Your Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 4:50  
clear_day Transit: 12:56  
SunsetSet: 21:02 south
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Dwarf Planets and Asteroids » 

Asteroid 3 Juno

3 Juno is a large main-belt asteroid located between the orbits of Mars and Jupiter. It was discovered on 1 September 1804 by German astronomer Karl Ludwig Harding and is one of the largest asteroids in the solar system, with a diameter of approximately 247 kilometers. Juno has an irregular shape, with a rotation period of about 7.2 hours, and its surface is covered in numerous impact craters, some of which are several kilometers in diameter. Juno's composition is thought to be a mixture of rock and metal, similar to the composition of the Earth's crust. Juno orbits the Sun once every 4.36 Earth years and has been observed by ground-based telescopes, as well as by the Hubble Space Telescope and the Dawn spacecraft. The observations have revealed insights into its geology, composition, and history, including potential signs of water and organic molecules on its surface.

Asteroid 3 Juno is currently in the constellation of Orion.

The current Right Ascension of Asteroid 3 Juno is 05h 04m 16s and the Declination is +14° 05’ 02” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom edit_location_alt). The current magnitude of Asteroid 3 Juno is 9.43 (JPL).

05h 04m 16s
+14° 05’ 02”

Today's rise, transit and set times of Asteroid 3 Juno from Greenwich, United Kingdom edit_location_alt (all times relative to the local timezone Europe/London):

Azimuth: 75.9°
Max altitude: 52.6°
Azimuth: 284.1°
  • 3 Juno is above the horizon from Greenwich, United Kingdom edit_location_alt.
  • Right now it is placed in the South-South-East direction at an altitude of 51° above the horizon.
  • Given its current magnitude, 3 Juno is visible with the help of a binocular with a 50mm 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.

Available Resources

Asteroid 3 Juno Position and Finder Charts

Below we provide Asteroid 3 Juno finder charts showing where the object is right now in the sky with respect to the brightest stars. The first finder chart has a field of view of 50 degrees, while the second one has a field of view of 10 degrees. Click on each finder chart to access a full screen interactive Online Planetarium.

Finder chart of 3 Juno in Orion on May,30 2023
Map showing Asteroid 3 Juno in Orion on May, 30 2023
Field of view: 50x30 degrees
View fullscreen
Finder chart of 3 Juno
Map showing Asteroid 3 Juno in Orion on May, 30 2023
Field of view: 10x6 degrees
View fullscreen

Higher precision deep sky finder chart, 60 arcmin wide, showing where Asteroid 3 Juno is right now. Click on the image to see a more detailed fullscreen tracker view.

3 Juno
RA: 05h 04m 16s
Dec: +14° 05’ 02”
Deep sky finder chart for Asteroid 3 Juno
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Asteroid 3 Juno?, a page that provides all the information needed to find Asteroid 3 Juno in the sky and additional links to sky charts.

Asteroid 3 Juno Distance from Earth

The distance of Asteroid 3 Juno from Earth is currently 448,734,287 kilometers, equivalent to 2.999603 Astronomical Units. Light takes 24 minutes and 56.8165 seconds to travel from Asteroid 3 Juno and arrive to us.

24 minutes and 56.8165 seconds

The following chart shows the distance of Asteroid 3 Juno 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 Asteroid 3 Juno 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 3 Juno from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest Approach of Asteroid 3 Juno to Earth

Between 1 January 1600 and 30 December 2499, the closest approach of Asteroid 3 Juno to Earth happens on Thu Nov 5 1874 at a distance of 1.028769 Astronomical Units, or 153,901,649 kilometers:

Thu Nov 5 1874

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

Asteroid 3 Juno Brightness and Light Curve

The following chart is the predicted light curve (visual magnitude as a function of time) of Asteroid 3 Juno, 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 Asteroid 3 Juno as a function of time

Asteroid 3 Juno Orbital Elements

The following table lists the orbital elements of Asteroid 3 Juno at epoch 24 February 2023 00:00 UTC (JD: 2460000.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.25646772
Orbit inclination i 12.99066193°
Perihelion distance q 1.98533293 AU
297,001,580 km
Aphelion distance Q 3.35494071 AU
501,891,988 km
Semi-major axis a 2.67013682 AU
399,446,784 km
Orbital period period 4.3632 years
1,593.6711 days
Date of perihelion transit Tp 2023-Apr-02 04:38:39
2,460,036.6935 JD
Next perihelion transit 2027-Aug-12 20:45
2,461,630.3646 JD
Argument of perihelion peri 247.73653371045°
Longitude of the ascending node node 169.84300685997°
Mean anomaly M 351.82411888186°
Mean motion n 0.22589353°/day

Visualization of Asteroid 3 Juno Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Asteroid 3 Juno with respect of the Sun and the orbits of the major planets. The position of Asteroid 3 Juno and the planets along their orbits in this diagram accurately represents the current configuration of the objects in the Solar System. This is an experimental feature and it requires a WebGL enabled browser. Please provide us feedback!

Asteroid 3 Juno Physical Data

The following shows the known values of the most important physical parameters of Asteroid 3 Juno. Source: JPL Small-Body Database

Physical Parameter Value Relative to Earth
Diameter 233.92 km 0.0184
Sideral Rotation 7.2100 hours 0.3012
Absolute Magnitude 5.33
Geometric Albedo 0.2383

Asteroid 3 Juno 15 Days Ephemeris

The following table lists the ephemerides of Asteroid 3 Juno computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Asteroid 3 Juno in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2023 May 23 04h 46m 30s +13° 34’ 41” 9.44 Orion
2023 May 24 04h 48m 51s +13° 39’ 11” 9.44 Orion
2023 May 25 04h 51m 15s +13° 43’ 32” 9.44 Orion
2023 May 26 04h 53m 36s +13° 47’ 44” 9.44 Orion
2023 May 27 04h 55m 59s +13° 51’ 51” 9.43 Orion
2023 May 28 04h 58m 22s +13° 55’ 47” 9.43 Orion
2023 May 29 05h 00m 43s +13° 59’ 38” 9.43 Orion
2023 May 30 05h 03m 06s +14° 03’ 19” 9.43 Orion
2023 May 31 05h 05m 29s +14° 06’ 52” 9.43 Orion
2023 Jun 01 05h 07m 50s +14° 10’ 18” 9.42 Orion
2023 Jun 02 05h 10m 14s +14° 13’ 36” 9.42 Orion
2023 Jun 03 05h 12m 35s +14° 16’ 45” 9.42 Orion
2023 Jun 04 05h 14m 58s +14° 19’ 48” 9.42 Orion
2023 Jun 05 05h 17m 21s +14° 22’ 41” 9.42 Orion