Why is space junk increasing every year?

In one line

The rule

Space junk (also called space debris) is made up of old satellites, rocket parts, and tiny pieces from collisions, all left behind in Earth's orbit.

There is no formula for space junk, but the number of objects increases when:

• More satellites and rockets are launched
• Old objects are not removed
• Collisions break objects into smaller pieces

Let's understand it simply

Imagine your classroom. Every day, students bring snacks and leave wrappers on the floor. If no one picks them up, the wrappers pile up. Soon, the classroom is full of waste, making it hard to move around. Space is like that classroom. Every time a rocket launches, it leaves behind parts. Old satellites stop working but stay in space. No one goes to clean them up. Over time, the number of junk pieces grows.

Now, think of Diwali rockets. If you keep bursting rockets on your terrace and never clean up the sticks and wrappers, the terrace gets crowded and messy. Space around Earth is becoming like that messy terrace.

How it works

1. We launch satellites and rockets for TV, internet, weather, and science.
2. Each launch leaves behind parts like rocket stages or covers.
3. Satellites stop working after a few years but stay in orbit.
4. Sometimes, old satellites or rocket parts crash into each other, breaking into thousands of smaller pieces.
5. These pieces keep flying around Earth at very high speeds.
6. Every year, more launches add more junk, but almost nothing is removed.

The story behind it

The problem of space junk started in the late 1950s, when humans first launched satellites. At first, there were only a few objects in space. But as more countries and companies sent up rockets and satellites, the number of leftover parts grew. In 1978, a scientist named Donald Kessler warned that too much junk could cause a chain reaction of collisions, making space dangerous for new satellites. This is called the "Kessler Syndrome."

One memorable event was in 2009, when two satellites (one working, one dead) crashed into each other, creating thousands of new pieces of debris.

Where you see it in real life

• TV satellites: The dish on your roof gets signals from satellites. When these satellites die, they often stay in space as junk.
• Weather satellites: Used for monsoon predictions. Old ones become debris.
• Rocket launches: ISRO launches rockets from Sriharikota. The used-up rocket parts sometimes stay in orbit.
• GPS satellites: Help your phone find your location. Old GPS satellites can become junk.
• Collisions: In 2007, China tested a missile on its own satellite, creating over 3,000 pieces of debris.
• International Space Station: Sometimes has to move to avoid hitting space junk.

Why it matters

• Space junk can hit working satellites, damaging TV, internet, and weather services.
• It can threaten astronauts in the International Space Station.
• More junk makes it risky and expensive to launch new satellites.
• If junk keeps increasing, it could block access to space for everyone.

Worked example

Let’s see how quickly junk can multiply:

Given: 1 satellite breaks into 100 pieces after a collision
Step 1: Start with 1 dead satellite
Step 2: It crashes with another, both break into 100 pieces each
Step 3: Now there are 200 pieces of junk
Step 4: If just 10 of these pieces hit other satellites, and each collision creates 100 more pieces:
Step 5: 10 × 100 = 1,000 new pieces
Step 6: Total junk = 200 + 1,000 = 1,200 pieces

Common mistakes

• Thinking space is empty: Actually, the area around Earth is crowded with thousands of objects.
• Believing junk falls to Earth quickly: Most junk stays in orbit for years or even centuries.
• Assuming only big pieces matter: Even a small screw can damage a satellite because it moves very fast.
• Thinking someone is cleaning it up: Right now, almost no junk is removed from space.

Remember it

Space junk is like litter in space — we keep adding more, but almost never clean it up.