Perihelion: 4,452,940,833 km, 29.76607095 AE
Aphelion: 4,553,946,490 km, 30.44125206 AE
Semi-major axis: 4,503,443,661 km, 30.10366151 AE
Orbital period: 60,190 days, 164.79 years
Synodic period: 367.49 days
Average orbital speed: 5.43 km/s
Mean anomaly: 267.767281°
Longitude of ascending node: 131.794310°
Argument of perihelion: 265.646853°
Satellites/moons: 13 (Naiad, Thalassa, Despina, Galatea, Larissa, Proteus, Triton, Nereid, Halimede, Sao, Laomedeia, Psamathe, Neso)
Equatorial radius: 24,764 km (3.883 x Earth)
Flattening: 0.0171 ± 0.0013
Surface area: 7.6408×109 km2 (14.98 x Earth)
Volume: 6.254×1013 km3 (57.74 x Earth)
Mass: 1.0243×1026 kg (17.147 x Earth)
Mean density: 1.638 g/cm3
Equatorial surface gravity: 11.15 m/s2
Escape velocity: 23.5 km/s
Sidereal rotation period: 0.6713 day Earth days, 16 h 6 min 36 s Earth hours
Average surface temperatures: 59 K, -214 °C, -353 °F
Apparent magnitude: 8.0 to 7.78
Angular diameter: 2.2″ - 2.4″
Composition: 80±3.2% Molecular Hydrogen (H2)
1.5±0.5% Methane (CH4)
192 ppm Hydrogen Deuteride (HD)
1.5 ppm Ethane (C2H6)
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NASA Breaking News
Media Invited to Preview Expedition to Ocean Twilight Zone
Media are invited to Seattle on Thursday, Aug. 9, to preview a seaborne expedition to study microscopic organisms in the dark depths of the sea that play a critical role in removing carbon dioxide from Earth’s atmosphere.
NASA Television to Air Launch of Next Space Station Resupply Mission
NASA commercial cargo provider SpaceX is targeting no earlier than 5:42 a.m. EDT Friday, June 29, for the launch of its 15th resupply mission to the International Space Station. Live coverage will begin on NASA Television and the agency’s website Thursday, June 28, with prelaunch events.
New York, Washington, California Students to Call Space Station
Students from across America are set to participate in three live events with astronauts aboard the International Space Station next week.
NASA to Host Media Teleconference on National Near-Earth Object Preparedness Report
NASA will host a media teleconference at 1 p.m. EDT Wednesday, June 20, to discuss a new report detailing U.S. plans for near-Earth objects (NEOs) that could pose a hazard to Earth.
NASA Administrator Statement on Space Policy Directive-3
The following is a statement from NASA Administrator Jim Bridenstine on Monday’s signing of Space Policy Directive-3 by President Donald Trump:
NASA, NSF Plunge Into Ocean ‘Twilight Zone’ to Explore Ecosystem Carbon Flow
A large multidisciplinary team of scientists, equipped with advanced underwater robotics and an array of analytical instrumentation, will set sail for the northeastern Pacific Ocean this August.
Brooklyn Students to Link Up with NASA Astronauts on Space Station
Students from Brooklyn, New York, will have the opportunity to talk with astronauts on the International Space Station this week as part of NASA’s Year of Education on Station.
Record-Setting NASA Astronaut Peggy Whitson Retires
NASA astronaut Peggy Whitson, who holds the U.S. record for most cumulative time in space, is retiring from the agency, effective Friday.
Ramp-Up in Antarctic Ice Loss Speeds Sea Level Rise
Ice losses from Antarctica have tripled since 2012, increasing global sea levels by 0.12 inch (3 millimeters) in that timeframe alone, according to a major new international climate assessment funded by NASA and ESA (European Space Agency).
NASA to Hold Media Teleconference on Martian Dust Storm, Mars Opportunity Rover
NASA will host a media teleconference at 1:30 p.m. EDT Wednesday, June 13, to discuss a massive Martian dust storm affecting operations of the agency’s Opportunity rover and what scientists can learn from the various missions studying this unprecedented event.