A satellite stays in orbit because it is:

A projectile that keeps falling around the Earth

Why is a heat shield needed when a spacecraft re-enters the atmosphere?

Because friction with the air produces a lot of heat

Communication and weather satellites

Objects in space emit across the whole spectrum

14questions. Pick an answer and you'll see why right away.

Which law explains how a rocket produces thrust?
A rocket lifts off when:
A 600 kg probe is on Mars where g is 3.7 N/kg. What is its weight there?
When an astronaut travels from Earth to the Moon, the astronaut's mass:
A satellite stays in orbit because it is:
Why is a heat shield needed when a spacecraft re-enters the atmosphere?
Which of these is a benefit of space exploration?
Why do astronomers use telescopes for many bands of the electromagnetic spectrum?
What does a line spectrum allow astronomers to determine about a star?
Redshift of light from a distant galaxy means the light is shifted towards:
What does the redshift of distant galaxies provide evidence for?
A line of rest wavelength 600 nm is observed at 630 nm. What is the redshift z?
A 5000 kg rocket has a thrust of 70000 N (g = 9.8 N/kg). What is the resultant upward force at lift-off?
Which radiation is used to detect the leftover glow of the early universe?