Exam 21: The Moon and Mercury: Comparing Airless Worlds

The moon's distance from Earth is measured very accurately by bouncing a laser beam off of a small mirror left on the surface of the moon.If a laser is fired at the moon and the signal returns in 2.6 seconds,what is the distance to the moon? (Hint: speed of light c = 300,000 km/s)

Major types of surface features or terrain on the Moon are.....

The moon still has moonquakes deep in its interior.

The moon has _____ as the Earth.

The Earth's moon is airless and inert because its mass is ____ Earth's.

The vesicular basalts found among the lunar samples were caused by fragmenting during meteorite impacts.

____________________ are great lava flows covering 17% of the lunar surface.

The moon is no longer geologically active because

The daytime surface of Mercury is ____________________ than that of the Earth's moon.

In terms of escape velocity,considering Mercury,Earth,and the Earth's moon,____________________ can hold an atmosphere best,with ____________________ next best,and ____________________ least able.

________ is/are believed to have formed on Mercury just after a giant meteorite created the Caloris Basin..

The fission theory of the moon's origin has been criticized because

The theory that Mercury shrank slightly when it was young has been proposed to explain...

Mercury's smooth plains are probably the ____________parts of its crust.

Mercury's major atmospheric gas is

The theory that Mercury shrank slightly when it was young has been proposed to explain Mercury's

If Mercury is 1.5*10⁸ km from Earth and has a diameter of 2,400 km,what is its angular diameter as viewed from Earth?

The moon's highlands

The Earth's moon has a dense atmosphere

The lunar maria are