how old is the earth and how long do u think it will last from now?

Answer 1

Our earth is 4.5 billion years old

"The disappearance of our planet is still 7.5 billion years away, but people really should consider the fate of our world and have a realistic understanding of where we are going," said UW astrophysicist Donald Brownlee. "We live in a fabulous place at a fabulous time. It's a healthy thing for people to realize what a treasure this is in space and time, and fully appreciate and protect their environment as much as possible."

In "The Life and Death of Planet Earth," Brownlee and UW paleontologist Peter Ward use current scientific understanding of planets and stars, as well as the parameters of life, to provide a glimpse of the second half of life on Earth and what comes after.

The book, a sort of biography of our planet, is being published today by Times Books, a division of Henry Holt and Co. It is a sequel to Ward and Brownlee's best-selling and much-discussed book "Rare Earth," in which they put forth the hypothesis that simple life is relatively common in the universe but complex, Earth-like life is exceedingly rare.

"The Life and Death of Planet Earth" explains how the myriad life on Earth today was preceded by a long period of microbial dominance, and the authors contend that complex life eventually will disappear and be succeeded again by a period of only microbial life. They say that higher life will be removed much as it came into being, ecosystem by ecosystem. Aspects of the planet's past, such as numbingly cold ice ages, will be relived in the period of devolution.

"If we do begin to slide into the next glacial cycle, there probably are grand, planetary-scale engineering projects that might stop or lessen the effects," Ward said.

"The big unknowns are whether we can afford to do such projects and would we really know what to do. If the planet was cooling, we could, in principle, begin painting the surface black to collect more heat. Could we afford it? And what would be the many possible ramifications of a planet suddenly covered in black paint? Any planetary remediation project would always run the risk of making things worse."

Eventually, though, scorching heat will drive land creatures to the sea for respite. Those that can adapt will survive for a time, but eventually the oceans will warm too much for the complex life forms to continue.

"The last life may look much like the first life – a single-celled bacterium, survivor and descendant of all that came before," the authors write. Finally, even the surviving microbes "will be seared out of existence."

The prospects of humans surviving by moving to some other habitable planet or moon aren't good, Brownlee and Ward contend, because even if such a place were found, getting there would be a huge obstacle. Various probes sent into space could survive Earth's demise, and just a few grams of material could arguably carry a DNA sample from every human, they say, but it's not likely the human species itself will survive. Long before the planet's final end, life will become quite challenging, and finally impossible, for humans.

As the sun gets hotter and grows in size, it will envelop Mercury and Venus. It is possible it will stop just short of Earth, the authors say, but the conditions still would make this a most-inhospitable planet. More likely, though, the sun will consume Earth as well, severing all the chemical bonds between molecules and sending its individual atoms out into space, perhaps eventually to form new planets. That would leave Mars as the nearest planet to the sun, and on Mars the fading sun's glow would be like that of Earth's moon.

That end is still some 7.5 billion years distant, but by then Earth will have faced a variety of "ends" along the way, the authors say. The last dinosaur perished long ago. Still to come are the last elephant, the last tree, the last flower, the last glacier, the last snowflake, the last ocean, the last life.

"The Life and Death of Planet Earth" is like its predecessor, "Rare Earth," in that the authors collected and distilled some of the latest scientific ideas about the Earth's place in the universe, Brownlee said. He hopes the new book, like "Rare Earth," will spark widespread discussion, and give people a fundamental and realistic view of the past and future of their planet.

"It's a healthy thing to think of the place of Earth among the other planets, and its place in the sun. The sun gave life and ultimately it will bring death."

Answer 2

how old is the earth?

Geologists now think the Earth is about four and a half billion years old.

This is known from radiometric dating of rocks. In radiometric dating, scientists measure the amounts of different isotopes of certain elements in a rock sample. Since radioactive isotopes are known to decay at a certain constant rate, the amounts remaining in the rock will tell how old it is. For igneous rocks this is the time when it solidified from molten magma.

The oldest rocks ever found on Earth are actually slightly younger than this, about 3.8 billion years old. Most rock found on the Earth's surface is much younger because Earth's crust is "recycled" by plate tectonics. The radioactive "clock" in the rock is reset when it is melted or heated to high temperature.

So if the oldest rocks ever found on Earth are 3.8 billion years old, how do we know that the Earth is older than that?

Because we have some rocks that are not from the Earth!

Moon rocks and meteorites are older than any Earth rocks we know of. The Moon rocks collected on the Apollo missions and most meteorites that have hit the Earth are about 4.5 billion years old. The Moon doesn't have plate tectonics, so its crust is not recycled. The rock now on the Moon's surface was formed when the Moon was formed. Meteorites also would have been made when the solar system was formed, and of course the Earth would have been made at the same time as the rest of the solar system.

By the way, the search for the world's oldest rock still continues. Every decade or two someone finds a rock that is a little older and sets a new record. I think the current record is a rock from Canada found by Sam Bowring. Who knows? Maybe someday you could find a little remnant chunk of the Earth's original crust hidden away in some remote wilderness! Good luck hunting!

how long do u think it will last from now?

The upper limit on the lifetime of Earth is about 5 billion years. In about 5 billion years, the Sun will have used up its hydrogen reserves and will expland to become a Red Giant, with a radius of about Earth's orbital distance. The Earth will most likely be swallowed up when this occurs.

The Earth will only make it that far, however, if it avoids a collision with an asteroid or comet large enough to blast it apart. The movies Armageddon and Deep Impact seem implausible, but an Earth-destroying collision is possible. For example, a theory for the formation of our moon is that a body the size of Mars collided with the Earth, throwing debris into orbit that collected to become the Moon. A slightly larger body would have destroyed Earth. According to experts, a "civilization-threatening" impact (such as the one that ended the age of the dinosaurs) occurs about once every 200,000 years. The frequency of an Earth-threatening impact is much much larger, but it is still possible that a body large enough to destroy Earth may arrive in the next 5 billion years. However, civilization may have developed technology that could allow us to alter the path of such an asteroid or comet and save the Earth. So, actually, it's hard to say just how much longer Earth will be around. But I'd venture to say a long, long time!

Answer 3

The current geological/cosmological estimate of the age of the Earth is around 4.5 billion years.

As to how long it will last.......... Who knows? The meteroite that whacked the Dinosaurs happened about 65 million years ago, and there is plenty of evidence to support at least 4 (or maybe 5) other 'great dyings' that have occurred in the Earths past. Maybe the next one will be big enough to shatter the planet and our Solar System will be graced with *two* asteroid belts ☺

And, even if that doesn't happen, the Sun itself will, during it's last dying phases, expand until its surface is at about the edge of Venus's orbit and the Earth will be pretty much a molten ball of liquid rock as a result. But that won't be for another 8 to 10 billion years, so don't sweat it ☺


Doug

Answer 4

Scientists say Earth is 4.5 to 4.7 billion years old. It alone will last at least 5 billion years until the Sun expands into a red giant and probably absorbs it or at least burns it into a cinder as it comes closer. Life on our planet may not last as long as the planet itself does, of course.

Answer 5

The earth's crust seems to have solidified from the molten state about 4 billion (4,000,000,000) years ago. In principle, it should now survive as an intact, rocky body, until the sun runs low on fuel and expands into a 'red giant'. This newly expanded object should be wide enough to engulf the earth's orbit. That event is several billion years away.

Answer 6

I believe the earth is about 6000 years old, since that is how far back we can account for people in the Bible. This is not a Religious point of view, simply historic. I don't believe in the big bang theory for the existence of the earth, because lets face it, there's not exactly any concrete proof.

Answer 7

The earth is about 6000 years old. There is absolutely no way to tell how long it will last.


Bob

Answer 8

Earth is several billion years old. It will last at least several hundred million more years. The planet itself will last billions, but gradual warming of the Sun will make the Earth too hot in "only" one billion years or less.

Answer 9

About 4.2 or 4.3 billion years old. It should last for another 4 or 5 billion years (until our sun becomes a red giant). However, life on earth may last only for another ...?

Answer 10

In around 5 billion years time the sunlight will swell up destroying all existence on earth, it ought to or won't vapourise the planet. That plenty isn't particular. i may be extra stressful with regards to the collision between the Andromeda Galaxy and the Milky way, which will ensue long in the past that. this would the two: a) haven't any result b) throw the earth out into deep intergalactic area with or without our sunlight c) throw the earth with or without our sunlight into the centre of the mixed Milky way-Andromeda galaxy which has been stated as d) perturb the earth's orbit so as that it: .........i) spirals into the sunlight ........ii) spirals out into deep area .......iii) is gravitationally ripped aside to type extra asteroids. To be honest the estimates I even have heard for this are as much as now aside as to make it tricky to renowned which which will ensue first, some estimates have been as quickly as 2 billion years others as late as 7 billion years. Even the earliest estimate however is two billlon years sooner or later, no longer something you will desire to leap in the canal approximately. to place this into context human beings in ordinary terms discovered to stand up at modern-day and not drag their knuckles approximately one hundred,000 years in the past and human historic previous is basically approximately 10,000 years long. In one hundred,000 years we've long previous from dragging our knuckles and swinging in the timber to construction the international area Station, basically think of what's going to ensue in the subsequent one hundred,000 years? return sixty 5 million years and the T-Rex became into roaming the earth our ancestors have been small rodents. yet those issues won't ensue in one hundred,000 years time or sixty 5,000,000 years time yet in a minimum of two,000,000,000 years time. we actually can no longer say what's going to ensue to the human race or in spite of if there'll be a human race in 2,000,000 years time. this is sufficient time for a cataclysm to wipe out almost all existence on earth and for a sparkling dominant existence type to adapt from scratch. i think of we've sufficient room to experience confident that assuming the human race would not go extinct we've extra advantageous than sufficient time to spread out over the entire galaxy.