MARS

Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, being larger than only Mercury. In English, Mars carries the name of the Roman god of war and is often referred to as the "Red Planet". The latter refers to the effect of the iron oxide prevalent on Mars's surface, which gives it a reddish appearance distinctive among the astronomical bodies visible to the naked eye. Mars is a terrestrial planet with a thin atmosphere, with surface features reminiscent of the impact craters of the Moon and the valleys, deserts and polar ice caps of Earth.
The days and seasons are comparable to those of Earth, because the rotational period as well as the tilt of the rotational axis relative to the ecliptic plane are similar. Mars is the site of Olympus Mons, the largest volcano and highest known mountain on any planet in the Solar System, and of Valles Marineris, one of the largest canyons in the Solar System. The smooth Borealis basin in the northern hemisphere covers 40% of the planet and may be a giant impact feature. Mars has two moons, Phobos and Deimos, which are small and irregularly shaped. These may be captured asteroids, similar to 5261 Eureka, a Mars trojan.
Mars has been explored by several uncrewed spacecraft. Mariner 4, launched by NASA on 28 November 1964, was the first such craft to visit Mars, making its closest approach to the planet on 15 July 1965. Mariner 4 detected the weak Martian radiation belt, measured at about 0.1% that of Earth, and captured the first images of another planet from deep space. The Soviet Mars 3 mission included a lander, which achieved a soft landing in December 1971; however, contact was lost seconds after touchdown. On 20 July 1976, Viking 1 performed the first successful landing on the Martian surface. On 4 July 1997, the Mars Pathfinder spacecraft landed on Mars and on 5 July released its rover, Sojourner, the first robotic rover to operate on Mars. The Mars Express orbiter, the first European Space Agency (ESA) spacecraft to visit Mars, arrived in orbit on 25 December 2003. In January 2004, the Mars Exploration Rovers, named Spirit and Opportunity, both landed on Mars. Spirit operated until 22 March 2010 and Opportunity lasted until 10 June 2018. On 24 September 2014, the Indian Space Research Organisation (ISRO) became the fourth space agency to visit Mars when its maiden interplanetary mission, the Mars Orbiter Mission spacecraft, arrived in orbit.

Interesting Facts:

• Named after the Roman God of war, Mars is the fourth planet from the sun in our solar system.
  
• Mars is also known as the ‘Red Planet’ because, well, it’s red! This signature colour comes from the large amount of a chemical called iron oxide (or ‘rust’ as you might know it) in its rocks and soil.
  
• Mars is the second smallest planet in the solar system after Mercury. With a diameter (distance through the middle) of 6,791 kilometres, it’s roughly half the size of Earth.
  
• It can get pretty cold on Mars –– much colder than our own planet, since it’s further away from the sun. At the equator, temperatures can reach 20°C, but at its poles they can plummet to as low as -140°C. Brr!
  
• Mars is home to the highest mountain in our solar system –– a volcano called Olympus Mons. Standing a whopping 24 kilometres high, it’s about three times the height of Mount Everest!
  Did you know…? There are bits of Mars here on Earth! In the past, asteroids hit the Red Planet, sending debris into space. Some of this debris landed on our planet as meteorites.
  
• You could jump around three times higher on Mars than you can on Earth. Boing! This is because the planet’s gravity – the force that keeps us on the ground – is much weaker.
  
• Do you like to look at the moon at night? Well, check this out –– Mars has two moons! One is called Phobos and the other Deimos.
  
• A day on Mars is 24 hours and 37 minutes –– only a little bit longer than a day on our own planet. A year on Mars, however, is almost twice as long, lasting 687 Earth days! This is because it takes a lot longer than Earth to complete its orbit around the Sun.