Largest planets likely formed first from icy “planetary pebbles”

This artist’s concept of a young star system shows gas giants forming first, while the gas nebula is present. Southwest Research Institute scientists used computer simulations to nail down how Jupiter and Saturn evolved in our own solar system. These new calculations show that the cores of gas giants likely formed by gradually accumulating a population of planetary pebbles — icy objects about a foot (30 centimetres) in diameter. Image credit: NASA/JPL-Caltech.

Researchers at Southwest Research Institute (SwRI) and Queen’s University in Canada have unravelled the mystery of how Jupiter and Saturn likely formed. This discovery, which changes our view of how all planets might have formed, will be published today in Nature.
Ironically, the largest planets in the solar system likely formed first. Jupiter and Saturn, which are mostly hydrogen and helium, presumably accumulated their gasses before the solar nebula dispersed. Observations of young star systems show that the gas discs that form planets usually have lifetimes of only 1 to 10 million years, which means the gas giant planets in our solar system probably formed within this time frame. In contrast, the Earth probably took at least 30 million years to form, and may have taken as long as 100 million years. So how could Jupiter and Saturn have formed so quickly?

The most widely accepted theory for gas giant formation is the so-called core accretion model. In this model, a planet-sized core of ice and rock forms first. Then, an inflow of interstellar gas and dust attaches itself to the growing planet. However, this model has an Achilles heel; specifically, the very first step in the process. To accumulate a massive atmosphere requires a solid core roughly 10 times the mass of Earth. Yet these large objects, which are akin to Uranus and Neptune, had to have formed in only a few million years.

In the standard model of planet formation, rocky cores grow as similarly sized objects accumulate and assimilate through a process called accretion. Rocks incorporate other rocks, creating mountains; then mountains merge with other mountains, leading to city-sized objects, and so on. However, this model is unable to produce planetary cores large enough, in a short enough period of time, to explain Saturn and Jupiter.

“The timescale problem has been sticking in our throats for some time,” said Dr. Hal Levison, an Institute scientist in the SwRI Planetary Science Directorate and lead author of the paper. Titled “Growing the Gas Giant Planets by the Gradual Accumulation of Pebbles,” the paper is co-authored by SwRI Research Scientist Dr. Katherine Kretke and Dr. Martin Duncan, a professor at Queen’s University in Kingston, Ontario.

“It wasn’t clear how objects like Jupiter and Saturn could exist at all,” continued Levison. New calculations by the team show that the cores of Jupiter and Saturn could form well within the 10-million-year time frame if they grew by gradually accumulating a population of planetary pebbles — icy objects about a foot (30 centimetres) in diameter. Recent research has shown that gas can play a vital role in increasing the efficiency of accretion. So pebbles entering orbit can spiral onto the protoplanet and assimilate, assisted by a gaseous headwind.

In their article, Levison, Kretke, and Duncan show that pebble accretion can produce the observed structure of the solar system as long as the pebbles formed slowly enough that the growing planets have time to gravitationally interact with one another.

“If the pebbles form too quickly, pebble accretion would lead to the formation of hundreds of icy Earths,” said Kretke. “The growing cores need some time to fling their competitors away from the pebbles, effectively starving them. This is why only a couple of gas giants formed.”

“As far as I know, this is the first model to reproduce the structure of the outer solar system, with two gas giants, two ice giants (Uranus and Neptune), and a pristine Kuiper belt,” says Levison.

“After many years of performing computer simulations of the standard model without success, it is a relief to find a new model that is so successful,” adds Duncan.

With Just A Few Ingredients, You Can Make Your Very Own Shampoo!

Most people wash their hair a few times a week, if not every day, so it's understandable that we go through giant containers of shampoo and conditioner in no time. If you're picky about what you put on your body or are especially sensitive to chemicals, finding hair products that work for you can be tough. It can also get pretty expensive.

If you've exhausted your patience (and your bank account), check out this quick tutorial, which teaches you how to make your own shampoo!

Who knew all you really needed was coconut milk, baby wash, and almond oil to make shampoo? I'm tired of looking at the back of bottles not knowing how to pronounce any of the ingredients -- so this is perfect for me!

Will you try this trick out?

Google's terrifying humanoid robot runs through forest

A terrifying humanoid robot was built by Boston Dynamic.They built a one of a kind humanoid robot that can walk through the forest and surpass obstacles.
They say "this robot may not like us, who can do everything, but if they will get pushing, they maybe have it in the future".
Watch the entire video of how amazing this robot, and of what capabilty it can do.

However, it's the humanoid robots that begin to make one fear that the prawns from the movie "District 9" were mere pets compared with what our scientists might think up.

Balance and dynamics are the two main thrusts of humanoid robot development. But when Boston Dynamics founder Marc Raibert shows the six-foot-tall Atlas humanoid robot marauding through the woods, you wonder about the juxtaposition between future and nature.

This robot looks like one of those people/things that want to stab characters in movies. If he/she/it suddenly produced a chainsaw, I wouldn't be surprised.

When it breaks into a trot, you get the sense that it has spotted someone it needs to assault and will continue to advance until its preprogrammed task is complete. A tree would be safer from it than a human.

It's not hard to conceive that we might be looking at the future boots on the ground, as the saying goes. This would make for a fearsome soldier.

Raibert admits Atlas isn't quite human yet. However, he said: "You can imagine if we keep pushing, we'll get there."

I think I can imagine, yes. I imagine that this Atlas isn't so fond of shrugging as he is of relentlessly pursuing.

This Mysterious Disease Causes Its Victims To Cry Sharp Crystals

No matter how advanced science becomes, some medical oddities will always perplex doctors and researchers alike.
At least two people on Earth suffer from a rare condition that sounds like the most self-damaging mutant superpower since Rogue's inability to touch those she loves. Inexplicably, this condition causes its victims to cry hard, glass-like crystals. The condition is so rare that it doesn't even have a name.

Very little is known about this affliction, and at this point, scientists can only make educated guesses about its cause.

YouTube / massieVtech

The most popular theory is that a patient's tears aren't protecting the cornea from bacteria, causing their eyes to resort to more desperate measures.

These eyes create a layer of keratin, which remains liquified until coming into contact with air, which causes crystallization.

YouTube / massieVtech

Hasnah Mohamed Meselimi is a 12 year old Labanese girl and one of the patients with this bizarre condition. Watch as she produces several crystals from her eyes and act like its nothing!

The intensity of the crystallization appears to vary between the two known patients. As you saw in the video, Hasnah, is said to cry seven razor-sharp crystals a day, and she says the crystals don't appear to do significant damage to her eyes. In the second case, a Brazilian woman says that the 30 crystal tears that she cries every day are immensely painful.

What These Two Magnets Can Do Together Will Make Your Day

Let's be real. The only people who understand how magnets work are scientists and students who happen to be studying them right this second. What we do know about them, however, is that they stick to metal and they are repelled by other magnets.

 But who cares about all of that? Let's watch some magnets destroy stuff.

(via mental_floss)
That was way more fun than hearing about the boring science behind it. Sure, that would have been more educational, but sometimes you just want to watch magnets ruin things. It's way cooler. We'll save the learning for school, because right now, it's summertime and we don't care.

Magnets don't just destroy stuff, either. You can use them as the coolest home decor ever.

If You've Been To Yosemite Lately, You Might Want To Go To The Doctor

The year is 2015, but for people who have visited Yosemite National Park lately, it might feel a lot more like 1346. That was the exact year when the bubonic plague, also known as the Black Death, began its sweep through Europe. Now, the plague is back, and in a place much closer to home...

Last week, health officials in California released news that a young child from Colorado, who had visited the park with family, contracted the plague.

Wikimedia Commons

According to officials, the child picked up the disease somewhere in the park while camping with family. However, no other family members contracted the disease.

This comes hot on the heels of another Colorado resident contracting and succumbing to the ancient disease last week.

Flickr/Tim Evanson

Catching the plague can lead to nasty things if left untreated. The bacteria that causes the plague kills you by attacking lymph nodes in the arm pit and groin areas. Within days of contracting the disease, the lymph nodes become swollen and painful. If left untreated, the plague can kill its victims within four painful days. Other plague symptoms include vomiting blood, aching limbs, and gangrene of the fingers and toes.

The primary carriers of the plague are oriental rat fleas.

Wikimedia Commons

Rat fleas primarily feed off of rats and make the jump to humans when they're in close quarters together.

At the moment, park officials are urging people to take precautions about the plague.

Wikimedia Commons

Officials are advising people to avoid dead animals and treat their clothes with bug spray while hiking. Those who suspect they might have contracted the plague are advised to seek medical attention immediately. Catching the disease in time is the key to combatting it.

While we're pretty far from mass graves of plague victims, you can never be too safe about a disease like this.

Wikimedia Commons

Will 2015 be the new 1346? Probably not, but it is a terrifying prospect to imagine. The plague has been around for a long time. Perhaps it's due for an evolutionary overhaul?

Watch This Awesomely Gross Parasite Come Out Of A Dead Praying Mantis

Don't you just hate mind-controlling parasites? They might be my least favorite aspect of the animal kingdom, especially ones that mess with awesome bugs like the praying mantis. Sadly, these villainous, vile creatures are very real, and they are truly terrifying.

Horsehair worms, the most common of these parasites, hitch a ride into their host — usually bugs like beetles, cockroaches, or mantises — through infected water. Then, when the time is right, they hijack the brain of their host and force it to drown itself. This is so the worm can return to water to breed.

Sometimes, though, that doesn't always work out, as you can see in the video below. WARNING! This is not for the squeamish.

This just makes me afraid of everything now. How long until these worms evolve with the capability of controlling human minds and making us drown ourselves!? I don't even want to think about that.