Colors of the Sky

Akku: Mommy, why is the sky red during sunset and sunrise?

Wow Akku, this is a very common question all the kids love to know. First let me explain why the sky is blue.

The light from the Sun looks white. But it is really made up of all the colors of the rainbow. Earth’s atmosphere is a mixture of the molecules (both gas and other types) that surround the earth. When sunlight reaches Earth’s atmosphere, light of longer wavelengths, like red, yellow, and orange, easily passes through, while light of shorter wavelengths, such as blue and violet, is absorbed and then scattered in all directions by the gas molecules. 

When you look up at the sky during the day, this scattered blue and violet light reaches your eyes, however, the human eye is more receptive to blue frequencies than violet frequencies, so the sky looks blue. Scientists call this Rayleigh scattering. This is why we see a blue sky most of the time.

Akku: Wow, that’s so cool. So mommy, is the sky blue on other planets, too?

It all depends on what’s in the atmosphere. For example, Mars has a very thin atmosphere made up of carbon dioxide and filled with fine dust particles. These fine particles scatter light differently than the gases and particles in Earth’s atmosphere. Photos from NASA’s rovers and landers on Mars have shown that at sunset there is actually the opposite of what we experience on Earth. During the daytime, the Martian sky takes on an orange or reddish color. But as the Sun sets, the sky around the Sun begins to take on a blue-grey tone.

Akku: Interesting! But mommy, then why is the sky red during sunset and sunrise?

During sunsets and sunrises, when the Sun is closer to the horizon, sunlight passes through more air than during the day, when the sun is higher in the sky. More atmosphere means more molecules to scatter the violet and blue light away from your eyes.

If the path is long enough, all of the blue and violet light scatters out of our line of sight. The other colors continue on their way to our eyes. This is why sunsets are often yellow, orange, and red. And because red has the longest wavelength of any visible light, the sun is red when it’s on the horizon.

Akku: Wow nice. Thanks Mommy! This is a lot of info. See you later.

Sure Sweetie! Waiting for more curious questions! 


Extinction of dinosaurs

Akku: Mommy, Why aren’t there any more dinosaurs?

Well, about 65 million years ago, a huge rock from outer space called an asteroid smashed into the Earth, changing the climatic conditions so dramatically that dinosaurs could not survive.

Akku: Wow! How big was it? And where did it hit?

Oh dear, it was huge! It was about 10 miles in diameter and that asteroid’s name is ‘Chicxulub Impactor’. Scientists say it hit some where in Mexico.

asteroid

Akku : WOW! That asteroid was really BIG!!  But it hit just Mexico,  how did it create such a big impact, that it wiped out all the dinosaurs???

Well baby, that giant asteroid landed with a huge  impact. The asteroid made lots of dust, dirt and rocks fly up into the air. All that dust and dirt covered around the planet and made the sky dark and covered the Sun. And many forest fires were caused too.

Akku : Then what happened?

All this dust led to a deadly chain of events. The dust blocked sun for a very long time. Without the Sun, all the plants died. Without the plants, all the plant-eaters died and without the plant-eaters, all the meat-eaters died.

Akku : That’s so sad. The asteroid made a HUGE difference in the world! And I really feel sorry for the dinosaurs. They also must have cared for their families, just like humans.

Yes true! But human race wouldn’t be there on earth today, if not for that asteroid.

Akku : What do you mean?

If not for the extinction of dinosaurs, mammals probably would’ve remained in the shadows, as they had been for over a hundred million years. Humans then, probably would’ve never been here.

mammals

Akku : That’s so interesting. What is the real meaning of the word extinct and why did just dinosaurs go extinct?

An animal is extinct when it doesn’t exist anymore anywhere in the world. It wasn’t just dinosaurs that went extinct. Among others that went extinct were: flying reptiles called pterosaurs, huge reptiles that swam in the ocean called plesiosaurs and pliosaurs, creatures with curled, spiral shells called ammonites, and lots of other plants and animals. But others survived. Different types of insects, lizards, crocodiles, mammals, birds, sharks, fish, crabs, snails, flowers, ferns and trees all made it through.

 

 

 

 

 

 

 

 

 

 

 

 

Akku : But without food and sunlight, how did they survive, Mom?

Scientists have many different theories on how other animals survived the extinction of dinosaurs. It could be because the animals were small and didn’t need much food. Maybe it was because they could eat crunchy seeds the dead plants left behind. Maybe it was because they could burrow into the ground to keep warm. And maybe some of those dry, crunchy seeds could grow into plants after they were buried for a long time.

 

Akku : Cool. But I wish still I could see dinosaurs.

Don’t worry baby. If you like to learn more about dinosaurs we could go to museums, and look at the intact skeletons and fossils. You can always read about them in books and watch them in movies and documentaries.

fossil

Akku : Thanks for the explanation Mama! I still have more questions, but I’ll ask you those later. Well then, see you later!

Ok baby! I am always here to help you.