Neptune  

Neptune

Neptune
Orbital Characteristics of Neptune

Orbital Characteristics

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
Eccentricity: 0.011214269
Orbital period: 60,190 days, 164.79 years
Synodic period: 367.49 days
Average orbital speed: 5.43 km/s
Mean anomaly: 267.767281°
Inclination: 1.767975°
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)

Physical Characteristics of Neptune

Physical Characteristics

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
Axial tilt : 28.32°
Albedo: 0.41
Average surface temperatures: 59 K, -214 °C, -353 °F
Apparent magnitude: 8.0 to 7.78
Angular diameter: 2.2″ - 2.4″
The Atmosphere of Neptune

The Atmosphere

Composition:
  • 80±3.2% Molecular Hydrogen (H2)
  • 19±3.2% Helium
  • 1.5±0.5% Methane (CH4)
  • 192 ppm Hydrogen Deuteride (HD)
  • 1.5 ppm Ethane (C2H6)

    Neptune images:


    www.flickr.com

    back to main page

  • NASA Breaking News


    NASA to Host Media Briefing on Mission to Return Asteroid Sample to Earth
    NASA will host a media teleconference at 2 p.m. EDT Friday, Aug. 24, to provide an update on upcoming activities related to the agency’s first mission to return a sample of an asteroid to Earth.
    read more...

    NASA Hosts Live Science Chat: One Year After Eclipse 2017
    On the one-year anniversary of the historic 2017 Eclipse Across America, NASA will host a Science Chat at 10:30 a.m. EDT, Tuesday, Aug. 21, to discuss new science data and the public impact of the celestial event experienced by millions.
    read more...

    NASA to Host Media Briefing on New Ice-Monitoring Mission
    NASA will host a media teleconference at 1 p.m. EDT Wednesday, Aug. 22, to discuss the upcoming launch of the Ice, Cloud and land Elevation Satellite (ICESat-2), which will fly NASA’s most advanced laser altimeter to measure Earth’s changing ice.
    read more...

    NASA Awards Contract for Construction of New Research Support Building
    NASA has selected Walsh Construction Company II, LLC of Chicago to build a new Research Support Building (RSB) at the agency’s Glenn Research Center in Cleveland.
    read more...

    NASA, ULA Launch Parker Solar Probe on Historic Journey to Touch Sun
    Hours before the rise of the very star it will study, NASA’s Parker Solar Probe launched from Florida Sunday to begin its journey to the Sun, where it will undertake a landmark mission. The spacecraft will transmit its first science observations in December, beginning a revolution in our understanding of the star that makes life on Earth possible.
    read more...

    NASA Awards $2.3 Million in Grants to Minority Serving Institutions to Expand STEM Education
    NASA's Minority University Research and Education Program (MUREP) Aerospace Academy (MAA) has selected seven Minority Serving Institutions (MSIs) for cooperative agreement awards totaling nearly $2.3 million.
    read more...

    NASA Astronaut to Speak with Students, Parents, Teachers at YouthSpark
    Students attending Microsoft’s YouthSpark event will have the opportunity to speak with NASA astronauts aboard the International Space Station next week as part of NASA’s Year of Education on Station.
    read more...

    NASA Television to Air Russian Spacewalk at International Space Station
    Russian cosmonauts living and working on the International Space Station will venture outside Wednesday, Aug. 15, for a spacewalk expected to last about six hours. Live coverage of the excursion will air on NASA Television and the agency’s website.
    read more...

    NASA Invests in Concepts for a Vibrant Future Commercial Space Economy
    In an ongoing effort to foster commercial activity in space, NASA has selected 13 companies to study the future of commercial human spaceflight in low-Earth orbit, including long-range opportunities for the International Space Station.
    read more...

    NASA Announces New Partnerships to Develop Space Exploration Technologies
    NASA is partnering with six U.S. companies to develop 10 “tipping point” technologies that have the potential to significantly benefit the commercial space economy and future NASA missions, including lunar lander and deep space rocket engine technologies.
    read more...