Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Classifying Matter by Composition03:35

Classifying Matter by Composition

78.6K
Matter: Pure Substances and Mixtures
According to its composition, the matter can be classified into two broad categories — pure substances and mixtures. 
A pure substance is a form of matter that has a constant composition throughout with uniform properties. For example, any sample of sucrose has the same composition and same physical properties, such as melting point, color, and sweetness, regardless of the source from which it is isolated. 
A mixture is composed of two or...
78.6K
¹H NMR: Complex Splitting01:13

¹H NMR: Complex Splitting

1.7K
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
1.7K
Mass Spectrometry: Molecular Fragmentation Overview01:20

Mass Spectrometry: Molecular Fragmentation Overview

5.2K
The ionization of a molecule into a molecular ion inside the mass spectrometer causes instability in the molecule's structure due to the loss of an electron. This eventually leads to the fragmentation or breaking of some bonds in the molecule. The fragmentation occurs predominantly at specific bonds to yield relatively stable fragments.
One type of fragmentation pattern is the cleavage of a single bond in the molecular ion. The cleavage leads to a radical and a cation. The cleavage can occur at...
5.2K
¹H NMR Chemical Shift Equivalence: Homotopic and Heterotopic Protons01:03

¹H NMR Chemical Shift Equivalence: Homotopic and Heterotopic Protons

3.9K
Protons in identical electronic environments within a molecule are chemically equivalent and have the same chemical shift. The replacement test is a useful tool to identify chemical equivalence and predict NMR spectra. A substituent replaces each of the protons being examined and the resulting molecules are compared. If the same molecule is obtained, the protons are equivalent or homotopic. Replacement of any hydrogens in ethane by chlorine yields chloroethane because all six protons are...
3.9K
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule01:10

Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule

2.9K
In the AX proton spin system, proton A can sense the two spin states of a coupled proton X, resulting in a doublet NMR signal with two peaks of equal (1:1) intensity. When proton A is coupled to two equivalent protons (AX2 spin system), the spin states of each X can be aligned with or against the external field, creating three possible scenarios. This results in a 1:2:1  triplet signal, where the central peak corresponds to the chemical shift of A and is twice as large or intense as the...
2.9K
¹³C NMR: ¹H–¹³C Decoupling01:04

¹³C NMR: ¹H–¹³C Decoupling

1.7K
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
1.7K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Future Exploration of the Outer Heliosphere and Very Local Interstellar Medium by Interstellar Probe.

Space science reviews·2023
Same author

Pluto's Interaction With Energetic Heliospheric Ions.

Journal of geophysical research. Space physics·2022
Same author

Color, composition, and thermal environment of Kuiper Belt object (486958) Arrokoth.

Science (New York, N.Y.)·2020
Same author

The geology and geophysics of Kuiper Belt object (486958) Arrokoth.

Science (New York, N.Y.)·2020
Same author

The solar nebula origin of (486958) Arrokoth, a primordial contact binary in the Kuiper Belt.

Science (New York, N.Y.)·2020
Same author

Detection of ammonia on Pluto's surface in a region of geologically recent tectonism.

Science advances·2019

Related Experiment Video

Updated: May 5, 2026

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
08:51

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Published on: August 18, 2017

9.6K

Compositional homogeneity in the fragmented comet 73P/Schwassmann-Wachmann 3.

N Dello Russo1, R J Vervack, H A Weaver

  • 1Space Department, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723-6099, USA. neil.dello.russo@jhuapl.edu

Nature
|July 13, 2007
PubMed
Summary

Cometary ice composition, studied in fragments of 73P/Schwassmann-Wachmann 3, shows surprising uniformity. This suggests that the observed carbon-chain chemistry in comets is primordial, not a result of solar evolution.

More Related Videos

Scattering And Absorption of Light in Planetary Regoliths
11:34

Scattering And Absorption of Light in Planetary Regoliths

Published on: July 1, 2019

11.5K
Author Spotlight: Unveiling the Role of SNF2L in Replication Fork Stability and Genome Duplication
05:55

Author Spotlight: Unveiling the Role of SNF2L in Replication Fork Stability and Genome Duplication

Published on: August 23, 2024

1.2K

Related Experiment Videos

Last Updated: May 5, 2026

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
08:51

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Published on: August 18, 2017

9.6K
Scattering And Absorption of Light in Planetary Regoliths
11:34

Scattering And Absorption of Light in Planetary Regoliths

Published on: July 1, 2019

11.5K
Author Spotlight: Unveiling the Role of SNF2L in Replication Fork Stability and Genome Duplication
05:55

Author Spotlight: Unveiling the Role of SNF2L in Replication Fork Stability and Genome Duplication

Published on: August 23, 2024

1.2K

Area of Science:

  • Cometary science
  • Astrochemistry
  • Solar system formation

Background:

  • Cometary volatile ice composition varies greatly, influenced by formation environments, storage, and solar processing.
  • Understanding this diversity requires analyzing cometary nuclei chemistry with depth.
  • Previous observations were limited in assessing formative conditions and evolutionary effects.

Purpose of the Study:

  • To investigate the chemical composition of distinct fragments of comet 73P/Schwassmann-Wachmann 3.
  • To assess the role of formative conditions versus evolutionary processes in cometary ice composition.
  • To determine if compositional variation exists with depth in short-period comets.

Main Methods:

  • Analysis of the chemical composition of two separate fragments from comet 73P/Schwassmann-Wachmann 3.
  • Comparison of fragment compositions with each other and with the broader cometary population.
  • Assessment of volatile ice depletion in relation to known cometary reservoirs.

Main Results:

  • The two fragments of 73P/Schwassmann-Wachmann 3 exhibited highly similar chemical compositions.
  • This uniformity contrasts sharply with the expected compositional diversity in short-period comets.
  • Comet 73P/Schwassmann-Wachmann 3 is depleted in highly volatile ices compared to other comets.

Conclusions:

  • The uniform composition of 73P/Schwassmann-Wachmann 3 fragments challenges expectations of evolutionary processing in short-period comets.
  • The observed depletion in volatile ices and carbon-chain chemistry suggests a primordial origin, not evolutionary.
  • Cometary ice composition may be more reflective of initial formation conditions than previously thought.