Related Experiment Video
Updated: Jul 22, 2026
09:44
Laboratory Drop Towers for the Experimental Simulation of Dust-aggregate Collisions in the Early Solar System
Published on: June 5, 2014
Dark matter in the outer solar system.
T Owen1, D Cruikshank, C de Bergh
1University of Hawaii Institute for Astronomy, Honolulu 96822, USA.
Advances in Space Research : the Official Journal of the Committee on Space Research (COSPAR)
|January 1, 1995
Summary
Scientists are studying dark materials on outer solar system bodies. Current spectral data lacks clear absorption features, hindering material identification, with the composition of 5145 Pholus remaining unknown.
Area of Science:
- Planetary Science
- Astronomy
- Spectroscopy
Background:
- Numerous small bodies in the outer solar system are covered by dark, unidentifiable material.
- Previous attempts to characterize this material have been unsuccessful due to a lack of distinct spectral absorption features.
Purpose of the Study:
- To investigate the composition of dark materials on outer solar system small bodies.
- To identify the nature of unexplained spectral absorptions observed in these objects.
Main Methods:
- Analysis of reflection spectra from outer solar system small bodies.
- Review of observational data for spectral features, including a previously reported 2.2 micrometer absorption.
- Examination of the spectrum of the red planetesimal 5145 Pholus.
Main Results:
- Absence of discrete absorption features in the reflection spectra of most studied objects.
- A previously suggested 2.2 micrometer absorption feature has not been confirmed by new observations.
- Three well-established absorptions exist in the spectrum of 5145 Pholus, but their origin is unknown.
Conclusions:
- The composition of dark materials on outer solar system small bodies remains largely unidentified.
- Further research is needed to understand the nature of spectral features, particularly those observed in 5145 Pholus.
Related Concept Videos
01:18Conservation of Angular Momentum: Application
A system's total angular momentum remains constant if the net external torque acting on the system is zero. Examples of such systems include a freely spinning bicycle tire that slows over time due to torque arising from friction, or the slowing of Earth's rotation over millions of years due to frictional forces exerted on tidal deformations. However in the absence of a net external torque, the angular momentum remains conserved. The conservation of angular momentum principle requires a change...
01:27Gravity between Spherical Bodies
Newton's law of gravitation describes the gravitational force between any two point masses. However, for extended spherical objects like the Earth, the Moon, and other planets, the law holds with an assumption that masses of spherical objects are concentrated at their respective centers.
This assumption can be proved easily by showing that the expression for gravitational potential energy between a hollow sphere of mass (M) and a point mass (m) is the same as it would be for a pair of extended...
This assumption can be proved easily by showing that the expression for gravitational potential energy between a hollow sphere of mass (M) and a point mass (m) is the same as it would be for a pair of extended...
01:29Kepler's Second Law of Planetary Motion
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. His first law states that all planets orbit the Sun in an elliptical orbit, with the Sun at one of the ellipse's foci. Therefore, the distance of a planet from the Sun varies throughout its revolution around the Sun.
While in an elliptical orbit, the total energy of the planet is conserved. Therefore, the planet slows down when it is at apogee and...
While in an elliptical orbit, the total energy of the planet is conserved. Therefore, the planet slows down when it is at apogee and...
01:18Kepler's Third Law of Planetary Motion
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. In 1909, he formulated his first two laws based on the observations of his forebears, Nikolaus Copernicus and Tycho Brahe. However, in 1918, he published his third law of planetary motion, which gives a precise mathematical relationship between a planet's average distance from the Sun and the amount of time it takes to revolve around the Sun. It...
01:10Detection of Black Holes
Although black holes were theoretically postulated in the 1920s, they remained outside the domain of observational astronomy until the 1970s.
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
01:12Reduced Mass Coordinates: Isolated Two-body Problem
In classical mechanics, the two-body problem is one of the fundamental problems describing the motion of two interacting bodies under gravity or any other central force. When considering the motion of two bodies, one of the most important concepts is the reduced mass coordinates, a quantity that allows the two-body problem to be solved like a single-body problem. In these circumstances, it is assumed that a single body with reduced mass revolves around another body fixed in a position with an...