Atmospheric Conditions of the Inner Planets in the Solar System

January 26^th, 2020

By: Haris Ahmad[1]

The Solar system is the gravitationally bound planetary system of the Sun and the objects orbiting it. There are 8 planets that orbit the Sun excluding the dwarf planets. Due to the large distances from the Sun and different compositions, many planets are significantly different from each other in many aspects. The Inner planets are Mercury, Venus, Earth, and Mars.

Mercury: This planet is the closest to the Sun in the whole Solar System being 57 million km away from it. It actually lacks an atmosphere. This means that there is no shield protecting the planet from intense cosmic radiation.

Image source: https://www.nationalgeographic.com/science/space/solar-system/mercury/

Due to the fact that this planet has no atmosphere, cosmic rays and micrometeorites hit the surface of the planet, ejecting atoms off the rocks creating and an exosphere made of ionized particles and dust. So, when the solar winds interact with this planet’s magnetic field, it forms plasma tornadoes that bring hot winds to the surface. Temperatures on this planet reach up to 427 degrees Celsius. This planet is clearly not the right place for humans to live in.

Venus: This planet is the second closest to the Sun is 108 million km away from it. It has an extremely thick atmosphere made up of carbon dioxide and pockets of sulfuric acid clouds. This creates a dense atmosphere with about 90 times more pressure than on Earth.

Image Source: https://en.wikipedia.org/wiki/Venus

This planet is the exact example of what can happen to Earth due to global warming. The thick carbon dioxide atmosphere doesn’t let the heat from the Sun escape and the surface temperatures can rise till 462 degrees Celsius. The high levels of clouds experience winds over 354 km, and the lightning in the atmosphere lights up the murky sky in the clouds.

Earth: This planet is what we call home. It is 149 million km away from the Sun. It has an atmosphere, which contains 78% Nitrogen, 21% Oxygen, 0.97% Argon and Carbon dioxide, 0.04% trace amounts of other gases, and water vapor. This mixture of gases is commonly known as air.

Image Source: https://en.wikipedia.org/wiki/Earth

This atmosphere protects life on this planet by absorbing the UV solar radiation and reducing temperatures between day and night. 

Mars: This planet is also known as the dead planet. It is 227 million km away from the Sun. Mars also rotates around the Sun in a tilted motion and so, it has seasons. On this planet, the daytime temperatures can reach up to 26 degrees Celsius, which doesn’t seem bad at all. But, due to the fact that this planet has an extremely thin atmosphere, approximately 100 times less thick than Earth’s atmosphere.

Image Source: https://en.wikipedia.org/wiki/Mars

As this planet has no atmosphere to trap the heat, temperatures quickly drop at night, falling as low as –128 degrees Celsius.

Every planet in the Solar system has its own composition of elements and atmospheric conditions. In this vast variety, some conditions can sustain life. Sadly, we humans are destroying ourselves and are making our planet inhabitable. I said this before and am saying this again that if we don’t take climate change and global warming seriously, Earth will end up like Venus, a dead planet with unbearable conditions for humans to live in. Save Earth before it’s too late. I will cover the outer planets of the Solar system in the next blog. 

---

[1] Haris Ahmad is currently studying in 9^th grade (O levels) in The City School Islamabad.

What does a planet require to sustain life?

January 19^th, 2020

By: Haris Ahmad[1]

Planets are overwhelmingly cool. They are celestial bodies that orbit a star in an elliptical orbit. As much as we know, most of the stars in the universe have planets orbiting. We know the planets in our Solar System as ‘planets’. However, the planets that exist beyond the Solar System are called ‘exoplanets. Lastly, there is also another type of planets, which wander around the universe. By this, I mean that these planets do not orbit any star and move freely in the universe. There are many planets in the universe, some are very cold, some are very hot and some are water worlds. However, only some of the planets in the universe can sustain life. By this, I mean that life, as we know it can survive there without difficulties. Earth is one of these planets. Almost all of us know why humans and many other animal species can inhabit Earth. In this blog, I’ll explain what planets need in order to sustain intelligent life.

Firstly, the planet should have a rocky surface just like Earth has. Technically, it should have elements on it that are, let’s say heavier than helium. This will help us a lot as we can easily move around, planets can be planted and grown, the shelter can be placed easily. We will be able to move around easily to explore the new planet and planets, as well as trees, could be benefited from.

Secondly, the planet should be revolving around a stable star, which has stable brightness. Some stars change their brightness after some centuries or even years. Therefore, the planet won’t be stable if it orbits around such a star. We also want the planet to be orbiting around a single star, not binary (two stars) which is very common. Even if the planet exists in a binary star system, the stars should be either too close or too far from each other for the stability of the planet as well as normal orbit.

Moreover, the most important thing, which we require from such a planet, is water. The planet should have liquid water on its surface. For this, the planet has to orbit its star in the goldilocks zone. Goldilocks zone is the zone around a star where liquid water can exist. If the planet is too far from its star, it’ll be very cold for water to exist in liquid form and if the planet is very close to its star, the surface would be extremely hot and the water won’t be liquid too. We can take examples of Mars and Venus. Venus is literally hell. It has a surface temperature of 462 degrees Celsius. On the other hand, 
Mars is very cold and has an average surface temperature of 60 degrees Celsius.

Furthermore, we want the planet to be neither too big and dense nor too small or too dense. If the is too dense and large then it would be like, lets sat Jupiter (gas giant). On the contrary, if it is very low in density and has a small size, then it would face the fate of Mars. As I have said in one of my first blogs, Mars was once a planet like Earth. However, due to its very low density and size, it couldn’t hold on to its atmosphere. Therefore, it lost its atmosphere to Solar winds and is now a dead planet though it can be revived if we terraform it.

Picture credit: www.usnews.com

Habitable planets are very hard to find but, we have still found a lot of planets that can be inhabited by intelligent life. However, the main problem is, how do we go to these planets. It would take us billions of years to reach these planets. We have also found a habitable planet in the closest star to us (Proxima Centauri) but, even traveling to this planet with the current technology would take us almost 60,000-80,000 years. Till we come up with technology that can help us travel to these distant planets, we will have to wait on Earth.

---

[1] Haris Ahmad is currently studying in 9^th grade (O levels) in The City School Islamabad.

2019 and Space Science

January 5^th, 2020

By: Haris Ahmad[1]

2019 was a great year, though it ended very quickly. This year, humans made great discoveries and took a picture that rewrote history. Humans accomplished as well as failed in a lot of their missions but the thing that matters is that they tried. We should never give up on anything, even if you fail, you have to try over and over again because one day you’re going to accomplish your dreams. A lot of events happened this year but I will highlight the main ones. Firstly, Beresheet, a technology demonstration mission was launched and operated by Space IL and IAI (Israel Aerospace Industries) failed because of a problem in its gyroscopes that prevented its main engine to start. It destructively landed on the Moon. This is not what I want to highlight. The main thing is that it contained thousands of Tardigrades. Tardigrades are microscopic animals that are almost indestructible. Thus, they can even survive in space. All these Tardigrades likely spilled over after the crash landing.

Secondly, a mission named Hayabusa 2 was launched by the Japanese space agency (JAXA) on 3 Dec 2013, which is an asteroid sample return mission. It took samples from 162173 Ryugu asteroids.

Image Source: https://en.wikipedia.org/wiki/Hayabusa2

TheBadAstronomer (A YouTuber) says, “The Japanese spacecraft Hayabusa 2 made a second touchdown on the surface of the asteroid Ryugu on July 11, 2019. It fired a bullet into the surface to send shrapnel flying, which is collected in a horn, packed away, and will return to Earth in December 2020”. JAXA (Japanese Aerospace Exploration Agency) has also uploaded a video of the touchdown and retreat (https://www.youtube.com/watch?v=-3hO58HFa1M)

Moreover, this year another event happened that we all should know and should take actions concerning. This year, the UN released a statement warning us. UN said that we have 12 years to stop climate change. We should stop the climate while we can. Therefore, if we don’t take action, we will undergo destruction that would be very bad for the future of planet Earth as the continuity of the human race. I have explained all about climate change in two of my previous blogs. If global warming and pollution will remain at the current rate is that by 2100 the temperatures will rise by 4 degrees Celsius. This number might seem mathematically small but it can cause the loss of millions of lives. Climate change will affect the environment very badly. It will bring a lot of problems. The temperatures will significantly rise causing a lot of heatwaves and drought. There will be changes in precipitation patterns, which will cause a change in rain patterns. The hurricanes will become stronger and intense. The sea levels will rise 1-4 feet by 2100 causing a lot of floods. The Arctic will likely become ice-free.

We have to take action or will have to face the destruction of this beloved planet.

Last but not least, as I mentioned earlier, we took a picture that rewrote history and the books of astronomy. It was the picture of the black hole present in the center of the galaxy known as Messier 87 that exists 55 million light-years away from us.

 

Image source:  Veritasium

”Four scientists affiliated with the Event Horizon Telescope project, which released the image of the black hole earlier this year, testified at the hearing about how the image was created, the importance of scientific research and education, and the future of the project itself. Throughout the hearing, the scientists' enthusiasm for black holes and the image was clear”, said Meghan Bartels from Space.com.

This year was the best for many people but it passed too quick. I hope that 2020 brings happiness to all of you. I hope it will be a good year for space scientists as well.

---

[1] Haris Ahmad is currently studying in 9^th grade (O levels) in The City School Islamabad.