2003 QQ47
|
|
| Discovery A (http://cfa-www.harvard.edu/iau/lists/NumberedMPs.html) | |
|---|---|
| Discoverer | LINEAR |
| Discovery date | August 24, 2003 |
| Alternate designations | B (http://cfa-www.harvard.edu/iau/MPDes.html) |
| Category | Apollo asteroid |
| Orbital elements C (http://asteroid.lowell.edu/) Epoch October 22, 2004 (JD 2453300.5) | |
| Eccentricity (e) | 0.187 |
| Semi-major axis (a) | 162.380 Gm (1.085 AU) |
| Perihelion (q) | 132.005 Gm (0.882 AU) |
| Aphelion (Q) | 192.756 Gm (1.288 AU) |
| Orbital period (P) | 413.057 d (1.13 a) |
| Mean orbital speed | 28.34 km/s |
| Inclination (i) | 62.102° |
| Longitude of the ascending node (Ω) | 1.014° |
| Argument of perihelion (ω) | 105.042° |
| Mean anomaly (M) | 290.754° |
| Physical characteristics | |
| Dimensions | 1.24 km |
| Mass | 2.0×1012 kg |
| Density | 2.0? g/cm³ |
| Surface gravity | 0.0003 m/s² |
| Escape velocity | 0.0007 km/s |
| Rotation period | ? d |
| Spectral class | ? |
| Absolute magnitude | 17.3 |
| Albedo | 0.10? |
| Mean surface temperature | ~267 K |
2003 QQ47 (also written 2003 QQ47) is an asteroid which became famous briefly upon its discovery in late August 2003 when media outlets played up a preliminary report that it had a 1:250,000 chance of colliding with Earth on March 21, 2014.
A NASA spokesman said,
- "Newly discovered asteroid 2003 QQ47 has received considerable media attention over the last few days because it had a small chance of colliding with the Earth in the year 2014 and was rated a "1" on the Torino impact hazard scale, which goes from 0 to 10. The odds of collision in 2014, as estimated by JPL's Sentry impact monitoring system, peaked at 1 chance in 250,000, a result which was posted on our Impact Risk Page on Saturday, August 30, 2003. Impact events at the Torino Scale 1 level certainly merit careful monitoring by astronomers, but these events do not warrant public concern. In fact, each year several newly discovered asteroids reach Torino Scale 1 for a brief period after discovery; 2003 QQ47 is the fourth such case this year.
- On September 2, 2003, new measurements of QQ47's position allowed us to narrow our prediction of its path in 2014, and thus we could rule out any Earth impact possibilities for 2014." [1] (http://neo.jpl.nasa.gov/news/news138.html)
2003 QQ47 has a diametre of approximately 1.24 km, and a mass of approximately 2.0×1012 kg. If it were to hit the Earth, it would be a major event, with an energy of approximately 350,000 megatons (1.5 ZJ), enough to cause global damage.
Dr. Sara Russell, a meteorite researcher at London's Natural History Museum, told the BBC that she was not worried that 2003 QQ47 would be a danger.
- "The odds are very, very low... We have to keep some kind of perspective," she said.
See the article on risk for more on dread, the perception of risk.
As a result of the press coverage of asteroids such as 2003 QQ47, astronomers are now planning to re-word the Torino scale, or to phase it out completely in favour of a scale which is less likely to generate false alarms which may reduce public confidence in genuine alerts.
External links
- Asteroid 2003 QQ47's Potential Earth Impact in 2014 Ruled Out (http://neo.jpl.nasa.gov/news/news138.html) - NASA
- BBC news story on 2003 QQ47 (http://news.bbc.co.uk/1/hi/uk/3200019.stm)
- New Scientist story on astronomers' reactions to press coverage of 2003 QQ47 (http://www.newscientist.com/news/news.jsp?id=ns99994178)
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| (For a complete listing, see: List of asteroids. For pronunciation, see: Pronunciation of asteroid names.) |