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Aliens are likely huge, says scientist

Aliens are likely huge, says scientist

This video game publicity image released by 2K Games shows extraterrestrial invaders in “XCOM: Enemy Unknown.” (AP Photo/2K Games, File)

If you’re traveling to distant planets anytime soon, you might think twice about raising a ruckus: The inhabitants likely weigh an average of 650 pounds, a cosmologist says.

Apparently it all comes down to planet size and the conservation of energy,CNET reports. “Throughout the animal kingdom, species which are physically larger invariably possess a lower population density, possibly due to their enhanced energy demands,” says Fergus Simpson of the University of Barcelona.

That’s quite true on Earth, where we have seven billion (relatively big) people, and, the BBC noted last year, up to 100 trillion (tiny) ants.

Which brings us to outer space, where, Simpson says, “most inhabited planets are likely to be closer in size to Mars than the Earth.” And “since population density is widely observed to decline with increasing body mass, we conclude that most intelligent species are expected to exceed 300kg (660lbs),” he adds.

A scientist in Scotland says Simpson’s “average size calculation is reasonable,” but doesn’t account for gravitational pull—and planets with stronger gravity would probably have smaller animals, Newsweek reports.

SETI Institute researcher Seth Shostak says Simpson’s paper, published at arXiv.org, also leaves out evolutionary theory: With humans, for example, it’s our ability to walk upright and use opposable thumbs that gave us the upper hand on Earth.

“Polar bears are large but do not write great literature and build radio towers,” he says, “and a lot of that is probably because they are walking around on all fours.” (See which moon is the top contender for life outside Earth.)

This article originally appeared on Newser: Scientist: Aliens Are Likely Huge

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Astronomers Have Found the First Earth-Sized, Habitable Zone Planet

Astronomers Have Found the First Earth-Sized, Habitable Zone Planet

Robert T. Gonzalez

4/17/14 12:05pm

Scientists today announced the discovery of Kepler-186f, a faraway planet that’s perhaps the most Earth-like yet discovered. It’s the same size as our home world, and at the right distance from its parent star to have liquid water. So, have we at last discovered Earth 2?

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Above: An artist’s conception of Kepler-186f Credit: NASA Ames/SETI Institute/JPL-CalTech

“The ultimate goal of all this searching for exoplanets – the real reason we’re doing this – is to answer the question ‘are we alone?'” So says Tom Barclay, a research scientist working with NASA’s planet-hunting Kepler mission, and co-author of the paper recounting the discovery of Kepler-186f, published in today’s issue of Science.

Barclay says that the answer to that big, ultimate question is almost certainly contained in the answers to a host of smaller ones, starting with: Are there other places out there like Earth? Today, Barclay tells us, it’s clearer than ever that “the answer to that question is ‘Yes.'”

A Habitable World

Kepler-186f shares a number of key characteristics with our home planet. For starters, it’s roughly the same size. Size is important when it comes to planets. Astronomers suspect that smaller bodies tend to be more rocky, and less gaseous, than larger worlds. How does Kepler-186f rank relative to the exoplanets we’ve discovered to date? When Kepler scientists announced a year ago the discovery of Kepler-62f, a planet roughly 40% bigger than Earth, they called it one of the most similar objects to Earth yet discovered. Kepler-186f, by comparison, is a mere 10% bigger than Earth. In fact, of the five planets that make up the Kepler-186 system, not a single one of them possesses a radius more than 1.5-times that of our home planet.

But planets that are Earth-sized (and smaller) have been detected before. What really sets Kepler-186f apart is its distance from its parent star. The outermost planet in its solar neighborhood, Kepler-186f orbits at the edges of what astronomers call the “habitable zone” of its star, i.e. the region around a star within which planets can potentially host liquid water and, scientists believe, life.

For a planet to be habitable, it must engage in something of a balancing act. It needs enough solar radiation to keep its water in a liquid state, while still remaining distant enough to keep that water from vaporizing outright. There are other things that can dictate whether a planet can host water – how much radiation its atmosphere lets through, for example – but it’s this not-too-much, not-too-little business that astronomers see as the biggest key to habitability (and why the habitable zone is known colloquially as the “Goldilocks Zone”).

A Very Different Sun

Barclay says there’s one major characteristic Kepler-186f doesn’t share with Earth. In Kepler-186’s size and orbital distance, he says, “we have two things that we would need to call it an Earth twin,” but a true twin, Barclay says, would orbit a Sun-like star. Kepler-186f orbits an M-dwarf, a class of star cooler and dimmer than our own. If you want to get technical, Barclay says, Kepler-186f “isn’t so much an Earth-twin as it is an Earth cousin.”

But these two cousins could still look an awful lot alike. Barclay says that because Kepler-186f receives roughly one-third the energy that we do on Earth, the light it receives would appear redder, its sun a few shades oranger than our own. We don’t know if the planet has an atmosphere, but, assuming the gases surrounding it are similar to those enveloping Earth, its skies would appear slightly duller than what we’re used to here at home. A sunny day on Kepler-186f, he says, would look similar to a day here on Earth about an hour before sunset.

Two Out of Three Isn’t Bad

Kepler’s mission is to find planets that meet three criteria: they must be rocky, Earth-like worlds; they must be within habitable zones; and they must have stars like our own Sun. A find like Kepler-186f, which meets two of those three criteria, suggests the search for Earth 2.0 could be nearing its end. “What we’re seeing more and more is that there are places that do look like Earth out there, that remind us of home,” says Barclay.

So what’s the holdup on that third criterion? According to Barclay, Earth-like planets orbiting Sun-like stars take longer to identify and confirm than those orbiting relatively wimpy stars like M-dwarfs. There are two big reasons for this. The first is that Kepler detects exoplanets by measuring how much light they block when they orbit in front of their parent stars. Astronomers call this a “transit.”

When a planet transits its parent star, Kepler detects a brief dip in the star’s light – but the ratio of planet size to star size affects how obvious that signal is. Imagine a tennis ball flying across the face of one of those big, honking prison spotlights. Now imagine that same tennis ball flying across the face of a cheapo, handheld flashlight. Bigger, brighter stars are like the prison light, while smaller, cooler ones (like M-dwarfs) are more like the handheld; if you fix the size of the planet and shrink the the size of the star, the signal goes up, making its orbiting planets easier for Kepler to detect.

The second reason is that cooler stars tend to have planets with smaller orbits. A smaller orbit means you can spot more transits in a smaller window of time, and say with greater certainty that the signals you’re picking up are, in fact, attributable to orbiting planets. Kepler might expect to see an Earth-like planet transit a Sun-like star roughly once every 365 days. The scientists observing Kepler-186f saw it pass before its parent star at more than twice that frequency. Remember: Kepler’s only been in orbit since 2009. In a few years, we could be up to our ears in planets that meet all three of the criteria laid out above. In fact, astronomers have made it clear that they expect this. It’s really just a matter of time.

All that being said, it’s unlikely anyone reading this will ever set foot on Kepler-186f. At 500 light years away, it’s not exactly in our backyard, cosmically speaking. But it is a landmark discovery, nonetheless – and there’s no telling what we’ll find tomorrow.

Read the full details on Kepler-186f, and the rest of the Kepler-186 system, in today’s issue of Science.

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Earth: Judgment Day (flash fiction)

An unpublished flash fiction by yours truly.  Not for everyone, but I hope you like it.

judgment day

Earth:  Judgment Day

by Michael Bradley

Andrew looked up at the sky, so pretty, blue and distant.  He sighed heavily.

Dennis heard him and turned, “How do you know for sure?”

“They told me Dennis.  They appeared to me and said it was Judgment Day, and they would pour out destruction upon the Earth and start anew.”  Andrew look at the soft turf growing from the rich soil.

“How do you know they were real?  Maybe you just ate something that made you hallucinate?”

Molly strolled over, hearing the part from Dennis.  “Hey Andrew, hey Dennis!  What’s this I hear you telling everyone Andrew?”

Andrew appreciated the beauty of young Molly.  If they had any time left, he could see himself raising a family with her.  Now, what was the point?  “The world ends today Molly, at least for us.”

“How could you know that?  Why say such terrible things Andrew?”  Molly choked back a sob.  “It’s so nice out today, why ruin it with all this doomsday talk?”

Andrew thought about that.  Why ruin the day indeed?  What difference would it make?  Why not let them enjoy their last few hours in ignorance?  Andrew looked at his friends.  “You’re right, it must have just been something I ate.  I’m sorry, I’ll stop talking about it.”

Dennis and Molly, satisfied and peace restored to their moods, took off running.  Hunger overrode conversation.

Andrew looked back at the sky.  How long will it be now?  They had come to him in some sort of flaming object from the sky.  Cloaked in bright white light with wings of white feathers and flaming shafts in their arms.

The middle of three communicated to him, but in his mind, there had been no words spoken.  He saw visions of Creation, how the one great spirit had made the Earth, the sky above, the creatures that lived in it.  These three were his angels, spirits that lived with him in peace and looked after the Earth.

There were legends and religions among them for thousands of years that they had been created and this life was but a test.  One day, Judgment Day, they would be weighed and found worthy or be destroyed.  Andrew was horrified to find that all life on the planet had been found wanting.  The day of destruction would be today.

Andrew remembered with fear the images of a huge stone being directed at Earth from the skies.  It would hit with tremendous power, followed by a change in everything.  All life as Andrew knew it would cease.  The Earth would be made new, and the spirits would try again.

Andrew was fearful.  There was nothing he could do.  He could not stop the rock from falling, and telling his friends just made them sad.  He felt rooted to this spot.  Why had the angels told him?

He remembered the parting message, that in an instant, he would be transformed into a creature of light.  He was the last soul to be saved.  Everyone else had turned to fighting and killing, selfishness, greed, and had rejected the Creator.  Judgment Day had been postponed to squeeze out every last successful spirit.  That spirit was Andrew.

If only Molly or Dennis could come.  He had asked the angels, can I take my friends?

They smiled but said ‘no’ inside his mind.  It would be alright they reassured.  A travel through light, then all would be forgotten of this world.  He would feel peace, love, and be able to look after those who would come next.  He was told it would be a long time, but that time would not matter anymore.

Still, Andrew hated to say goodbye.  He just stood looking at the sky, waiting.

Then, it came.  The sky darkened, the ground shook, temperature rose and there was a sudden shock.  Andrew the dinosaur left his mortal coils.

Millions of years later, he watched as spirits were placed into the small pale mammals called humans.  He cheered them on, hoping they would last longer than his people, but he was to be disappointed.

 

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Calculate Your Age on Other Planets

Calculate Your Age on Other Planets

To calculate your age on other planets, go here:

http://www.stumbleupon.com/su/1qn2IT/:MCPwjZdf:Z2eCLwS_/www.exploratorium.edu/ronh/age/

Below is a partial listing of the link to give you an idea of how it works.  Enjoy!

 

Want to melt those years away? Travel to an outer planet!


  • Fill in your birthdate below in the space indicated. (Note you must enter the year as a 4-digit number!)
  • Click on the “Calculate” button.
  • Notice that your age on other worlds will automatically fill in. Notice that Your age is different on the different worlds. Notice that your age in “days” varies wildly.
  • Notice when your next birthday on each world will be. The date given is an “earth date”.
  • You can click on the images of the planets to get more information about them from Bill Arnett’s incredible Nine Planets web site.

MM DD YYYY

 


 

MERCURY

Your age is  Mercurian days
 Mercurian years
 

Next Birthday 

VENUS

Your age is  Venusian days
 Venusian years
 

Next Birthday 

EARTH

Your age is Earth days
 Earth years
 

Next Birthday 

 


 

MARS

Your age is Martian days
 Martian years
 

Next Birthday 

JUPITER

Your age is Jovian days
 Jovian years
 

Next Birthday 

SATURN

Your age is Saturnian days
 Saturnian years
 

Next Birthday 

 


 

URANUS

Your age is Uranian days
 Uranian years
 

Next Birthday 

NEPTUNE

Your age is Neptunian days
 Neptunian years
 

Next Birthday 

PLUTO

Your age is Plutonian days
 Plutonian years
 

Next Birthday 

 


 

 

The Days (And Years) Of Our Lives

Looking at the numbers above, you’ll immediately notice that you are different ages on the different planets. This brings up the question of how we define the time intervals we measure. What is a day? What is a year?The earth is in motion. Actually, several different motions all at once. There are two that specifically interest us. First, the earthrotates on its axis, like a spinning top. Second, the earthrevolves around the sun, like a tetherball at the end of a string going around the center pole.

The top-like rotation of the earth on its axis is how we define the day. The time it takes the earth to rotate from noon until the next noon we define as one day. We further divide this period of time into 24 hours, each of which is divided into 60 minutes, each of which is broken into 60 seconds. There are no rules that govern the rotation rates of the planets, it all depends on how much “spin” was in the original material that went into forming each one. Giant Jupiter has lots of spin, turning once on its axis every 10 hours, while Venus takes 243 days to spin once.

The revolution of the earth around the sun is how we define the year. A year is the time it takes the earth to make one revolution – a little over 365 days.

We all learn in grade school that the planets move at differing rates around the sun. While earth takes 365 days to make one circuit, the closest planet, Mercury, takes only 88 days. Poor, ponderous, and distant Pluto takes a whopping 248 years for one revolution. Below is a table with the rotation rates and revolution rates of all the planets.

 

Planet Rotation Period Revolution Period
Mercury 58.6 days 87.97 days
Venus 243 days 224.7 days
Earth 0.99 days 365.26 days
Mars 1.03 days 1.88 years
Jupiter 0.41 days 11.86 years
Saturn 0.45 days 29.46 years
Uranus 0.72 days 84.01 years
Neptune 0.67 days 164.79 years
Pluto 6.39 days 248.59 years

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There’s more water on Jupiter’s moon Europa than there is on Earth

 

 

 

 

 

Excerts from the Article posted on  May 24, 2012  1:30 PM  by Robert T. Gonzalez:

“Remember that image from a few weeks back that showed Earth with all its water gathered up in a sphere beside it? Well here’s that image again, only this time, it also features Jupiter’s moon Europa, along with all of itswater. Notice anything interesting?

Based on data acquired by NASA’s Galileo satellite, astronomers think the global oceans sloshing around beneath Europa’s icy exterior are likely 2—3 times more voluminous than the oceans here on Earth. Not 2—3 times more proportionally, 2—3 times more in total volume.

Yeah. That “little” moon is packing quite the supply of H2O — and with it, scientists think, a significant chance of harboring life.”

It is pretty amazing to me that within in our own solar system there is a moon with so much water on it.  Some have speculated about drilling through the ice and searching for life underneath the frozen surface.  Others about mining it for water.  What would happen if we found a moon with that much oil on it?  Would we have huge oil barges and worry about space spills?

Also, if you look at the globe sans all its water, doesn’t it remind you of the new M&M commercials with the brown M&M they think is naked because it has no shell?  The Earth is meant to be the Big Blue Marble, not the dusty grey ball…

 

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