Which two planets can support life?

Three (Venus, Earth, and Mars) out of eight planets might be able to support life. Based on recent discoveries of planets outside of our Solar System, it was estimated that 1 in 5 planets could exist in the habitable zone of their star: Average lifetime of a planet.

futurelearn.com - How many planets in our galaxy can support life? - FutureLearn

Is $2 million enough to retire at 70?

Yes, for some people, $2 million should be more than enough to retire. For others, $2 million may not even scratch the surface. The answer depends...

Last updated Jul 12, 2019

How can I save 1k in 6 months?

How to Save $1,000 in Six Months Open a savings account. I wasn't joking about not keeping the cash in your wallet. ... Automate. Does money burn a...

Last updated Nov 13, 2022

Awaken your dormant DNA ability to attract wealth effortlessly

The simple yet scientifically proven Wealth DNA method laid out in the report allows you to effortlessly start attracting the wealth and abundance you deserve.

Learn More »

Promotion

We can’t expect to find a definitive answer, but we can think about the ingredients needed for life to exist and the probability that it could There was a cascade of extreme events that led to Earth forming and becoming able to support life.

But in general, how likely or unlikely do you think it is that a planet can support life?

Are there other planets in our Solar System that had the potential to support life?

Are there other planets in our galaxy that could support life?

Planets in our Solar System

Let’s start with our Solar System. There are eight planets in our Solar System. Given that liquid water and plate tectonics are two essential ingredients, which of our neighbouring planets have the potential for life (at least in their early days)?

Well, Venus and Mars are thought to have had both plate tectonics and liquid water early in their development.

Planets in our galaxy

What about elsewhere in our galaxy? This question obviously becomes more speculative and we can’t expect to find a definitive answer, but we can think about the ingredients needed and the probability that they could exist.

The Drake equation

There’s a well known equation developed by the American astronomer and astrophysicist Frank Drake, which in part seeks to answer these questions. The equation (or our expression of it) aims to provide a number for N:

N = Number of planets in our galaxy that can support life

Our version of the equation is as follows:

N = R* x fp x ne x L

Value Description R the average rate of star formation in our galaxy fp the fraction of those stars that have planets ne the average number of planets that can potentially support life per star that has planets L the average lifetime of a planet

How to calculate N

By covering the steps and events that led to Earth being able to support life, we can begin to estimate what N might be:

What old pennies are worth saving?

So before you say, “Keep the change,” check to see if you have any of these valuable pennies: 1943 Bronze Lincoln. (Image: Heritage Auctions,...

Last updated Oct 9, 2021

Why do they cover the legs in a casket?

It is always easier to light up the upper half of the body and present the face under the best light. By covering the legs, funeral directors save...

Last updated Sep 23, 2018

Awaken your dormant DNA ability to attract wealth effortlessly

The simple yet scientifically proven Wealth DNA method laid out in the report allows you to effortlessly start attracting the wealth and abundance you deserve.

Learn More »

Promotion

Average rate of star formation in our galaxy. There are roughly seven new stars formed in the Milky Way each year. Fraction of those stars that have planets. When discussing the formation of planets, it is reasonable to assume that nearly all stars have planets orbiting them:

Average number of planets with potential to support life.

Here we could take our own Solar System as an example. Three (Venus, Earth, and Mars) out of eight planets might be able to support life. Based on recent discoveries of planets outside of our Solar System, it was estimated that 1 in 5 planets could exist in the habitable zone of their star:

Average lifetime of a planet.

Planets only exist for a finite length of time. You can assume that the average lifetime of a planet is 10 billion years.

Finding N

Bringing all of these numbers together, here’s the answer we get for N: N = R* x fp x ne x L = 7/year x 1 x 3/8 x 109 year = 7/year x 1 x 0.375 x 109 year = 1.4 x 109 = 2.625 billion An alternative answer: N = R* x fp x ne x L = 7/year x 1 x 1/5 x 109 year = 7/year x 1 x 0.2 x 109 year = 1.4 x 109 = 1.4 billion We may expect to find either 2.625 or 1.4 billion planets with the potential to create and maintain life. The exact number is not important as we are dealing with an estimate that contains large uncertainties. However, the number does indicate that we could be dealing with vast numbers of planets that have characteristics similar to Earth, Venus, and Mars.

futurelearn.com - How many planets in our galaxy can support life? - FutureLearn

How many years was it from Adam to Jesus?

So 69 weeks amount to 483 years; for, from the said year of Darius, unto the 42nd year of Augustus, in which year our Saviour Christ was born, are...

Last updated Jun 3, 2019

Why is the 1944 wheat penny valuable?

The 1944 Lincoln penny is particularly desirable in the eyes of collectors not only because of its design, but also due to its scarcity. Being that...

Last updated Sep 21, 2022

Awaken your dormant DNA ability to attract wealth effortlessly

The simple yet scientifically proven Wealth DNA method laid out in the report allows you to effortlessly start attracting the wealth and abundance you deserve.

Learn More »

Promotion

Which zodiac is classy?

Capricorn Dignified, mature, confident and sorted Capricorn is always the most sophisticated person according to astrology. They never get...

Last updated Dec 18, 2019

Awaken your dormant DNA ability to attract wealth effortlessly

The simple yet scientifically proven Wealth DNA method laid out in the report allows you to effortlessly start attracting the wealth and abundance you deserve.

Learn More »

Promotion

Which planet is pink?

GJ 504b Named GJ 504b, the planet is made of pink gas. It's similar to Jupiter, a giant gas planet in our own solar system. But GJ 504b is four...

Last updated Feb 17, 2019