Astronomy:2004 TN1
| Discovery[1][2] | |
|---|---|
| Discovered by | NEAT |
| Discovery site | Palomar Obs. |
| Discovery date | 5 October 2004 (first observed only) |
| Designations | |
| 2004 TN1 | |
| Minor planet category | Apollo · NEO · PHA[1][2] |
| Orbital characteristics[2] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 6 · 5[1] | |
| Observation arc | 30 days |
| |{{{apsis}}}|helion}} | 4.6652 AU |
| |{{{apsis}}}|helion}} | 0.8304 AU |
| 2.7478 AU | |
| Eccentricity | 0.6978 |
| Orbital period | 4.55 yr (1,664 d) |
| Mean anomaly | 52.982° |
| Mean motion | 0° 12m 59.04s / day |
| Inclination | 8.4407° |
| Longitude of ascending node | 213.96° |
| 233.55° | |
| Earth MOID | 0.0010 AU (0.38 LD) (151000 km) |
| Jupiter MOID | 0.8187 AU |
| TJupiter | 2.9230 |
| Physical characteristics | |
| Mean diameter | 0.13 km (est. at 0.20)[3] 0.24 km (est. at 0.057)[3] |
| Absolute magnitude (H) | 21.8[1][2] |
2004 TN1 is a sub-kilometer near-Earth asteroid and potentially hazardous object of the Apollo group, approximately 180 meters (600 ft) in diameter. It was first observed by the Near-Earth Asteroid Tracking at Palomar Observatory on 5 October 2004. The asteroid has a notably low sub-lunar Earth-MOID of 0.38 LD. (As of 2019), it has only been observed in Fall 2004.[1][2]
Orbit and classification
2004 TN1 is a member of the Apollo group of asteroids, which are Earth-crossing asteroids. They are the largest group of near-Earth objects with approximately 10 thousand known members. It orbits the Sun at a distance of 0.8–4.7 AU once every 4 years and 7 months (1,664 days; semi-major axis of 2.75 AU). Its orbit has an eccentricity of 0.70 and an inclination of 8° with respect to the ecliptic.[2] Due to its highly eccentric orbit it also crosses the orbit of Mars at 1.66 AU. The body's observation arc begins with its first observation at Palomar on 5 October 2004.[1]
However, its orbit is poorly determined, with observations taken over a few weeks in 2004, yielding an orbital certainty of 5 and 6, respectively, with 0 being a well-determined orbit and 9 being an extremely poorly determined orbit. More observations are needed to improve the precision of the asteroid's orbital parameters to determine its potentially hazard it may pose to Earth in the distant future.[1][2]
Close approaches
The asteroid has an Earth minimum orbital intersection distance of 0.00100677 AU (151,000 km; 93,600 mi), which corresponds to 0.38 lunar distances and makes it a potentially hazardous asteroid due to its sufficiently large size.[2] On 24 November 2004, it passed Earth at a nominal distance of 0.0935379 AU (14,000,000 km; 8,690,000 mi).[2] It has the fourth smallest geocentric Minimum Orbital Intersection Distance of any asteroid, after 2008 TC3 which exploded in Earth's atmosphere in 2008, 1994 GV, and 2014 AA which also impacted the Earth in 2014. The asteroid, however, will not make any significant close approaches to Earth in at least the next century, as it is expected to pass close to Earth again on 8 October 2114.[2]
Numbering and naming
This minor planet has neither been numbered nor named by the Minor Planet Center, which requires repeated observations on more than one opposition.[1]
Physical characteristics
2004 TN1 has an unknown spectral type and could be of siliceous (S-type) or carbonaceous (C-type) composition with high or low albedo, respectively.[2][4]
Rotation period
As of 2019, no rotational lightcurve of this asteroid has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.[2][4]
Diameter and albedo
Based on an magnitude-to-diameter conversion and a measured absolute magnitude of 21.8, 2004 TN1 measures between 130 and 240 meters in diameter for an assumed geometric albedo of 0.20 (siliceous) and 0.057 (carbonaceous), respectively.[1][3] A theoretical impact into porous rock at 45°, assuming the asteroid to have a density of 2 g/cm3, would yield a crater between 1.7 and 3.2 kilometers wide, slightly larger than Meteor Crater in Arizona.[5]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 "2004 TN1". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=2004+TN1. Retrieved 29 November 2019.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 "JPL Small-Body Database Browser: (2004 TN1)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3255979;cad=1. Retrieved 29 November 2019.
- ↑ 3.0 3.1 3.2 "Asteroid Size Estimator". CNEOS NASA/JPL. https://cneos.jpl.nasa.gov/tools/ast_size_est.html. Retrieved 29 November 2019.
- ↑ 4.0 4.1 "Asteroid 2004 TN1". Small Bodies Data Ferret. https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=2004+TN1. Retrieved 29 November 2019.
- ↑ Melosh, H. J.; Bey, Ross A.. "Crater size from projectile diameter". http://www.lpl.arizona.edu/tekton/crater_c.html. Retrieved 1 November 2014.
External links
- 2004 TN1 at NeoDyS-2, Near Earth Objects—Dynamic Site
- Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
- 2004 TN1 at ESA–space situational awareness
- 2004 TN1 at the JPL Small-Body Database
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