Splat or subsurface ocean? The mysterious positioning of Pluto’s heart
Planetary Radio: Space Exploration, Astronomy and Science
Deep Dive
What is Sputnik Planitia and how does it relate to Tombaugh Regio?
Sputnik Planitia is the bright nitrogen ice deposit within the larger Sputnik Basin, which is part of Tombaugh Regio. Tombaugh Regio encompasses both the western lobe (Sputnik Planitia) and the eastern lobe of Pluto's heart-shaped feature.
Why is the location of Sputnik Planitia unusual?
Sputnik Planitia is located near Pluto's equator, which is unusual for a large impact basin. Typically, such features migrate toward the poles due to mass redistribution, but the basin's placement suggests a mass positive rather than a mass negative.
What is the 'splat' theory and how does it relate to Pluto's heart-shaped feature?
The 'splat' theory suggests that Sputnik Planitia formed from a large, oblique impact that hit Pluto at a glancing angle, creating an elliptical crater. This theory challenges the idea that a subsurface ocean is responsible for the basin's stability.
What evidence supports the idea of a subsurface ocean on Pluto?
The presence of a subsurface ocean could explain the mass positive at Sputnik Planitia, as water is denser than ice. This would stabilize the basin near the equator, but other explanations, like a buried rocky core, are also possible.
What is the significance of Pluto's ridge trough system?
The ridge trough system is the oldest feature on Pluto's surface, with Sputnik Planitia forming later and overprinting it. This suggests a complex geological history spanning billions of years.
How does the formation of Pluto and Charon relate to giant impacts?
Pluto and Charon likely formed from a giant impact, similar to the Earth-Moon system. This impact would have created the binary system, with Charon tidally locking to Pluto relatively quickly after the collision.
What role does computer modeling play in understanding Pluto's geology?
Computer modeling, such as smooth particle hydrodynamics (SPH) simulations, helps scientists simulate impacts and predict how features like Sputnik Planitia might have formed. These models provide insights into Pluto's history but are approximations of real-world processes.
What are the implications of debris from the Sputnik Planitia impact?
Debris from the impact likely scattered across Pluto and possibly reached Charon. Some of this material could still be present in the system, though tracking its exact distribution requires further exploration.
Why is a Pluto orbiter mission important for understanding Pluto's geology?
A Pluto orbiter would provide detailed gravity and topography data, helping to confirm whether a subsurface ocean or a buried rocky core is responsible for the mass anomaly at Sputnik Planitia.
What other bodies in the solar system could benefit from the 'splat' theory?
The 'splat' theory could be applied to other binary systems in the Kuiper Belt, such as Eris or Haumea, which have complex formations and multiple satellites. Understanding these systems could provide insights into their impact histories.
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