Planets

What proof do you have that planets are made from gas and dust?
Does a sunset in the west and a moonrise in the east ever happen at exactly the same time?
Why do comets not get captured by Earth's gravity during a close flyby?
Why does only one side of the Moon face the Earth?
Is there public domain software to calculate the orbit of a spacecraft?
If the Moon was formed out of a giant collision, why is there no ring of debris surrounding Earth?
Why does the atmosphere of Pluto have a blue tint?
Can we find exoplanets (and possibly extraterrestrial life) by beaming low-frequency waves towards them?
About 100 tons of cosmic dust fall on the Earth every day. Will this cause Earth's orbit to change over time?
What is the evidence that early astronomers used to show that the Earth is turning on its axis?
Is there a way to provide a magnetic field for Mars?
How does the direction of the moonrise change?
Is Jupiter a failed star?
Is there is a policy to not send probes anywhere that conditions might support life?
How long does it take for a planet to be born?
Is Pluto still a planet?
Can a hypothetical Planet X whip around from behind the Sun in a 3600-years orbit?
Is it possible to colonize and terraform Mars at the same time?