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Solar System Astronomy

How large the Sun looks from other planets [Apparent Size of the Sun]

Have you ever wondered what the Sun would look like 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 life on Earth. It 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 of 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.

But, have you ever wondered how the Sun would look from the other planets in our solar system?

Apparent Size of the Sun from other planets (plus Pluto)

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

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

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 [Sun’s angular diameter: 1.377°]

The Sun’s angular diameter in Mercury’s sky is about 1.377°.

How the Sun would look like from Mercury - NASA MESSENGER spacecraft orbiting Mercury
This is how our Sun would look like from Mercury. The apparent size of the Sun on Mercury’s surface would be about three times greater than it is on Earth. This image is an artist’s concept of NASA’s MESSENGER spacecraft orbiting Mercury. 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. Image source: NASA

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 (see 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 (see notes 2), which is about 69.8 million km (43.3 million miles).

From Mercury, the apparent angular diameter of the 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 [Sun’s angular diameter: 0.7°]

The Sun’s angular diameter in Venus’s sky is about 0.7°.

How the Sun would look like from Venus - Magellan Spacecraft orbiting Venus
The Sun cannot be seen from Venus’ surface because of its dense, cloudy atmosphere, but this is how our Sun would look like from Venus’ orbit. This image is an artist’s concept of the Magellan spacecraft making a radar map of Venus. Magellan was launched on May 4, 1989, and entered Venus’ orbit on August 10, 1990. After mapping 98 percent of Venus’ surface at a resolution of 100 to 150 meters, the spacecraft was commanded to plunge into Venus’ atmosphere on October 13, 1994, as part of a final experiment to gather atmospheric data.. Image source: NASA

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 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 were 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 1.5 times larger than it appears in Earth’s sky and about 2.25 times brighter.

Earth [Sun’s angular diameter: 0.53°]

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
The Sun and moon appear the same size in Earth’s sky. Image: “Beautiful, colorful sky and sunset at the sea” on Deposit Photos

Mars [Sun’s angular diameter: 0.35°]

The Sun’s angular diameter in Mars’s sky is about 0.35°.

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.

How the Sun would look like from Mars - Sunset on Mars
Sunset on Mars! The sun on Mars appears about 2/3 of what it appears in the Earth’s sky. 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 is a cropped image. You can see the full-size image on the NASA Jet Propulsion Laboratory website

Jupiter [Sun’s angular diameter: 0.11°]

The Sun’s angular diameter in Jupiter’s sky is about 0.11°.

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).

Sun as seen from Europa (Jupiter moon)
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 [Sun’s angular diameter: 0.057°]

The Sun’s angular diameter in Saturn’s sky is about 0.057°.

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.

Apparent size of Sun from Saturn - Cassini spacecraft, Saturn, and Sun
This is what Sun would look like from 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 [Sun’s angular diameter: 0.044°]

The Sun’s angular diameter in Uranus’ sky is about 0.044°.

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 [Sun’s angular diameter: 0.0177°]

The Sun’s angular diameter in Neptune’s sky is about 0.0177°.

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 (Neptune)
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 [Sun’s angular diameter: 0.0177° – 0.0107°]

The Sun’s angular diameter in Pluto’s sky is about 0.0177° when it is closest to the Sun (perihelion) and 0.0107° when it is furthest from the Sun (aphelion).

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 has never been 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.

A fun fact, the sunlight in Pluto is still bright enough that you could easily read a book on the surface.

Pluto at High Noon (Artist's Concept)
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

Learn your Pluto time!

For just a moment near dawn and dusk each day, the illumination on Earth matches that of high noon on Pluto.

NASA calls this Pluto Time. If you go outside at this time on a clear day, the world around you will be as bright as the brightest part of the day on Pluto.

You can learn your Pluto time by using NASA’s Find Your Pluto Time webpage!

The amount of sunlight received by each planet relative to Earth

Here’s the amount of sunlight received by each planet relative to Earth (at the top of their atmospheres):

  • Mercury: 668%
  • Venus: 191%
  • Earth: 100%
  • Mars: 43%
  • Jupiter: 3.7%
  • Saturn: 1.1%
  • Uranus: 0.3%
  • Neptune: 0.1%

And the solar energy in Watts per meter² (% relative to Earth):

  • Mercury: 9,090 Wm⁻² (V/m²) (668%)
  • Venus: 2,605 Wm⁻² (191%)
  • Earth: 1,361 Wm⁻² (100%)
  • Mars: 589 Wm⁻² (43%)
  • Jupiter: 50 Wm⁻² (3.7%)
  • Saturn: 15 Wm⁻² (1.1%)
  • Uranus: 3.7 Wm⁻² (0.3%)
  • Neptune: 1.5 Wm⁻² (0.1%)

Video: The Apparent Size of the Sun from other planets

A video about how our Sun would look like from the other planets of the Solar System.

The apparent size of the Sun – what will the Sun look like From other Planets?

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
Özgür Nevres

By M. Özgür Nevres

I am a software developer and a science enthusiast. I was graduated from the Istanbul Technical University (ITU), Computer Engineering. In the past, I worked at the Istanbul Technical University Science Center as a science instructor. I write about the planet Earth and science on this website, ourplnt.com. I am also an animal lover! I take care of stray cats & dogs. This website's all income goes directly to our furry friends. Please consider supporting me on Patreon, so I can help more animals!

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