Start each day with the Word of the Day in your inbox!

Word of the Day

Word of the day

⚛️ Today's Word was chosen in partnership with the Museum of Science as the Science Word Of The Week! ⚛️


[ air-ee-ol-uh-jee ] [ ˌɛər iˈɒl ə dʒi ] Show IPA Phonetic Respelling


the observation and study of the planet Mars.

learn about the english language

Why the Museum of Science chose areology is collaborating with the Museum of Science, Boston, to bring science—and words—to life for millions around the world through “Science Word of the Week,” a weekly series that will describe scientific terms, their meanings, and how they are used. The partnership stems from a common theme in mission between us to inspire a love of words and science in everyone.
Right now, a rover on Mars is collecting rock samples that will help us learn more about the planet and may help us determine if life ever existed on Mars. Watch the video below to hear more fun facts about areology from science communicator, Alex Dainis, Ph.D.

More about areology

Areology is based on the Ancient Greek word for Ares, the god of war, plus -logy, which indicates the science or study of a topic. Some linguists have traditionally derived Ares from the Greek word for “damage, disaster, doom,” but others consider the name to come from a lost language once spoken in what is now Greece. Take care not to confuse the god Ares with the constellation Aries, which is unrelated and comes from the Latin word for “ram.” Areology was first recorded in English in the early 1880s.

From Galileo’s observations to NASA’s missions, interest in areology has fueled scientific discoveries for centuries!

While geology refers to the study of the planet Earth, areology is the Martian version. Learn more fun facts at the Museum of Science.

quiz icon
Think you're a word wizard? Try our word quiz, and prove it!
arrows pointing up and down
Double your word knowledge with the Synonym of the Day!
Word of the Day Calendar

Word of the day


[ ih-vek-shuhn ] [ ɪˈvɛk ʃən ] Show IPA Phonetic Respelling


a periodic irregularity in the moon's motion, caused by the attraction of the sun.

learn about the english language

More about evection

Evection, “a periodic irregularity in the moon’s motion,” comes from Latin ēvectiō (stem ēvectiōn-) “a going upwards, flight.” Ēvectiō is based on the verb ēvehere “to carry forth, move forth,” from ē (or ex) “out of, from, beyond” and vehere “to carry, drag.” Vehere has two common stems in English: veh-, as found in vehement and vehicle, and vect-, as in convection and vector. Distant relatives of vehere in English include way, wagon, weigh, wiggle, and even Norway (literally “north way”). Evection was first recorded in English in the 1650s.

how is evection used?

The point at which a moon and its planet come closest together, known as periapsis, is not constant …. When the period of this precession matches the time it takes the planet itself to orbit the sun, the sun’s gravity will distort the moon’s orbit. This is evection.

“Saturn’s rings and several of its moons may be recent creations,” The Economist, March 22, 2018

Jeremiah Horrocks[’s] … life was short, but he accomplished a great deal, and rightly ascribed the lunar inequality called evection to variations in the value of the eccentricity and in the direction of the line of apses, at the same time correctly assigning the disturbing force of the Sun as the cause.

George Forbes, History of Astronomy, 1909
Word of the Day Calendar

Word of the day


[ kuh-nik-yuh-ler ] [ kəˈnɪk yə lər ] Show IPA Phonetic Respelling


pertaining to the rising of the Dog Star (also called Sirius) or to the star itself.

learn about the english language

More about canicular

Canicular, “pertaining to Sirius, the Dog Star,” is equivalent to Latin Canīcula “Sirius” plus -āris, an adjective-forming suffix. Canīcula literally means “little dog” and is based on canis “dog,” plus the feminine diminutive suffix -cula (compare English -cle or -cule, as in molecule and particle). Canis survives today as French chien, Italian cane, and Portuguese cão, but Spanish can has declined in favor of perro, of unclear origin. A direct descendant of Canīcula is French canicule “heat wave,” which previously referred to the dog days of summer. This period of the year takes its name in both English and Romance languages from the appearance of Sirius in the northern sky, and the co-occurrence with hot weather gives dog days as well as French canicule their heated sense. Canicular was first recorded in English in the late 14th century.

how is canicular used?

Sirius was then above the horizon during daylight hours, so it was believed the star’s heat was added to that of the Sun to give a run of scorching temperatures. The interval from early July to mid-August of Dante’s “great scourge of canicular days” is still referred to as the dog days of summer in modern times.

John Flannery, “What to see in the sky in April: Venus and Mercury to meet in a conjunction,” The Irish Times, April 1, 2021

​​Now beat the pulse and burned the flame of that canicular time when Sirius, rising with the sun, adds his glow to the lesser planet for earth’s delight.

Eden Phillpotts, The Girl and the Faun, 1916
Word of the Day Calendar
Word of the Day Calendar