MERCURY
INSIDER
It is the closest planet to the Sun at a distance of about 36 million miles. SMALLEST Mercury is the smallest planet in our Solar System—only slightly larger than Earth's Moon. LONG DAYS, SHORT YEARS One day on Mercury (the time it takes for Mercury to rotate or turn once) takes 59 Earth days. One day-night cycle on Mercury takes 175.97 Earth days. Mercury makes a complete orbit around the Sun (a year in Mercury time) in just 88 Earth days. ROUGH SURFACE Mercury is a rocky planet, also known as a terrestrial planet. Mercury has a solid, cratered surface, much like the Earth's moon. CAN'T BREATHE IT Mercury's thin atmosphere is composed mostly of oxygen (O2), sodium (Na), hydrogen (H2), helium (He), and potassium (K). Atoms that are blasted off the surface by the solar wind and meteoroid impacts create Mercury's exosphere. MOONLESS Mercury has no moons. RINGLESS There are no rings around Mercury. |
TOUGH PLACE TO LIVE
No evidence for life has been found on Mercury. Daytime temperatures can reach 430 degrees Celsius (800 degrees Fahrenheit) and drop to -180 degrees Celsius (-290 degrees Fahrenheit) at night. It is unlikely life (as we know it) could survive on this planet.
BIG SUN
Standing on Mercury's surface at its closest approach to the Sun, our star would appear more than three times larger than it does on Earth.
ROBOTIC VISITORS
The two spacecraft of ESA-JAXA's BepiColombo are en route to Mercury. NASA's Mariner 10 was the first mission to explore Mercury. NASA's MESSENGER was the first to orbit the innermost planet.
No evidence for life has been found on Mercury. Daytime temperatures can reach 430 degrees Celsius (800 degrees Fahrenheit) and drop to -180 degrees Celsius (-290 degrees Fahrenheit) at night. It is unlikely life (as we know it) could survive on this planet.
BIG SUN
Standing on Mercury's surface at its closest approach to the Sun, our star would appear more than three times larger than it does on Earth.
ROBOTIC VISITORS
The two spacecraft of ESA-JAXA's BepiColombo are en route to Mercury. NASA's Mariner 10 was the first mission to explore Mercury. NASA's MESSENGER was the first to orbit the innermost planet.