Although the comet's brightness had fallen to about 4th or 5th magnitude, it's extraordinarily broad dust tail
spanned an arc of no less than 110[degrees], even though its overall length didn't exceed a stubby 3[degrees] to 4[degrees].
The changing appearances of Comet Lovejoy's brilliant, sweeping dust tail
and slender, straight gas tail are evident in this daily sequence obtained by the Heliospheric Imager on the STEREO A spacecraft between December 16th and 19th as the comet moved away from the Sun.
That's when the magnificent extent of its dust tail
Using the 8.1-meter Gemini North telescope on Mauna Kea, Henry Hsieh and David Jewitt (University of Hawaii) found that main-belt asteroid 118401, discovered in 1999, is ejecting a comet-like dust tail
. Although the tail is too faint for spectroscopic measurements, Hsieh and Jewitt infer from the dust's velocity and the long duration of activity that the material is ejected when subsurface water ice sublimates, that is, turns directly from solid to gas.
Bright moonlight obscured much of Halley's dust tail
leading up to the full Moon on April 24th.
The hood's eastern end blended into the comet's broad dust tail
, which itself was comprised of fine or wispy striations.
Each of the 10 parts have comet-like dust tails
, and the biggest four chunks are each double the size of a football field.
Most meteor showers originate from comets composed of ice emitting millions of kilometres of dust tails
. But Geminids are different.
He covers dynamics, physical aspects, spectra, spectra of coma, gas production rates in coma, dust tails
, light scattering theory, the nature of dust particles, ion tails, nucleus, origin, and relations to other solar system studies.
Imaging the fainter ones can present an interesting challenge; they require much longer exposures to reveal any streaming ion or dust tails
, which leads to more complex issues when assembling your image.
As well as flaunting two dust tails
, it sported a ghostly bluish-white stream of charged particles, extending a third of the way across the sky (SN: 6/1/96, p.