How did water first get on Earth?

Currently, the most favored explanation for where the Earth got its water is that it acquired it from water-rich objects (planetesimals) that made up a few percent of its building blocks. These water-rich planetesimals would have been either comets or asteroids.

epl.carnegiescience.edu - Where did Earth's water come from? - Earth and Planets Laboratory

How do I check if my kidneys are OK?

Blood Tests. Because your kidneys remove waste, toxins, and extra fluid from the blood, a doctor will also use a blood test to check your kidney...

Last updated Dec 2, 2019

Who is Sonic's biggest enemy?

Doctor Ivo Robotnik, better known by his alias Doctor Eggman, is a human mad scientist and the main antagonist of the series. Debuting in the first...

Last updated Aug 7, 2021

Promotion

By Conel Alexander

The origin of Earth’s water is an open question and quite controversial. It really is part of a larger question about how Earth got its very volatile elements that include not just the hydrogen in water, but also carbon, nitrogen, and the noble gases (helium, neon, argon, krypton, and xenon) amongst others. Ultimately, any complete explanation must be able to reproduce both the volatile element abundances and isotopic compositions. It must also be compatible with what we know about how and on what timescales planetary systems form from the disk of gas and dust (protoplanetary disk) that surrounds a young star. In the case of the Solar System, the protoplanetary disk around the young Sun is generally referred to as the Solar Nebula. Currently, the most favored explanation for where the Earth got its water is that it acquired it from water-rich objects (planetesimals) that made up a few percent of its building blocks. These water-rich planetesimals would have been either comets or asteroids. From what we know about comets, they are not a good match to either the volatile element abundances or isotopic compositions of the Earth. It may also have been difficult to deliver enough comets to the Earth. At present, asteroids up to a few hundred kilometers across seem the most likely sources of most of Earth’s water, specifically the types of asteroid that dominate the outer asteroid belt between Mars and Jupiter. We have pieces of some of these asteroids in the form of two types of carbonaceous chondrite meteorites—the CMs and CIs. When they formed, these asteroids/meteorites contained water-ice, but radioactive heating and impacts caused the ice to melt and react with the anhydrous minerals to make clays. The meteorites also contain quite a bit of organic matter that contains hydrogen, carbon, and nitrogen —the hydrogen would have reacted to form water when the asteroids vaporized on impacting the early Earth. Noble gases even seem to be associated with the organics. The CM chondrites, in particular, match many aspects of Earth’s highly volatile elemental and isotopic compositions, although small amounts of cometary and solar wind (or Solar Nebula) material produce an even better fit. Nevertheless, disagreements between the meteorite-comet-solar and Earth compositions remain and there is much debate about whether these are due to some combination of (i) inaccuracies in the estimates of the Earth’s volatile contents, (ii) storage of hydrogen and other volatiles in the Earth’s core or deep mantle, and (iii) loss of volatiles to space in the giant impacts that dominated the final stage of Earth’s formation. If CM- and/or CI-like chondrites were the main sources of Earth’s water, where did they come from? It looks like they are representatives of a swarm of planetesimals that formed in the colder regions of the Solar Nebula beyond the orbit of Jupiter where water-ice-rich dust was plentiful, and they were gravitationally scattered by a growing Jupiter into the regions where Earth and the asteroid belt formed.

What blocks out nuclear radiation?

Shielding: Barriers of lead, concrete, or water provide protection from penetrating gamma rays. Jul 5, 2022

Last updated Feb 25, 2020

What should be in a 72 hour pack?

What is in a 72-hour kit? Bottled water. Store four litres of water per person per day. ... Food. ... Medication. ... First Aid kit. ... Wind-up...

Last updated Aug 14, 2018

Promotion

How to purify yourself in the Bible?

Well then, here is what you must do: Cleanse yourself of all that dishonors God. “Flee youthful passions and pursue righteousness, faith, love, and peace, along with those who call on the Lord from a pure heart” (2 Timothy 2:22).

openthebible.org - Cleanse Yourself | Open the Bible

Video Notes:

We can apply what we learn from these battles in the Old Testament to the many struggles we face as Christians with sin and temptation in our own lives. Here’s the principle: If you want to do a great work for God, you must deal first with sins that remain embedded in your life. Listen to these words of Paul to Timothy, a young Christian leader: “If anyone cleanses himself from what is dishonorable, he will be a vessel for honorable use, set apart as holy, useful to the master of the house, ready for every good work” (2 Timothy 2:21). Timothy, you want to be useful to the Master? You want to be ready for every good work? You want to be a vessel for honorable use? Well then, here is what you must do: Cleanse yourself of all that dishonors God. “Flee youthful passions and pursue righteousness, faith, love, and peace, along with those who call on the Lord from a pure heart” (2 Timothy 2:22). Here is a great motive for pursuing holiness of life, for waging war against the sin that remains in your life. Think what you could be for the Lord. Think what you might do. Think how he might use you if the sins that have gained power over you were driven out! Don’t let an impure heart put you on the sidelines of usefulness to God! Any great work of God begins with a person who gets serious about the pursuit of holiness. [Taken from Pastor Colin’s sermon “When God Says ‘No’—Part 2″ in the series A Leader You Can Follow ]

What is the best alternative to Tesla Powerwall?

There are many alternatives to the Powerwall from well-known companies such as LG, Panasonic, and sonnen. The LG Chem battery is our top pick for...

Last updated Dec 1, 2018

Which animal can live without food forever?

Tardigrades belong to an elite category of animals known as extremophiles, or critters that can survive environments that most others can't. For...

Last updated May 9, 2020

Promotion

What are lazy people good at?

Lazy people are very creative when it comes to organizing their work. They don't waste time on unnecessary things and get strict to the point. A...

Last updated Mar 19, 2020

Promotion

What is the root of self-esteem?

Self-esteem is influenced by evolution, childhood, rejection, social group stability, and, most importantly, beliefs. Jul 3, 2018

Last updated Jul 19, 2020