Planet Data Comparator

What is a planet information tool?

This tool provides detailed data about the eight planets in our solar system — Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Each planet entry includes orbital parameters, physical characteristics, atmospheric composition, and key facts. Whether you are a student researching a school project or an astronomy enthusiast, this is a quick reference guide.

The solar system's planets are divided into two groups: the inner rocky planets (Mercury, Venus, Earth, Mars) and the outer gas and ice giants (Jupiter, Saturn, Uranus, Neptune). Each has unique characteristics — from Mercury's extreme temperature swings to Jupiter's Great Red Spot, a storm larger than Earth that has raged for centuries.

The inner planets

• Mercury — smallest planet, closest to the Sun, no atmosphere, extreme temperature range (-180 to 430 degrees C).
• Venus — similar size to Earth, thick CO2 atmosphere creates 460 degree C surface temperature, rotates backwards.
• Earth — only known planet with liquid water and life, one natural satellite (the Moon).
• Mars — the Red Planet, thin atmosphere, has the tallest volcano (Olympus Mons) and deepest canyon (Valles Marineris) in the solar system.

The outer planets

• Jupiter — largest planet (11x Earth's diameter), has 95 known moons, Great Red Spot, strong magnetic field.
• Saturn — famous ring system made of ice and rock, second largest planet, least dense (would float in water).
• Uranus — ice giant, rotates on its side (98-degree axial tilt), blue-green color from methane.
• Neptune — farthest planet, strongest winds in the solar system (up to 2,100 km/h), deep blue color.

Example in practice

Compare Earth and Jupiter in the tool. Earth has a radius of about 6,371 km and one moon; Jupiter's radius is 11 times larger and it hosts at least 95 known moons. Yet a day on Jupiter lasts under 10 hours because the gas giant spins so fast, while its year — one orbit of the Sun — stretches to nearly 12 Earth years. Density tells a story too: rocky Earth is far denser than gaseous Jupiter.

Common mistakes

A common error is assuming the largest planet is also the most massive relative to its size; in fact the gas giants are huge but low in density, so Saturn would float in water. Another is confusing rotation (a planet's day) with revolution (its year) — Venus famously has a day longer than its year. And the order of planets is easy to misremember: the four small rocky worlds come first, then the four gas and ice giants.

Frequently asked questions

Why is Pluto no longer a planet?

In 2006, the International Astronomical Union redefined 'planet' to require that the object has cleared its orbital neighborhood of other debris. Pluto shares its orbital zone with many other Kuiper Belt objects and has not gravitationally dominated its region. It is now classified as a dwarf planet, along with Eris, Ceres, Haumea, and Makemake.

Which planet is most similar to Earth?

Mars is the most similar in terms of day length (24.6 hours), axial tilt (25 degrees vs Earth's 23.4), and having seasons. Venus is the most similar in size and mass. However, neither has conditions suitable for human life without significant protection — Mars is too cold and has almost no atmosphere, while Venus is extremely hot with a crushing, toxic atmosphere.

Which planet is the hottest?

Venus, not Mercury. Although Mercury is closer to the Sun, it has almost no atmosphere to trap heat. Venus's thick carbon-dioxide atmosphere creates a runaway greenhouse effect, holding surface temperatures around 465 °C — hot enough to melt lead — day and night.