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Hank brings you news from around the universe, including what you can't blame on global warming, why being unfaithful is hazardous to your health, and how to watch a particularly awesome spectacle coming to a sky near you.

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References for this episode can be found in the Google document here: http://dft.ba/-3jlX
We here at the SciShow news desk are just coming down from our week-long high of Curiosity rover excitement and I can promise you, that you haven't heard the last from me about it.

But! It's time to get up to speed on some other news from around the Universe including what you can't blame on global warming, why being unfaithful is hazardous to your health, and how to enjoy a particularly awesome spectacle coming to a sky near you.

It's about to get smart in here!

{THEME MUSIC PLAYS}

First, let's boost our understanding of what's up with earth, shall we?

You might have recently heard some disturbing climate news coming out of Greenland specifically satellite observations made by NASA in several US universities found that within just a few days in July, nearly all of the ice cover on the island started to melt.

Now, this is true, but the findings have been mischaracterized in a lot of places ranging from media reports to half-baked blogs and backyard summer parties so let me tell you the whole story.

The scary sounding fact is that in less than a week, Greenland's surface ice melted over the largest area ever seen in more than 30 years of satellite observations.

In a typical summer, about half of Greenland's ice sheet undergoes some melting and by July 8th of this year, as you can see in the image on the left, 40% of it had begun to melt.

But just four days later, on July 12, that's the image on your right, a full 97% of the ice had started to thaw including, at the very summit of the sheet, some three kilometers above sea level.

But, undergoing melting or beginning to thaw is not the same thing as completely melting away, which I keep hearing.

NASA's official statement said that nearly all of Greenland's ice sheet "experienced some degree of melting" but it added that after these summer thaws, much of the meltwaters quickly refreeze.

So, in case you're packing your bag for a golfing trip to Greenland, don't! It's still covered in ice.

And, while it's true that satellites have never observed melt this widespread before, there are other records that show it isn't necessarily a unique event.

Ice cores, for instance, hold evidence of melting patterns going back for thousands of years and samples drilled from Greenland's icy summit show that melts like this happen every 150 years or so.

Since the last one happened back in 1889, NASA glaciologist  Lora Koenig said that the last month's melt was "right on time, give or take a couple of decades".

So, I'm happy to finally tell you about something that doesn't seem to be a result of us screwing up our environment but, of course, if Greenland pulls this crap again over the next few years, that's a different story.

And, in case any global warming deniers are tempted to do a victory lap over this one, James Hanson is here to shut your yap.

This week Hanson, the out-spoken NASA climate scientist, published a new study in the journal PNAS, linking recent extreme weather to human-caused climate change.

Hanson and his colleagues compared summer surface temperatures from the past six years to records from 1951-1980. They found that extreme heat, defined as three standard deviations higher than the average temperature, has been much more frequent in recent years. Whereas during the base period it was practically non-existent.

Plus, they found that extreme summers are now affecting about 10% of the world's land area while, from the 50's to 70's, any such events affected less than 1%.

Since the sweltering temperatures we see today were so statistically unlikely more than 30 years ago, the study concludes that recent extreme summers can only be explained by global warming.

And, if you are a regular SciShow News viewer, this isn't news to you. I recently interviewed the senior scientist for the National Center for Atmospheric research, Dr. Kevin Trenberth, who told me that this year's extreme weather, from heat waves across the US to record rainfall in the UK and Russia is, in his words, "climate change in action".

Now, I know some of you are going to fight about this in the comments so I just ask that you keep your flames to yourself. It's hot enough around here already.

You may have noticed that we recently posted an infusion about the evolutionary history of monogamy. If you haven't seen it, you should, because some of you out there could learn a few things. I'm looking at you, Kristen Stewart; you heard me. 

See, all the media blah blah about Stewart cheating on her Twilight co-star, Robert Pattinson, got me thinking about the science of monogamy's natural enemy: infidelity. And the fact is, a lot of research has gone into the behavioral science of cheating and the risks that we run into if we are unfaithful.

For instance, a recent study published in The Journal of Sexual Medicine, found that people's behavior during extra-marital affairs tends to be unhealthy in a lot of different ways.

Psychologists at the University of Michigan interviewed 800 people who were in secret sexual relationships and no, I don't know how they found those people, but they did, and what they found was that they practiced safe sex about 30% less often when they were cheating and they were 64% more likely to use drugs and alcohol during their elicit encounters.  

Furthermore, in 2011 a study of 1700 men in Italy found that those who were in regular, extra-marital relationships were twice as likely to suffer from cardio-vascular disease. The researchers speculated that this was because of all the stress that comes from cheating; from the anxiety of lying to the fear of getting caught and the guilt of not getting caught.

Now, I'm not passing judgment here, though Kristen, really. That man is beautiful-what are you thinking? But, it's worth pointing out that scientists talk about monogamy in two different ways.  Social monogamy is when a pair lives and mates and raises offspring together which is different from sexual monogamy, which is what it sounds like.

Lots of different species practice social monogamy, and it's true that many take part in what scientists are nice enough to call extra-pair copulation but sexual monogamy has also been found in nature including about 10% of songbirds. Also, the California mouse and the African Dik-Dik Dik-Dik, whose name I just enjoy saying...dik-dik. Dik-Dik dik dik dik dik dik.

So, monogamy. It comes in many different forms and so do the ill effects of cheating, and like I always say when I talk about this stuff, I am not a relationship counselor, I am a scientist! I'm not even really a scientist! I'm just a guy who talks about science!

The last thing you want is for the weirdos I work with to give you personal advice.

Finally, friends, I am always looking for chances for you to pursue and enjoy science at home, and this week you have a golden opportunity. That's because tomorrow night, August 11th, and the wee hours of August 12th, marks the height of the Perseid Meteor Shower.  As regular celestial events go, the Perseids are one of my favorites. They're not only one of the most prolific and brightest meteor showers, it's also just hard to beat staying up late on a summer night gazing at the night sky. But maybe that's just me.

The Perseids happen around this time every year because that's when the Earth passes through what's known as the Perseid Cloud, a long trail of dust particles left behind by the comet Swift-Tuttle. As we plow through the cloud those particles, called meteoroids, enter Earth's atmosphere and burn up to create a heck of a light show. 

Because of the tilt of the comet Swift-Tuttle's orbit, the Perseids are only visible from the Northern Hemisphere, so sorry other half of the planet! But for those of you who can see it, look for the constellation Perseus in the Eastern night sky below the W-shaped Cassiopeia and above Orion, that's where most of the action will be.

The best times for viewing are between midnight and the early morning hours, just before dawn. At the shower's peak, you can expect to see as many as 50 meteors an hour. And, since there is a nice waning-crescent moon out, there shouldn't be too much light interference. 

But you don't have to wait until tomorrow to catch the show, the Perseids started a few days ago and will continue until at least the 13th. So, get your lawn chair and some lemonade, loosen up your neck muscles, and enjoy! 

Thank you for watching this episode of SciShow News, if you have any questions or comments or ideas for us, please leave them in the comments below or on Facebook or Twitter. 

And, if you want to keep getting smarter with us here at SciShow, go to http://youtube.com/scishow and subscribe!

We'll see you next time!

{CREDITS THEME PLAYS}