Asteroid impact prediction

Asteroid impact prediction is the prediction of the dates and times of asteroids impacting Earth, along with the locations and severities of the impacts. The process of impact prediction follows three major steps: Discovery of an asteroid and initial assessment of its orbit, based on a short observation arc of less than 2 weeks. Follow up observations to improve the orbit determination Calculating if, when and where the orbit may intersect with Earth at some point in the future. In addition, although not part of the prediction process, once an impact has been predicted, an appropriate response needs to be made. Most asteroids are discovered by a camera on a telescope with a wide field of view. Image differencing software compares a recent photograph with earlier ones of the same part of the sky, detecting objects that have moved, brightened, or appeared; those systems obtain a few observations per night which can be linked up into a preliminary orbit. This predicts approximate positions over the next few nights and follow up can be carried out by any telescope powerful enough to see the newly detected object.

Orbit intersection calculations are carried out by two independent systems, one run by NASA and the other by ESA. A few near misses by medium-size asteroids have been predicted, years in advance, with a tiny chance of striking Earth. A handful of actual small impactors have been detected hours in advance. All were small, struck wilderness or ocean, hurt nobody. Current systems only detect an arriving object when several factors are just right the direction of approach relative to the Sun and phase of the Moon; the result is a low rate of success for smaller asteroids. Performance is improving as existing systems are upgraded and new ones come on line, but the blind spot issue which all current systems face around the Sun can only be overcome by a dedicated space based system. In 1992 a report to NASA recommended a coordinated survey to discover and provide follow-up observations for Earth-crossing asteroids; this survey was scaled to discover 90% of all objects larger than one kilometer within 25 years.

Three years a further NASA report recommended search surveys that would discover 60–70% of the short-period, near-Earth objects larger than one kilometer within ten years and obtain 90% completeness within five more years. In 1998, NASA formally embraced the goal of finding and cataloging, by 2008, 90% of all near-Earth objects with diameters of 1 km or larger that could represent a collision risk to Earth; the 1 km diameter metric was chosen after considerable study indicated that an impact of an object smaller than 1 km could cause significant local or regional damage but is unlikely to cause a worldwide catastrophe. The impact of an object much larger than 1 km diameter could well result in worldwide damage up to, including, extinction of the human race; the NASA commitment has resulted in the funding of a number of NEO search efforts, which made considerable progress toward the 90% goal by the target date of 2008 and produced the first successful prediction of an asteroid impact. However the 2009 discovery of several NEOs 2 to 3 kilometers in diameter demonstrated there were still large objects to be detected.

Three years in 2012, the small asteroid 367943 Duende was discovered and predicted to be on close but non-colliding approach to Earth again just 11 months later. This was a landmark prediction as the object was only 20 m × 40 m, it was monitored as a result. On the day of its closest approach and by coincidence, a smaller asteroid was approaching Earth and undetected, from a direction close to the Sun. Unlike 367943 Duende it was on a collision course and it impacted Earth 16 hours before 367943 Duende passed, becoming the Chelyabinsk meteor, it injured 1,500 people and damaged over 7,000 buildings, raising the profile of the dangers of small asteroid impacts if they occur over populated areas. The asteroid is estimated to have been 17 m across. In April 2018, the B612 Foundation stated "It's 100 per cent certain we'll be hit, but we're not 100 per cent sure when." In 2018, physicist Stephen Hawking, in his final book Brief Answers to the Big Questions, considered an asteroid collision to be the biggest threat to the planet.

In June 2018, the US National Science and Technology Council warned that America is unprepared for an asteroid impact event, has developed and released the "National Near-Earth Object Preparedness Strategy Action Plan" to better prepare. The first step in predicting impacts is determining their orbits. Finding faint Near-Earth objects against the background stars is much a needle in a haystack search, it is achieved by sky surveys. Unlike the majority of telescopes that have a narrow field of view and high magnification, survey telescopes have a wide field of view to scan the entire sky in a reasonable amount of time with enough sensitivity to pick up the faint Near-Earth objects they are searching for. NEO focused surveys revisit the same area of sky several times in succession. Movement can be detected using image differencing techniques. Anything that moves from image to image against the background of stars is compared to a catalogue of all known objects, if it is not known is reported as a new discovery along with its precise position and the observation time.

This allows other observers to confirm and add to the data about the newly discovered object

Marcella Silvestri

Marcella Silvestri is an Italian voice actress. She contributes to voice characters in cartoons, anime and more content. Silvestri is well known for providing the voice of the protagonist Hamtaro in the Italian language of the anime series Hamtaro, she provided the voice of Koyuki Azumaya in the Italian-language version of the anime series Keroro Gunso. And She Known The Voice of Misaki Uzumaki in the Italian-language version of the anime series of Naruto, she works at Merak Film, Studio P. V. Studio Asci and other dubbing studios in Italy. Miki in Angel's Friends Hay Lin in W. I. T. C. H. Hamtaro in Tottoko Hamtaro Hamtaro in Tottoko Hamutaro Hai! Luna in Ronin Warriors Koyuki Azumaya in Keroro Gunso Emma in Stoked Princess Ami in Puppy in My Pocket: Adventures in Pocketville Alice Gehabich in Bakugan Battle Brawlers Alice Gehabich in Bakugan Battle Brawlers: New Vestroia Simon in Alvin and the Chipmunks Shirousa in Sugarbunnies Shirousa in Sugarbunnies: Chocolat! Shirousa in Sugarbunnies: Fleur Krillin in Dragon Ball Z Krillin in Dragon Ball Z: Cooler's Revenge Krillin in Dragon Ball Z: Return of Cooler Mme.

Fluffé in Best Ed Angelina Jeanette Mouseling in Angelina Ballerina Angelina Jeanette Mouseling in Angelina Ballerina: The Next Steps Ruby in Jewelpet Miki in Shugo Chara! Burdine Maxwell in Bratz Zoisite in Sailor Moon Berthier in Sailor Moon R VesVes in Sailor Moon S Francis X. Bushlad in Taz-Mania Misuzu Midorikawa in Lady!! Misuzu Midorikawa and Sophie Montgomery in Hello! Lady Lynn Harley Quinn in The Batman Doremi Harukaze in Ojamajo Doremi Jirōmaru Takaba in Bakusō Kyōdai Let's & Go!! Reika in Genesis of Aquarion Milo Oblong in The Oblongs Benji in Jin Jin and the Panda Patrol Ally in Eon KidInagawa in Comic Party Natsue Awayuki in Prétear Stashia in Megami Paradise Keshimaru in Pastel Yumi, the Magic Idol Madoka Ayukawa in Kimagure Orange Road Corona in Spider Riders Kanade Yumeno in Onegai My Melody Arnold Perlstein in The Magic School Bus' Nancy in The Story of Pollyanna, Girl of Love Athena Gilnande in Najica Blitz Tactics Nut in Magical Angel Sweet Mint Arbell, Kodama, Nico Olvia, Michael and Hoichael's mother in One Piece Shuzo "Shu" Matsutani in Legendz Sherry LeBlanc in Yu-Gi-Oh!

5D's Miyu in Vampire Princess Miyu Ryoko Tsugumo in Area 88 Lum Invader in Urusei Yatsura 2: Beautiful Dreamer Juliet in Romeo x Juliet Geo in Team Umizoomi Gerty in Pic Me Susan Test in Johnny Test Sidney Poindexter in Danny Phantom Mooris Moony in Ricky Sprocket: Showbiz Boy Willow in A Kind of Magic Ethelbert the Tiger in Ethelbert the Tiger Kyoko Aoi in Future GPX Cyber Formula Aiko Nonohara in Hime-chan's Ribbon Tsukushi Makino in Boys Over Flowers Ken in Floral Magician Mary Bell Damia in Bosco Adventure Verdi in The Mozart Band and others Marie Rogers in Romeo! Geena Fabiano in Unfabulous Dulcea in Mighty Morphin Power Rangers: The Movie Katie in I Hate My 30's Raquel'Rocky' Donatelli in Laguna Beach: The Real Orange County Maddie Harrington in Ally McBeal Samantha Morgan in Hang Time Julia Field in Rituals and others List of non-English language Stoked voice actors Marcella Silvestri at Anime News Network's encyclopedia