What some people are calling the comet of the century will be paying a visit to our part of the solar system in November, but scientists, including UCF 麻豆精品 S檚 Yan Fernandez, are already hard at work preparing for its arrival.
Comet ISON comes from the Oort Cloud, a refuge for icy debris jettisoned by Jupiter and the other giant planets to the distant reaches of the Sun 麻豆精品 S檚 influence back when the planets were just forming. ISON is creating quite the buzz within the space community since it is now making its first trip back toward the sun since then.
麻豆精品 S淚t 麻豆精品 S檚 been in deep freeze for about four and a half billion years, 麻豆精品 S� Fernandez said. 麻豆精品 S淚t 麻豆精品 S檚 pretty exciting because it likely has some clues locked inside its nucleus about how our solar system formed. Because comets from the Oort Cloud are so old and relatively pristine, we want to take advantage of what they can tell us about our solar system 麻豆精品 S檚 earliest days. 麻豆精品 S�
Fernandez is part of NASA 麻豆精品 S檚 Comet ISON Observing Campaign team that 麻豆精品 S檚 been coordinating and facilitating observations of the comet since January. He is also part of another team that took the first infrared images of ISON with the Spitzer Space Telescope in June and released the
麻豆精品 S淎s it gets closer to the Sun we expect to get more detailed information than ever before about the comet, 麻豆精品 S� Fernandez said. 麻豆精品 S淎nd on Thanksgiving Day, ISON will get to within only 750,000 miles of the Sun 麻豆精品 S檚 surface, so it 麻豆精品 S檚 going to get really hot. That 麻豆精品 S檚 pretty fantastic. It means all sorts of materials that we can study are going to be boiling off the comet 麻豆精品 S� ices, rocks, metals. For the general public it could be a-once-in-a-lifetime opportunity to see a really bright comet. We 麻豆精品 S檙e hoping that in November and December you can see it with the naked eye at night right from your backyard. 麻豆精品 S�
That is, if ISON doesn 麻豆精品 S檛 blow apart first.
ISON, like all comets, is a dirty snowball made up of dust and frozen gases such as water, ammonia, methanol, carbon monoxide and carbon dioxide. These are some of the fundamental building blocks of planets. As a comet gets closer to the sun, it heats up and its outer layers evaporate away. Spitzer images revealed that ISON is gassed up, with the carbon monoxide and carbon dioxide in its icy outer layer already boiling away and producing a bright tail. There is a possibility that as ISON gets closer to the sun, the evaporation of ices will become so intense that they will destroy the structural integrity of the comet before observers on Earth get a clear look.
Right now ISON is still too far away (well beyond Mars 麻豆精品 S檚 orbit) to know for sure how big it is and what its make up is exactly, Fernandez said.
麻豆精品 S淲e might then get a better idea of what the comet will do and how bright it might get in November, but that 麻豆精品 S檚 one of the crazy things about comets 麻豆精品 S� they like to defy predictions, 麻豆精品 S� he said. 麻豆精品 S淚SON might disintegrate to nothingness, it might survive but under perform, or it might indeed be a comet-of-the-century. We 麻豆精品 S檒l just have to wait. 麻豆精品 S�
Estimates are that ISON is less than 2 1/2 miles in diameter, about the size of a small mountain, and that it weighs between a few billion and several trillion pounds.
Should ISON remain intact come the fall, and if it seems like it will become bright enough, Fernandez said he will be organizing observation nights for the public from on UCF 麻豆精品 S檚 main campus. Fernandez is the observatory 麻豆精品 S檚 director.
麻豆精品 S淲e 麻豆精品 S檙e in the planning stages right now, 麻豆精品 S� Fernandez said. 麻豆精品 S淏ut if people are willing, we expect to have some opportunities in mid to late November for the public. It may mean getting up at 4 a.m. for best viewing, but we 麻豆精品 S檒l do it. 麻豆精品 S�
Should ISON keep it together as it loops around the sun and boomerangs back toward the outer solar system, Fernandez says more viewing nights will be added in December. But it would still mean getting up before dawn.
麻豆精品 S淲e 麻豆精品 S檒l have a better idea when it gets a wee-bit closer, say some 200 million miles from the Sun in early September, so stay tuned, 麻豆精品 S� he said.