It is widely accepted by both geologists and astronomers that Earth is roughly 4.6 billion years old.
This age has been obtained from the isotopic analysis of many meteorites as well as of soil and rock samples from the Moon by such dating methods as rubidium–strontium and uranium–lead..
Measurements made by NASA's WMAP spacecraft have shown that the universe is 13.77 billion years plus or minus 0.059.
The age was further refined by ESA's Planck spacecraft to be 13.8 billion years old..
The fruits of scientific and technological development in astronomy, especially in areas such as optics and electronics, have become essential to our day-to-day life, with applications such as personal computers, communication satellites, mobile phones, Global Positioning Systems, solar panels and Magnetic Resonance .
For example, it is critical to study the Sun's influence on Earth's climate and how it will affect weather, water levels etc.
Only the study of the Sun and other stars can help us to understand these processes in their entirety..
The nearest stars to Earth are three stars that lie about 4.37 light-years away in the Alpha Centauri triple-star system.
The closest of these stars, Proxima Centauri, is just about 4.24 light-years away. (for reference, one light-year is approximately equivalent to 5.88 trillion miles (9.46 trillion kilometers))..
So the furthest out we can see is about 46.5 billion light years away, which is crazy, but it also means you can look back into the past and try to figure out how the universe formed, which again, is what cosmologists do..
Summary: Because of astronomy we have been able to come up with new theories for how the universe was created, getting more religius freedom and separating us from christianity more and more.
We have also gotten a way of predicting the course of asteroids and giving us more knowledge of how the universe works..
“There are 2 trillion galaxies in observable universe.
For all 2 trillion galaxies, each one has 100 billion stars.
Next, one in five stars has an Earth-like planet.
That means there are as many as 40 billion Earth-sized planets.”.
Many independent lines of scientific evidence show that the Earth and Universe are billions of years old.
Current measurements yield an age of about 4.54 billion years for the Earth and about 13.8 billion years for the Universe..
We have dated Earth at 4.567 billion years (Ga) based on lead isotope data from meteorites [1].
Meteorites are the “ingredients” that formed Earth and the other terrestrial planets..
ASTRONOMY: FROM THE EARTH TO THE UNIVERSE describes the current state of astronomy, both the fundamentals of astronomical knowledge that have been built up over decades and the exciting advances that are now taking place..
This technique is called the transit method and it finds both large and small (terrestrial) planets.
Earth-like means the same size as the Earth within factors of a few..
Meteorologists study the earth's atmosphere and how it affects the weather and climate.
Oceanographers study the earth's oceans, including their composition, movement, and processes.
Astronomy, or the study of the universe, is considered to be an earth science because what occurs in space affects the world..
We have dated Earth at 4.567 billion years (Ga) based on lead isotope data from meteorites [1].
Meteorites are the “ingredients” that formed Earth and the other terrestrial planets..
In 1543, Nicolaus Copernicus detailed his radical theory of the Universe in which the Earth, along with the other planets, rotated around the Sun.
His theory took more than a century to become widely accepted..
How does astronomy help answer the question 'what are we'? It locates us in space and time.
It shows how we fit into the physical processes that govern the Universe..
The Earth was the center of the Universe according to Claudius Ptolemy, whose view of the cosmos persisted for 1400 years until it was overturned — with controversy — by findings from Copernicus, Galileo, and Newton..
In 1515, a Polish priest named Nicolaus Copernicus proposed that the Earth was a planet like Venus or Saturn, and that all planets circled the Sun..
Copernicus is often described as a lone astronomer who defiantly argued that the sun, not the Earth was at the center of the cosmos.
Copernicus' contributions to astronomy are so significant that they warrant their own term: The Copernican Revolution..
NASA studies Earth because Earth is a planet, too In fact, it is the planet that NASA has studied the most.
It is important to study Earth because it is the one place in the entire solar system where humans can live.
Credit: NASA Goddard Space Flight Center..
“What’s interesting is
In the 10 years since then
It still feels that close.” But astronomers had already realized they might not need a true Earth analog to find a planet where life could exist.
Rocky worlds orbiting smaller
Dimmer stars than the sun are easier to find
And might be just as friendly to life.
In other words
The universe was expanding.
By the end of the century
Astronomers knew that the universe was dotted with billions of galaxies of all shapes and sizes.
In April 1990
NASA launched the first optical space telescope into Earth’s orbit
Giving the world a new perspective on space.
On 8 December 1990
Galileo was due to skim past Earth
Just 960 kilometres above the surface.
The tickling became an itch that Sagan had to scratch.
He talked NASA into pointing the spacecraft’s instruments at our planet.
The resulting paper was titled ‘A search for life on Earth from the Galileo spacecraft’ 1.
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Visit Century of Science:
Other worlds.
The last 100 years have brought a series of revolutions in astronomy
Each one kicking Earth a bit farther from the center of things.
Along the way
People have not exactly been receptive to these blows to our home planet’s centrality.
the light shifts to shorter
wavelengths; as it moves away
the light grows redder.
Calculating the velocity of a star’s back-and-forth motion
astronomers could figure out the minimum mass and length of the year of whatever was tugging that star.
The shifts Mayor was looking for were still minuscule.
The universe was expanding.
By the end of the century
Astronomers knew that the universe was dotted with billions of galaxies of all shapes and sizes.
In April 1990
NASA launched the first optical space telescope into Earth’s orbit
Giving the world a new perspective on space.
Time elapsed since the Big Bang
Based on a number of studies that all show similar figures for the age.These studies include
Researches of the microwave background radiation by the Planck spacecraft
The Wilkinson Microwave Anisotropy Probe and other space probes.Measurements of the cosmic background radiation give the cooling time of the universe since the Big Bang
And measurements of the expansion rate of the universe can be used to calculate its approximate age by extrapolating backwards in time.The range of the estimate is also within the range of the estimate for the oldest observed star in the universe.
