asteroid

rocky objects revolving around the sun that are too small and numerous to be considered planets

If that should happen, the asteroid might eventually hit Earth.

l’astéroïde

astronomy

the study of the Moon, stars, and other objects in space

Though massive, these galaxies have escaped detection by conventional astronomy.

l’astronomie

axis

an imaginary line that passes through Earth’s center and its North and South Poles

Of course, the planet now rotates on a different axis.

l’axe

Big Bang

theory that an explosion created the universe many billions of years ago

In modern astronomy the Big Bang theory is the dominant postulation.

le Big Bang

black hole

an object so massive and dense that even light cannot escape its gravity

Nothing that happens inside a black hole matters to the outside world.

le trou noir

comet

a ball of dust and ice that orbits the Sun

What if the comet pieces that hit Jupiter had hit Earth?

la comète

constellation

an imaginary pattern of stars in the sky

Early Tuesday, the constellation will lie in the northeastern sky.

la constellation

dark matter

matter that does not give off electromagnetic radiation but is quite abundant in the universe

The final topic dealt with dark matter distribution in the Milky Way.

la matière noire

eclipse

the partial or total blocking of one object in space by another

Head for Cartagena in Colombia for total eclipse of the Sun.

l’éclipse

ellipse

an elongated circle, or oval shape; shape of planetary orbits

This is the major axis of the ellipse, its greatest diameter.

l’ellipse

equinox

the first day of spring or fall when the Sun is directly over the Equator

But fierce storms are no more likely around the equinox specifically.

l’équinoxe

galaxy

a collection of stars, star systems, dust, and gas bound together by gravity

Theorists believe such galaxies have supermassive black holes at their centers.

la galaxie

gravity

the force of attraction between all masses in the universe

But gravity will be enormously complicated to create on a spaceship.

la gravitation

light year

the distance that light travels in one year; about 9.46 trillion kilometers

The object is about 30 light years away in the constellation Ophiuchus.

l’année-lumière

lunar eclipse

when the Earth passes between the Sun and the Moon and casts a shadow on the Moon

Also, under special circumstances, a lunar eclipse can occur on the 12^th.

l’éclipse de lune

mass

the amount of matter in an object

The mass of the Sun has decreased since the time it formed.

la masse

meteor

a bright streak of light that results when a meteoroid burns up in the Earth’s atmosphere

A meteor landing in the desert is news for a day.

le météore

nebula

a huge cloud of dust and gas in space

However, this would have created a shell around the nebula.

la nébuleuse

orbit

the path of an object as it revolves around another object in space

From that orbit, you can hardly see the horizon curve.

l’orbite

rotation

the spinning motion of a planet on its axis

All these techniques also serve to monitor Earth rotation irregularities as well as plate tectonic motions.

la rotation

solar eclipse

when the Moon passes between the Sun and the Earth

Looking at a solar eclipse with the naked eye can be dangerous.

l’éclipse solaire

solar wind

a stream of electrically charged particles given off from the Sun

This flood of electrically charged particles is known as the solar wind.

le vent solaire

solstice

the time that Earth’s poles point at their greatest angle toward or away from the Sun

The calendar suggests the solstice is still a long way off.

le solstice

tide

the periodic rise and fall of the sea level under the gravitational pull of the Moon

I think the tides have a lot to do with it.

la marée

universe

all of space and everything in it

How could the universe be younger than some of its components?

l’univers