Facts Know Understand about Meteor Shower life cycle Meteoroids

Facts Know Understand about  Meteor Shower life cycle Meteoroids

A meteor shower is a celestial event where numerous meteors, often called "shooting stars," streak through the night sky. 

These meteors are tiny fragments of cometary or asteroidal material burning up as they enter Earth's atmosphere at high speeds. 

Here's a detailed explanation:

What Causes a Meteor Shower?

Meteor showers occur when Earth passes through the debris trail left by a comet or, in some cases, an asteroid. 

As comets orbit the Sun, they shed dust, ice, and small rocky particles due to solar heating. 

These particles spread out along the comet's orbit. When Earth intersects this orbital path, the particles collide with our atmosphere, creating bright streaks of light due to friction and heat.

Key Features of Meteor Showers - 

Radiant Point: 

Meteors appear to radiate from a specific point in the sky called the radiant. 

The name of the meteor shower is often derived from the constellation in which its radiant is located (e.g., the Perseids radiate from Perseus).

Meteor Trail: 

The streak of light we see is the result of the intense heat generated as the meteoroid vaporizes upon entering the atmosphere. 

Some brighter meteors, called "fireballs," may leave a glowing trail that lingers for a few seconds.

Frequency:

During a meteor shower's peak, you might see dozens of meteors per hour. 

The frequency varies depending on the density of the debris field.

Famous Meteor Showers

Perseids: 

Occur in August and are associated with Comet Swift-Tuttle. Known for their bright meteors and high activity rate.

Leonids: 

Happen in November, tied to Comet Tempel-Tuttle. 

These can sometimes produce meteor storms with hundreds or even thousands of meteors per hour.

Geminids: 

Peak in December and are unusual because they're caused by an asteroid (3200 Phaethon) rather than a comet.

Best Way to Watch a Meteor Shower -

Timing: 

Meteor showers are best viewed during their peak, which typically occurs over a couple of nights. 

The darkest hours just before dawn offer the best visibility.

Location: 

Find a dark, open space far from city lights. 

Elevated areas with minimal light pollution are ideal.

Preparation: 

Dress warmly, bring a blanket or reclining chair, and lie back to take in as much of the sky as possible. 

It takes about 20-30 minutes for your eyes to fully adjust to the darkness.

No Equipment Needed: 

While binoculars or telescopes aren't necessary, they can be used to explore other celestial objects while waiting for meteors.

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Video What is the real colour of Sun White or Yellow ?

Video What is the real colour of Sun White or Yellow ?

The Sun appears yellow when observed from Earth. 

However, if you were to view the Sun from space, it would actually appear white. 

When we see it from Earth, it often looks yellow, orange, or red because of how its light scatters in our atmosphere, especially during sunrise or sunset. 

But if you were to observe the Sun from space, where there’s no atmosphere to filter its light, it would appear as a bright, pure white. 

This is because the Sun emits light across all visible wavelengths more or less equally, and when combined, that mix of colors gives us white light. 

This is because the Sun emits light across the entire spectrum, and in the absence of the Earth's atmosphere, all the colors combine to produce white light. 

The yellow color we see from Earth is due to the scattering of shorter wavelengths (like blue and violet) by the Earth's atmosphere, leaving the longer wavelengths (yellow and red) to dominate. 

 Sun Video - Sun Photo

The Sun sported a whole slew of substantial sunspots over the past 11 days (July 1-10, 2014). 

This movie and still show the Sun in filtered white light speckled with more and larger sunspots than we have seen in quite some time. 

Sunspots are darker, cooler regions on the Sun created by intense magnetic fields poking through the surface. 

The Sun may have passed its peak level of activity, but it will still be producing many more sunspots and solar storms during the rest of this solar cycle. 

The still image was taken on July 8 at 22:24 UT. Credit: Solar Dynamics Observatory/NASA.

Know about Selenium’s cosmic journey birth ancient stars , meteorite alien world

Know about Selenium’s cosmic journey is a tale that stretches back to the fiery hearts of ancient stars

Selenium’s cosmic journey is a tale that stretches back to the fiery hearts of ancient stars, weaving through the vastness of space before landing in the rocks beneath our feet. 

Let’s take a trip through its stellar origins and interstellar travels:

Birth in the Stars

Stellar Nurseries: 

Selenium wasn’t born on Earth—it’s a product of nucleosynthesis, the process where stars forge elements. 

Most of its isotopes, like Se-74, Se-76, Se-77, Se-78, and Se-80, come from a slow dance of neutron capture called the "s-process." 

This happens in aging, massive stars—think red giants or asymptotic giant branch (AGB) stars—where nuclei grab neutrons over thousands of years, building heavier elements step by step.

Explosive Beginnings: 

The oddball isotope, Se-79 (radioactive with a long half-life), likely traces back to the rapid "r-process"—a chaotic burst of neutron capture during supernovae. 

When a massive star runs out of fuel, it collapses and explodes, spewing newly minted elements like selenium into space. 

These cataclysmic blasts, happening billions of years ago, seeded the cosmos with selenium.

Journey Through the Galaxy

Cosmic Dust: 

After its stellar birth, selenium didn’t just hang around. 

It mixed into clouds of gas and dust—nebulae—swirling through the Milky Way. 

Over eons, gravity pulled these clouds together, forming new stars and planets. Some selenium hitched a ride in meteorites and cosmic debris, drifting until it crashed into the forming Earth about 4.5 billion years ago.

Meteorite Evidence: 

Scientists have found selenium in chondrites—primitive meteorites that are snapshots of the early solar system. 

Its isotopic ratios (like Se-80 to Se-76) match what we’d expect from stellar production, confirming it’s a galactic traveler. 

These space rocks suggest selenium was part of the solar nebula, the spinning disk of material that birthed our Sun and planets.

Settling on Earth

Planetary Mix: 

As Earth coalesced, selenium got baked into its mantle and crust, likely delivered by those meteorite impacts during the Late Heavy Bombardment—a cosmic pummeling 3.8 to 4 billion years ago. It’s not a headliner like iron or oxygen, but it’s there in trace amounts, about 0.05 parts per million in the crust.

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Aurora Australis and the International Space Station

6 December 2024 

#Astronomy #Photo 

Aurora Australis and the International Space Station 

 This snapshot from the International Space Station was taken on  while orbiting about 430 kilometers above the Indian Ocean, Southern Hemisphere, planet Earth. 

 The spectacular view looks south and east, down toward the planet's horizon and through red and green curtains of aurora australis. 

 The auroral glow is caused by emission from excited oxygen atoms in the extremely rarefied upper atmosphere still present at the level of the orbiting outpost. 

 Green emission from atomic oxygen dominates this scene at altitudes of 100 to 250 kilometers, while red emission from atomic oxygen can extend as high as 500 kilometers altitude. 

 Beyond the glow of these southern lights, this view from low Earth orbit reveals the starry sky from a southern hemisphere perspective. 

 Stars in Orion's belt and the Orion Nebula are near the Earth's limb just left of center. 

 Sirius, alpha star of Canis Major and brightest star in planet Earth's night is above center along the right edge of the southern orbital skyscape. 

The Moona Lisa

6 December 2024 

#Astronomy #Photo 

The Moona Lisa

 Only natural colors of the Moon in planet Earth's sky appear in this creative visual presentation. 

 Arranged as pixels in a framed image, the lunar disks were photographed at different times. 

 Their varying hues are ultimately due to reflected sunlight affected by changing atmospheric conditions and the alignment geometry of Moon, Earth, and Sun. 

 Here, the darkest lunar disks are the colors of earthshine. 

 A description of earthshine, in terms of sunlight reflected by Earth's oceans illuminating the Moon's dark surface, was written over 500 years ago by Leonardo da Vinci. 

 But stand farther back from your screen or just shift your gaze to the smaller versions of the image. You might also see one of da Vinci's most famous works of art.