How far away is Mercury now?

Last Updated: Today

mercury background

Where does this distance data come from?

I source Mercury’s distance from Earth via the Horizon JPL API. It is a free service provided by NASA’s Jet Propulsion Laboratory (JPL) that offers access to ephemeris (positional) data and related information for celestial bodies, such as planets, asteroids, and comets. The system can be accessed through various interfaces, including a web interface, a telnet interface, and an email interface.

This API contains the precise distance between Mercury and Earth from each day of the next few hundred years. 

So I simply created a system to check for today’s date, then go retrieve the accurate distance value directly from NASA’s database. The up-to-date value is then displayed on this page. 

How do scientists calculate the real-time distance between Mercury and earth?

Scientists calculate the live distance between Mercury and Earth using a combination of mathematics, astronomical data, and the principles of celestial mechanics. The positions of Earth and Mercury in their respective orbits are constantly changing due to their elliptical orbits and different orbital periods around the Sun.

Mercury's orbital parameters

Orbital parameters describe the way objects move around in space, such as planets, moons, and satellites. These parameters include the size, shape, and tilt of the orbit, as well as the object’s position and speed within the orbit. 

They help scientists understand and predict the paths of celestial bodies, which is crucial for planning space missions, observing astronomical phenomena, and monitoring satellites. 

Orbital PropertyExplanationVenusEarthRatio (Venus/Earth)
Semimajor axis (106 km)Avg. distance from the Sun108.210149.5980.723
Sidereal orbit period (days)Time for one orbit relative to fixed stars224.701365.2560.615
Tropical orbit period (days)Time for one orbit relative to the vernal equinox224.695365.2420.615
Perihelion (106 km)Closest distance to the Sun107.480147.0950.731
Aphelion (106 km)Farthest distance from the Sun108.941152.1000.716
Synodic period (days)Time to return to the same position relative to the Sun583.92
Mean orbital velocity (km/s)Avg. speed while orbiting the Sun35.0229.781.176
Max. orbital velocity (km/s)Highest speed in the orbit35.2630.291.164
Min. orbital velocity (km/s)Lowest speed in the orbit34.7829.291.187
Orbit inclination (deg)Angle between the orbital plane and the ecliptic plane3.3950.000
Orbit eccentricityDeviation of orbit shape from a perfect circle0.00680.01670.407
Sidereal rotation period (hrs)Time for one rotation relative to fixed stars-5832.623.9345243.690
Length of day (hrs)Time for one rotation relative to the Sun2802.024.0000116.750
Obliquity to orbit (deg)Angle between the equatorial plane and orbital plane177.3623.44
Inclination of equator (deg)Axial tilt of the planet2.6423.440.113

Mercury's greatest elongations (list for the next 5 years)

Greatest elongation is the term used in astronomy to describe the maximum angular separation of a planet from the Sun as viewed from Earth. In simpler terms, it refers to the point at which a planet appears farthest from the Sun as seen from our perspective on Earth.

As an inferior planet (meaning it orbits closer to the Sun than Earth), Mercury goes through phases similar to the Moon, as well as various positions relative to Earth and the Sun. These positions include inferior and superior conjunctions, and greatest elongations.

Date Type of Elongation Visual Magnitude
Jan 30, 2023 Greatest Elongation (West Morning) 0°59′
May 29, 2023 Greatest Elongation (West Morning) -3°31′
Sep 22, 2023 Greatest Elongation (West Morning) 0°50′
Jan 12, 2024 Greatest Elongation (West Morning) 1°35′
May 9, 2024 Greatest Elongation (West Morning) -3°08′
Sep 5, 2024 Greatest Elongation (West Morning) 0°02′
Dec 25, 2024 Greatest Elongation (West Morning) 2°03′
Date Type of Elongation Visual Magnitude
Apr 11, 2023 Greatest Elongation (East Evening) 2°43′
Aug 10, 2023 Greatest Elongation (East Evening) -1°40′
Mar 24, 2024 Greatest Elongation (East Evening) 2°25′
Jul 22, 2024 Greatest Elongation (East Evening) -0°55′
Nov 16, 2024 Greatest Elongation (East Evening) -2°38′
Feb 19, 2026 Greatest Elongation (East Evening) 1°10′
Jun 15, 2026 Greatest Elongation (East Evening) 1°00′
Oct 12, 2026 Greatest Elongation (East Evening) -2°54′
Feb 3, 2027 Greatest Elongation (East Evening) 0°23′
May 28, 2027 Greatest Elongation (East Evening) 1°55′
Sep 24, 2027 Greatest Elongation (East Evening) TBD

Just for fun, how long would it take to reach Mercury via different transportation means

The average distance between Earth and Mercury is 48 million miles (77 million km), so based on that distance, I have calculated the time it would take to reach the closest planet to the Sun at the speed of different means of transportation.

  • On foot (3 mph): Approximately 1,827.85 years
  • Bicycle (15 mph): Approximately 365.97 years
  • Horse (galloping at 25 mph): Approximately 219.18 years
  • Motorbike (average speed of 70 mph): Approximately 78.25 years
  • Boat (cruising speed of 20 knots): Approximately 238.08 years
  • Car (60 mph): Approximately 91.32 years
  • High-speed train (200 mph): Approximately 27.4 years
  • Commercial airplane (575 mph): Approximately 9.52 years
  • Concorde supersonic jet (1,350 mph): Approximately 4.06 years
  • SpaceX Starship (projected average speed of 16,777 mph): Approximately 0.33 years

How far away are the other planets of the solar system?

Tom Urbain

 I’ve been fascinated by space and astronomy from a very young age. When I’m not watching space-themed documentaries, movies or TV series, I spend most of my free time in my backyard admiring the planets and galaxies with my telescope.