spitzer Space Telescope have spotted strong carbon dioxide emissions from Comet ISON just before it is scheduled to pass through the inner solar system.
Comet ISON is emitting about 2.2 million pounds of what astronomers speculate to be carbon dioxide. The gas is reportedly steadily "fizzing" away from the comet and has a dust tail that is about 186,400 miles (300,000 kilometers) long, according to images captured June 13 with Spitzer's Infrared Array Camera.
"Previous observations made by NASA's Hubble Space Telescope and the Swift Gamma-Ray Burst Mission and Deep Impact spacecraft gave us only upper limits for any gas emission from ISON. Thanks to Spitzer, we now know for sure the comet's distant activity has been powered by gas," said Carey Lisse, leader of NASA's Comet ISON Observation Campaign, in a press release.
Comet ISON has a diameter of approximately 3 miles and weighs between 7 billion and 7 trillion pounds. Its true size and density is yet to be determined as the comet still lies very far from Earth. It is essentially made up of dust and frozen gases such as water, ammonia, methane and carbon dioxide.
The comet is scheduled to pass through the inner solar system later this year and will pass the Sun at a distance of 724,000 miles, November 28. ISON was positioned at a distance of 312 million miles from the Sun when the gas emission observations were made. This is 3.5 times the distance of Earth from the Sun.
"These fabulous observations of ISON are unique and set the stage for more observations and discoveries to follow as part of a comprehensive NASA campaign to observe the comet," said James L. Green, NASA's director of planetary science in Washington. "ISON is very exciting. We believe that data collected from this comet can help explain how and when the solar system first formed."
As the comet makes its first passage from the distant Oort Cloud, scientists reveal that the comet has begun warming up for the inbound journey which has led to some of its gases warming up to the point of evaporations. Carbon dioxide powers emission for most comets between the orbits of Saturn and the asteroids.
Vitali Nevski and Artyom Novichonok at the International Scientific Optical Network (ISON) near Kislovodsk, Russia first detected Comet ISON between Jupiter and Saturn last September. The gas emissions made its early detection possible.
With carbon dioxide emission reaching sky high levels, biologists have enough concerns to worry about and can definitely do without a carbon dioxide emitting comet on a collision course with our planet. Even then, increase in carbon dioxide levels will be the least of our problems because of the greater disasters such an impact may cause.
So how much of a threat is Comet ISON? Researchers assure that there is no threat of an impact at all. Comet ISON reaches its closest approach to us on Dec. 26, 2013; it's going to be approximately 2.8 million miles away, both above us and ahead of us in our orbit at that time. If anything, when the Earth passes ISON's orbit Jan. 16, sky grazers may be treated to a special kind of meteor shower.