Your guide to the Solar System and the night sky
🌎 Location: Greenwich, United Kingdom [change]


Mercury is currently in the constellation of Capricornus. The current Right Ascension of Mercury is 21h 29m 17s and the Declination is -15° 30’ 12” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current magnitude of Mercury is -0.79 (JPL).

Summary of key facts about Mercury [tip: you can also create a Quick Access page for this data if you access it frequently and would like to have a simpler view]:

21h 29m 17s
-15° 30’ 12”
  • Mercury is above the horizon from Greenwich, United Kingdom [change].
  • It is visible looking in the South direction at an altitude of 23° above the horizon.
  • Given its current magnitude, Mercury is visible to the naked eye, even from highly light polluted areas.
  • See also Mercury rise and set times.
  • 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 information about Mercury available on TheSkyLive:

Available Resources

Mercury Position and Finder Charts

Below we provide Mercury 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.

Map showing Mercury in Capricornus on January, 21 2021
Field of view: 50x30 degrees
View fullscreen
Map showing Mercury in Capricornus on January, 21 2021
Field of view: 10x6 degrees
View fullscreen
 = visible to the naked eye
 = binocular, brighter than 10th magnitude
= current altitude ≥ 30°   = current altitude < 30°   = below the horizon
Location: Greenwich, United Kingdom [change]

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

RA: 21h 29m 17s
Dec: -15° 30’ 12”
Deep sky finder chart for Mercury
Field of view: 60x40 arcmins
View fullscreen

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

Mercury Distance from Earth

The distance of Mercury from Earth is currently 154,875,589 kilometers, equivalent to 1.035279 Astronomical Units. Light takes 8 minutes and 36.6094 seconds to travel from Mercury and arrive to us.

8 minutes and 36.6094 seconds

The following chart shows the distance of Mercury 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.

Distance of Mercury from Earth between January 1900 and January 2100

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 Mercury from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest approach of Mercury to Earth

Between January 1900 and January 2100, the closest approach of Mercury to Earth happens on Sun May 31 2015 at a distance of 0.549036 Astronomical Units, or 82,134,610 kilometers:

Sun May 31 2015

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

Mercury brightness

The current visual magnitude of Mercury is -0.79.


The following chart is the predicted light curve (visual magnitude as a function of time) of Mercury, 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.

Predicted magnitude of Mercury between January 1900 and January 2100

Mercury rise and set times

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

Today's Mercury rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 105.6°
Max altitude: 23.0°
Azimuth: 254.6°

The rise and set times are defined as the time at which the upper limb of Mercury touches the horizon, considering the effect of the atmospheric refraction. As the atmospheric conditions cannot be modeled precisely the times reported here should be considered correct with an approximation of few minutes.

Mercury Physical Data

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

Physical Parameter Value Relative to Earth
Diameter 4879.4 km 0.3829
Mass 0.330104 x 1024 kg 0.0553
Density 5.427 gr/cm3 0.9843
Escape Velocity 4.25 km/s 0.3798
Sideral Rotation 1,407.5088 hours 58.8068
Absolute Magnitude -0.6
Geometric Albedo 0.106

Mercury 15 Days Ephemeris

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

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Apparent DiameterDiameter Constellation
2021 Jan 14 20h 46m 10s -19° 46’ 15” -0.87 5.6” Capricornus
2021 Jan 15 20h 52m 32s -19° 15’ 06” -0.87 5.7” Capricornus
2021 Jan 16 20h 58m 42s -18° 42’ 51” -0.86 5.8” Capricornus
2021 Jan 17 21h 04m 45s -18° 09’ 38” -0.86 5.9” Capricornus
2021 Jan 18 21h 10m 33s -17° 35’ 35” -0.86 6.0” Capricornus
2021 Jan 19 21h 16m 09s -17° 00’ 56” -0.85 6.1” Capricornus
2021 Jan 20 21h 21m 29s -16° 25’ 51” -0.83 6.3” Capricornus
2021 Jan 21 21h 26m 32s -15° 50’ 35” -0.81 6.4” Capricornus
2021 Jan 22 21h 31m 15s -15° 15’ 25” -0.77 6.6” Capricornus
2021 Jan 23 21h 35m 35s -14° 40’ 41” -0.73 6.7” Capricornus
2021 Jan 24 21h 39m 29s -14° 06’ 41” -0.66 6.9” Capricornus
2021 Jan 25 21h 42m 56s -13° 33’ 50” -0.58 7.1” Capricornus
2021 Jan 26 21h 45m 52s -13° 02’ 31” -0.47 7.4” Capricornus
2021 Jan 27 21h 48m 15s -12° 33’ 11” -0.33 7.6” Capricornus