99942 Apophis ' onMouseout='HidePop("91745")' href="http://www.absoluteastronomy.com/topics/Provisional_designation_in_astronomy">provisional designation
A provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been calculated...
) is a near-Earth asteroid that caused a brief period of concern in December 2004 because initial observations indicated a small probability (up to 2.7%) that it would strike the
EarthEarth is the third planet from the Sun. It is the fifth largest of the eight planets in the solar system, and the largest of the terrestrial planets in the Solar System in terms of diameter, mass and density...
in 2029. Additional observations provided improved predictions that eliminated the possibility of an
impact on EarthAn impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Impact events have been a plot and background element in science fiction since knowledge of real impacts became established in the scientific mainstream.-Sizes and...
or the
MoonThe Moon is Earth's only natural satellite and the fifth largest satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is , about thirty times the diameter of the Earth. The common centre of mass of the system is located at about —a quarter the Earth's...
in 2029. However, a possibility remains that during the 2029 close encounter with Earth, Apophis would pass through a
gravitational keyholeA gravitational keyhole, or resonance keyhole, is a small region of space that could alter the course of a passing asteroid due to Earth's gravity in a way that could cause such an asteroid to collide with the Earth on its next orbital pass...
, a precise region in space no more than about 600 meters across, that would set up a future impact on April 13, 2036. This possibility kept the asteroid at Level 1 on the
Torino impact hazard scaleThe Torino Scale is a method for categorizing the impact hazard associated with near-Earth objects such as asteroids and comets.It is intended as a tool for astronomers and the public to assess the seriousness of collision predictions, by combining probability statistics and known kinetic damage...
until August 2006. It broke the record for the highest level on the Torino Scale, being, for only a short time, a level 4, before it was lowered.
Additional observations of the trajectory of Apophis revealed the keyhole would likely be missed and on August 5, 2006 Apophis was lowered to a Level 0 on the Torino Scale. As of October 7, 2009, the impact probability for April 13, 2036, is calculated as 1 in 250,000. An additional impact date in 2037 was also identified; the impact probability for that encounter was calculated as 1 in 12.3 million.
Many
scientistA scientist, in the broadest sense, is any person who engages in a systematic activity to acquire knowledge or an individual that engages in such practices and traditions that are linked to schools of thought or philosophy. In a more restricted sense, a scientist is an individual who uses the...
s agree that Apophis warrants closer scrutiny and, to that end, in February 2008 the
Planetary SocietyThe Planetary Society is a large, publicly supported, non-government and non-profit organization that has many research projects related to astronomy. It was founded in 1980 by Carl Sagan, Bruce Murray, and Louis Friedman, and has members from 125 countries around the world...
awarded $50,000 in prize money to companies and
studentThe word student is etymologically derived through Middle English from the Latin second-type conjugation verb studēre, meaning "to direct one's zeal at"; hence a student could be described as "one who directs zeal at a subject"...
s who submitted designs for
space probeA robotic spacecraft is a spacecraft with no humans on board, that is usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to...
s that would put a tracking device on or near the asteroid.
Basic data
Based upon the observed brightness, Apophis' length was estimated at ; a more refined estimate based on spectroscopic observations at
NASAThe National Aeronautics and Space Administration is an agency of the United States government, responsible for the nation's public space program. NASA was established by the National Aeronautics and Space Act on July 29, 1958, replacing its predecessor, the National Advisory Committee for...
's Infrared Telescope Facility in Hawaii by Binzel, Rivkin, Bus, and Tokunaga (2005) is .
In October 2005 it was predicted that the asteroid will pass just below the altitude of
geosynchronous satelliteA geosynchronous satellite is a satellite whose orbital track on the Earth repeats regularly over points on the Earth over time. If such a satellite's orbit lies over the equator and the orbit is circular, it is called a geostationary satellite. The orbits of the satellites are known as the...
s, which are at . Such a close approach by an asteroid of this size is expected to occur only every 1,300 years or so. Apophis’s brightness will peak at
magnitudeThe apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, normalized to the value it would have in the absence of the atmosphere...
3.3, with a maximum angular speed of 42° per hour. The maximum apparent
angular diameterThe angular diameter or apparent size of an object as seen from a given position is the “visual diameter” of the object measured as an angle. In the vision sciences it is called the visual angle. The visual diameter is the diameter of the perspective projection of the object on a plane through its...
will be ~2 arcseconds, so that it will be barely
resolvedOptical resolution describes the ability of an imaging system to resolve detail in the object that is being imaged.An imaging system may have many individual components including a lens and recording and display components...
by telescopes not equipped with
adaptive opticsAdaptive optics is a technology used to improve the performance of optical systems by reducing the effects of rapidly changing optical distortion. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, and in retinal imaging systems...
.
Naming
When first discovered, the object received the provisional designation (sometimes written 2004 MN4), and news and scientific articles about it referred to it by that name. When its orbit was sufficiently well calculated it received the permanent number 99942 (on June 24, 2005). Receiving a permanent number made it eligible for naming, and it received the name "Apophis" on July 19, 2005.
ApophisIn Egyptian mythology, Apep was an evil demon, the deification of darkness and chaos , and thus opponent of light and Ma'at , whose existence was believed from the Middle Kingdom onwards...
is the
GreekGreek , an independent branch of the Indo-European family of languages, is the language of the Greeks. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. In its ancient form, it is the language of classical...
name of the Ancient Egyptian enemy of
RaRA is an abbreviation or code which may refer to :Science* Right ascension, an astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system...
:
ApepIn Egyptian mythology, Apep was an evil demon, the deification of darkness and chaos , and thus opponent of light and Ma'at , whose existence was believed from the Middle Kingdom onwards...
, the Uncreator, a serpent that dwells in the eternal darkness of the
DuatIn Egyptian mythology, Duat is the underworld.This was the region through which the sun god Ra traveled from west to east during the night, and where he battled Apep. It also was the place where people's souls went after death—for judgment...
(earth's middle) and tries to swallow Ra during His nightly passage. Apep is held at bay by
SetIn Ancient Egyptian mythology, Set is an ancient god, who was originally the god of the desert, Storms, Darkness, and Chaos...
, the Ancient Egyptian god of Chaos.
Although the Greek name for the Egyptian god may be appropriate, Tholen and Tucker — two of the co-discovers of the asteroid — are reportedly fans of the TV series
Stargate SG-1Stargate SG-1 is an American-Canadian military science fiction television series and part of Metro-Goldwyn-Meyer's Stargate franchise. The show, created by Brad Wright and Jonathan Glassner, is based on the 1994 feature film Stargate by Dean Devlin and Roland Emmerich...
. The show's most persistent villain is an alien also named for the Egyptian god.
Close approaches
After the Minor Planet Center confirmed the June discovery of Apophis, an April 13, 2029 close approach was flagged by NASA's automatic
SentrySentry is a highly automated collision monitoring system that continually scans the most current asteroid catalog for possibilities of future impact with Earth over the next 100 years. Whenever a potential impact is detected it will be analyzed and the results immediately published on the Near...
system and
NEODySNEODyS is an Italian and Spanish service that provides information on Near Earth Objects with a convenient Web-based interface. It is based on a continually and automatically maintained database of near earth asteroid orbits. This site provides a number of services to the NEO community...
, a similar automatic program run by the
University of PisaThe University of Pisa is located in Pisa, Tuscany. It was formally founded on the September 3, 1343 by an edict of Pope Clement VI, although there had been lectures on law in Pisa since the 11th century...
and the
University of ValladolidThe University of Valladolid is a university in the city of Valladolid in the Valladolid province of the autonomous region of Castile-Leon, in Spain...
. On that date, it will become as bright as magnitude 3.3 (visible to the
naked eyeThe naked eye is a figure of speech referring to human visual perception that is unaided by enhancing equipment, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...
from rural as well as darker suburban areas, visible with
binocularsBinoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes with binocular vision when viewing distant objects. Most are sized to be held...
from most locations). This close approach will be visible from
EuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural River, the Caspian Sea, the Caucasus Mountains , and the Black Sea to the southeast...
,
AfricaAfrica is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area. With a billion people in 61 territories, it accounts for about 14.8% of the...
, and western
AsiaAsia is the world's largest and most populous continent, located in the eastern and northern hemispheres. It covers 8.6% of the earth's total surface area and with approximately 4 billion people, it hosts 60% of the world's current human population.Asia is traditionally defined as part of the...
. As a result of its close passage, it will move from the Aten to the
ApolloThe Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo, the first asteroid of this group to be discovered by Karl Wilhelm Reinmuth. They are Earth-crosser asteroids that have orbital semi-major axes greater than that of the Earth and a perihelion distance < 1.017 AU...
class.
After Sentry and NEODyS announced the possible impact, additional observations decreased the uncertainty in Apophis' trajectory. As they did, the probability of an impact event temporarily climbed, peaking at 2.7% (1 in 37). Combined with its size, this caused Apophis to be assessed at level 4 on the
Torino ScaleThe Torino Scale is a method for categorizing the impact hazard associated with near-Earth objects such as asteroids and comets.It is intended as a tool for astronomers and the public to assess the seriousness of collision predictions, by combining probability statistics and known kinetic damage...
and 1.10 on the
Palermo scaleThe Palermo Technical Impact Hazard Scale is a logarithmic scale used by astronomers to rate the potential hazard of impact of a near-earth object . It combines two types of data—probability of impact, and estimated kinetic yield—into a single "hazard" value...
, scales scientists use to represent the danger of an asteroid hitting Earth. These are the highest values for which any object has been rated on either scale.
On Friday, April 13, 2029, Apophis will pass Earth within the orbits of geosynchronous communication satellites. It will return for another close Earth approach in 2036.
PrecoveryPrecovery is a term used in astronomy that describes the process of finding the image of an object in old archived images or photographic plates, for the purpose of calculating a more accurate orbit...
observations from March 15, 2004 were identified on December 27, and an improved orbit was computed.
RadarRadar astronomy is a technique of observing nearby astronomical objects by reflecting microwaves off target objects and analyzing the echoes. This research has been conducted for four decades. Radar astronomy differs from radio astronomy in that the latter is a passive observation and the former an...
astrometry further refined the orbit. The 2029 pass will actually be much closer than the first predictions, but the uncertainty is such that an impact is ruled out. Similarly, the pass on April 13, 2036 carries little risk of an impact.
2013 refinement
The close approach in 2029 will substantially alter the object's orbit, making predictions uncertain without more data. "If we get radar ranging in 2013 [the next good opportunity], we should be able to predict the location of out to at least 2070." said Jon Giorgini of JPL. Apophis will pass within 0.09666
AUAn astronomical unit is a unit of length roughly equal to the mean distance between the Earth and the Sun. It is approximately 150 million kilometres ....
(14.4 million km) of the Earth in 2013 allowing astronomers to refine the trajectory for future close passes.
In July 2005, former Apollo astronaut
Rusty SchweickartRussell Louis "Rusty" Schweickart aka Schweikart is an American astronaut. Schweickart was born in Neptune, New Jersey. He earned an B.S. and M.S. in Aeronautics/Astronautics from MIT in 1956 and 1963 respectively....
, as chairman of the
B612 FoundationThe B612 Foundation is a private foundation dedicated to protecting the Earth from asteroid strikes. Their immediate goal is to "significantly alter the orbit of an asteroid in a controlled manner by 2015"....
, formally asked NASA to investigate the possibility that the asteroid's post-2029 orbit could be in
orbital resonanceIn celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...
with Earth, which would increase the probability of future impacts. Schweickart asked for an investigation of the necessity of placing a transponder on the asteroid for more accurate tracking of how its orbit is affected by the
Yarkovsky effectThe Yarkovsky effect is a force acting on a rotating body in space caused by the anisotropic emission of thermal photons, which carry momentum...
.
History of impact estimates
- The original NASA report on December 23, 2004, mentioned impact chances of "around 1 in 300", which was widely reported in the media. The actual NASA estimates at the time were 1 in 233; they resulted in the Torino scale rating of 2, the first time any asteroid had received a rating above 1.
- Later that day, based on a total of 64 observations, the estimates were changed to 1 in 62 (1.6%), resulting in an update to the initial report and an upgrade to a Torino scale rating of 4.
- On December 25, the chances were first reported as 1 in 42 (2.4%) and later that day (based on 101 observations) as 1 in 45 (2.2%). At the same time, the asteroid's estimated diameter was lowered from 440 m to 390 m and its mass from 1.2×1011 kg to 8.3×1010 kg.
- On December 26 (based on a total of 169 observations), the impact probability was still estimated as 1 in 45 (2.2%), the estimates for diameter and mass were lowered to 380 m and 7.5×1010 kg, respectively.
- On December 27 (based on a total of 176 observations), the impact probability was raised to 1 in 37 (2.7%); diameter was increased to 390 m, and mass to 7.9×1010 kg.
- On December 27 in the afternoon, a precovery increased the span of observations to 287 days and allowed more accurate calculations to re-rate the asteroid's 2029 approach as level zero on the Torino scale (no threat). The cumulative impact probability was estimated to be around 0.004%, a lower risk than asteroid , which once again became the greatest risk object. A 2053 approach to Earth still poses a minor risk of impact, and Apophis was still rated at level one on the Torino scale for this orbit.
- On December 28 at 12:23 GMT and (based on a total of 139 observations), produced a value of one on the Torino scale for 2044-04-13.29 and 2053-04-13.51.
- By 01:10 GMT on December 29 the only pass rated 1 on the Torino scale was for 2053-04-13.51 based on 139 observations spanning 287.71 days (2004-Mar-15.1104 to 2004-Dec-27.8243).
- By 19:18 GMT on December 29 this was still the case based upon 147 observations spanning 288.92 days (2004-Mar-15.1104 to 2004-Dec-29.02821), though the close encounters have changed and been reduced to 4 in total.
- By 13:46 GMT on December 30 no passes were rated above 0, based upon 157 observations spanning 289.33 days (2004-Mar-15.1104 to 2004-Dec-29.44434). The most dangerous pass was rated at 1 in 7,143,000.
- By 22:34 GMT on December 30, 157 observations spanning 289.33 days (2004-Mar-15.1104 to 2004-Dec-29.44434). One pass at 1 (Torino scale) 3 other passes.
- By 03:57 GMT on January 2, 2005, 182 observations spanning 290.97 days (2004-Mar-15.1104 to 2004-Dec-31.07992) One pass at 1 (Torino scale) 19 other passes.
- By 14:49 GMT on January 3, 2005 observations spanning 292.72 days (2004-Mar-15.1104 to 2005-Jan-01.82787) One pass at 1 (Torino scale) 15 other passes.
- Extremely precise radar
Radar is an object detection system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain. The term RADAR was coined in 1941 as an acronym for RAdio Detection And...
observations at Arecibo ObservatoryThe Arecibo Observatory is a radio telescope located close to the city of Arecibo in Puerto Rico. It is operated by Cornell University under cooperative agreement with the National Science Foundation. The observatory works as the National Astronomy and Ionosphere Center although both names are...
on January 27, 28, and 30 refine the orbit further and show that the April, 2029 close approach will occur at only 5.6 Earth radii, approximately one-half the distance previously estimated.
- A radar observation on August 7, 2005, refines the orbit further and eliminates the possibility of an impact in 2035. Only the pass in 2036 remains at Torino Scale 1.
- A new radar observation at Arecibo Observatory on May 6, 2006 slightly lowered the Palermo scale rating, but the pass in 2036 remained at Torino Scale 1 despite the impact probability dropping by a factor of four.
- Additional observations through 2006 resulted in Apophis being lowered to Torino Scale 0 on August 6, 2006. Around this time, the impact probability was lowered to 1 in 45,000.
- As of October 7, 2009, refinements to the precovery
Precovery is a term used in astronomy that describes the process of finding the image of an object in old archived images or photographic plates, for the purpose of calculating a more accurate orbit...
images of Apophis by the University of Hawaii's Institute for AstronomyThe Institute for Astronomy is a research unit within the University of Hawaii system, led by Dr. Rolf-Peter Kudritzki as Director. IfA main headquarters are located at 2680 Woodlawn Drive in Honolulu, Hawaii; additional facilities are located at Pukalani, Maui and Hilo on the Big Island. IfA...
, the 90-inch Bok TelescopeThe Bok Telescope is the largest telescope operated solely by Steward Observatory. It finds much use from astronomers from University of Arizona, Arizona State University, and Northern Arizona University, with instruments capable of both imaging and spectroscopy...
, and the Arecibo ObservatoryThe Arecibo Observatory is a radio telescope located close to the city of Arecibo in Puerto Rico. It is operated by Cornell University under cooperative agreement with the National Science Foundation. The observatory works as the National Astronomy and Ionosphere Center although both names are...
have generated a refined path that reduces the odds of a April 13, 2036 impact to about 1 in 250,000.
Possible impact effects
NASA initially estimated the energy that Apophis would have released if it struck Earth as the equivalent of 1,480 megatons of
TNTTrinitrotoluene , or more specifically, 2,4,6-trinitrotoluene, is a chemical compound with the formula C
6H
23CH
3. This yellow-coloured solid is a reagent in chemistry but is best known as a useful explosive material with convenient handling properties...
. A later, more refined NASA estimate was 880 megatons. The impacts which created the Barringer Crater or the
Tunguska eventThe Tunguska Event, or Tunguska explosion, was a powerful explosion that occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai of Russia, at around 7:14 a.m...
are estimated to be in the 3–10 megaton range The 1883 eruption of
KrakatoaKrakatoa , also spelled Krakatau or Kracatoa, is a volcanic island made of a'a lava in the Sunda Strait between the islands of Java and Sumatra in Indonesia...
was the equivalent of roughly 200 megatons.
The exact effects of any impact would vary based on the asteroid's composition, and the location and angle of impact. Any impact would be extremely detrimental to an area of thousands of square kilometres, but would be unlikely to have long-lasting global effects, such as the initiation of an
impact winterAn impact winter is a period of prolonged cold weather caused by the impact on the Earth of a large asteroid or comet. If such an impact occurred on land or the floor of a shallow sea, it could cause large amounts of dust or ash to be thrown into the Earth's atmosphere, blocking the Sun's light...
.
The
B612 FoundationThe B612 Foundation is a private foundation dedicated to protecting the Earth from asteroid strikes. Their immediate goal is to "significantly alter the orbit of an asteroid in a controlled manner by 2015"....
made estimates of Apophis' path if a 2036 Earth impact were to occur as part of an effort to develop viable
deflection strategiesAsteroid mitigation strategies are methods by which near-Earth objects could be diverted, preventing potentially catastrophic impact events. A sufficiently large impact would cause massive tsunamis and/or, by placing large quantities of dust into the stratosphere blocking sunlight, an impact winter...
. The result is a narrow corridor a few miles wide, called the path of risk, and it includes most of southern
RussiaRussia , officially known as both Russia and the Russian Federation , is a country in northern Eurasia . It is a semi-presidential republic, comprising 83 federal subjects...
, across the north Pacific (relatively close to the coastlines of
CaliforniaCalifornia is the most populous state in the United States, and the third largest by area. California is the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...
and
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
), then right between
NicaraguaNicaragua officially the Republic of Nicaragua , is a representative democratic republic. It is the largest country in Central America with an area of 130,373 km
2. The country is bordered by Honduras to the north and Costa Rica to the south. The Pacific Ocean lies to the west of...
and
Costa RicaCosta Rica, officially the Republic of Costa Rica is a country in Central America, bordered by Nicaragua to the north, Panama to the east and south, the Pacific Ocean to the west and south and the Caribbean Sea to the east.Costa Rica, which translates literally as "Rich Coast", constitutionally...
, crossing northern
ColombiaColombia , officially the Republic of Colombia , is a constitutional republic in northwestern South America. Colombia is bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the northwest by Panama; and to the west by the Pacific Ocean...
and
VenezuelaVenezuela , officially titled Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It is a continental mainland with numerous islands located off its coastline in the Caribbean Sea...
, ending in the Atlantic, just before reaching
AfricaAfrica is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area. With a billion people in 61 territories, it accounts for about 14.8% of the...
. Using the computer simulation tool NEOSim, it was estimated that the hypothetical impact of Apophis in countries such as Colombia and Venezuela, which are in the path of risk, would have had more than 10 million casualties. An impact several thousand miles off the West Coast of the US would produce a devastating tsunami.
Amateur calculations
- Nico Marquardt, a 13-year-old from Germany, was reported to have produced a collision estimate of 1 in 450 (100 times NASA's calculation) in April 2008, by factoring in the possibility of Apophis running into one or more of the geosynchronous satellites orbiting Earth during its flyby on April 13, 2029. This estimate was allegedly then confirmed by ESA and NASA but in an official statement, NASA denied having contact with Marquardt. The release went on to explain that the angle of Apophis' approach to the Earth's equator means the asteroid will not travel through the belt of existing equatorial
Equatorial has different meanings:* In geography it relates to the equator of the Earth.* In meteorology, an Equatorial climate is the type of climate experienced near the equator....
geosynchronous satellites and the extremely small size of satellites relative to the size of their orbits means that there is currently no risk of collision; and the effect on Apophis' trajectory of any such impact would be insignificant.
- On April 16, 2008, NASA News Release 08-103 reaffirmed that its estimation of a 1 in 45,000 chance of impact in 2036 remains valid.
Potential space missions
In 2008, The
Planetary SocietyThe Planetary Society is a large, publicly supported, non-government and non-profit organization that has many research projects related to astronomy. It was founded in 1980 by Carl Sagan, Bruce Murray, and Louis Friedman, and has members from 125 countries around the world...
, a
CaliforniaCalifornia is the most populous state in the United States, and the third largest by area. California is the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...
-based space advocacy group, organized a $50,000 competition to design an unmanned space probe that would 'shadow' Apophis for almost a year, taking measurements that would "determine whether it will impact Earth, thus helping governments decide whether to mount a deflection mission to alter its orbit." The society received 37 entries from 20 countries on 6 continents.
The commercial competition was won by a design called 'Foresight' created by SpaceWorks Engineering. SpaceWorks proposes a simple orbiter with only two instruments and a radio beacon at a cost of ~140 million USD, launched aboard a
Minotaur IVThe Minotaur is a family of American solid fuel rockets derived from converted Minuteman and Peacekeeper intercontinental ballistic missiles. They are built by Orbital Sciences Corporation....
between 2012 and 2014, to arrive at Apophis five to ten months later. It would then rendezvous with, observe, and track the asteroid.
Foresight would orbit the asteroid to gather data with a multi-spectral imager for one month. It would then leave orbit and fly in formation with Apophis around the Sun at a range of two kilometers (1.2 miles). The spacecraft would use laser ranging to the asteroid and radio tracking from Earth for ten months to accurately determine the asteroid's orbit and how it might change.
Pharos, the winning student entry, would be an orbiter with four science instruments (a multi-spectral imager, near-infrared spectrometer, laser rangefinder, and magnetometer) that would rendezvous with and track Apophis. Earth-based tracking of the spacecraft would then allow precise tracking of the asteroid. The Pharos spacecraft would also carry four instrumented probes that it would launch individually over the course of two weeks. Accelerometers and temperature sensors on the probes would measure the seismic effects of successive probe impacts, a creative way to explore the interior structure and dynamics of the asteroid.
Second place, for $10,000, went to a European team led by Deimos Space S.L. of Madrid, Spain, in cooperation with
EADS AstriumEADS Astrium Satellites, one of the three business units of EADS Astrium, this company being a subsidiary of EADS, is a European space manufacturer involved in the manufacture of spacecraft used for science, Earth observation and telecommunication, as well as the equipment and subsystems used...
, Friedrichshafen, Germany;
University of StuttgartThe University of Stuttgart is a university located in Stuttgart, Germany. It was founded in 1829 and is organized in 10 faculties....
, Germany; and Università di Pisa, Italy. Juan L. Cano was Principal Investigator.
Another European team took home $5,000 for third place. Their team lead was EADS Astrium Ltd, United Kingdom, in conjunction with EADS Astrium SAS, France; IASF-Roma, INAF, Rome, Italy;
Open UniversityThe Open University is the distance learning university founded and funded by the UK Government. It is notable for having an open entry policy, i.e. students' previous academic achievements are not taken into account for entry to most undergraduate courses...
, UK; Rheinisches Institut für Umweltforschung, Germany; Royal Observatory of Belgium; and
TelespazioTelespazio is a space systems services company, based in Rome, Italy. Telespazio was founded in 1961; however the company as it exists today was formed on July 1 2005 with the merger of the original Telespazio with the space services division of Alcatel...
, Italy. The Principal Investigator was Paolo D'Arrigo.
Two teams tied for second place in the Student Category:
Monash UniversityMonash University is a public university based in Melbourne, Australia. It is Australia's largest university with about 55,000 students.The University has a total of eight campuses: six in Victoria, Australia , one in Malaysia and one in South Africa...
, Clayton Campus, Australia, with Dilani Kahawala as Principal Investigator; and
University of MichiganThe University of Michigan, Ann Arbor is a public research university located in the state of Michigan in the United States. It is the state's oldest university, the flagship campus of the University of Michigan, and one of the top public universities in the world...
, with Jeremy Hollander as Principal Investigator. Each second place team won $2,000. A team from
Hong Kong Polytechnic UniversityThe Hong Kong Polytechnic University specialises in professional education in Hong Kong. The University’s teaching units are grouped under six faculties and two schools; the Faculty of Applied Science and Textiles, Faculty of Business, Faculty of Construction and Land Use, Faculty of Engineering,...
and
Hong Kong University of Science and TechnologyThe Hong Kong University of Science and Technology is a public university located in Hong Kong. Established in 1991 under Hong Kong Law Chapter 1141 , it is one of the nine universities in Hong Kong.Professor Tony F. Chan is the current president of HKUST...
, under the leadership of Peter Weiss, received an honorable mention and $1,000 for the most innovative student proposal.
In addition to the unmanned Planetary Society project, NASA's
Project ConstellationConstellation is a human spaceflight program within NASA, the space agency of the United States. The stated goals of the program are gaining significant experience in operating away from Earth's environment, developing technologies needed for opening the space frontier and conducting fundamental...
is researching a manned
Orion Asteroid MissionThe Orion Asteroid Mission is a proposed NASA mission to a Near-Earth Asteroid using the standard Orion spacecraft and a landing module based on Altair. Techniques could be developed to protect the Earth from asteroid impact...
, with 99942 Apophis being one of the potential destinations of the mission. The mission would use the Orion spacecraft to land astronauts on the surface of the asteroid. Such a mission would provide valuable testing for a later manned Orion Mars Mission.
Scenarios for Dealing with Apophis, a paper presented by Donald B. Gennery at the 2007 Planetary Defense Conference held in Washington, DC, outlines a number of proposals for deflecting Apophis including
gravitational tractorIn asteroid deflection, a gravitational tractor is a way to use the gravitational attraction between a spaceship and an asteroid to modify its trajectory to prevent it from colliding with the Earth. In the plan, the spaceship hovers above the asteroid's surface using thrusters, and gravitational...
,
kinetic impactAsteroid mitigation strategies are methods by which near-Earth objects could be diverted, preventing potentially catastrophic impact events. A sufficiently large impact would cause massive tsunamis and/or, by placing large quantities of dust into the stratosphere blocking sunlight, an impact winter...
, and nuclear bomb methods.
Apophis in Pop Culture
- In 2005 the Goth Metal band Type O Negative
Type O Negative is a heavy metal band from Brooklyn, New York City. Although commonly viewed as a gothic metal band, Type O has also incorporated elements of doom metal, and thrash metal. Their dramatic lyrical emphasis on themes of romance, depression, and death has resulted in the nickname "The...
released their album "Dead Again", Featuring a song entitled the "Profit of Doom", in which a reference to Apophis is made.
Risk assessment
These sources are updated as new orbital data becomes available:
- Apophis Orbital Prediction Page at NASA JPL
- Impact Risk (NASA JPL)
- page and impactor table from NEODyS
NEODyS is an Italian and Spanish service that provides information on Near Earth Objects with a convenient Web-based interface. It is based on a continually and automatically maintained database of near earth asteroid orbits. This site provides a number of services to the NEO community...
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ESA
NASA
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