Search results
Results From The WOW.Com Content Network
Mars has an orbit with a semimajor axis of 1.524 astronomical units (228 million km) (12.673 light minutes), and an eccentricity of 0.0934. [1] [2] The planet orbits the Sun in 687 days [3] and travels 9.55 AU in doing so, [4] making the average orbital speed 24 km/s. The eccentricity is greater than that of every other planet except Mercury ...
Solar radius is a unit of distance used to express the size of stars in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun 's photosphere where the optical depth equals 2/3: [1] 695,700 kilometres (432,300 miles) is approximately 10 times the average radius of Jupiter, 109 times the radius ...
Mars is the fourth planet from the Sun. The surface of Mars is orange-red because it is covered in iron (III) oxide dust, giving it the nickname " the Red Planet ". [ 21][ 22] Mars is among the brightest objects in Earth's sky, and its high-contrast albedo features have made it a common subject for telescope viewing.
Mars has an axial tilt of 25.19°, quite close to the value of 23.44° for Earth, and thus Mars has seasons of spring, summer, autumn, winter as Earth does. As on Earth, the southern and northern hemispheres have summer and winter at opposing times. However, the orbit of Mars has significantly greater eccentricity than that of Earth.
The large eccentricity causes the insolation on Mars to vary as the planet orbits the Sun. (The Martian year lasts 687 days, roughly 2 Earth years.) As on Earth, Mars' obliquity dominates the seasons but, because of the large eccentricity, winters in the southern hemisphere are long and cold while those in the north are short and relatively warm.
The speed of light in vacuum, commonly denoted c, is a universal physical constant that is exactly equal to 299,792,458 metres per second (approximately 300,000 kilometres per second; 186,000 miles per second; 671 million miles per hour). [Note 3] According to the special theory of relativity, c is the upper limit for the speed at which ...
Since this value is close to zero, the center of the orbit is relatively close to the center of the Sun (relative to the size of the orbit). As seen from Earth, the planet's orbital prograde motion makes the Sun appear to move with respect to other stars at a rate of about 1° eastward per solar day (or a Sun or Moon diameter every 12 hours).
Mercury (planet) Surface temp. Mercury is the first planet from the Sun and the smallest in the Solar System. In English, it is named after the ancient Roman god Mercurius ( Mercury ), god of commerce and communication, and the messenger of the gods. Mercury is classified as a terrestrial planet, with roughly the same surface gravity as Mars.