Which planet of the solar system is eldest and youngermost evolution out of sun?

Question

As is learnt Earth was once in molten state and probably as bright as sun. Then it cooled and is getting cooled each day since it was formed. But ppl now say that earth is not losing any heat and may gain more of it with greenhouse effect. Does it suggest that earth is again likely to start glowing just like sun. But earth's past experience reveals that in case it was formed out of sun it has cooled over the years.

DOES IT NOT SUGGEST THAT PLANETS WITH LOWEST TEMPERATURE HAVE LIVED A LONGER LIFE THAN THE PLANETS HAVING RELATIVELT HIGHER TEMPERATURE?

Answer 1

All the planets where formed at the same time during the formation of the solar system. This is around 4,540,000,000 years ago.

Answer 2

Earth was never as hot as the Sun, although its surface was once molten - so it was as hot as a volcano (maybe as much as 2000 degrees F) but never as hot as the surface of the Sun (roughy 10000 degrees F). This heat was the result of the energy released during formation - when lots of rocks come together to form a planet, a lot of heat is generated. The heat of the Sun is caused by nuclear fusion at its core. That will never happen in Earth.

Today Earth's interior is still molten, but it is not leftover heat from formation. The interior is heated by the energy released by radioactive decay of rocks inside Earth. Over time (billions and billions of years) the interior of Earth will cool down and eventually solidify. Smaller worlds like Mercury, Mars, and the Moon, have already solidified.

Global warming and the greenhouse effect are things that happen in our atmosphere. Sunlight comes through our atmosphere with no problem (if we ignore the clouds). The light is absorbed by the ground, so the ground warms up (ever try to walk barefooted on black pavement? that heat is from the Sun, not the interior of Earth). So the ground emits heat, but that heat gets trapped by our atmosphere, it doesn't all return to space. This is called the greenhouse effect, and it keeps Earth's average temperature a nice, comfortable 68 degrees F (roughly).

Certain gases in our atmosphere are better at trapping the heat than others - these are collectively called greenhouse gases. Carbon dioxide is an excellent greenhouse gas. Unfortunately, carbon dioxide is also part of human pollution. If we continue to add more carbon dioxide to our atmosphere than was originally there, more heat will be trapped in our atmosphere and the average global temperature will increase - global warming.

All the planets (and everything else) in our solar system were formed at about the same time as the Sun, four and a half billion years ago. The smallest planets have cooled more than Earth because they are smaller - just like a small drop of coffee will cool off much faster than a huge cup of coffee will, so we can't look to the temperature of a planet to see how old it is.

The planets (and everything else) were made out of essentially the same stuff the Sun was made up of, but the planets were not formed by the Sun or formed from the Sun. Do a search on 'solar system formation' for more details on how our solar system formed.

Answer 3

I couldn't find any information about this. I believe this to be because a lot, if not most, scientists subscribe to the Big Bang theory, which would indicate that all the planets are the same age.

And just for informational value, I learned that as of about 2 weeks ago, Pluto is no longer considered a planet - it has been stripped of its title. This is because they consider it to be too small, and because it has an eliptical orbit, which intersects with that of Neptune.