Singular, Plural, and Possessive Nouns 2

Scientists believe that the Moon came from an ancient planet that crashed into the Earth billions of years ago.

Neil Armstrong was the first person to walk on the Moon.

Halley's Comet passes by the Earth every 76 years, so your next chance to see it will be in middle of the year 2061.

Pluto's status as a planet was called into question after other large icy objects were found orbiting the Sun.

The Milky Way is our home, but there are many other galaxies in the Universe.

When a meteor crashes into the Earth, it becomes a meteorite.

Saturn's rings are made almost entirely of ice.

Edwin Hubble proved that the Universe is expanding.

The North Star changes its position in the sky very little throughout the night.

No one's ever seen a black hole, but scientists believe that they have witnessed their effects.

A comet's tail only becomes visible as it approaches the Sun.

Galileo did not invent the ________, but he did improve it.

The Sun is so large that over one million planet ________ could fit in it.

The ________ atmosphere is held in place by the force of gravity.

Jupiter is more than two and a half times larger than all of the other planets in our Solar ________ combined.

The rings of ________ were not discovered until 1977 because they are dark and distant.

The temperature on ________ surface ranges from -280 F at night to 800 F during the day.

The planet Venus is named after the Roman ________ of love.

The surface of ________ is covered in iron oxide, or rust, which gives the planet its red appearance.

Neptune has been the farthest planet from the Sun since 2006, when ________ status was downgraded to dwarf planet.

NASA is an agency in the United ________ that handles space travel.

No one really knows what causes an ________ colorful lights.

There are millions of ________ in the Asteroid Belt.

The second closest star to Earth is in the Alpha Centauri star system, which is a mere 4.37 ________ away.

The surface of ________ is covered in liquid water, which all known life forms require.

It would take us 21,585 Earth ________ to travel one light-year using current technology.

Astronauts take their breaks in the ________ break-room.

The ________ boundaries are unknown.

________ best theory about the origin of the Universe is that it began with the Big Bang.

It took almost 10 years for ________ New Horizons space probe to get to Pluto from Earth.