These trails--a phenomenon related to, but separate from, the
dust tails comets flaunt in visible light as they move near the sun--consist of larger, pebble-size debris that scatter sunlight poorly.
Dust tail: The part of the comet that is most spectacular to the naked eye, though faint comets never grow a tail.
Additionally, you can take longer exposures to reveal the faintest extent of the comet's gas and
dust tails, as well as faint deep-sky objects nearby.
dust tail (type II) length: [10.sup.6] - [10.sup.7] km particle size: 0.1 - 100 microns direction: initially anti solar, becoming curved as dust particles follow independent orbits.
Since Comet 1973f has a perihelion distance that is only about a quarter that of Comet Bennett, it should become much brighter; and if it develops a
dust tail, it could be the most spectacular comet of the century.
While Comet PanSTARRS took the spotlight in March, fainter Comet C/2012 F6 Lemmon displayed a complex
dust tail and greenish coma for astroimagers in the Southern Hemisphere.
Noted Austrian astroimager Michael Jager's photograph on March 16th was among the earliest to illustrate the great breadth of PanSTARRS's
dust tail, along with a drastically weaker ion tail.
Comet PanSTARRS exhibited a broad, curved
dust tail in this image captured over the Very Large Array radio telescope in New Mexico during the early evening twilight of March 17th.
The SOHO images obtained around 4:00 UT on December 15th showed the comet was about magnitude -1 and sporting a long, bright, slightly curving
dust tail. Also visible was a long but decidedly fainter tail of ionized gas, which was a bit of a surprise because an ion tail had never been positively seen on earlier pygmy sungrazers.
I was thinking of something that I and relatively few other observers detected in very dark, clear skies in late April and early May 1986: the mostly very faint but amazingly long
dust tail of Halley's Comet.
A
dust tail is produced by microscopic dust particles released from the comet by the Sun's heat and driven away by sunlight (solar radiation pressure).
"THE LENGTH OF OPHIUCHUS HUGE." In late November and December 1618 a great comet traversed the predawn sky from Libra to north of Ursa Major, developing a
dust tail maybe 70[degrees] long as it passed Arcturus.