The questions everyone asks

Who has been to the Moon?

Twelve people have walked on the Moon — all NASA astronauts on Apollo missions between 1969 and 1972. In total twenty-fo…

How many people have walked on the Moon?

Twelve people have walked on the Moon — all of them NASA astronauts, on six Apollo landings between 1969 and 1972.…

How many people are in space right now?

This page counts the people currently off the planet from the live crew record — the number below is current as of the m…

How far is the Moon from Earth?

The Moon is about 384,400 km (238,900 miles) from Earth on average — but the distance changes constantly, from roughly 3…

How long does it take to get to the Moon?

About three days for a crewed mission on a direct trajectory — that's how long Apollo took, and how long Artemis is plan…

How many planets are there in the Solar System?

Eight: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto was reclassified as a dwarf planet in 20…

What is the closest planet to Earth?

Venus comes closest to Earth in its orbit — but averaged over time, Mercury is the planet nearest to Earth. Surprisingly…

How hot is the Sun?

The Sun's visible surface is about 5,500°C (9,940°F). Its core is far hotter — around 15 million°C — where nuclear fusio…

How cold is space?

Empty space far from any star sits at about 2.7 kelvin — roughly −270°C (−455°F), just a few degrees above absolute zero…

How old is the universe?

About 13.8 billion years, measured from the Big Bang — the best current figure from the Planck satellite's mapping of th…