In the previous posts, we have visited Mercury, Venus, Earth, and our favorite moon. Today we are going to visit some more planets of our solar system.


Mars, famously known as the red planet. The significant red color of mars is because iron minerals in the Martian soil oxidize causing soil and atmosphere to look red.

It is the fourth planet from Sun and orbits around 228 million km or 1.52 AU (AU= Astronomical Unit i.e. the distance between Earth and Sun). Its year is equal to 687 earth days and a Martian day is equal to 24 hours, 39 minutes and 35 seconds.

the orbit of Mars around Sun
The diameter of Mars is 6790km, slightly more than the diameter of the earth (12750km). And it is 10 times lighter than Earth, weighing 6.42×1023kg. Less mass means weaker gravity thus gravity on the surface of Mars is 38% of Earth’s gravity.

Earth As Seen from Surface of Mars
Mars compared to Earth
Martian surface temperature varies from -143 degrees C to 35 degrees C. Martian atmosphere is very thin less than 1% of Earth’s. That is because Mars has lost its magnetosphere 4 billion years ago thus solar winds interact directly with ionosphere of Mars resulting in the stripping of outer layers of its atmosphere.
This thin atmosphere consists mainly CO­2 (96%), Argon (1.93%) and Nitrogen (1.89%) along with oxygen and water traces.

Olympus Mon compared to Mt. Everest and Mauna Kea
Mars is home to Olympus Mons, tallest mountain on any planet in our solar system with stunning 21.9km high peak.
Mars is a very Earth-like planet, with polar ice caps and Earth-like terrain. Its axis is tilted at 25.19 degrees relative to its orbital plane, thus it has seasons similar to Earth’s season but twice as long.

Moons of Mars
It has two moons, Phobos and Deimos. They are thought to be asteroids captured by the gravitational pull of mars. Phobos orbits Mars at only 6000 km and crosses horizon thrice a Martian day. It is gradually spiraling inward at a rate of six feet per century and within 50 million years either it will crash into surface or break up to form a ring around the planet.
 That’s why it has been in focus and considered most favorable planet other than the Earth for humans to live.

Mars Orbiter Mission, ISRO
We have sent dozens of probes to Mars, currently, there are eight functioning space crafts on Mars. Six in orbits including Mars Orbiter Mission by ISRO and two on surface Opportunity and Curiosity rovers.

SpaceX proposed terraforming of Mars
SpaceX is the private space company with the most ambitious mission to launch space tourists to Mars in 2024. NASA is also planning to send the man to Mars by 2030.
So let’s put you on Mars, we do not have enough money to give you all spacesuits so you are on your own. You will be frozen there as temperatures are generally lower than freezing point. Let’s say hope you survived freezing temperatures and suffocation by CO­2. Then you will witness the barren waste red landscape of mars.

Barren LandScape of Mars

If you survived mars let’s take you to next planet……..


Largest planet of the solar system and fifth planet from Sun here comes heavyweight champion of planets Jupiter. Its mass equals 21/2 times the total mass of other planets combined.

Mainly made of hydrogen (90%) and helium (10%). We don’t know much about the core of Jupiter, but it is thought to be made of mixtures of elements, surrounded by a layer of metallic hydrogen with some helium.

Jupiter in Orbit around Sun

A day on Jupiter is about 10 hours but it takes 12 Earth years to complete its orbit around the Sun. It is the fastest rotating planet in the Solar system.  And orbit Sun at about 778 million kilometers.
According to theoretical models, if Jupiter had much more mass than it does at present, it would shrink. Thus Jupiter is thought to have the largest diameter as a gas giant can have.

Great Red spot size compared to Earth
The most prominent visible feature of Jupiter is a great red spot about 1.3 times  the size of the earth. The size of red spot is continuously decreasing earlier it could swallow three earths but now it has space for only one. (edited) 

Great Red spot on Jupiter
Jupiter has 79 known moons out of which only four moons are large while others are less than 10 km in diameter. Four visible from Earth moons are called Galilean moons, namely Io, Europa, Ganymede, and Callisto.

Moons of Jupiter; Io, Europa, Ganymede, and Callisto (From left to right)
Pioneer 10 space probe was the first spacecraft to get close to Jupiter, after which several more space crafts have made flybys to Jupiter.
The first spacecraft to orbit Jupiter was the Galileo probe in 1995 it lasted in orbit for 7 years. It released a 340kg titanium atmospheric probe in July 1995 which entered Jupiter’s atmosphere on December 7. It lasted for 57 minutes going 150km in the atmosphere after which it lost signal at a pressure of 23 atmospheres at a temperature of 1530C.

Juno Orbiter
Recent orbiter in Jovian orbit is Juno which arrived there on July 4, 2016, which will orbit until July 2021 and then it will perform controlled deorbit and disintegrate into Jupiter’s atmosphere.
The future mission includes European Space Agency’s Jupiter Icy Moon Explorer (JUICE) due to launch in 2022.
Enough of facts, let’s put you on Jupiter (well there is no solid surface so we can’t say on Jupiter but who cares). So if you are going to land on Jupiter you would have a velocity of thousands of kilometer per hour due to immense pull of Jupiter’s gravity. After a few minutes, you will hit the denser atmosphere which is enough to stop you. After 3 minutes you will reach cloud tops 250km down, here wind speeds will be about 480 kmph. About 120 km below clouds, you will reach the limit of human exploration.  Let’s hope you survived the immense pressure of 100 atmospheres, by 700km down pressure is 1,150 times higher than that on Earth. After this limit, Jupiter’s deep atmosphere absorbs radio waves so you will not be able to communicate. As you reached 4000km down, the temperature is 3400degrees C enough to melt tungsten. You have been falling for at least 12 hours and still, you haven’t traveled halfway through. At 22000km you reach Jupiter’s innermost layer. Here pressure is 2 million atmosphere and temperature hotter than the surface of the sun. These conditions change the chemistry of the hydrogen around you. Hydrogen here exists as metallic hydrogen, as dense as a rock. So you would be suspended between buoyant force and gravitational force, stuck there forever.


Following Jupiter, sixth planet from the Sun here comes Saturn with its marvelous rings. Second largest planet of the solar system with diameter nine times diameter of Earth. Its density is 1/8th of Earth still it is 95 times massive than Earth.

Size of Saturn Compared to Earth
With similar composition as Jupiter, Saturn mainly made up of hydrogen and helium gases with a proposed solid core. It looks pale yellow due to ammonia crystals in its upper atmosphere.

Saturn in orbit around Sun
Saturn rotates on its axis once every 10.7 hours but takes 29 Earth years to complete orbit around Sun at 1.4 billion kilometers away from Sun.

Saturn has 62 moons of which 53 confirmed and 9 still awaiting confirmation. Titan Saturn’s largest moon is larger than planet Mercury, and have an atmosphere.

Titan; moon of the Saturn
Pioneer 11 was the first spacecraft to visit Saturn in September 1979. Following it, Voyager 1 sent high-resolution images of the planet in November 1980 before launching out of the plane of the Solar system.

Image by Cassini
Cassini’s mission was the most impressive one, orbiting Saturn from July 2004 to September 15, 2017. Finally burning in the atmosphere of Saturn to prevent contamination of Saturn’s moon. It revealed amazing facts of Saturn and its moon, which may harbor life-supporting elements.
Future plans are by NASA to send atmospheric entry probe on Saturn’s moons Titan and Enceladus.

Okay, let’s launch you toward Saturn, similar to Jupiter you will fall through layers of clouds until you reach metallic hydrogen layer.  But here clouds are mostly of ammonia and ammonium sulfide. You will witness astonishing wind speeds of nearly 700kmph blowing you sideways, Flashes of Lightning are very frequent here, making chances of you being electrocuted pretty high. No invention of tech is yet able to handle such immense pressures and temperatures. So Saturn is no go.

In the next segment, we are going to visit the Ice Giants of the Solar System. Till then stay curious and love Science.

(All media and images are a property of their respective owners.)

Categories: Solar System


Leave a Reply

Your email address will not be published. Required fields are marked *