Discrete Auroras

In News

Recently, the Hope spacecraft, sent by the United Arab Emirates (UAE) to orbit Mars, has captured images of discrete auroras on Mars.

Discrete Auroras

• The data gathered by the oribter include far and extreme ultraviolet auroral emissions which have never been imaged before at Mars.
• The beacons of light that stand out against the dark nightside disk are highly structured discrete auroras, which trace out where energetic particles excite the atmosphere after being funneled down by a patchy network of crustal magnetic fields that originate from minerals on the surface of Mars.
• Unlike auroras 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.

(Image Courstery: IT)

Auroras on Earth

• Auroras are caused when solar wind, charged particles ejected from the Sun’s surface, enter the Earth’s atmosphere.
• These particles are harmful and the Earth’s geomagnetic field acts as a shield to protect humans from these harmful solar winds.
• 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.
• On the north pole of Earth, these lights are called Aurora Borealis or Northern Lights, and are seen from the US (Alaska), Canada, Iceland, Greenland, Norway, Sweden and Finland.
• On the south pole, they are called Aurora Australis or Southern Lights and are visible from high latitudes in Antarctica, Chile, Argentina, New Zealand and Australia.

(Image Courtesy: NOSWE)

Differences

• Unlike Earth, which has a strong magnetic field, the Martian magnetic field has largely died out due to the cooled iron at the interior of the planet.
  • The molten iron at the interior of a planet produces magnetism.
• Although the Martian crust hardened billions of years ago, it still 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.
• Studying Martian auroras is important for scientists because it can offer clues as to why Mars lost its magnetic field and thick atmosphere, which are key among the essential requirements for sustaining life.

(Image Courtesy: BI)

Hope Mission

• It is the Arab world’s first mission to Mars, took off from Earth in July 2020 and has been orbiting Mars since February 2021.
  • With this development, UAE has joined a league of just five space agencies in history that have pulled off a functioning Mars mission. 
  • It is the country’s first venture beyond Earth’s orbit.
• The primary objective of the mission is to study Martian weather dynamics.
• By correlating the lower atmosphere and upper atmosphere conditions, the probe will look into how weather changes the escape of hydrogen and oxygen into space.
  • By measuring how much hydrogen and oxygen is spilling into space, scientists will be able to look into why Mars lost so much of its early atmosphere and liquid water.
• It is expected to create the first complete portrait of the planet’s atmosphere.
• With the information gathered during the mission, scientists will have a better understanding of the climate dynamics of different layers of Mars’ atmosphere.

(Source: TOI)