The Future of New Horizons: Beyond Pluto

With the historic fly-by of Pluto last month, NASA’s New Horizons spacecraft gave us an up-close look at the former 9th planet, showing that it is a dynamic world with icy plains, tall mountains, and an atmosphere.  But now that New Horizons has passed by Pluto, it has the infinite cosmic horizon in its stead.  So what’s next for the $700 Million spacecraft? Its battery will keep it going for a few more decades, and it will likely pass beyond the edge of the solar system, in the stead of the Voyager crafts.  What else is ahead?

An artist’s conception shows the New Horizons spacecraft flying past a Pluto-like object in the Kuiper Belt, the ring of icy material that lies billions of miles away from the sun. (Credit: Alex Parker / NASA / JHUAPL / SwRI)

The good news is that, as vast and empty as space is, there are a lot of small islands of rock.  Most are icy bodies several kilometres across, most akin to comets than planets.  But understanding the large population of what we call Kuiper Belt Objects (KBOs), gives us insights into the abundance of raw materials that were present 4.5 Billion years ago during the formation of the solar system.  Understanding what was there can help us understand what life needs to develop, and what life on Earth used during its 3 Billion years of evolution.

The most promising of the icy rocks that happen to pass close to the trajectory of New Horizons is called 2014 MU69, an icy rock suspected to be about 50 kilometres wide.  There were actually three candidate objects for New Horizons to target, but 2014 MU69 was chosen because there is a 100% chance of reaching it with the fuel that the spacecraft has left after the Pluto flyby.

This chart shows the path of NASA’s New Horizons spacecraft toward its next potential target, the Kuiper Belt object 2014 MU69, also known as PT1. Other dwarf planets are indicated on the chart as well. (Credit: Alex Parker / NASA / JHUAPL / SwRI)

The flyby won’t take place for another four years, in 2019, but it also depends on a mission extension that the New Horizons team will have to apply for next year.  Presuming all goes well we should get an up close view of a KBO that we have never seen before.  In the meantime, New Horizons continues to send back data from the Pluto flyby, and once analysed, we should see some new and interesting science yet to come from Pluto.

Why does this Nebula Have Two Lobes?

I am always fascinated by the diversity of colours, shapes, and scenarios that pop up throughout our universe.  Even though we can classify things into categories like ‘planetary nebula,’ ‘galaxy,’ ‘dwarf star,’ and such, there is still a huge amount of variability among these categories.  The most diverse group may be nebulae, since their shape relies on what elements are present, the environment in which they formed, and how far along they are in their evolution.  A great example of a strange and interesting nebula is the PN M2-9, the Twin Jet Nebula.

Hubble image of the Twin Jet Nebula. Image credit: NASA / ESA / Hubble / Judy Schmidt.

Lying 5,560 light years away, in the constellation Ophiuchus, it clearly has two visible lobes of material jetting out from the centre.  Planetary nebulae result from the death of a star with similar mass to our Sun.  In the case of the Twin Jet nebula, the streams are being produced by two stars forming a binary system.  One of the stars is an evolved white dwarf, while the other is a sun-like star at the end of its life, spewing out material.

The shape of the wings is likely due to the motion of the stars around each other and how they interact gravitationally. There is still some debate as to whether all bipolar nebulae are caused by a double star system, but the Twin Jet nebula certainly is, and it is still expanding.

Calculations show that the nebula formed only about 1200 years ago, which is not long at all in astronomical terms, especially when the two stars take 100 years to orbit each other. The orbit also allows the white dwarf to accrete material from the larger star, which forms a huge disk around the pair that extends far from the stars.  If the white dwarf continues to absorb material from the other star, it will eventually reach the 1.4 solar mass limit and explode as a supernova.

The galaxy has some pretty amazing hidden treasures.

Earth May Have 1,500 Undiscovered Minerals

Minerals are formed when geological or biological activity create unique combinations of elements. The type of mineral you get is dependent on the environment in which it forms.  For geological minerals, pressure and temperature can vary to give different combinations that are difficult to replicate in a lab.  For biological minerals, life slowly but surely undergoes processes that shift and shape minerals, usually as a waste product from obtaining energy. But with 3 billion years of life forming and reforming on our planet, springing up new diversity and losing countless species to extinction, there may be minerals that we simply haven’t heard of, residing deep underground waiting to be discovered. But which process gives rise to more minerals? Biological or Geological?

A rhodochrosite specimen from Butte, Mont. Credit: Robert Downs

About ten years ago, Robert Hazen from the Carnegie Institution showed that the two-thirds of the diversity seen in Earth’s minerals primarily arose as a byproduct of life, and specifically around 2.4 Billion years ago with the rise of photosynthesis in plants. This gave the planet an atmosphere rich in oxygen.

Now, taking it one step further, Hazen and colleagues are using statistical models of ecosystem research and analysis of mineralogical databases to study the potential of our ecosystem to produce minerals, and the results are fascinating.

They calculated that there is a 22 percent chance that a particular mineral is found in only one place on Earth, while 65 percent are found in 10 or less places, called localities.  This means that most minerals should be rare.

“Minerals follow the same kind of frequency of distribution as words in a book,” Hazen explained. “For example, the most-used words in a book are extremely common such as ‘and,’ ‘the,’ and ‘a.’ Rare words define the diversity of a book’s vocabulary. The same is true for minerals on Earth. Rare minerals define our planet’s mineralogical diversity.”

The research suggests that as many as 1,500 minerals are somewhere on the planet waiting to be found, or once existed somewhere on Earth in the past.   However, there are patterns to the missing minerals.  Colour is a big one, since white minerals may be tougher to distinguish from other rocks.  Hazen has predicted that about 35% of Sodium minerals haven’t been discovered due to poor crystallization, solubility in water, and white colour.

The Earth’s mineral composition also acts like a fingerprint, with the specific history of the planet leading to what we see. “This means that despite the physical, chemical, and biological factors that control most of our planet’s mineral diversity, Earth’s mineralogy is unique in the cosmos,” Hazen said.

 

Mysteries Between Stars

We know that solar systems form in a disk shape, with the star forming in the middle and any other rocks, presumably planets, form out from the center in whatever dust and gas remains. But what about the space between stars? Is it truly empty? And if there is something out there, how could we find it? How did it get there?

This artist’s conception symbolically represents complex organic molecules, known as polycyclic aromatic hydrocarbons, seen in the early universe. These large molecules, comprised of carbon and hydrogen, are among the building blocks of life. Credit: NASA/JPL-Caltech/T. Pyle (SSC)

For years, astronomers and chemists (believe it or not) have been trying to answer these questions and more.  The specific problem is that when we take a spectrum of a distant star, we see a collection of 400 or so absorption features that have been named the Diffuse Interstellar Bands (DIB).  After decades of research, the identity of the DIBs remain elusive, though research seems to indicate that they are formed by a collection of hydrocarbon molecules that have not been reproduced in a laboratory on Earth, and hence do not have a recorded spectrum.

Diffuse Interstellar Bands shown across the visible spectrum.

Of all the potential candidate molecules, Polycyclic Aromatic Hydrocarbons (PAH) are considered the most promising, since they have been observed in the interstellar medium previously.  However, the width of the DIB features, which indicate the lifetimes of excited states in the absorption process, are considered an argument against PAHs.

However, astronomers from university of Lyon aided by theoretical input from scientists at the universities of Heidelberg, Hyderabad and Leiden, have performed an experiment showing that the lifetimes of excited states for small and medium sized PAHs are consistent with the DIB line widths.

People often ask me how often I get to look at telescopes as an astronomer, and the answer is not very much.  Astronomy is a science that is influenced by technology and a wide range of other sciences performed in laboratories all around the world.  Chemistry, Biology, Geology, and Climatology are just some of the sciences that help us uncover the mysteries of the universe, both large and small scale.

Future laboratory work will help us pinpoint the culprit when it comes to the DIBs, giving us an understanding of what is actually happening in the vast space between stars.

Astrophotography Reflections

I was doing my daily check of some astronomy and space news sites to see what was happening today, as I do every morning before I decide what to write about in my daily blog post.  I looked at today’s astronomy picture of the day, a gorgeous work of astrophtographic art showing Mt.Rainier and dozens of meteors, all in front of the sharp filaments of gas of the Milky Way.

Image Credit & Copyright: Matthew Dieterich

As a newbie in the world of astrophotography, I look at this picture and try to think about how it was done.  Did he take a foreground shot to get the mountain and then a series of 30 second exposures for the meteors and Milky Way? I want to be able to produce images like this some day, but I am still on the long journey to learn how.  I’ve had many clear nights this summer to get outside and take some pictures, and I’ve done pretty well, but I still have to master the skill of which images to take, how long for each exposure, and how to properly post-process the images to get the best out of them.

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I am good when it comes to Moon and planet shots, like the one above with Luna and Venus, but it’s those pesky star shots that get me.  Beyond that the Milky Way images are even tougher.  I will post my latest post-processed images as I can, and hopefully we all see a pattern of progression in the way my shots turn out.

Actually doing astrophotography reveals a lot of truths about space and light.  It shows that most of the gorgeous images from space taken by the biggest and best telescopes are incredibly enhanced to be beautiful to human eyes.  The real images of a galaxy or a nebula are much less colourful and much more likened to fog when seen with our biological cameras.  It makes sense, since we have evolved to enjoy the beauty of the oceans, mountains, and forests constituting the bright world around us.

The beauty of the universe is not, however, locked up in the pictures we see.  The true beauty of the universe is in the interactions of matter and energy. It’s in the understanding of the vastness of the dark cosmic ocean.  It’s in our growing yet primitive understanding of the laws that govern the evolution of the structures within and how we use those laws to predict the future and reveal the past. Our modern technology simply allows us to take the flows of foggy photons and turn them into what astronomers already see when we look through the eyepiece of a telescope, so that the rest of the world can enjoy the beauty of it all in their own tangible way.