seven earths or layers of the earth

NASA's Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.

The discovery sets a new record for greatest number of habitable-zone planets found around a single star outside our solar system. All of these seven planets could have liquid water – key to life as we know it – under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.

“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen, associate administrator of the agency’s Science Mission Directorate in Washington. “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”

At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets.

This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system. Assisted by several ground-based telescopes, including the European Southern Observatory's Very Large Telescope, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.

The new results were published Wednesday in the journal Nature, and announced at a news briefing at NASA Headquarters in Washington.

Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them, allowing their density to be estimated.

Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces. The mass of the seventh and farthest exoplanet has not yet been estimated – scientists believe it could be an icy, "snowball-like" world, but further observations are needed.

"The seven wonders of TRAPPIST-1 are the first Earth-size planets that have been found orbiting this kind of star," said Michael Gillon, lead author of the paper and the principal investigator of the TRAPPIST exoplanet survey at the University of Liege, Belgium. "It is also the best target yet for studying the atmospheres of potentially habitable, Earth-size worlds

Exoplanet discovery: seven Earth-sized planets found orbiting nearby .

 

 

7 Earth-Size Planets Orbit Dwarf Star, NASA and European ..

 

 

Star's seven Earth-sized worlds set record - BBC News

There are two meaning of saba'a (seven in arabic)

1)    It is used for the number "seven". (Mufridaat-ul-Quran).

2)   It is also used in the meaning of "several" or "many" (lughat-ul-Quran).

 

 " It is Allah Who created the seven heavens and of the earth the same number, the Command descending down through all of them, so that you might know that Allah has power over all things and that Allah encompasses all things in His knowledge."
[Qur'an, 65:12]

 

 Earth consists of seven strata. These, as scientists have identified, are:

1st layer: Lithosphere (water)

2nd layer: Lithosphere (land)

3rd layer: Asthenosphere

4th layer: Upper Mantle

5th layer: Inner Mantle

6th layer: Outer Core

7th layer: Inner Core

 

  Structure of the Earth

 

 

 

Seven Layers:
crust
lithosphere
upper mantle
astenoshpere
lower mantle
outer core
inner core

Seven Continents:
North America
South America
Australia
Asia
Africa
Antarctica
Europe

 The word lithosphere is derived from the Greek word lithos, meaning stone, which is a hard stratum forming the Earth's top layer. It is quite thin in comparison to the other strata. The lithosphere under the oceans is still thinner, and is a region with volcanic activity. Its average thickness is 80 km. It is colder and harder than the other strata, and therefore, forms the earth's shell.

Below the lithosphere is the stratum known as the asthenosphere, from the Greek word for "weak," asthenes. This layer is thinner than the lithosphere and shifts. It was formed of hot, semi-solid substances capable of melting when exposed to high temperatures and pressure over geological time. It is thought that the hard lithosphere floats or moves over the slowly moving asthenosphere.23 Under these layers is a high-temperature layer some 2,900 km thick, made up of semi-solid rock known as the mantle. This contains more iron, magnesium and calcium than the crust, and is also hotter and denser, because temperature and density in the Earth increase with depth.

 At the centre of the Earth is the core, approximately twice as dense as the mantle. The reason for that density is that it contains a higher proportion of metals (iron-nickel alloy) than rock. The Earth's core consists of two parts. One is the 2,200 km thick liquid outer core, the other a 1,250 km thick solid inner core. The liquid outer core provides the Earth's magnetic field as the planet rotates.

The truth of this similarity between the sky and the layers of the Earth, only identified by 20th century technology, is without doubt another of the Qur'an's scientific miracles.

 

 

 Meanings of Ardh: One of the meanings is earth,Another meaning is land,One of the most indications of Ardh is seven Ardhean (plural of Ardh: The interior and lower part of the Universe) Also the word Ardh can mean a field, and a part of the land.  In Arabic, the lower part of anything is called ardh.  For example, the ardh of a vehicle, room and so on is its floor.

 

 There are many earths according to the Glorious Quran.***