Auroras on Mars

Context:

The UAE’s Hope spacecraft, which is orbiting Mars since February this year, has captured images of glowing atmospheric lights known as discrete auroras.

Auroras on Mars

Phenomena of auroras on mars is same as on earth which are seen only near the north and south poles, discrete auroras on Mars are seen all around the planet at night time.

Auroras on Earth:

• Auroras occur when charged particles from space interact with atoms in the atmosphere, energizing them and causing them to glow. On Earth, this plays out as the northern and southern lights.
• When high-energy particles from the sun hit the planet’s magnetic field, they energize atoms in the upper atmosphere to create spectacular displays of green, purple, red and blue lights.
• These particles are harmful, and our planet is protected by the geomagnetic field, which preserves life by shielding us from the solar wind.
• However, at the north and south poles, some of these solar wind particles are able to continuously stream down, and interact with different gases in the atmosphere to cause a display of light in the night sky.
• This display, known as an aurora, is seen from the Earth’s high latitude regions (called the auroral oval), and is active all year round.

How are Martian auroras different?

Unlike Earth, which has a strong magnetic field, the Martian magnetic field has largely died out. This is because the molten iron at the interior of the planet– which produces magnetism– has cooled. However, the Martian crust, which hardened billions of years ago when the magnetic field still existed, retains some magnetism. So, in contrast with Earth, which acts like one single bar magnet, magnetism on Mars is unevenly distributed, with fields strewn across the planet and differing in direction and strength.

These disjointed fields channel the solar wind to different parts of the Martian atmosphere, creating “discrete” auroras over the entire surface of the planet as charged particles interact with atoms and molecules in the sky– as they do on Earth.

Significance:

Studying Martian auroras is important for scientists, for it can offer clues as to why the Red Planet lost its magnetic field and thick atmosphere– among the essential requirements for sustaining life.

Hope Mission

• The Emirates Mars Mission called “Hope” was announced in 2015 with the aim of creating mankind’s first integrated model of the Red planet’s atmosphere.
• Hope weighs over 1500 kg and will carry scientific instruments mounted on one side of the spacecraft, including the Emirates exploration Imager (EXI), which is a high-resolution camera among others.
• The spacecraft will orbit Mars to study the Martian atmosphere and its interaction with outer space and solar winds.
• Hope will collect data on Martian climate dynamics, which should help scientists understand why Mars’ atmosphere is decaying into space.

Objectives of the mission

• Once it launches, Hope will orbit Mars for around 200 days, after which it will enter the Red planet’s orbit by 2021, coinciding with the 50th anniversary of the founding of UAE.
• The mission is being executed by the Mohammed bin Rashid Space Centre, UAE’s space agency.
• It will help answer key questions about the global Martian atmosphere and the loss of hydrogen and oxygen gases into space over the span of one Martian year.

About Mars:

• Size and Distance:
  
  • It is the fourth planet from the Sun and the second-smallest planet in the Solar System.
  • Mars is about half the size of Earth.

• Similarity to the Earth (Orbit and Rotation):
  • As Mars orbits the Sun, it completes one rotation every 24.6 hours, which is very similar to one day on Earth (23.9 hours).
  • Mars’ axis of rotation is tilted 25 degrees with respect to the plane of its orbit around the Sun. This is similar with Earth, which has an axial tilt of 23.4 degrees.
  • Like Earth, Mars has distinct seasons, but they last longer than seasons on Earth since Mars takes longer to orbit the Sun (because it’s farther away).
  • Martian days are called sols—short for ‘solar day’.

• Surface:
  • It has colors such as brown, gold and tan. The reason Mars looks reddish is due to oxidation or rusting of iron in the rocks, and dust of Mars. Hence it is also called Red Planet.
  • Mars has the largest volcano in the solar system i.e. Olympus Mons. It’s three times taller than Earth’s Mt. Everest with a base the size of the state of New Mexico.

• Atmosphere:
  • Mars has a thin atmosphere made up mostly of carbon dioxide, nitrogen and argon gases.

• Magnetosphere:
  • Mars has no magnetic field till date, but areas of the Martian crust in the southern hemisphere are highly magnetized, indicating traces of a magnetic field.

• Moons:
  • Mars has two small moons, Phobos and Deimos, that may be captured asteroids.

• Previous Mars Missions:
  • The Soviet Union in 1971 became the first country to carry out a Mars landing, Mars 3.
  • The second country to reach Mars’s surface is the United State of America (USA). Since 1976, it has achieved 8 successful Mars landings, the latest being the ‘InSight’ in 2019.
  • European Space Agency has been able to place their spacecraft in Mars’s orbit through the Mars Express Mission.

• India’s Mars Orbiter Mission (MOM) or Mangalyaan:
  • It was launched from the Satish Dhawan Space Centre in Andhra Pradesh by Indian Space Research Organisation in November 2013.
  • It was launched on board a PSLV C-25 rocket with aim of studying Martian surface and mineral composition as well as scan its atmosphere for methane (an indicator of life on Mars).

• Reasons for Frequent Missions to Mars: There are two primary reasons:
  • Similar to Earth:
    • First, Mars is a planet where life may have evolved in the past. Conditions on early Mars roughly around 4 billion years ago were very similar to that of Earth.
    • It had a thick atmosphere, which enabled the stability of water on the surface of Mars.
    • If indeed conditions on Mars were similar to those on Earth, there is a real possibility that microscopic life evolved on Mars.

• Most Suitable among Other Planets:
  • Mars is the only planet that humans can visit or inhabit in the long term. Venus and Mercury have extreme temperatures – the average temperature is greater than 400 degree C. All planets in the outer solar system starting with Jupiter are made of gas – not silicates or rocks – and are very cold.
  • Mars is comparatively hospitable in terms of temperature, with an approximate range between 20 degrees C at the Equator to minus 125 degrees C at the poles.

Source: Indian Express

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