- The correct title of this article is 1997 XR2. It features superscript or subscript characters that are substituted or omitted because of technical limitations.
1997 XR2 (also written 1997 XR2) is an asteroid discovered in 1997. It has a diameter of 0.1-0.3 km and an estimated mass on the order of 1010 kilograms. From early 2002 to February 24, 2006, 1997 XR2 was considered to have about a 1 in 10,000 chance of colliding with Earth on June 1, 2101, based on 144 observations going back to December of 1997. It was ranked a one on the Torino Scale of impact risk, and was the only NEO to be ranked higher than zero (the scale is 0–10) until it was joined by 2004 VD17 at level one in November 2004, and then when 99942 Apophis (then known only by its provisional designation 2004 MN4) was temporarily assessed at level four in December 2004. Currently 2004 VD17 and 99942 Apophis are rated at level zero (as of February 2007). On February 24, 2006, 1997 XR2 was observed by the Mt. Lemmon Survey after being lost for more than 8 years. The refinement of its orbit eliminated the possibility of impact in 2101.
References
- NASA Near Earth Object Program. "Current Impact Risks" http://neo.jpl.nasa.gov/risk/ (accessed 30 Sep. 2005).
- Ibid. "1997 XR2 Earth Impact Risk Summary" (29 May 2002). http://neo.jpl.nasa.gov/risk/1997xr2.html (accessed 3 Apr. 2004).
- Asteroid/Comet Connection. "Consolidated Risk Tables" http://www.hohmanntransfer.com/crt.htm#news (accessed 25 Feb. 2006).
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| Vulcanoids · Near-Earth asteroids · Main belt · Jupiter Trojans · Centaurs · Damocloids · Neptune Trojans · Comets · Trans-Neptunians (Kuiper belt • Scattered disc objects • Oort cloud) |
| For other objects and regions, see Asteroid groups and families, Binary asteroids, Asteroid moons, meteoroids and the Solar System. For a complete listing, see List of asteroids. See also Pronunciation of asteroid names and Meanings of asteroid names. |
