http://neo.jpl.nasa.gov/cgi-bin/neo_ca?type=NEO;hmax=all;tlim=recent_future;dmax=0.1AU;max_rows=200;action=Display%20Table;show=1&sort=dist_min&sdir=ASC73P/Schwassmann-Wachmann 3 너무 근접하지 않았으면 합니다....

NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring!
Comet 73P/Schwassmann-Wachmann은 태양을 5.6년 주기로 도는 혜성이라고합니다.
그러나 어떤일인지 1995년 밝능 빛의 섬광과 함께 폭발하여 많은 조각으로 분리되었다고합니다.
이후 분열된 행성체는 몇년동안의 과도기를 거쳐 안정궤도를 잡았다고 하는데....
그중 73P/Schwassmann-Wachmann 3-BD 로 명명된 혜성체의 근접거리가 나사의 NEOs (Near-Earth Objects)에서 발표한바에 의하면 0.04 LD(지구와 달의거리를 1로 본단위 약 38만 Km), 0.0001AU(지구와 태양의거리를 1로 본 천문학 단위 1억5천만 KM)의 거리로 지구와 접근하다는 기록이 발표 되었습니다.

아무래도 계산 오류가 있는것으로 보이지만 5월 11일 에 관심이 쏠립니다.
이계산대로라면 73P/Schwassmann-Wachmann 3-BD는 몇만 KM 거리로 지구를 스친다는 이야기 !!!.

9/11과 5/11...


Comet 73P/Schwassmann-Wachmann 3 는...

Comet 73P/Schwassmann-Wachmann 3 was discovered by Arnold Schwassmann and Arno Wachmann
on May 2, 1930 at Hamburg Observatory in Germany. It approached within 0.062 AU six
weeks after its discovery, when it reached 6th magnitude. The comet has an orbital period
of 5.36 years, but due to uncertainties in its orbit, faint visual magnitudes, and relatively
close approaches to Jupiter in 1953 and 1965 that altered its orbit, it wasn't recovered until
1979. In the fall of 1995 the comet's magnitude brightened dramatically, and then in December
of that year, multiple fragments were discovered. In other words, the comet's nucleus split.
Three of the fragments, B, C, and E, were observed again during the subsequent perihelion passage in 2001.

Fragment C was recovered in August, 2005 and fragment B was recovered in January, 2006.
The comet has since split multiple times, and as of early May, about dozens of fragments
been observed. Fragment B has split into at least one large fragment and a cloud of smaller ones.
In contrast, fragment C apparently has not split (yet).

During May, 2006 fragments B, C, and most of the others will approach within 0.079 AU.
Fragment E was last observed in December, 2000. It is predicted to approach within 0.051 AU
several days after the other fragments, when we hope to observe it, presuming, of course,
that it still exists.

Sekanina (1989) estimated a pre-breakup (prior to 1995) diameter of about 2 km.

Toth et al. (2005) estimate that fragment C (prior to recent splitting) had a diameter of 1.3 km.

Fragment C is the largest and (as of early May) is already bright enough to see in binoculars.
Fragment B is also visible in binoculars but it's fainter than fragment C. The other fragments
require a telescope to observe.

These will be combined Goldstone and Arecibo observations.
Goldstone observations are scheduled on May 9, 12, 14, 21, and 23 and Arecibo observations are
scheduled on several dates between April 30-May 22. We know little about the sizes and rotation
periods of the fragments, so it's hard to estimate the SNRs. Comet SW3 could be a moderately strong
radar target at Goldstone, and if we're lucky, we may be able to resolve the nucleus with
coarse-resolution ranging. Alternatively, it could be weak, but in any event, we should be able
to detect it.

The approach by Schwassmann-Wachmann 3 will be the closest by any comet since
comet Sugano-Saigusa-Fujikawa approached within 0.063 AU in June, 1983.


Orbital and Physical Characteristics: Fragment C
orbit type Jupiter-family periodic comet
semimajor axis 3.063 AU
eccentricity 0.693
inclination 11.4°
perihelion distance 0.939 AU
aphelion distance 5.186 AU
orbital period 5.360 years
diameter ~1 km (Z. Sekanina, pers. comm.)
rotation period unknown
pole direction unknown
lightcurve amplitude unknown

Orbital parameters for fragment B are similar.

Last updated: 2006 May 03