What conditions are required for life?

Strange as it may seem, there isn't really one standard definition of life. We can't say that life requires something as specific as breathing or growing; there's just too much variety to living things to nail down one specific criterion.

What we can do is talk about some things that all living things on Earth share: They're carbon-based; they require water; they use energy. Perhaps most important for survival, they can grow or reproduce in some way.

So is that all scientists and astrobiologists are looking for when searching for signs of life outside the Earth? Let's take a deeper look at what is required for life to exist.

As we just said, a main requirement is water, which is necessary for many chemical reactions [source: NASA]. Liquid water allows for chemicals to be transported or dissolved, so we do need the water to be between 59 and 239 degrees Fahrenheit (15 and 115 degrees Celsius) so it doesn't vaporize or freeze [source: NASA].

Energy -- either in light or chemical form -- is also required for life. Both forms fuel the metabolic reactions that allow life to reproduce. Along with energy, we must make sure that any planet has a protective atmosphere that keeps the radiation from a sun out, while still keeping the planet warm.

Of course, life also needs nutrients that will help sustain it. The atmosphere of a planet or moon can even provide these. Methane, for instance, can produce carbohydrates and fats, which might contribute to my mandatory-cheese-and-wine planet [source: NASA]. These systems need to be able to replenish nutrients, which is no problem if your planet has events like volcanic eruptions or weather systems that produce water.

But here's the rub: While scientists can pretty confidently assert those things might be necessary for life on Earth, we should remember that we're basing all our assumptions on, well, Earth. We can't know for sure if other planets or moons could be harboring a "life" form that doesn't require the same things Earth-bound systems do. In the meantime, we'll look for the planets with nutrients, energy and water.

Comments

4 Best Personal Finance Apps of 2018

Managing money, sticking to a budget and even handling investment decisions are easier than even before with today's crop of personal finance apps. But not every tool out there is actually worth downloading and learning to use. You can take some of the guesswork out of moving your finances to mobile with this list of the best personal finance apps for 2018. 1. Mint: Best app for managing your money. Hands down, the free Mint app from Intuit Inc. (INTU) – the name behind QuickBooks and TurboTax – is an effective all-in-one resource for creating a budget, tracking your spending and getting smart about your money. You can connect all your bank and credit card accounts, as well as all your monthly bills, so all your finances are in one convenient place – no more logging in to multiple sites. Mint lets you know when bills are due, what you owe and what you can pay. The app can also send you payment reminders so you can avoid late fees. Based on your spending habits, Mint even gi...

Jackie Robinson in Reverse, Eddie Klep Integrated Negro Leagues

WASHINGTON President Bush presented the Congressional Gold Medal to the family of Jackie Robinson this week, in posthumous honor of the man who broke through major league baseball’s racial barrier in 1947. Unmentioned and unmourned was the late Eddie Klep, who crossed baseball’s color line a year earlier in the opposite direction. Klep was the first white man to play Negro League ball. A short-lived pioneer, he washed out in his first season as a Cleveland Buckeye. A few years later he was wearing the uniform of the Rockview (Pa.) State Prison baseball team. In talent, character and impact, he was no Jackie Robinson. But Eddie Klep’s exploits, such as they were, serve as a reminder that integration is a two-way street. Beyond the brave tales of celebrated black breakthroughs, the path toward racial progress is also adorned with intriguing stories of white Americans willing to go where others feared to tread, everyday people distinguishing themselves with simpl...

Subtle ways to change your life - Nudge theory.

The nudge theory The theory states that small changes when subtly encouraged can lead to big results . The nudge theory enables us to focus on the minuscule aspects of our life that makes up the big goal or the main objective we desire. The subtle tasks could include setting your alarm 5minutes earlier to encourage you to be prompt. This is a typical example of you nudging yourself to becoming a major partaker in your life’s goals. Hence, there are 7 main steps to encourage you to nudge yourself to task completion: 1. Pursue a single goal that contributes to your well-being, set targets and deadlines: As humans, we tend to fixate on goals we think makes us happy. Say for example, your goal may be to buy a sport car which you think makes you happy, the irony is that it isn’t realistic. Even according to research, the 5 top factors that improves well-being are: social relationship, health and activity, generosity, learning new things and building curiosity. So, it is very impor...

The Art of Reading

Search This Blog