Do you fear those awkward silences at star parties and observing nights? These ‘Did you know’ ice-breakers will surely captivate your astronomy-loving friends and even those you’ve just met!
So the next time you find yourself in a conversation lull, simply drop one of these fun facts and watch as the room lights up with interest and intrigue*.
*Not guaranteed.
The planets in order of closest to furthest from the Sun
Did you know Neptune is about 30 times further from the Sun than Earth?
The average distances of the planets from the Sun are:
Mercury: 57 million kilometres (35 million miles)
Venus: 108 million kilometres (67 million miles)
Earth: 150 million kilometres (93 million miles)
Mars: 228 million kilometres (142 million miles)
Jupiter: 779 million kilometres (484 million miles)
Saturn: 1.43 billion kilometres (889 billion miles)
Uranus: 2.88 billion kilometres (1.79 billion miles)
Neptune: 4.50 billion kilometres (2.8 billion miles)
These distances are averages because the planets have elliptical orbits, so their distances from the Sun change depending on where they are in their orbits.
The planets in order of lightest to heaviest based on mass
Did you know Earth has more mass than Venus, Mars and Mercury?
The order of the planets in our Solar System from lightest to heaviest, based on mass is:
Mercury: 3.30×10^23 kilograms (7.27×10^23 pounds)
Mars: 6.41×10^23 kilograms (1.41×10^24 pounds)
Venus: 4.86×10^24 kilograms (1.07×10^25 pounds)
Earth: 5.97×10^24 kilograms (1.31×10^25 pounds)
Uranus: 8.68×10^25 kilograms (1.91×10^26 pounds)
Neptune: 1.02×10^26 kilograms (2.25×10^26 pounds)
Saturn: 5.68×10^26 kilograms (1.25×10^27 pounds)
Jupiter: 1.89×10^27 kilograms (4.17×10^27 pounds)
10^ followed by a number is a way of expressing very large numbers and is known as scientific notation. 10^27 means 10 raised to the power of 27, which is a 1 followed by 27 zeros. So, 10^27 equals 1,000,000,000,000,000,000,000,000,000.
The planets ordered by the length of day
Did you know Earth and Mars have almost equal lengths of day?
The planets in our solar system, ordered from shortest to longest length of day (a full rotation on its axis) are:
Jupiter: 10 hours
Saturn: 11 hours
Neptune: 16 hours
Uranus: 17 hours
Earth: 24 hours
Mars: 25 hours
Mercury: 1,408 hours (58.67 Earth days)
Venus: 5,832 hours (243 Earth days)
These lengths of day are averages and can vary depending on factors such as the planet’s axial tilt and the eccentricity of its orbit.
The planets in order of smallest to biggest
Did you know the biggest planet in our solar system is Jupiter?
The planets in our solar system, ordered from smallest to largest in terms of diameter, are:
Mercury: Diameter of roughly 4,880 kilometres
Mars: Diameter of about 6,779 kilometres
Venus: Diameter of approximately 12,104 kilometres
Earth: Diameter of 12,742 kilometres
Neptune: Diameter of 49,244 kilometres
Uranus: Diameter of about 50,724 kilometres
Saturn: Diameter of 116,464 kilometres
Jupiter: Diameter of about 139,822 kilometres
These diameters are averages because the planets are not perfect spheres.
The planets in order of least to most dense
Did you know, while Saturn is one of the biggest planets in our solar system is it the least dense and can float on water (if there was a large enough sea to put it in)?
The planets in order of least to most dense, are:
Saturn: 0.687 g/cm³
Uranus: 1.27 g/cm³
Jupiter: 1.326 g/cm³
Neptune: 1.638 g/cm³
Mars: 3.934 g/cm³
Venus: 5.243 g/cm³
Mercury: 5.427 g/cm³
Earth: 5.514 g/cm³
These densities are averages and are given in grams per cubic centimetre (g/cm³). The density of a planet can vary throughout its radius due to different layers such as the crust, mantle, and core.
The coldest to the hottest planet
Did you know Venus, while not the closest to the Sun is the hottest planet in our solar system?
The average temperatures of the planets ordered from coldest to hottest are:
Neptune: -200°C (-330°F)
Uranus: -195°C (-320°F)
Saturn: -140°C (-220°F)
Jupiter: -110°C (-166°F)
Mars: -65°C (-85°F)
Earth: 15°C (59°F)
Mercury: 167°C (333°F)
Venus: 464°C (867°F)
These temperatures are averages and can vary depending on factors such as the planet’s distance from the Sun and the composition of its atmosphere. Venus, despite not being the closest planet to the Sun, is the hottest due to its thick atmosphere causing a strong greenhouse effect.
Planets ranked from most to least amount of moons
Did you know, that Mars' moon Phobos is so close to Mars' surface, it can't be seen in some places?
The order of planets in our solar system based on the number of recorded moons they have:
Saturn has 146 moons
Jupiter has 95 moons
Uranus has 27 moons
Neptune has 14 moons
Mars has 2 moons
Earth has 1 moon
Mercury and Venus do not have any moons.
Pluto has not been included because it was reclassified as a “dwarf planet” by the International Astronomical Union in 2006.