The well-developed tail structure of was captured in this image taken March 5, 1986. At this point in its orbit, Halley had recently passed on February 9, 1986 and was at its most active. This 10-minute exposure was recorded at Mauna Kea Observatory on IIIa-J emulsion without filters.
ion tail Thin stream of ionized gas that is pushed away from the head of a comet by the solar wind. It extends directly away from the Sun. Often referred to as a plasma tail.
ionized State of an atom that has had at least one of its electrons removed.
The relatively straight tail of a comet produced by the solar wind acting on ions.
A meteorite composed primarily of iron.
The straight tail of a comet which is generated by particles from the solar wind.
One of the four categories of galaxies as defined by Hubble. Irregular galaxies have no consistent structure and are large gatherings of young stars and interstellar gases.
Ion Tail: A tail of charged gases (ions) always faces away from the sun because the solar wind (ions streaming from the sun at high velocities) pushes it away (it is also called the plasma tail).
~ - up to 100 million km long, it is composed of ions that interact with the solar wind.
plasma laced with rays and streamers up to 100 million km long
caused by interactions with the solar wind
Hydrogen Cloud ...
The ~ is formed as a result of the photoelectric effect of solar ultra-violet radiation acting on particles in the coma. Once the particles have been ionised, they attain a net positive electrical charge which in turn gives rise to an "induced magnetosphere" around the comet.
Eugene Shoemaker, Carolyn Shoemaker, David Levy ...
The 'ion tail' is made of glowing electrically charged particles pushed away by the steady wind of charged particles from the Sun. This tail remains straight and often glows blue or blue-green.
As the nucleus begins to disintegrate, it also produces a trail of dust or dust tail in its orbital path and a gas or ion tail pointing away from the Sun. Comet comas can extend up to a million miles from the nucleus and comet tails can be millions of miles long.
dust tail: up to 10 million km long composed of smoke-sized dust particles driven off the nucleus by escaping gases; this is the most prominent part of a comet to the unaided eye;
ion tail: as much as several hundred million km long composed of plasma and laced with rays and streamers ...
~ (comet): one of the two tails of a comet made of ionized particles that points directly away from the Sun from the action of the solar wind. It has a bluish color from the emission lines mostly of ionized carbon monoxide. irregular galaxy a galaxy with no definite structure.
~ (of a comet) Filamentary tail of a comet (separate from the dust tail), resulting from the interaction of the solar wind with ions in the comet's head. irregular galaxy galaxy without symmetrical form.
Many comets have two tails, a gas tail (also called the ion tail) composed of ions blown out of the comet away from the Sun by the solar wind, and a dust tail composed of dust particles liberated from the nucleus as the ices are vaporized.
These include the gas tail (also called the ion tail), which is made up of material that is blown straight back by the solar wind. This is generally made of the really lightweight gases. Within the gas tail you find stuff such as water vapor, CO, CO2, N2, ammonia and methane gases and particles.
The solar wind of high-speed protons and electrons sweeps cometary ions in a direction away from the Sun, producing a straight plasma or ion tail. A second tail consisting of dust particles about a micrometer in size may appear.
The solar wind and the ion tail are both so rarefied that collisions between their particles hardly ever occur.
hydrogen envelope - Hydrogen gas that surrounds the coma of the comet and trails along for millions of miles (it is usually between the ion tail and the dust tail). The hydrogen envelope is about 10 million km across at the nucleus of the comet and about 100 million km long.
Well:- the comet DID survive perihelion, amd sprouted a faint ion tail in the process. the LASCO images posted just a few hours ago by NASA are truely stunning!!
The comet's discoverer:- Terry Lovejoy managed a marginal set of brief images in his C8 on December 17.049 UT making the comet ~ Mv -1.
At the same time, the ion tail, made of gases, always points directly away from the Sun, as this gas is more strongly affected by the solar wind than is dust, following magnetic field lines rather than an orbital trajectory.
The ~ or plasma tail is formed when photons from the Sun ionise the gas in the coma. These ions follow the magnetic fields carried by the solar wind and so this tail usually appears pointing directly away from the Sun.
~s develop because of the pressure of sunlight, which drives very small particles out of the head of comets, while dust tails are due to the pressure of the solar wind; in general an ion tail is straight, while a dust tail is curved.
The ~ is much less massive, and is accelerated so greatly that it appears as a nearly straight line extending away from the comet opposite the Sun. Thus, comets should have two distinct tails.
Thus, relatively massive dust tails are accelerated slowly and tend to be curved. The ion tail is much less massive, and is accelerated so greatly that it appears as a nearly straight line extending away from the comet opposite the sun.
The ions - electrically charged particles - interact with the sun's solar wind, causing a comet magnetotail that points away from the sun. The ions travel along the magnetic field lines, so the ion tail points away from the sun.
See also: What is the meaning of Dust, Comet, Solar, Sun, Earth?