Kurt Kremitzki
@kkremitzki@mastodon.social  ·  activity timestamp 3 days ago
AkaSci 🛰️
@AkaSci@fosstodon.org  ·  activity timestamp last month
AkaSci 🛰️
@AkaSci@fosstodon.org  ·  activity timestamp last month
Snippet from paper about the more precise definition of a planet - A planet is a celestial body that (a) orbits one or more stars, brown dwarfs, or stellar remnants, and (b) has sufficient mass to dynamically dominate the neighborhood around its orbit, i.e., m > 0.0012 (mcentral)^(5/8) a^(9/8), where m is the mass of the planetary body expressed in Earth masses, mcentral is the mass of the central body expressed is solar masses, and a is the semimajor axis expressed in astronomical units, and (c) has sufficient mass for its self-gravity to overcome rigid body forces so that it is approximately in hydrostatic equilibrium and assumes a nearly triaxial shape, i.e., m > 10^21 kg, and (d) has a true mass below the limiting mass for thermonuclear fusion of deuterium (currently calculated to be 13 Jupiter masses for objects of solar metallicity), and (e) has a mass ratio with the central object below the L4/L5 instability, i.e., m/mcentral < 2/(25 + √621) ≃ 1/25. A satellite is a celestial body that orbits a planet.
Snippet from paper about the more precise definition of a planet - A planet is a celestial body that (a) orbits one or more stars, brown dwarfs, or stellar remnants, and (b) has sufficient mass to dynamically dominate the neighborhood around its orbit, i.e., m > 0.0012 (mcentral)^(5/8) a^(9/8), where m is the mass of the planetary body expressed in Earth masses, mcentral is the mass of the central body expressed is solar masses, and a is the semimajor axis expressed in astronomical units, and (c) has sufficient mass for its self-gravity to overcome rigid body forces so that it is approximately in hydrostatic equilibrium and assumes a nearly triaxial shape, i.e., m > 10^21 kg, and (d) has a true mass below the limiting mass for thermonuclear fusion of deuterium (currently calculated to be 13 Jupiter masses for objects of solar metallicity), and (e) has a mass ratio with the central object below the L4/L5 instability, i.e., m/mcentral < 2/(25 + √621) ≃ 1/25. A satellite is a celestial body that orbits a planet.
Snippet from paper about the more precise definition of a planet - A planet is a celestial body that (a) orbits one or more stars, brown dwarfs, or stellar remnants, and (b) has sufficient mass to dynamically dominate the neighborhood around its orbit, i.e., m > 0.0012 (mcentral)^(5/8) a^(9/8), where m is the mass of the planetary body expressed in Earth masses, mcentral is the mass of the central body expressed is solar masses, and a is the semimajor axis expressed in astronomical units, and (c) has sufficient mass for its self-gravity to overcome rigid body forces so that it is approximately in hydrostatic equilibrium and assumes a nearly triaxial shape, i.e., m > 10^21 kg, and (d) has a true mass below the limiting mass for thermonuclear fusion of deuterium (currently calculated to be 13 Jupiter masses for objects of solar metallicity), and (e) has a mass ratio with the central object below the L4/L5 instability, i.e., m/mcentral < 2/(25 + √621) ≃ 1/25. A satellite is a celestial body that orbits a planet.
AkaSci 🛰️
@AkaSci@fosstodon.org  ·  activity timestamp last month
AkaSci 🛰️
@AkaSci@fosstodon.org  ·  activity timestamp last month
Enhanced color global view of Pluto. Created using four images from New Horizons' Long Range Reconnaissance Imager (LORRI) combined with color data from the Ralph instrument. (The lower right edge of Pluto in this view currently lacks high-resolution color coverage.) The images, taken when the spacecraft was 450,000 km away, show features as small as 2.2 km, twice the resolution of the single-image view taken on July 13, 2015. https://pluto.jhuapl.edu/Galleries/Featured-Images/image.php?page=1&gallery_id=2&image_id=265 Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Enhanced color global view of Pluto. Created using four images from New Horizons' Long Range Reconnaissance Imager (LORRI) combined with color data from the Ralph instrument. (The lower right edge of Pluto in this view currently lacks high-resolution color coverage.) The images, taken when the spacecraft was 450,000 km away, show features as small as 2.2 km, twice the resolution of the single-image view taken on July 13, 2015. https://pluto.jhuapl.edu/Galleries/Featured-Images/image.php?page=1&gallery_id=2&image_id=265 Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Enhanced color global view of Pluto. Created using four images from New Horizons' Long Range Reconnaissance Imager (LORRI) combined with color data from the Ralph instrument. (The lower right edge of Pluto in this view currently lacks high-resolution color coverage.) The images, taken when the spacecraft was 450,000 km away, show features as small as 2.2 km, twice the resolution of the single-image view taken on July 13, 2015. https://pluto.jhuapl.edu/Galleries/Featured-Images/image.php?page=1&gallery_id=2&image_id=265 Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
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