Mars, also known as: Hỏa Tinh, is the fourth planet from the Sun in the Solar System. This planet is sometimes referred to as Hỏa Tinh. It is often called the “Red Planet”, due to the presence of iron oxide on its surface, which gives it a distinctive red appearance.
Mars is a rocky planet with a thin atmosphere, featuring surface characteristics reminiscent of both impact craters found on the Moon and Earth’s volcanoes, valleys, deserts, and polar ice caps.
Mars captured by the Viking 1 orbiter in 1980.
Physical Characteristics of Mars
The radius of Mars is approximately half that of Earth. Its density is lower than that of Earth, with a volume only 15% that of Earth and a mass just 11%. The surface area of the Red Planet is slightly smaller than the total land area on Earth.
Scientists have found that the surface of Mars primarily consists of basaltic rock. Some evidence suggests that certain areas on the Martian surface are richer in silica than basalt, possibly resembling andesite found on Earth.
The soil on Mars is weakly alkaline and contains elements such as magnesium, sodium, potassium, and chlorine. These nutrients are also found in Earth’s agricultural soil and are essential for plant growth.
The terrain on Mars strongly suggests that liquid water may have existed on the surface of this planet at some point in time.
The Atmosphere of Mars
Mars lost its atmosphere approximately 4 billion years ago, allowing solar winds to directly interact with the planet’s ionosphere, gradually stripping away atoms from the outer layers of its atmosphere.
The Martian atmosphere is composed of 95% carbon dioxide, 3% nitrogen, 1.6% argon, and trace amounts of oxygen and water vapor. It is quite dusty, containing particles about 1.5 µm in diameter, which gives the Martian sky a yellow-brown color when viewed from its surface.
The thin atmosphere of Mars, viewed from the horizon in a low-orbit photo.
The Climate on Mars
Among the planets in the Solar System, the seasons on Mars are most similar to those on Earth, due to the close alignment of the axial tilt between the two planets. The length of the seasons on Mars is roughly twice that on Earth, as the distance from Mars to the Sun is greater, resulting in a year on Mars being about two Earth years long. Temperatures on Mars range from very low -87°C during the winter at the poles to -5°C in the summer.
The Orbit of Mars
The average distance from Mars to the Sun is about 230 million km (1.5 AU), and its orbital period is 687 Earth days.
The Moons of Mars
Mars has two relatively small natural satellites, Phobos and Deimos, which orbit quite close to the planet.
Life on Mars
Many pieces of evidence support the idea that Mars once had conditions suitable for life to develop more than it does today, but whether any living organisms ever existed remains a mystery.
Exploration of Mars
The Spirit rover landed on Mars in 2004.
Dozens of spacecraft, including orbiters, landers, and rovers, have been sent to Mars by the Soviet Union, the United States, Europe, and Japan to study the surface, climate, and geology of the Red Planet.
Active missions as of 2011 include the Mars Reconnaissance Orbiter (since 2006), Mars Express (since 2003), and 2001 Mars Odyssey (since 2001), with the Opportunity rover on the surface (since 2004). Recent missions that have ended include the Mars Global Surveyor (1997–2006) and the Spirit rover (2004–2010).
Plans for Human Mars Missions
The European Space Agency (ESA) hopes to land humans on Mars between 2030 and 2035. This process will follow successful launches of large spacecraft to the planet, starting with the ExoMars mission and the NASA-ESA collaboration to return Martian soil samples to Earth.
The United States’ human exploration plans have been outlined as a long-term goal in the Vision for Space Exploration announced in 2004 by President George W. Bush. The plan to develop the Orion spacecraft to return humans to the Moon in the 2020s is seen as a foundational step toward sending humans to Mars. On September 28, 2007, NASA Administrator Michael D. Griffin stated that NASA aims to send humans to Mars by 2037.
