Comet Tails
Comet Tails - Related Videos
10:00
Assaying DNA Damage in Hippocampal Neurons Using the Comet Assay
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Cited by 21 •
2012
The comet assay is an efficient way of detecting single- and double-strand breaks, including alkali-labile sites and DNA-DNA/DNA-protein cross-links on the DNA in all cells including hippocampal neurons. The method takes advantage of the differential migration of DNA in an electric field due to differences in amount of DNA damage.
06:19
Comet Assay for DNA Damage Detection in Cells
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2025
The video demonstrates the comet assay for detecting DNA damage following exposure to harmful agents. Under alkaline conditions, the DNA unwinds and denatures, and upon electrophoresis, the undamaged and damaged DNA migrate differently in the agarose gel, forming a comet-shaped structure. The slowly migrating undamaged DNA forms the circular comet head, while the rapidly migrating damaged DNA fragments form the elongated comet tail.
08:23
Comet Assay as an Indirect Measure of Systemic Oxidative Stress
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Cited by 23 •
2015
Comet assay measures DNA breaks, induced by different factors. If all factors (except oxidative stress) causing DNA damage are kept constant, the amount of DNA damage is a good indirect parameter of oxidative stress. The goal of this protocol is to use comet assay for indirect measurement of oxidative stress.
10:38
In Vivo Alkaline Comet Assay and Enzyme-modified Alkaline Comet Assay for Measuring DNA Strand Breaks and Oxidative DNA Damage in Rat Liver
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Cited by 17 •
2016
The alkaline comet assay measures DNA strand breaks in eukaryotic cells. By adding an Endonuclease III or human 8-oxoguanine-DNA-N-glycosylase digestion step, the assay can efficiently detect oxidative DNA damage. We describe methods for using these assays to detect DNA damage in rat liver.
10:17
The Tail Suspension Test
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Cited by 534 •
2012
The tail-suspension test is validated as an experimental procedure to assess antidepressant efficacy of drug treatments in mice. Mice are suspended by their tails for six minutes and escape-related behaviors are assessed. We describe procedures used in conducting the tail suspension test.
FAQs
Dust and ionized gas respond differently to the Sun’s influence, so comet tails do not form as a single uniform structure. Solar radiation pressure acts on released dust and produces a broad tail, whereas the solar wind transports ionized gas into a straighter ion tail. This contrast links visible morphology to distinct physical forces.
The direction of an ion tail is controlled primarily by the solar wind rather than by the comet’s path alone. Once gas becomes ionized, the outward-flowing solar wind carries it away from the Sun, producing a straighter feature. This makes tail orientation a visible indicator of how the comet interacts with its solar environment.
Tail brightness and extent change as the comet’s distance from the Sun and its activity change. Greater solar heating causes the nucleus to release more gas and dust through sublimation, altering the material available for the tails. Tracking these changes helps connect observed tail behavior with energy-driven transformation of the cometary body.
Researchers can use observations made at different comet-Sun distances to compare tail changes with changing activity. They examine the distribution of dust and the direction of ionized gas, then relate those patterns to radiation pressure, solar-wind transport, and sublimation. This approach turns changing appearance into evidence about physical processes rather than mere visual description.
Comet tails provide indirect information about cometary material because the released gas and dust originate from the nucleus. Observing how these materials appear and respond to solar influences helps researchers investigate composition alongside sublimation. The resulting evidence supports broader studies of how small bodies evolve as they encounter changing solar conditions.
In physics, comet tails connect small-body behavior with solar energy and solar-wind interactions. Their changing structure offers a natural context for studying how radiation pressure and flowing ionized material affect matter released from an icy nucleus. These observations also help improve models of small-body evolution and conditions in the early Solar System.