Blue sky? Not!

The sky

The sky is not blue!
It's just light playing tricks on you!
(I knew I was never a good poet)






Sunset

A prism

The sun produces white light, but if you use a prism then the "white" light splits up into the colours of the rainbow. Blue light waves are shorter then red ones so they scatter more easily than other colours so the sky is blue. But, during sunset the sky is red in colour. Why is that so? Well, red has the longest waves so they are the hardest to scatter. During, sunset light has to go through more gas particles in the atmosphere so every colour except red gets scattered so the sky looks red.

Oh and in case you are wondering why the sky is not violet, the shortest wave length, it is because some of it is absorbed by the atmosphere and our eyes are not that sensitive to it. Clouds are white because they consists of particles larger than the wavelengths so all of the colours are scattered equally.

The structure of a type of terpene called Myrcene

Blue haze

                                    Mountainous regions sometimes have a
blue haze. This is because of terpene, which is a class organic materials from insects and plants, particularly conifers which is commonly found on mountains. These terpene chemicals react with the ozone layer and form particles around 200 Nano-metres across so they scatter blue light like the sky.




A blue moon

 Also there is the rare blue moon caused by forest fires or volcano eruptions on Earth. These events cause particles no more than 800 Nano-metres in diameter to spread out. These particles scatter out red light, so the only colour left is blue and that what makes a blue moon.





Conclusion: Because the science behind the topic is fascinating, I give it a 10/10!

Photo Credits:

The Sky: By Mohammed Tawsif Salam (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
http://commons.wikimedia.org/wiki/File%3AAppearance_of_sky_for_weather_forecast%2C_Dhaka%2C_Bangladesh.JPG

Sunset: By Alvesgaspar (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
http://commons.wikimedia.org/wiki/File%3ASunset_2007-1.jpg

A prism: By Spigget (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
http://commons.wikimedia.org/wiki/File%3ADispersive_Prism_Illustration_by_Spigget.jpg

Blue haze: http://www.flickr.com/photos/peasap/2152975621/lightbox/

The structure of a type of terpene called Myrcene: By Ben Mills and Jynto [Public domain], via Wikimedia Commons
http://commons.wikimedia.org/wiki/File%3AMyrcene-3D-balls.png

A blue moon: http://spacefellowship.com/news/art17463/blue-moon-on-new-year-s-eve.html

HD 189773b: The Blue Planet that Rains Glass

HD 189773b

The planet named as HD 189773b looks cosy and Earth-like. Doesn't it? However, you would not like to live there. Firstly, the surface temperature there is 1,000°C (1,832°F) and secondly, it rains glass, sideways, at the speed of 4000 mph.

In space terms, this planet not far from Earth. It is actually a mere 63 light years (370,353,398,510,567 miles) away . So that is why Hubble and other telescopes that are orbiting Earth can see it in so much details. On October 5th 2005, an astronomer in France found this planet orbiting the star HD 189733a (note that our sun is also a star). It orbits the star at a speed of 341,000 mph (549,000 kph). In comparison, our Earth's average orbiting speed is 67,000mph(107,200 kph). This planet has a mass that is 13% more than the mass of Jupiter (which is the largest planet in our solar system and is made of gas). This makes it a hot Jupiter (which means it is a hot gas planet about the same size of Jupiter) and destroy almost all prospects of extra-terrestrial life. Every year on HD 189773b is equivalent to 2.2 Earth days because it orbits its star very closely.


A graph of the visible-light colours of planets 
including HD 189733b

On March 2010 it was found out that this planet is evaporating at a rate of 1,000,000,000 to 100,000,000,000 grams every second. In July (which, by the way is the month I was born in :-)) this year, NASA also found out that this planet blocks three times more X-rays than visible light.  

The blue colour of the planet is thought to have come from silicate particles which scatter blue lights. These particles, which are found in the planets atmosphere, then condense into glass due to very hgih temperature. That is why it rains glass.

Conclusion: It is very unusual to find a planet like this. However there is not a lot of interesting stuff about this planet because no extra-terrestrial life can survive there. I give it a 7/10



Image Credit:






HD 189773b: http://commons.wikimedia.org/wiki/File%3AHD_189733_b_deep_blue_dot.jpg: 
By NASA, ESA, M. Kornmesser [Public domain], via Wikimedia Commons

Visible-light Colours of Planets: The colour of HD 189733b compared to our Solar system. Credit: NASA [This file is in public domain because it was solely created by NASA. NASA copyright states that "NASA material is not pretected by copyright unless stated"] 

Europa: A Possible Source of Extraterrestrial (ET) life?

In our Solar system, the planet Jupiter has 67 moons. Europa is one of those 67 moons. It is the sixth largest moon in the Solar System. It was discovered by Galileo Galilei in 1610. But what most people do not know was that Europa was possibly discovered by Simon Marius, a German astronomer, around the same time that Galileo discovered it. At that time people thought that it was just an insignificant and tiny dot in the sky, but recent studies suggest that Europa might be a potential harbour for life.

Europa

There is an ocean with liquid water beneath the icy crust! The reason? Tidal flexing which cause the ice to melt into water. What is tidal flexing? Well, it is hard to explain so click here to read an article about it. Anyway, scientists believe that life there could be similar to life found in the deep ocean (that region it also called the Hadalpelagic zone) on Earth.

The internal structure of Europa with Jupiter in the background

Now, if your looking at the labels of this blog post you may be wondering what bullets have got to do with Europa. Well, researchers at University College London  have designed a 19.6 kg bullet that is loaded with scientific equipments such as seismograph to measure tremors and a miniature chemistry lab to study the ice and the water beneath it. This giant missile could smash through the icy crust of Europa. This could be deployed around 2023 and it could answer one of the greatest mysteries in our solar system: Is there life on Europa (and if the answer is yes, whether it likes getting shot at by a giant bullet).

Conclusion: Europa is a very exciting natural satellite (moon) and I love the simplicity the research plan. I think if there is life up there then it would look very familiar to tube worms and other deep sea creatures. For this innovative method and awesomeness at the prospect of finding extraterrestrial life that is so close to our planet, I give this research and Europa a 10/10.

Image credits:

Europa: Wikimedia Commons: http://commons.wikimedia.org/wiki/File:Europa-moon.jpg 
The internal structure of Europa with Jupiter in the background:By Kelvinsong (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons: http://commons.wikimedia.org/wiki/File%3AEuropa_poster.svg

The late heavy bombardment: an important source of life on the Earth?

An artists impression of our moon during
and after the late heavy bombardment

You might wonder how comes there are so many craters on the planets and moons. Scientists say that this is due to the late heavy bombardment which is an hypothetical event that happened around 3.8 to 4.1 billion years ago. During this event a large number of comets and meteoroids would have collided with Earth and all the other planets and moon.

The late heavy bombardment had also affected our planet Earth. There had been 22,000 or more craters with diameters less than 20 km and about 40 craters with diameters that are about 1000 km and several craters that are about 5000 km in diameter on Earth. These collisions could have been the source of life on Earth because some of these comets that collided with Earth were made of ice and then the ice melted to form water which paved the way for life.


An artists impression of Eta Corvi and
a planet being hit by a shower of comets

Such event not only happened in our solar system. Evidence shows that another star from the constellation Corvus also had an event that is similar to our own late heavy bombardment. That star is called Eta Corvi. It is a F-type main sequence star which is similar to the sun in our own solar system. Eta Corvi is a white star that is in its main stage of life. It is 40% larger than the sun but 30% younger than the sun.



A meteorite

There are many theories on how this event had happened, but to me the most probable reason is the hypothesis put forwarded by Professor Brian Cox in my favourite BBC documentary "Wonders of the Solar System". He suggested that Jupiter and Saturn would meet up once every two years due to their different orbits. When they met up around 3 to 4 billion years ago, their combined gravity had pushed Neptune into the directions of some comets and meteorites. Neptune would have then knocked the comets and meteorites out of their usual orbits. These comets and meteorites disturbed by Neptune then hit all the planets and moons.

Conclusion: This solar system would have been very different and less interesting if this event had not happened. Also we might not be here if this event did not happen. For these reasons I give this event on the level of importance a 9/10.

Photo Credits:
An artists impression of our moon during and after the late heavy bombardment: By Timwether (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons http://commons.wikimedia.org/wiki/File%3ALunar_cataclysm.jpg:

An artists impression of Eta Corvi and a planet being hit by a shower of comets: By NASA/JPL-Caltech [Public domain], via Wikimedia Commons
http://commons.wikimedia.org/wiki/File%3AIt's_Raining_Comets_(Eta_Corvi).jpg

A meteorite: By NASA [Public domain], attraverso Wikimedia Commons
https://commons.wikimedia.org/wiki/File%3AGalileo_Gaspra_Mosaic.jpg