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.

Find it in the Sky

Chose a date & time and view the position of Neptune in the sky on our interactive planetarium.

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Major Bodies »

Neptune

Above the horizon. Rise: 1:22 | Tran: 7:19 | Set: 13:17

Alt: 8.51° Az: 94.51° Direction: South

Neptune is in the constellation of Pisces, at a distance of 4,466,585,985.0 kilometers from Earth. The current Right Ascension is 00h 09m 57s and the Declination is -00° 21’ 24” (apparent coordinates). The magnitude of Neptune is 7.77. Check out tonight's visibility information of Neptune for tonight.

Finder Charts

The sky charts below show, at different resolutions, the position of Neptune in the sky. Click on each chart to access the interactive star map tool.

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Star map showing the position of Neptune in the constellation of Pisces on F, d Y. Field of view: 50x30 degrees. View interactive star map.

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Star map showing the position of Neptune in the constellation of Pisces on F, d Y. Field of view: 15x9 degrees. View in interactive star map.

The following map uses photographic imagery from the Digitized Sky Survey (DSS) to realistically visualize the precise position of Neptune against the stars in the background. The horizontal size of the map measures 60 arcminutes. Click on the image to access a more detailed full-screen view.

Neptune
RA: 00h 08m 39s
Dec: -00° 29’ 54”

Simplified high-resolution deep sky chart showing the current position of Neptune. Field of view: 60 x 40 arcminutes. Go to the dedicated page

Equatorial Coordinates

Apparent

Right Ascension 00h 09m 57s

Declination -00° 21’ 24”

Hour Angle 18h 38m 28s

Sidereal Time 18h 48m 26s

J2000

Right Ascension 00h 08m 39s

Declination -00° 29’ 54”

Additional Information

Constellation Pisces

Magnitude 7.77

Rise and Set Times

The following table lists today's rise, transit and set times of Neptune from Cutler Ridge, United States (all times relative to the local timezone America/New_York):

Azimuth: 90.4° RISE 1:22

Max altitude: 64.1° TRANSIT 7:19

Azimuth: 269.6° SET 13:17

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.

Distance from Earth

The distance of Neptune from Earth is currently 4,466,585,985.0 kilometers, equivalent to 29.8572831558 Astronomical Units. Light takes 4h 8m 18.927s to travel from Neptune and arrive to us.

Distance Km 4,466,585,985.0

Distance AU 29.8572831558

Light Travel Time 4h 8m 18.927s

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

Chart of the distance of Neptune from Earth in Astronomical Units (au)
Note: The values in this chart may not be entirely accurate around the time of closest approach for objects passing very close to Earth at high speed (e.g., Near-Earth Objects).

The value of the distance of Neptune from Earth is also available as a real time updated value in the live position tracker.

Closest Approach to Earth

In the period between January 1, 1600 and December 30, 2499, the closest approach of Neptune to Earth will happen on Thursday 8 November 2373 at a distance of 28.806366 Astronomical Units, or 4,309,370,997 kilometers:

Date Thursday 8 November 2373

Distance Kilometers 4,309,370,997

Distance AU 28.806366

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

Light Curve

The following chart shows the light curve of Neptune, i.e., its apparent magnitude as a function of time. The curve is calculated using the latest ephemerides provided by JPL Horizons. The magnitude data is sampled with the interval of 2 days. Because of this sampling, inaccuracies may occur for objects that have large variations of brightness over a few days. For comets, large discrepancies can arise between the calculated brightness and the observations due to their highly dynamic, and not always precisely predictable, behavior.

Chart of the magnitude of Neptune as a function of time

Physical Properties

The table below lists the known key physical properties of Neptune.

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

15 Days Ephemeris

The following table lists the ephemerides of Neptune computed for the past and next 7 days, with a 24 hours interval. Apparent celestial coordinates are provided.

Date	Right AscensionR.A.	DeclinationDec.	MagnitudeMag	Apparent DiameterDiameter	Constellation
Jun 16 2025	00h 09m 44s	-00° 22’ 22”	7.78	2.3”	Pisces
Jun 17 2025	00h 09m 46s	-00° 22’ 12”	7.78	2.3”	Pisces
Jun 18 2025	00h 09m 48s	-00° 22’ 02”	7.78	2.3”	Pisces
Jun 19 2025	00h 09m 50s	-00° 21’ 53”	7.77	2.3”	Pisces
Jun 20 2025	00h 09m 52s	-00° 21’ 45”	7.77	2.3”	Pisces
Jun 21 2025	00h 09m 54s	-00° 21’ 37”	7.77	2.3”	Pisces
Jun 22 2025	00h 09m 55s	-00° 21’ 31”	7.77	2.3”	Pisces
Jun 23 2025	00h 09m 57s	-00° 21’ 25”	7.77	2.3”	Pisces
Jun 24 2025	00h 09m 58s	-00° 21’ 20”	7.77	2.3”	Pisces
Jun 25 2025	00h 09m 59s	-00° 21’ 15”	7.77	2.3”	Pisces
Jun 26 2025	00h 10m 00s	-00° 21’ 12”	7.77	2.3”	Pisces
Jun 27 2025	00h 10m 01s	-00° 21’ 09”	7.76	2.3”	Pisces
Jun 28 2025	00h 10m 02s	-00° 21’ 07”	7.76	2.3”	Pisces
Jun 29 2025	00h 10m 03s	-00° 21’ 06”	7.76	2.3”	Pisces

Ephemeris Calculator

Compute the position of Neptune for any date and time between January 1, 1600 and December 30, 2499 and display the results on an interactive star map.