Pluto

Journal Article · Fri Jun 01 04:00:00 EDT 1990 · Scientific American; (USA)

DOI:https://doi.org/10.1038/scientificamerican0690-50· OSTI ID:6315233

Binzel, R P ^[1]

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1. Massachusetts Institute of Technology, Cambridge (USA)

A new picture of Pluto has begun to emerge during the past decade. Dedicated observational efforts using a variety of modern instruments, aided by some fortuitous celestial alignments, have produced a number of surprises. Pluto has a satellite, Charon, so large that the two objects can virtually be considered a double planet. The planet has bright polar caps and a darker, mottled equatorial region. A layer of methane ice covers most of its surface. Pluto even possesses a thin atmosphere; when the planet is farthest from the sun, all or part of the atmosphere may freeze and fall to the surface as snow. Charon's surface, which appears to be quite different from Pluto's, may be a great expanse of water ice. Pluto's size and density are much like those of Triton, the large satellite of Neptune that was recently visited by the Voyager 2 probe. These and other similarities suggest that both bodies may be leftover planetesimals, relics from the early days of the solar system that managed not to be swept up by the giant outer planets. In this scenario, Triton was captured by Neptune, whereas Pluto was able to survive as a bona fide planet in an independent orbit about the sun.

• OSTI ID: 6315233
• Journal Information: Scientific American; (USA), Journal Name: Scientific American; (USA) Vol. 262:6; ISSN SCAMA; ISSN 0036-8733
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKANES
ARGON
ATMOSPHERES
BASIC INTERACTIONS
BRIGHTNESS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL COMPOSITION
DENSITY
DISTANCE
ECLIPSE
ELEMENTS
EXPLORATION
FLUIDS
GASES
GRAVITATIONAL INTERACTIONS
HYDROCARBONS
HYDROGEN COMPOUNDS
ICE
INTERACTIONS
MASS
METHANE
MOTION
NITROGEN
NONMETALS
OPTICAL PROPERTIES
ORBITS
ORGANIC COMPOUNDS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PLANETARY ATMOSPHERES
PLANETARY EVOLUTION
PLANETS
PLUTO PLANET
POLAR REGIONS
RARE GASES
ROTATION
SATELLITES
SIZE
SOLAR SYSTEM EVOLUTION
WATER