The 2012 TC4 asteroid, estimated\nto be 50 feet long and 25 feet wide, was expected to approach Earth\u2019s orbit in\nOctober 2017. In the months leading up to its approach, astronomers from the\nU.S., Canada, Colombia, Germany, Israel, Italy, Japan, the Netherlands, Russia,\nSouth Korea and South Africa tracked TC4 from both ground- and space-based\ntelescopes to study the asteroid\u2019s orbit, shape, rotation period and\ncomposition.<\/p>\n\n\n\n
As TC4 safely passed Earth on Oct. 12 at a distance of only\nabout 50,000 kilometers, or 31,000 miles, above Earth\u2019s surface, astronomers observed\nthe object using telescopes all over the world, including the Discovery Channel\nTelescope in Happy Jack. NAU professor David Trilling<\/strong> and graduate student Annika Gustafsson<\/strong> also contributed\nobservations and are listed in the paper. After the asteroid\u2019s flyby,\nThomas coordinated the results of the spectroscopy observations, which were\nused to determine the asteroid\u2019s composition. Thomas also did some observing for the lightcurve component\nof the campaign.<\/p>\n\n\n\n \u201cMy\nlightcurve observations were done using the four-meter Southern\nAstrophysical Research (SOAR) telescope on Cerro Pachon in Chile. The\nobservatory gave us a small part of their engineering time on the telescope\nbecause of the importance of the program,\u201d Thomas said. \u201cThe goal of the\nlightcurve observations was to determine how fast the object was rotating and whether\nthe rotation period was around a single rotation axis (like the Earth), or if\nit was what is called \u2018tumbling\u2019.\u201d <\/p>\n\n\n\n \u201cScientifically, there were no incredibly surprising\nfindings,\u201d Thomas said. \u201cThe object was certainly within the realm of what we\ncan expect from a near-Earth asteroid. In my opinion, the most interesting part\nof this work was the worldwide coordination and how well each of the different\ngroups worked together. Each group of observers used the information provided\nby other groups to help construct a more complete picture of 2012 TC4. This\neven extended to the inclusion of the compositional results into studies of\nwhat might happen if an object like 2012 TC4 were to impact the planet. Getting\nthis amount of detail on an object that was only bright enough for careful\nstudy for a short period of time is truly a group effort.\u201d<\/p>\n\n\n\n Thomas\nand many of the other scientists on the TC4 campaign, along with members of the\nInternational Asteroid Warning Network (IAWN), are working on the next NASA\ncampaign to characterize the near-Earth asteroid binary\n1999 KW4.<\/p>\n\n\n\n Thomas\nalso leads the observations working group for one of NASA’s next NEO priorities,\nthe Double Asteroid Redirection Test (DART) mission. <\/p>\n\n\n\n \u201cIt’s the first planetary defense mission and will impact the moon of the near-Earth asteroid Didymos in 2022,\u201d Thomas said.<\/p>\n\n\n\nWorldwide coordination on\nproject a success<\/strong><\/h4>\n\n\n\n
What\u2019s next for international\nasteroid-watchers?<\/strong><\/h4>\n\n\n\n
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