Tombaugh Regio () is the largest bright surface feature of the
dwarf planet
A dwarf planet is a small planetary-mass object that is in direct orbit of the Sun, smaller than any of the eight classical planets but still a world in its own right. The prototypical dwarf planet is Pluto. The interest of dwarf planets to ...
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the S ...
.
It is just north of the equator, to the northeast of
Cthulhu Macula and to the northwest of
Krun Macula
Krun is the westernmost of the "Brass Knuckles", a series of equatorial dark regions on Pluto. It is named after Krun, the greatest of the five Mandaean lords of the underworld.
Description
Krun is the third largest equatorial dark region on P ...
, which are both dark features.
Its western lobe, a -wide plain of
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
and other ices lying within a basin, is named
Sputnik Planitia
Sputnik Planitia , originally Sputnik Planum, is a high-albedo ice-covered basin on Pluto, about in size, named after Earth's first artificial satellite, Sputnik 1. It constitutes the western lobe of the heart-shaped Tombaugh Regio. Sputnik Pl ...
.
The eastern lobe consists of high-albedo uplands thought to be coated by nitrogen transported through the atmosphere from Sputnik Planitia, and then deposited as ice. Some of this nitrogen ice then returns to Sputnik Planitia via glacial flow. Named after
Clyde Tombaugh
Clyde William Tombaugh (February 4, 1906 January 17, 1997) was an American astronomer. He discovered Pluto in 1930, the first object to be discovered in what would later be identified as the Kuiper belt. At the time of discovery, Pluto was cons ...
, the discoverer of Pluto, it was nicknamed Pluto's "heart" after
its shape.
Description
Tombaugh Regio is a large, light-colored region about across.
The two lobes of the feature are geologically distinct. The western lobe,
Sputnik Planitia
Sputnik Planitia , originally Sputnik Planum, is a high-albedo ice-covered basin on Pluto, about in size, named after Earth's first artificial satellite, Sputnik 1. It constitutes the western lobe of the heart-shaped Tombaugh Regio. Sputnik Pl ...
, is smoother than the eastern, and they are of slightly different colors.
Early speculation was that the western lobe may be a large impact crater filled with
nitrogen snow. Bright spots within the region were initially speculated to be mountain peaks.
Photos, released on 15 July 2015, revealed mountains made of water ice in the feature; they also showed no craters in this same region. Subsequent data indicated that the center of Sputnik Planitia is rich in
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
,
carbon monoxide
Carbon monoxide ( chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simpl ...
, and
methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane ...
ices, and that features near the edges of the region show evidence of ice flow such as glaciers, and light material overlying the darker material at the eastern edge of
Cthulhu Macula.
The surface of Sputnik Planitia is divided into polygonal convection cells
and is less than 10 million years old, indicating that Pluto is geologically active.
The feature had been identified as a bright spot for six decades prior to the ''New Horizons'' flyby, although it was impossible to image it with enough resolution to determine its shape. Over these six decades the spot had been observed to be dimming.
In 2020, it was found that Tombaugh Regio controlled the wind circulation of Pluto, and could sculpt the landscape on its surface.
Naming and shape
On 15 July 2015, the region was provisionally named "Tombaugh Regio" by the ''New Horizons'' team in honor of astronomer
Clyde Tombaugh
Clyde William Tombaugh (February 4, 1906 January 17, 1997) was an American astronomer. He discovered Pluto in 1930, the first object to be discovered in what would later be identified as the Kuiper belt. At the time of discovery, Pluto was cons ...
, the discoverer of Pluto,
regio being Latin for "region".
On 7 September 2017, the name was officially approved by the
International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...
(IAU), together with names for 13 other surface features on Pluto.
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeedin ...
initially referred to the region as a "heart" in reference to
its overall shape. Some people find that it also resembles the Disney character
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the S ...
, an animated non-anthropomorphic dog which shares the name of the dwarf planet, in profile facing eastward.
The Walt Disney Company
The Walt Disney Company, commonly known as Disney (), is an American multinational mass media and entertainment conglomerate headquartered at the Walt Disney Studios complex in Burbank, California. Disney was originally founded on Octobe ...
acknowledged this perceived likeness in a short animation.
Gallery
See also
*
Geography of Pluto
The geography of Pluto entails the delineation and characterization of regions on Pluto. Plutonian geography is mainly focused on what is called physical geography on Earth; that is, the distribution of physical features across Pluto and their car ...
*
List of geological features on Pluto
This is a list of named geological features on Pluto, identified by scientists working with data from the ''New Horizons'' spacecraft. The International Astronomical Union (IAU) officially approved the first 14 names on 8 August 2017 (announced ...
References
*
{{Pluto
Regions of Pluto