What are shooting stars?

What are shooting stars?

Well shooting stars are not actually stars but space rocks that enter the Earth’s atmosphere at very high speeds. These space rocks are called meteoroids which are small rocky bodies in outer space floating around. They are smaller than asteroids and are not usually bigger than 1 meter in diameter. Meteoroids enter the Earths atmosphere at very high speeds, and compresses the air molecules in the upper atmosphere which heats up the air and meteoroid to very high temperatures. The meteoroid starts glowing and shedding matter which we see as a streak of glowing light in the night sky. It seems as if some star shot across the sky hence the name shooting star.

Most meteoroids come from the asteroid belt, having been perturbed by the gravitational influences of planets, but others are particles from comets, giving rise to meteor showers. Some meteoroids are fragments from bodies such as Mars or our moon, that have been thrown into space by an impact. Meteoroids enter the Earth’s atmosphere at speeds greater than 20km/s. In 2013, 1 meter-sized comet from the Oort cloud entered Earth atmosphere over a wide area in California and Nevada.It approached from the direction of the constellation Virgo, and collided head-on with Earth atmosphere at 72 ± 6 km/s!!! So in short, a meteoroid, small asteroid or small comet enters the Earth’s atmosphere, heats up and we see a glowing streak of light which is called meteor and if the rock is big enough that it survives and reaches the surface of Earth it is called a meteorite. Meteoroid-Meteor-Meteorite, same thing but different names for different phases.

 

Meteoroid is a space rock that is still in space. Meteor is a meteoroid that burns up in the earth’s atmosphere (Shooting Star) Meteorite is a meteoroid that hits the earth’s surface.

Its always exciting to watch a shooting star but its very rare as you need to go away from city and have clear skies. How about multiple shooting stars? It is possible if you plan on sky gazing when there’s a Meteor shower!  The Leonid meteor shower happens every year in November, when Earth’s orbit crosses the orbit of Comet Tempel-Tuttle. The comet makes its way around the sun every 33.3 years, leaving a trail of dust rubble in its wake. When Earth’s orbit crosses this trail of debris, pieces of the comet fall toward the planet’s surface. And we get to see many shooting stars, some might be faint but if you are lucky you might get to see a fireball! I went for sky-gazing during the peak days of Leonids meteor shower and I got lucky as I captured a shooting star while shooting images for timelapse!

 

Shooting star or Meteor ofLeonids Meteor Shower November 2017.

Can you see colours in the streak of light!? I was amazed to see the colours as they are of significance. The colours of the light emitted depends on the chemical composition and mineral layering of the meteoroid and also on superheated air. In the image we can see red, orange-yellow and violet hues.

  • Orange-yellow :-  Sodium
  • Yellow :- Iron
  • Blue-green :- Magnesium
  • Violet :- Calcium
  • Red :- Atmospheric Nitrogen and Oxygen

When the meteoroid or asteroid enters the Earth’s atmosphere they create ionization trail where the air molecules are ionized due to the path of meteor. These trails can last more than 30 minutes in few cases. Just as I captured the image of the meteor I was also able to capture the Ionization trail of this meteor!

Ionisation trail of Meteor from Leonid Meteor shower November 2017.

Watching a shooting star is kind of rare as it lasts for a very short duration and we need perfect weather conditions. So what’s the probability of getting hit by a meteorite? The only confirmed person in history to have been hit by a meteorite is Ann Hodges. On a clear afternoon in Sylacauga, Alabama in 1954, Ann was napping on her couch, covered by quilts, when a softball-size hunk of black rock broke through the ceiling, bounced off a radio, and hit her in the thigh, leaving a pineapple-shaped bruise. (Source: National Geographic)

 

Moody Jacobs shows a giant bruise on the side and hip of his patient, Ann Hodges, in 1954, after she was struck by a meteorite. CREDITS: PHOTOGRAPH BY JAY LEVITON, TIME & LIFE PICTURES/GETTY IMAGES

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