Bacteria have been the very first organisms to live on Earth. They made their appearance 3 billion years ago in the waters of the first oceans. At first, there were only anaerobic heterotrophic bacteria (the primordial atmosphere was virtually oxygen-free).

Instead life almost certainly originated in a series of small steps, each building upon the complexity that evolved previously: Simple organic molecules were formed. Experiments suggest that organic molecules could have been synthesized in the atmosphere of early Earth and rained down into the oceans.

In other words, every living thing – including you – is ultimately descended from a bacterium. This means we can define the problem of the origin of life more precisely. Using only the materials and conditions found on the Earth over 3.5 billion years ago, we have to make a cell.

Others think life began in ponds on land, perhaps geothermal pools like those in Yellowstone. Many other locations have been proposed, such as ice. A minority of scientists argue that life must have begun elsewhere in the universe and been carried to Earth, an idea known as “panspermia”.

Here are the 10 best dog breeds for home security:

1. Akita. The fearless and bold Akita is a breed that deserves the utmost praise and respect.
2. Belgian Mallinois.
3. Bullmastiff.
4. Doberman Pinscher.
5. German Shepherd.
6. Giant Schnauzer.
7. Great Pyrenees.
8. Pit Bull.

The Best Dogs for First Time Owners

• Poodle.
• Golden Retriever.
• King Charles Spaniel.
• Pug.
• Papillon.
• Greyhound.
• Bichon Frise.
• Boxer. If you’re looking for a medium-large, high-energy companion, the Boxer is perfect for you.

10 Easy-Maintenance Dog Breeds

• #1: Basenji. This wonderful breed has no “doggy smell,” so combined with his short coat and small size, he goes right to the top of the list.
• #2: Vizsla.
• #3: Whippet.
• #4: Boston Terrier.
• #5: Doberman Pinscher.
• #6: Toy Manchester and Manchester Terrier.
• #7: Pointer.
• #8: German Shorthaired Pointer.

25 dogs breeds with the most health issues

• #8. Rottweiler.
• #7. Labrador Retriever.
• #6. Basset Hound.
• #5. Saint Bernard.
• #4. Golden Retriever. Health Concern Level: High.
• #3. Bulldog. Health Concern Level: High.
• #2. German Shepherd. Health Concern Level: Very High.
• #1. Cocker Spaniel. Health Concern Level: Very High.

In July 2018, scientists reported that the earliest life on land may have been bacteria 3.22 billion years ago. In May 2017, evidence of microbial life on land may have been found in 3.48 billion-year-old geyserite in the Pilbara Craton of Western Australia.

The First Humans One of the earliest known humans is Homo habilis, or “handy man,” who lived about 2.4 million to 1.4 million years ago in Eastern and Southern Africa.

3.5 billion years ago

The earliest life forms we know of were microscopic organisms (microbes) that left signals of their presence in rocks about 3.7 billion years old.

The short answer is yes. The fossil record shows everything goes extinct, eventually. Almost all species that ever lived, over 99.9%, are extinct. Humans are inevitably heading for extinction.

During the past 200,000 years, homo sapiens have survived two ice ages. While this fact shows humans have withstood extreme temperature changes in the past, humans have never seen anything like what is occurring now.

Earth would flourish. It appears the vast over population and pollution of the world is the result of over thirty millennia of struggle to reach the Moon and determine its nature. If humans went extinct then the state of the earth would be of no consequence to us because we wouldn’t exist.

What if we all jumped at once? Because people are spread somewhat equally around the planet’s spherical surface , if we all jumped in place, nothing much would happen — all our lift-offs and impacts would cancel each other out, resulting in zero net force on the Earth, according to work by physicist Rhett Allain.

It is the pull of the Moon’s gravity on the Earth that holds our planet in place. Without the Moon stabilising our tilt, it is possible that the Earth’s tilt could vary wildly. It would move from no tilt (which means no seasons) to a large tilt (which means extreme weather and even ice ages).

Fortunately, Earth retains heat fairly well, so humans wouldn’t freeze instantly. Life would get much more difficult immediately, though. Without the Sun’s rays, all photosynthesis on Earth would stop. All plants would die and, eventually, all animals that rely on plants for food — including humans — would die, too.

The moon influences life as we know it on Earth. It influences our oceans, weather, and the hours in our days. Without the moon, tides would fall, nights would be darker, seasons would change, and the length of our days would alter.

The Moon also holds Earth’s 23.5-degree tilt fairly steady. Without that steadying hand, Earth would wobble much more, dramatically affecting the planet’s seasons and climate. “Everything we know about the seasons would be completely out of whack,” says Paul Sutter, astrophysicist at the Flatiron Institute.

A moonquake is the lunar equivalent of an earthquake (i.e., a quake on the Moon). They were first discovered by the Apollo astronauts. The largest moonquakes are much weaker than the largest earthquakes, though their shaking can last for up to an hour, due to fewer attenuating factors to dampen seismic vibrations.

The Moon’s weak atmosphere and its lack of liquid water cannot support life as we know it.

With no sunlight, photosynthesis would stop, but that would only kill some of the plants—there are some larger trees that can survive for decades without it. Within a few days, however, the temperatures would begin to drop, and any humans left on the planet’s surface would die soon after.

Our Sun is too small a star to end its life as a black hole. But what would happen if the Sun were suddenly replaced with a black hole of the same mass? Contrary to popular belief, the Solar System would not be sucked in: a solar-mass black hole would exert no more gravitational pull than our Sun.

In about 5.5 billion years the Sun will run out of hydrogen and begin expanding as it burns helium. It will swap from being a yellow giant to a red giant, expanding beyond the orbit of Mars and vaporizing Earth—including the atoms that make-up you.

For about a billion years, the sun will burn as a red giant. Then, the hydrogen in that outer core will deplete, leaving an abundance of helium. Astronomers estimate that the sun has about 7 billion to 8 billion years left before it sputters out and dies.

Our sun’s death is a long way off — about 4.5 billion years, give or take — but someday it’s going to happen, and what then for our solar system?

It’ll swell into a red giant, whose outer layers will engulf Mercury and Venus and likely reach the Earth. Life on Earth will end. If the sun were more massive – estimates vary, but at least several times more massive – it would explode as a supernova.

4.543 billion years

A billion years or giga-annum (109 years) is a unit of time on the petasecond scale, more precisely equal to 3.16×1016 seconds (or simply 1,000,000,000). It is sometimes abbreviated Gy, Ga (“giga-annum”), Byr and variants. The abbreviations Gya or bya are for “billion years ago”, i.e. billion years before present.

The planet is one of the oldest known extrasolar planets, believed to be about 12.7 billion years old….PSR B1620−26 b.

Discovery
Discovery site	United States
Discovery date	May 30, 1993 (confirmed July 10, 2003)
Detection method	Pulsar timing
Orbital characteristics

By dating the rocks in Earth’s ever-changing crust, as well as the rocks in Earth’s neighbors, such as the moon and visiting meteorites, scientists have calculated that Earth is 4.54 billion years old, with an error range of 50 million years.

The 2020s (pronounced “twenty-twenties”, shortened to “the ’20s”) is the current decade of the Gregorian calendar that began on 1 January 2020, and will end on 31 December 2029…

4.603 billion years

2021 (MMXXI) is the current year, and is a common year starting on Friday of the Gregorian calendar, the 2021st year of the Common Era (CE) and Anno Domini (AD) designations, the 21st year of the 3rd millennium, the 21st year of the 21st century, and the 2nd year of the 2020s decade.

History. The Anno Domini dating system was devised in 525 by Dionysius Exiguus to enumerate the years in his Easter table. His system was to replace the Diocletian era that had been used in an old Easter table because he did not wish to continue the memory of a tyrant who persecuted Christians.