On its sunny side, Mercury can reach a scorching 800 degrees Fahrenheit! (But Mercury is not the hottest planet in the solar system. The hottest planet is Venus.) On its dark side, Mercury gets very cold because it has almost no atmosphere to hold in heat and keep the surface warm.
At about three thousand miles in diameter, Mercury is the smallest planet in the solar system. But its core is massive — it accounts for more than three-quarters of the little planet's diameter, and more than half its mass. So even though Mars is bigger than Mercury, it's less dense — a rocky planet with a difference.
Mercury is one of the five classical planets visible with the naked eye and is named after the swift-footed Roman messenger god. It is not known exactly when the planet was first discovered - although it was first observed through telescopes in the seventeenth century by astronomers Galileo Galilei and Thomas Harriot.
The surface of the planet Mars appears reddish from a distance because of rusty dust suspended in the atmosphere. From closeup, it looks more of a butterscotch, and other common surface colors include golden, brown, tan, and greenish, depending on minerals.
Within the Solar System, the terrestrial planets are the inner planets closest to the Sun, i.e. Mercury, Venus, Earth, and Mars.
Venus compared to Earth. Venus, Mars and Earth, three out of the four inner or 'rocky' planets of the Solar System, have a lot in common – a solid surface you could walk on, a comparable surface composition, an atmosphere and a weather system.
List of exoplanets in the conservative habitable zone
| Object | Star | Radius (R⊕) |
|---|
| Earth | Sun (Sol) | 1.00 |
| Proxima Centauri b | Proxima Centauri | 0.8 – 1.1 – 1.4 |
| Gliese 667 Cc | Gliese 667 C | 1.1 – 1.5 – 2.0 |
| Kepler-442b | Kepler-442 | 1.34 |
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.
A gas giant is a large planet composed mostly of gases, such as hydrogen and helium, with a relatively small rocky core. The gas giants of our solar system are Jupiter, Saturn, Uranus and Neptune.
When and where to look. Currently, Mercury is visible about 35 to 40 minutes after sunset, very near to the horizon, about 25 degrees south of due west. Your clenched fist held at arm's length measures roughly 10 degrees, so approximately 2.5 "fists" to the left of due west, along the horizon, will bring you to Mercury
The Days (And Years) Of Our Lives
| Planet | Rotation Period | Revolution Period |
|---|
| Earth | 0.99 days | 365.26 days |
| Mars | 1.03 days | 1.88 years |
| Jupiter | 0.41 days | 11.86 years |
| Saturn | 0.45 days | 29.46 years |
The Romans knew of seven bright objects in the sky: the Sun, the Moon, and the five brightest planets. They named them after their most important gods. Because Mercury was the fastest planet as it moved around the Sun, it was named after the Roman messenger god Mercury. Mercury was also the god of travelers.
How long is a year on Mercury?
What does the Sun look like from Mercury? Since Mercury is the closest planet to the Sun, the Sun would look much larger from Mercury than it would from any other planet in the Solar System. From Mercury, the Sun would appear to be about 2 1/2 times larger than it appears from Earth.
A changing orbit. Gravity from Earth pulls on the closest tidal bulge, trying to keep it aligned. This creates tidal friction that slows the moon's rotation. Over time, the rotation was slowed enough that the moon's orbit and rotation matched, and the same face became tidally locked, forever pointed toward Earth.
Since Mercury has hardly any atmosphere, it does not have weather like storms, clouds, winds or rain. Its surface temperature can reach 801 Fahrenheit during the day (because it is so close to the Sun) and can drop to -279 Fahrenheit at night (because there is no atmosphere to trap the daytime heat).
Mercury has a diameter of 3,032 miles (4,879 km) making it a little more than one third the size of Earth. If Earth were the size of a baseball, Mercury would be about the size of a golf ball.
During their empiric reign, the Romans continued to worship several sun gods, but they replaced the Greek word for sun, Helios, with the Latin Sol, a root word that continues to refer to the sun in the present day, such as in the term “solar system.” The most powerful sun god in ancient Rome was Sol Invictus, meaning “
How far is the moon from Earth?
Mars (diameter 6790 kilometers) is only slightly more than half the size of Earth (diameter 12750 kilometers). Note the difference in color between the two planets. Almost 70% of Earth's surface is covered by liquid water. In contrast, Mars now has no liquid water on its surface and is covered with bare rock and dust.
Carbon dioxide atmosphere
By comparison, Mars' atmosphere is 95 percent carbon dioxide. "We need to breathe oxygen," said Lee. "There's no free oxygen in the Martian atmosphere. You cannot breathe this gas.In 1946, Ray Bradbury published "Frost and Fire", a short story that takes place on a planet described as being next to the sun. The conditions on this world allude to Mercury, where the days are extremely hot, the nights extremely cold, and humans live for only eight days.
Mercury's extreme temperatures and lack of an atmosphere would make it very difficult, if not impossible, for people to live on the planet. With its extreme temperature fluctuations, Mercury is not likely a planet that humans would ever want to colonize.
Neptune, like the other gas giants in our solar system, doesn't have much of a solid surface to live on. But the planet's largest moon, Triton, could make an interesting place to set up a space colony. So far, only a single spacecraft has ever visited Triton.
The exploration of Mercury has a minor role in the space interests of the world. It is the least explored inner planet. As of 2015, the Mariner 10 and MESSENGER missions have been the only missions that have made close observations of Mercury. MESSENGER made three flybys before entering orbit around Mercury.
Saturn and its rings are the jewel of the solar system, but the gas giant's lack of a surface means humans won't likely find a foothold there. Saturn's moons Titan and Enceladus, however, might be better choices. Without a solid surface, Saturn isn't likely a place we could ever live.
Recent data show that water ice may exist in the bottoms of craters at Mercury's poles. Although Mercury is the closest planet to the Sun, and can be extremely hot over most of its surface, ice may exist at the bottoms of some polar craters because the crater floors are permanently shadowed by the crater rims.
Living on the surface of Jupiter itself would be difficult, but maybe not impossible. The gas giant has a small rocky core with a mass 10 times less than Earth's, but it's surrounded by dense liquid hydrogen extending out to 90 percent of Jupiter's diameter.
(But Mercury is not the hottest planet in the solar system. The hottest planet is Venus.) On its dark side, Mercury gets very cold because it has almost no atmosphere to hold in heat and keep the surface warm. The temperature can drop down to minus 300 degrees Fahrenheit.
