Element Symbols
Match elements to their symbols in a free, timed browser game. Au, Ag, Fe, Pb — and why they do not match the English names.
ScienceSpace Objects
Astronomy has a vocabulary for everything from a speck of dust to a structure of billions of stars. Below: the definitions that separate the similar-sounding ones.
Choose your difficulty
Pick a level to start playing. You can switch at any time.
How to play
Read the object, then tap what it is.
Tip: your progress and best score are saved in this browser only.
Related games
Atomic Numbers
Match elements to their atomic number in a free, timed browser game. Hydrogen is 1, gold is 79, uranium is 92.
ScienceSI Units
Match physical quantities to their SI units in a free, timed browser game. Newton, joule, watt, pascal.
ScienceType the Symbol
Type the chemical symbol for each element, in a free timed browser game. Au, Ag, Pb — recall it and type it.
ScienceBody Systems
Match body systems and organs to what they do in a free timed browser game. Circulatory, respiratory, digestive and more.
ScienceWhat you are actually practicing
Astronomy has a vocabulary for everything from a speck of dust to a structure of billions of stars, and several of those words sound alike while meaning quite different things. A meteor, a meteorite and a meteoroid are three different objects, and a galaxy and a nebula are not interchangeable at all.
Learning the definitions rather than the associations is what makes these questions answerable, because the associations will mislead you.
How the game works
You are shown an astronomical object and four possible descriptions. Tap the correct one. A wrong pick shows the answer immediately.
Easy covers the seven objects with the strongest associations. Medium widens the pool. Hard uses the full list.
The links worth knowing
In the solar system: a comet is a ball of ice and dust that grows a tail near the Sun. An asteroid is a rocky body orbiting the Sun. A meteor is the streak of light as a meteoroid burns up, and a meteorite is a piece that survives the journey and lands on the ground. A planet is a large body that orbits a star and clears its path, and a moon is a natural satellite orbiting a planet.
Stars: a star is a huge ball of gas that shines by nuclear fusion. A protostar is a forming star before it starts fusing hydrogen. A red giant is a swollen, cooling star. A supernova is the explosive death of a star. A white dwarf is the dense leftover core of a dead small star, and a neutron star is the collapsed core of a massive one.
Big structures: a nebula is a cloud of gas and dust in space, and a galaxy is a huge collection of stars, gas and dust. A constellation is a pattern of stars named as a group. A solar system is a star and everything that orbits it.
The unusual: a black hole is a region where gravity is so strong nothing escapes. A pulsar is a rotating neutron star that beams radio waves. A quasar is a very bright galaxy powered by a black hole at its centre. A light year is the distance light travels in one year, not a measure of time.
How to get faster
Ask what makes the object shine or what it is made of. Anything with a tail is a comet, anything that collides with our atmosphere as a streak is a meteor, and anything that fuses hydrogen is a star.
A note on the look-alikes
A galaxy is far bigger than a nebula, even though both are made of gas and dust: a nebula is a cloud, a galaxy is a whole system of stars bound together by gravity. And a light year is a length, so an expression like "ten light years away" is a distance.