Rogue planets

Rogue planets are planetary masses which are not gravitationally bound to any star and hence wander freely through the cosmos. Due to this nature of them, they are also termed as free floating planets or also as isolated planetary-mass object.

These are not 'feed' by a star in terms of a 

They were first discovered by UK team Lucas & Roches with UKIRT in the Orion Nebula.

Formation:

There are two ways they are believed to be formed.

The first suggests that perhaps they formed independently by the gas and dust, like a star or something.

The other suggest that perhaps they got 'kicked out' of their solar system.  Most of the rogue worlds ore believed to be ejected out of their solar systems during the early stages.

What happens when a rogue planet enters a solar system?

Rogue planets are not very uncommon. Our galaxy alone has trillions of them. So a question comes to mind. 

What would happen if it entered a solar system? Now we come up with three possibilities. First, it could remain unbound of its gravity. Second, it could get weakly bound. or third, it could 'kick out' another planet and take its place, like one it had been ejected.

Poetic justice, isn't it?

Anyways, now a threat we can think of is that what would happen if one entered our solar system?

The same could happen. But good for us that the probability of a rogue planet entering out solar system is one in one trillion. This is so low because there are countless obstacles in the way of a star.

Detection:

How could things like these be detected. We can detect them by two means. 

First is by their own light. For smaller planets which do not emit any light, we would have to use the a method called gravitational microlensing, which is going to take another post in itself.

Meteors, meteorites, meteoroids, etc.

Meteors, meteorites, and meteoroids are kind of interconnected.

Meteoroids is a small rocky or metallic object that is travelling through the space. Meteor is the streak of light that follows it (like the tail or the shooting star), it happens when the meteoroid burns in earth's atmosphere. And when it finally hits the earth, it is termed as meteorite.

Comets are heavenly bodies made of ice, dust and rock. these orbit the sun just like our earth. They are believed to be the remains from the formation of our solar system.

these are huge and when in their frozen state, they could be about the size of your city.

When they come closer to the sun, they heat up and release heat and gases, forming a tail called coma.

Asteroids are kind of the same thing, but they are more rocky in composition compared to comets, which are more icy. Asteroids are also remnants from the formation of the solar system. 

However, these guys lack a tail! 

Black Dwarfs

 Black dwarfs are one of the most interesting objects in the universe to me. 

They are essentially a theoretical remain of a white dwarf after it cools down and stops emitting heat or light. Now pay attention to the fifth word of the previous sentence.

Theoretical.

This means that we don't have a black dwarf in existence right now. Why is that, you may ask. I am going to discuss that later.

First let me elaborate the definition. When a star which has a size similar to that of our sun loses it's fuel, it becomes a white dwarf, emitting a lot of heat and light. When this white hole cools down, it no longer emits radiation heat and light, forming black dwarfs. 

Now coming back to what I mean by that they are not in existence right now. A star takes about 10 to 100 quadrillion years to become a black dwarf! Because as i mentioned earlier, first the star has to become white dwarf and then cool to become a black dwarf. 

And our universe is only about 13.8 billion years old. Meaning it would literally take ages for the formation of a black dwarf. 

Now, why are they so interesting to me?

A black dwarf's fate is to eventually explode into a supernova, and this would take about 10^1100 to 10^3200 years!

ARE WE STARDUST?

 “Some people are just light, glow, and hope… human stars.”

You might have heard that we are made of stardust. So, let us discuss that today.

First, we need to have some basic knowledge about the formation of elements. Basically, elements like hydrogen, lithium and helium were formed along with the big bang. All the other elements were formed through a complex process called stellar nucleosynthesis. We are not going to learn about that very deeply because it is a complicated topic to understand. 

And for a basic context, all stars have limited fuel inside their cores. When they run out of fuel, they die, which means that they convert into white dwarfs, black holes, or neutron stars, depending on their size (I talked about this in my neutron star post) 

When a massive star dies, it causes a huge explosion and cools down, hence forming a supernova. (A supernova is very bright, by the way.) So, when a supernova is formed, the elements inside the stars get spread all over the universe.

This material that they spread is what we call stardust. Stardust has a lot of other components in it (like ice, rock, etc.) other than just elements. But we will be right now just talking about the elements.

Now let us talk about the history of stars and their connection with human beings. So millions of years ago, the first generation of stars was formed. So the stars of this generation were very big than the ones we see now.

And we have another concept according to which the size of a star determines how fast it will burn its fuel. The size of the star is directly proportional to the rate with which the star burns its fuel. The bigger a star, the faster it will burn its fuel. Due to their weight, the first stars burned their fuels really fast and exploded into a supernova. These stars burned so quickly that they could only produce elements like hydrogen, helium and trace amounts of heavy metals inside them.

As the further generations appeared, more complex elements began forming.

Now, what does this have to with us? 

So our bodies (and everything else on our earth) are also made up of elements, and all the elements (except hydrogen and helium) out of these were formed in stars.

The calcium in your bones, the carbon in your skin, the iron in your blood, they all trace back to the stars that formed ages ago. So in some sense, we are stardust. 

Space Tourism: can we now wonder through the cosmos?

 Space tourism sounds amazing doesn't it. I mean who wouldn't want to travel to space one in their lives.

In this post, we will be discussing space tourism- it's history, milestones, major companies, and pros and cons.

Let's dive in.

Space tourism has two main types- Orbital and suborbital. suborbital flights take you to the Karman line which is 100 km above space. This flight is about a few minutes long.

An orbital flight takes you around the earth and takes about a few days!

Space tourism was first conducted in the year 2001. The first space tourist was a gentleman named Dennis Tito who paid about $20 million! This flight was conducted by the company Russian Soyuz. He was carried to ISS. And this was an orbital flight, of course. 

After Tito, Mark Shuttleworth did another orbital flight in 2002. And in 2006, Anousheh ansari became the first woman to take an orbital flight. 

Suborbital space travel came into the picture more recently. The first commercial suborbital flight was Galactic, launched by Virgin Galactic on June 29, 2023. The flight carried a crew of four. 

Another important milestone was SpaceShipOne which could carry about three people to space at once.

At present, the companies which plan to invest in and develop space tourism in the long term include Blue Origin, Space X and Virgin Galactic which mainly focus on suborbital travel.

Pros:

• Space tourism can provide non specialists to also have the experience to travel to space.
• If the sector flourishes, it could generate thousands upon thousands of jobs.
• We gain a new perspective on out earth when we view it from the outside.

Cons:

• The launching of these the space ships causes a lot of air pollution.
• Ordinary people cannot afford space travel.
• Prolong stay in the outer space can cause health damage due to reasons such as radiation exposure.
• Another issue is a bit ethical, imagine spending a fortune on sending the rich on a tour to space while the poor sit here, lacking food.

What are you opinions about space tourism? Do write about them in the comments. 

See you next Sunday!