During its entry (viewed with the lunar origin theory) or re-entry (viewed with the terrestrial impact theory) to Earth’s atmosphere, a tektite tends to tumble so that its surface could be exposed to atmosphere in various directions. A typical example is a sphere-shaped tektite whose surface is commonly filled with pits and flow lines uniformly. If and only if tumbling stops, a tektite would have a particular part facing the Earth which becomes so called “windside”, receiving higher heating rate than other parts . The opposite part that is not facing the Earth becomes “leeside”. Reports on oriented tektites are scarce.

The manned space vehicle is always designed with blunt end as its windside, and a missile with a sharp tip forward (recent email from Prof. J. M. Wu). Which side of a teardrop tektite was facing the Earth during their atmospheric journey, the blunt end or the sharp end? Was a dish-shaped tektite oriented? What ablation features do we see? As far as we know, no detailed study on those issues has been done. We have some indochinites from Maoming, Guangdong, China, which we believe are oriented tektites.

(1) A disc-shaped indochinite with distinctive concave face full of pits and convex face of raised dots and flow lines. Prof. J. M. Wu of the Space Institute, University of Tennessee, was particularly helpful in analyzing the aerodynamic history of this piece.

td#31 windsideleeside(sold),

Generally speaking, the smoother surface of a dish-shaped tektite, commonly with flow lines, is corresponding to the windside; and the rougher one, with many pits, is the leeside. The high pressure and hot air flow would sculpture the surface and thus form flow lines. The pressure on the leeside was extremely low (near vacuum) and such sucking away surface irregularities which resulted in a rougher surface.

The concave and rough face of this piece was likely the leeside , and the convex the windside during its atmospheric passage. It had a relatively spherical shape as it was falling. Concentric flow lines suggested its spinning while it was falling.

Similar pieces: torb1, 47 mm, 59 g, $100

tor1, 68 g, $ 105(sold); tor2, 32 g, $48 (sold)

(2) An oriented pear-shaped tektite, tor3. Its sharp end was probably earthward, with flow lines convergent at the tip representing the "stagnent point", which is pit-free, in constract to deep pits on the windside.

Similar piece: tor4, 32 mm long, 22 g, $33.

(3) An oriented and flatened teardrop tektite, tor5, 56 mm long, 44 g, $66, flow lines are distributed in a different pattern from the piece described above.

Special thanks to Prof. J. M. Wu (Space Institute, University of Tennessee) for his related information.

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