Apparent Size of the Sun from other planets

Have you ever wondered how the Sun would look from the other planets in our solar system? Here is a visual showing the apparent size of the Sun from the planets of the solar system, including Earth.

The Sun is the primary source of energy for Earth’s climate system, and the life on Earth. It is a is a yellow dwarf star. With a diameter of about 1.39 million kilometers (864,337 miles, i.e. 109 times that of Earth), and a mass about 1.9885×1030 kg (330,000 times that of Earth, accounting for about 99.86% of the total mass of the Solar System), its gravity holds the whole solar system together, keeping everything from the biggest planets to the smallest particles of debris in its orbit.

It may be the biggest thing in this neighborhood, but it is actually just a medium-sized star among the hundreds of billions of stars in the Milky Way galaxy.

Here is the apparent size of the Sun from eight planets of the Solar System (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune).

Apparent size of the sun from the planets of the Solar System
Apparent size of the sun from the planets of the Solar System.

The apparent size of the Sun from the solar system planets

The sky is a sphere of 360°. When you look at the sky, you have a hemisphere of 180° above you where the stars shine. On this dome of 180°, the size of the Sun represents a number of degrees, which is its apparent size – in other words, its angular diameter. For example, the angular diameter of the Sun, when seen from the surface of Earth is approximately 0.53°.

Mercury

NASA's MESSENGER spacecraft orbiting Mercury - artist conception
An artist’s concept of NASA’s MESSENGER spacecraft orbiting Mercury. Image source: NASA MESSENGER was a NASA robotic spacecraft that orbited the planet Mercury between 2011 and 2015. The probe was launched on August 3, 2004, to study Mercury’s chemical composition, geology, and magnetic field. It entered orbit around Mercury on March 18, 2011, becoming the first spacecraft to do so. It successfully completed its primary mission in 2012. Following two mission extensions, the MESSENGER spacecraft used the last of its maneuvering propellant and deorbited as planned, impacting the surface of Mercury on April 30, 2015.

Mercury is the smallest and innermost planet in the Solar System. Its average distance from the Sun is 57.91 million km (36 million miles). But, it has the largest eccentricity of all known planets in the Solar System. At perihelion Notes 1, Mercury’s distance from the Sun, which is about 41 million km (25.5 million miles) is only about two-thirds (or 66%) of its distance at aphelion Notes 2, which is about 69.8 million km (43.3 million miles).

From Mercury, the apparent angular diameter of Sun is, on average, 1.377° (1.15430° at aphelion and 1.76106° at perihelion). In other words, on Mercury, the sun takes up almost three times larger space in the sky than it does on Earth.

Venus

Venus has a very dense, cloudy and nearly opaque (to visible light) atmosphere. As a result, the Sun cannot be seen from Venus’s surface.

If you somehow overcome the extremely high atmospheric pressure and high temperatures and land on the Venus and try to look at the sun, you may see a vague ill-defined illumination during the day but no definite source of light, just like a very cloudy day on earth. If the atmospheric clouds thin at the time, you could see a bright area in the sky denoting the sun but not the sun itself.

Venus’ average distance from the Sun is about 108.2 million km (67.2 million miles). If the Sun could be seen from its surface, it would be about half again larger than it appears in Earth’s sky and about 2.25 times brighter.

Earth

Earth orbits the sun at an average of 149.6 million km (93 million miles). The distance from Earth to the sun is called an astronomical unit, or AU, which is used to measure distances throughout the solar system.

As explained above, the angular diameter of the Sun, when seen from the surface of Earth is approximately 0.53°.

The Sun and moon appear the same size in Earth’s sky: the Sun’s diameter is about 400 times greater – but the sun is also about 400 times farther away. That’s how total solar eclipses occur when the Moon passes between the Sun and Earth.

Sunset on Earth

Mars

Mars is one-and-a-half times farther from the sun than Earth is – the average distance between the Sun and Mars is about 229 million km (142 million miles). As a result, the sun appears about 2/3 of what it appears in the Earth’s sky.

Apparent size of the sun from Mars.
NASA’s Curiosity Mars rover recorded this view of the Sun setting at the close of the mission’s 956th Martian day, or sol (April 15, 2015), from the rover’s location in Gale Crater. This was the first sunset observed in color by Curiosity. The image comes from the left-eye camera of the rover’s Mast Camera (Mastcam). The color has been calibrated and white-balanced to remove camera artifacts. Mastcam sees color very similarly to what human eyes see, although it is actually a little less sensitive to blue than people are. Dust in the Martian atmosphere has fine particles that permit blue light to penetrate the atmosphere more efficiently than longer-wavelength colors. That causes the blue colors in the mixed light coming from the sun to stay closer to sun’s part of the sky, compared to the wider scattering of yellow and red colors. The effect is most pronounced near sunset, when light from the sun passes through a longer path in the atmosphere than it does at mid-day. Malin Space Science Systems, San Diego, built and operates the rover’s Mastcam. NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for NASA’s Science Mission Directorate, Washington. JPL designed and built the project’s Curiosity rover. This is a cropped image. You can see the full-size image on NASA Jet Propulsion Laboratory website.

Jupiter

The distance from the Sun to Jupiter is approximately 779 million km (484 million miles). This is about 5.2 AU or 5.2 times farther than the distance from Earth to the Sun. Around the planet Jupiter, the Sun would be 5.2 times smaller than the one we see from Earth (Jupiter is a gas giant, it has no surface like the solar system’s rocky planets – Mercury, Venus, Earth, and Mars).

A view from Europa's surface - artist conception
An artist’s conception of the Sun as seen from Europa, the smallest of the four Galilean moons (Io, Europa, Ganymede, and Callisto) orbiting Jupiter. They were first seen by Galileo Galilei in January 1610 and recognized by him as satellites of Jupiter in March 1610. They were the first objects found to orbit another planet. Image source: NASA

Saturn

Saturn averages 1.4 billion km (886 million miles) from the sun, nine and a half times Earth’s average distance. At that distance, the sunlight is at least 90 times dimmer than on Earth, but the sun would still be far too bright to look at without eye protection.

Cassini Spacecraft, Sun and Saturn
An artist’s conception of NASA’s Cassini Spacecraft (bottom left on this image), Sun and Saturn. Launched on October 15, 1997, NASA’s Cassini spacecraft went into orbit around Saturn on July 1, 2004. Since then, it has taken thousands of photos of Saturn, the second-largest planet in the Solar System, its prominent rings, and moons. And on September 15, 2017, Cassini plunged into Saturn’s atmosphere and disintegrated.

Uranus

From an average distance of 1.8 billion miles (2.9 billion kilometers), Uranus is 19.8 astronomical units away from the Sun. The sun appears correspondingly smaller around Uranus, and the sunlight is about 390 times dimmer than on Earth.

Sun between Uranus rings
An artist’s conception of the Sun between Uranus’ rings. Planet Uranus has faint rings. The inner rings are narrow and dark. The outer rings are brightly colored and easier to see. The Uranian rings are composed of extremely dark particles, which vary in size from micrometers to a fraction of a meter. Thirteen distinct rings are presently known, the brightest being the ε ring. All except two rings of Uranus are extremely narrow – they are usually a few kilometers wide. The rings are probably quite young; the dynamics considerations indicate that they did not form with Uranus. The matter in the rings may once have been part of a moon (or moons) that was shattered by high-speed impacts.

Neptune

Neptune’s average distance from the Sun is 4.495 billion km (2.8 billion miles) or 30.1 AU. Its perihelion is 29.8 AU, and its aphelion is 30.4 AU. At that distance, the sun appears 30 times smaller than here on Earth. The sunlight is also at least 900 times dimmer.

 Sun as seen from Triton
The Sun as seen from Triton, the largest natural satellite of the planet Neptune, and the first Neptunian moon to be discovered. Neptune is slightly above the horizon. The discovery was made on October 10, 1846, by English astronomer William Lassell (Artist conception). Image source: Wikipedia

Pluto

Originally considered to be the ninth planet from the Sun after its discovery in 1930, Pluto is now a dwarf planet. It follows a highly elliptical orbit around the Sun. At the closest point of its orbit (perihelion), it is 29.658 AU (4.43682 billion km) away from the Sun – which occurred on September 5, 1989. And then at the most distant point of its orbit, called aphelion, Pluto gets 49.305 AU (7.37593 billion km) away from the Sun – which never observed to date. Pluto will be at its aphelion in February 2114.

Currently (as of 2019) Pluto is about 34 AU from the Sun. The sun appears correspondingly smaller on Pluto, and the sunlight is at least 1,150 times dimmer than on Earth. Still, it’s at least 180 times brighter than a full moon, bright enough to outshine every other object in the sky and hard to look at directly.

Pluto at High Noon
Pluto at High Noon (Artist’s Concept). Pluto’s largest moon Charon can be seen in the image. Pluto has five known moons: Charon (the largest, with a diameter just over half that of Pluto), Styx, Nix, Kerberos, and Hydra. Pluto and Charon are sometimes considered a binary system because the barycenter of their orbits does not lie within either body. Image source: NASA

Notes

  1. Perihelion is the point of the least distance for a body orbiting the Sun.
  2. Aphelion is the point of the greatest distance for a body orbiting the Sun.

Sources

M. Özgür Nevres

I am a software developer, an ex-road racing cyclist, and a science enthusiast. Also an animal lover! I write about the planet Earth and science on this website, ourplnt.com. You can check out my social media profiles by clicking on their icons.

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