Planetary Science Terms

noun a celestial object consisting of a nucleus of ice and dust and, when near the sun, a 'tail' of gas and dust particles pointing away from the sun

• A comet is a celestial body that orbits the sun and has a tail of gas and dust that streams behind it.
• Did you know that a comet is basically a big dirty snowball flying through space?
• That comet zoomed past Earth like a shooting star!
• Her sudden rise to fame was like a comet streaking across the sky.

noun a celestial body that is smaller than a planet but larger than an asteroid

adjective describing something related to or resembling a planetoid

• A planetoid is a celestial body that is smaller than a planet but larger than an asteroid.
• Did you know that Pluto is considered a planetoid?
• That little planetoid looks like a baby planet!
• Her creativity is like a planetoid, small but powerful in its impact.

noun A maneuver in which a spacecraft uses the resistance of a planet's atmosphere to slow down or adjust its trajectory

• Aerobraking is a spaceflight maneuver that uses a planet's atmosphere to slow down a spacecraft.
• They used aerobraking to slow down the spacecraft as it entered Mars' atmosphere.
• Aerobraking is like hitting the brakes with the atmosphere.
• In life, sometimes we need to aerobrake by slowing down and using our surroundings to help us navigate challenges.

noun the branch of science that deals with the upper atmosphere, especially with reference to its weather and climate

• Aeronomy is the study of the upper atmosphere and the ionosphere.
• I find aeronomy to be a fascinating field of study.
• Some people think aeronomy is just a bunch of hot air.
• In the world of aeronomy, ideas and theories float like clouds in the sky.