ICYMI: CME Week, Climate Summit, Earth's ancient water and a star older than the Universe?

Friday, September 26, 2014, 6:20 PM - This past week has seen some great science stories. Here's some you may have missed.

CME Week at NASA

Coronal Mass Ejections, or CMEs, are incredible eruptions from the Sun, which can hurl billions of tons of solar matter into space. Since Earth only takes up a very small bit of the space around the Sun at any time, most of these eruptions miss the planet. However, when they go off in our direction, they can produce some spectacular and sometimes worrisome effects. The magnetic field generated deep inside the Earth protects us from any direct impacts from these eruptions, but we can see spectacular auroras at higher latitudes, like many witnessed just two weeks ago.

This week, from Sept 22 to 26, was CME Week at NASA, with a week of stories specifically about these solar eruptions and their impacts. Included was a primer on the differences between solar flares and CMEs, photos of different kinds of CMEs, a video showing the immense size of the largest CME to ever be witnessed during the satellite era, and this simulation, which compares a fairly moderately-sized eruption from 2006, to the effects of the largest, and very first solar flare and CME on record - the Carrington Event of 1859.

UN summit raises hopes for climate action

With the call to action UN delegates witnessed in the streets of New York City and dozens of other cities around the world last week, all eyes were on them in New York this week. Although no specific deals will come out of this meeting (that will need to wait for the 2015 UN Climate Change Conference in Paris), we heard some of the strongest commitments so far from two of the world's leading emitters of greenhouse gases - the United States and China. With these two countries apparently taking a leading role in curbing emissions and reducing he man-made component to climate change, this gives other nations around the world (who may have been 'holding out' due to the lack of action from these major emitters) the incentive to take action as well. This may lead to an agreement next year that will produce much bigger results than those from the past (such as the Kyoto Protocol).

Some of Earth's water predates the birth of our Sun

Using a model of our early Solar System, an international team of scientists has shown that a significant fraction of the water here, including here on Earth, originated in the coldness of interstellar space, before the birth of our Sun.

Credit: Bill Saxton, NSF/AUI/NRAO

It all comes down to the abundance of deuterium, which replaces hydrogen in water to form what we call heavy water. Deuterium forms much more easily in the cold of interstellar space, so water that comes from there has a much higher ratio of deuterium to hydrogen. Producing a model to simulate the formation of deuterium in the disk of gas and dust that went into forming the objects in our Solar System, the scientists 'started from scratch' with zero deuterium and watched as the abundance in the model disk's water grew over a million years. If all the water in our solar system originated after the Sun ignited, the ratio of deuterium to hydrogen after that million years should have matched what we now see from the water found in Earth's oceans, in meteorites and those 'time capsule' comets we see that are making their first dive around the Sun (like ISON from 2013 and Siding Spring, which passes by Mars in Oct 2014). However, it didn't. The ratio in the model was too low.

"Our findings show that a significant fraction of our Solar System’s water, the most-fundamental ingredient to fostering life, is older than the Sun," Carnegie Institution for Science 'cosmochemist' Conel Alexander said in a press release, "which indicates that abundant, organic-rich interstellar ices should probably be found in all young planetary systems."

In other words, rather than the presence of water in a star system being solely dependent on the local environment, since our solar system drew at least some of its water from interstellar space, its just as likely that every other star system out there did the same. Since water is so essential for life (at least as we know it), this raises the chances that there is life out there in the universe!

The Universe's oldest star might be right in our cosmic backyard

Roughly 200 light years away from our Solar System is a bright subgiant star named HD 140283, which has earned the nickname 'the Methuselah star' due to its extreme age (Methuselah, being the longest-lived man ever, according to the Hebrew Bible).

Source: Hubblesite.org

Why do astronomers think this star is the oldest? Unlike younger stars, like our Sun, which contain some heavier elements, HD 140283 is almost entirely hydrogen and helium. For a star to have almost no heavy elements inside it means that it must have formed in similar conditions. Tracing the age of the universe back to a time when the  like it was during the early the universe, before the first stars went supernova and created the heavier elements.

How old is this star? According to this research, HD 140283 is 14.3 billion years old.

Now, you might say "Hey, the latest data from the Planck telescope revealed that the universe is only a little over 13.8 billion years old, so how can that be?" You'd be right. Scientists have been reliably calculating the age of the universe at around 13.7-13.8 billion years for awhile now, and any updates to that are pretty small adjustments. So, it's very unlikely that HD 140283 is actually 14.3 billion years old. Included in the calculations were errors totaling about plus or minus 800 million years, therefore the star could be as young as around 13.5 billion years, but it's probably a little older than that, which could beat out any other candidates that are also reaching for that coveted title.

Although the authors of this study first presented their findings at a meeting of the American Astronomical Society back in January 2013, their research on HD 140283 was published this month in The Astrophysical Journal (click here for free access from arXiv.org).

Why does this matter? Knowing the precise size, age and distance of a star like HD 140283 can help astronomers gauge those properties in other stars, even when dealing with stars much, much further away, and this improves our fundamental understanding of the universe.