We use cookies to deliver essential features and to measure their performance. By using this site you accept our Privacy Policies.
A Complete Guide to the Solar System and the Night Sky
Donate Now! Help keep this site free and ads-free!
public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
SunriseRise: 5:41  
clear_day Transit: 12:03  
SunsetSet: 18:26
sunny DaytimeWhat's Visible Now?
Major Bodies » 

Neptune

Altitude: 28.7°   Azimuth: 220.8°   Direction: South-West

Neptune is the eighth and farthest planet from the sun, and it is the fourth-largest planet in the solar system. It has a diameter of 49,244 kilometers and a mass of 1.02 x 10^26 kilograms, making it about 17 times more massive than Earth. Neptune is an ice giant planet, primarily composed of water, methane, and ammonia, and has a deep, turbulent atmosphere with strong winds and large storms, including the famous Great Dark Spot and the smaller Dark Spot. The planet has a day length of approximately 16.1 Earth hours and an orbital period of 165 Earth years. Neptune has 14 known moons, with the largest being Triton, a captured Kuiper Belt object with a highly inclined and retrograde orbit. Neptune also has a faint and dynamic ring system, which was discovered in 1984 during a stellar occultation. The planet has been explored by only one spacecraft, NASA's Voyager 2, which flew by the planet in 1989, providing the most detailed images and data of the planet and its moons to date.

Neptune is currently in the constellation of Pisces, at a distance of 4,619,428,091 kilometers from Earth.

Finder chart of Neptune in Pisces on March,29 2024
Map showing Neptune in Pisces on March, 29 2024. Field of view: 50x30 degrees
View interactive star map
The current Right Ascension of Neptune is 23h 52m 41s and the Declination is -02° 07’ 07” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom edit_location_alt). The current magnitude of Neptune is 7.83 (JPL).

23h 52m 41s
-02° 07’ 07”
Pisces
7.83

Today's rise, transit and set times of Neptune from Greenwich, United Kingdom edit_location_alt (all times relative to the local timezone Europe/London):

Azimuth: 92.1°
Max altitude: 36.4°
Azimuth: 267.9°
  • Neptune is above the horizon from Greenwich, United Kingdom edit_location_alt.
  • Right now it is placed in the South-West direction at an altitude of 29° above the horizon.
  • Given its current magnitude, Neptune is visible with the help of a binocular with a 30-40mm aperture, easy with a small telescope.
  • Go to interactive sky chart

If you need to access this information frequently for your observations, you can create a simple customized Quick Access page, so that you can easily bookmark it in your browser favorites or add a shortcut to your mobile phones' home screen.

Additional Resources

Neptune Position and Finder Charts

Finder chart of Neptune
Map showing Neptune in Pisces on March, 29 2024
Field of view: 10x6 degrees
View fullscreen

Higher precision deep sky finder chart, 60 arcmin wide, showing where Neptune is right now. Click on the image to see a more detailed fullscreen tracker view.

Neptune
RA: 23h 52m 41s
Dec: -02° 07’ 07”
Deep sky finder chart for Neptune
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Neptune?, a page that provides all the information needed to find Neptune in the sky and additional links to sky charts.

Neptune Distance from Earth

The distance of Neptune from Earth is currently 4,619,428,091 kilometers, equivalent to 30.878970 Astronomical Units. Light takes 4 hours, 16 minutes and 48.7535 seconds to travel from Neptune and arrive to us.

4,619,428,091
30.878970
4 hours, 16 minutes and 48.7535 seconds

The following chart shows the distance of Neptune from Earth as a function of time. In the chart the distance data is measured in Astronomical Units and sampled with an interval of 1 day.

Chart of the distance of Neptune from Earth in Astronomical Units (au)

The value of the reported distance might be somewhat inaccurate around the times of closest approach for objects passing extremely close to Earth. The value of the distance of Neptune from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest Approach of Neptune to Earth

Between 1 January 1600 and 30 December 2499, the closest approach of Neptune to Earth happens on Thu Nov 8 2373 at a distance of 28.806366 Astronomical Units, or 4,309,370,997 kilometers:

Thu Nov 8 2373
4,309,370,997
28.806366

NOTE: values for the closest approach are computed with a sampling interval of 1 day.

Neptune Brightness and Light Curve

The following chart is the predicted light curve (visual magnitude as a function of time) of Neptune, according to the most recent ephemerides data. Magnitude data is sampled with a 2 days interval and there might be inaccuracies for objects changing brightness very rapidly during the course of a few days. For comets there could be large discrepancies between the observed and predicted brightness because of their highly dynamic behaviour.

Chart of the magnitude of Neptune as a function of time

Neptune Physical Data

The following shows the known values of the most important physical parameters of Neptune. Source: JPL Small-Body Database

Physical Parameter Value Relative to Earth
Diameter 49244 km 3.8647
Mass 102.41 x 1024 kg 17.1478
Density 1.638 gr/cm3 0.2971
Escape Velocity 23.56 km/s 2.1055
Sideral Rotation 16.1100 hours 0.6731
Absolute Magnitude -6.87
Geometric Albedo 0.41

Neptune 15 Days Ephemeris

The following table lists the ephemerides of Neptune computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Neptune in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Apparent DiameterDiameter Constellation
2024 Mar 22 23h 51m 38s -02° 13’ 50” 7.83 2.2” Pisces
2024 Mar 23 23h 51m 47s -02° 12’ 56” 7.83 2.2” Pisces
2024 Mar 24 23h 51m 56s -02° 12’ 02” 7.83 2.2” Pisces
2024 Mar 25 23h 52m 04s -02° 11’ 08” 7.83 2.2” Pisces
2024 Mar 26 23h 52m 12s -02° 10’ 15” 7.83 2.2” Pisces
2024 Mar 27 23h 52m 20s -02° 09’ 23” 7.83 2.2” Pisces
2024 Mar 28 23h 52m 28s -02° 08’ 30” 7.83 2.2” Pisces
2024 Mar 29 23h 52m 36s -02° 07’ 37” 7.83 2.2” Pisces
2024 Mar 30 23h 52m 45s -02° 06’ 44” 7.83 2.2” Pisces
2024 Mar 31 23h 52m 54s -02° 05’ 53” 7.83 2.2” Pisces
2024 Apr 01 23h 53m 02s -02° 05’ 00” 7.83 2.2” Pisces
2024 Apr 02 23h 53m 09s -02° 04’ 09” 7.83 2.2” Pisces
2024 Apr 03 23h 53m 17s -02° 03’ 16” 7.83 2.2” Pisces
2024 Apr 04 23h 53m 26s -02° 02’ 25” 7.83 2.2” Pisces