Mini Sheet: Halley's comet: Streaking through the solar system (South Africa, Homelands 1986)
Halley's comet: Streaking through the solar system (South Africa, Homelands 1986)
20 March (South Africa, Homelands ) within release Ciskei goes into circulation Mini Sheet Halley's comet: Streaking through the solar system face value 10*12 South African rand
| Mini Sheet Halley's comet: Streaking through the solar system in catalogues | |
|---|---|
| Stamp Number: | Sn:ZA-CS 89 |
Mini Sheet is square format.
Also in the issue Ciskei:
- Stamp - Halley's comet-6 face value 12;
- Mini Sheet - Halley's comet: Streaking through the solar system face value 10*12;
- Stamp - Halley's comet-1 face value 12;
- Stamp - Halley's comet-2 face value 12;
- Stamp - Halley's comet-3 face value 12;
- Stamp - Halley's comet-4 face value 12;
- Stamp - Halley's comet-5 face value 12;
- Stamp - Halley's comet-7 face value 12;
- Stamp - Halley's comet-8 face value 12;
- Stamp - Halley's comet-9 face value 12;
- Stamp - Halley's comet-10 face value 12;
Mini Sheet Halley's comet: Streaking through the solar system it reflects the thematic directions:
A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or coma surrounding the nucleus, and sometimes a tail of gas and dust gas blown out from the coma. These phenomena are due to the effects of solar radiation and the outstreaming solar wind plasma acting upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times Earth's diameter, while the tail may stretch beyond one astronomical unit. If sufficiently close and bright, a comet may be seen from Earth without the aid of a telescope and can subtend an arc of up to 30° (60 Moons) across the sky. Comets have been observed and recorded since ancient times by many cultures and religions.
