Mark Showalter and his research team at the SETI Institute in Mountain View, California, are on a roll. They’ve shown us yet again how much we have to learn about our closest planetary neighbors.

In 2011 and 2012, Showalter’s team discovered two additional moons orbiting Pluto. (The International Astronomical Union recently decided on the names Kerberos and Styx for these moons, despite an overwhelming public vote to name one of them Vulcan.) Using the Hubble Space Telescope, the same researchers recently discovered a new moon orbiting Neptune.

“I got nice pictures of the arcs [segments of the planet’s rings], which was my main purpose, but I also got this little extra dot that I was not expecting to see,” says Showalter.

At 65,400 miles from Neptune, the speedy, newly-discovered moon completes an orbit every 23 hours. This moon is hard to track, but more than 150 archived images from Hubble between 2004 and 2009 enabled Showalter to track down the orbit of the new moon.

“The moons and arcs orbit very quickly, so we had to devise a way to follow their motion in order to bring out the details of the system,” he says. “It’s the same reason a sports photographer tracks a running athlete—the athlete stays in focus, but the background blurs.” (Showalter compares capturing the new moon to Eadweard James Muybridge’s famous racehorse photographs in a blog post earlier this week.)

This 12-mile wide moon is the smallest of the Neptunian system (which currently includes 14 moons), and revolves around Neptune between the orbits of Larissa and Proteus. For now the tiny dot is called S/2004 N 1. The official name may not be put to vote this time (but Star Trek fans can get cracking on ideas).

S/2004 N 1’s discovery brings up additional questions besides its new name. A mini moon like this should have had trouble forming in the neighborhood of much larger moons.

“How you can have a 20-kilometre object around Neptune is a little bit of a puzzle,” says Showalter. “It’s far enough away that its orbit is stable. Once you put it there it will stay there. The question is, how did it get there?”

Triton is Neptune’s biggest moon, orbiting in the direction opposite Neptune’s spin. Astronomers originally thought that a moon of this type would have to be captured by Neptune’s gravity, destroying all smaller moons in the process.

Stay tuned to learn S/2004 N 1’s new name, and perhaps new theories about how it originated in the first place!

Alyssa Keimach is an astronomy and astrophysics student at the University of Michigan and interns for the Morrison Planetarium.

Image: NASA, ESA, M. Showalter

I’m not going to get into exoplanet announcements such as this one or this one from yesterday morning’s meeting (as one attendee tweeted in summary, “There’s more exoplanets than you can shake an exostick at.”). We have ten press conferences scheduled, and three of them revolve around (pun intended) exoplanet discoveries. So I’ll plan for an exoplanet wrap-up toward the end of the conference.

Instead, I’d like to talk about the work of a few of those spiffy space-based telescopes—yes, the ever-popular Hubble Space Telescope, but also Chandra X-Ray Observatory and a new mission known as NuSTAR.

A grand effort known as the Hubble Ultra Deep Field (HUDF) has imaged the same, small, seemingly-dull part of the sky repeatedly at numerous, finely-tuned wavelengths of light, revealing distant galaxies that reside farther than just about anything we can see. Looking out into space means looking back into time, so the HUDF reveals an important epoch in the history of the Universe.

It turns out the Universe in its youth went through an unusual phase when most of the hydrogen in deep space was in the form of molecules, with no net electrical charge… By the time the Universe reached the age of about 800 million years, however, most of the hydrogen had become ionized, which is to say broken down into electrons and protons (both of which have electrical charge). But it takes energy to ionize hydrogen, so where did that energy come from?

This is the kind of puzzle that keeps astronomers busy (and employed) for decades. Since 2004, astronomers have refined and extended the HUDF observations to eke out more information about this epoch, and the most recent observations have allowed scientists to reach some well-founded, long-sought conclusions.

We know that young galaxies would emit radiation that could ionize the Universe, but can they produce enough radiation to light up the “Cosmic Dawn,” as it’s sometimes called? Astronomers love to come up with more exotic theories, such as the annihilation of dark matter, to explain things like this, but are such puzzling processes required?

Turns out they aren’t. Galaxies can do the job on their own. That’s not the sexiest answer, but it should ultimately feel quite satisfying: the Universe behaves in a way that we understand and can predict. But it took a remarkable amount of sleuthing to come up with this relatively mundane response.

First off, we tally up the galaxies we see, and we estimate how much radiation they would emit. And the first surprise? Small, faint (the researchers like to call ’em “feeble”) galaxies make a significant contribution to the total energy output, and the large, luminous can’t do the job on their own.

Turns out that the currently-observed population of galaxies does not produce enough radiation to ionize all that intergalactic hydrogen. Bummer. But we know that we’re not seeing all the galaxies! We can detect only the brightest ones at these great distances, and the HUDF team’s work suggests that an earlier generation of galaxies existed before the ones we’re seeing. So how can we estimate the energy contribution from what we’re not seeing directly?

The team of astronomers undertook the challenge of tallying the luminous galaxies versus the number of feeble galaxies, and projecting those estimates back in time. Based on HUDF and other observations from, for example, the Wilkinson Microwave Anisotropy Probe (WMAP), we can determine when stars and galaxies started lighting up the Universe, so when the team added up all the light from all the galaxies they estimated to have existed over that time… Bingo! Just enough light energy to ionize the Universe’s hydrogen.

All this work actually pushed Hubble to its limits. And it promises many more discoveries from the James Webb Space Telescope, due to launch in 2018, which will peer back farther in time to see earlier generations of galaxies.

Hubble isn’t alone out there, and x-ray astronomy in particular benefits from having telescopes in space. Stephen S. Murray from Johns Hopkins gave a review of “50 Years of X-Ray Astronomy,” describing remarkable successes in the field. From 1962 to 1999, x-ray astronomy has experienced an increase in sensitivity of 10 billion! (And Murray noted that it took astronomers 400 years to achieve that kind of gain in optical sensitivity…) That kind of revolutionary change has led to spectacular discoveries related to some of the most exotic objects in astronomy—including black holes, pulsars, and supernovae.

An impressive video from Chandra shows a curlicue jet streaming from the pulsar at the center of the Vela Supernova Remnant. This complex structure provides a nifty puzzle for astronomers to describe its origin.

And the recently-launched Nuclear Spectroscopic Telescope Array (NuSTAR), one of the least expensive missions ever launched by NASA, has released its first images. The pair of telescopes spotted two bright, energetic sources of x-rays in the galaxy IC 342—capturing black holes in the process of “feeding” (as NuSTAR team leader Fiona Harrison puts it).

Stay tuned for more spacy stuff the rest of the week…

NuSTAR image courtesy of CalTech

UC Santa Cruz researchers, using Hubble’s powerful Wide Field Planetary Camera 3, have looked 13.2 billion years into the past, discovering a small, compact galaxy of blue stars that existed only 480 million years after the Big Bang.

Creatively named UDFj-39546284, it ranks as the most distant galaxy yet observed. And it is pretty small by galaxy standards—over one hundred such mini-galaxies would fit inside our Milky Way.

Although individual stars can’t be resolved by Hubble, evidence suggests that this is a compact galaxy of hot stars that first started to form 100 to 200 million years earlier in a pocket of dark matter.

How do scientists find these distant, infant galaxies? According to Universe Today,

Astronomers gauge the distance of an object from its redshift, a measure of how much the expansion of space has stretched the light from an object to longer (“redder”) wavelengths.

Nature published the paper describing UDFj-39546284 last week. But astronomers calculate a 20% chance that the distant light is not a galaxy. It will take the pricey James Webb Telescope to confirm its galactic standing. Webb’s infrared vision should provide spectroscopic measurements that can confirm the tremendous distance of the reported object. For now, UDFj-39546284 will have to wait—the telescope won’t launch for at least another three years. But heck, what’s three years compared to 13.2 billion?

Image credit: NASA, ESA, G. Illingworth (University of California, Santa Cruz), R. Bouwens (University of California, Santa Cruz, and Leiden University), and the HUDF09 Team

Earth

The Gulf oil spill—the number of gallons spilled and the controversy surrounding the damage seems to top many lists this year. Nature even named Jane Lubchenco, head of NOAA, its newsmaker of the year for how she handled the crisis.

Natural disasters often took the front page in 2010 with the Haitian earthquake and the eruption of Eyjafjallajökull topping many lists. The hard-to-pronounce Icelandic volcano also made many of the best science images of the year lists.

DiscoveryNews ends the year on a positive note with “How Humans Helped the Earth in 2010,” a slide show with text concerning recent strides in alternative energy, species and habitat conservation efforts and individual efforts to go green (electric cars, white roofs and saving energy).

For more environmental news of the year, New Scientist’s Short Sharp Science has a great review and the Nature Conservancy has a best/worst list on its site.

Life

Teeny, modified life stole the spotlight this year—the J. Craig Venter Institute’s so-called “synthetic cell” and GFAJ-1—the bacteria that incorporates arsenic into its DNA—or so NASA scientists claimed.  Science writer Carl Zimmer discredited the arsenic bacteria paper on Slate; NASA author Felisa Wolfe-Simon defended herself in Science. Fun stuff!

The spread of pesky bedbugs was number six in Discover’s “Top 100 Science Stories of 2010.”

Nature’s great article this past summer on eradicating mosquitoes was among its readers’ top choices of the year.

Looking for something a little bigger and less controversial? New Scientist has “The coolest animals of 2010,” which includes a scorpion-eating bat and a fly thought to be extinct for over 160 years!

NPR found it was a very good year for Neanderthals—their genome was sequenced, brain examined and diet expanded.

Remarkably, the Census of Marine Life tops the BP oil spill in the Deep Type Flow blog’s biggest marine science stories of the year for its sheer numbers:

…over 500 research expeditions covering every ocean, over 2,500 scientists and the discovery of over 6,000 species new to science and published in over 2600 peer-reviewed papers.

Space

ScienceNow’s most popular story of all time, not just 2010, was “Does Our Universe Live Inside a Wormhole?” A wonderful theory that we also covered last spring.

Exoplanets, in part thanks to the Kepler mission, were all over the news this year—whether it had to do with size, atmosphere or number within a star system. Discover’s interview with local exoplanet hunter (and California Academy of Sciences Fellow) Geoff Marcy made number 11(!) on their 100 top stories list.

A little closer to home, Jupiter’s missing stripe and Neptune’s tale of cannibalism are included in New Scientist’s most popular space stories of 2010.

Our Moon and Saturn’s moons made news throughout the year and the top lists on Universe Today and Wired this week.

Universe Today also included SDO’s new views of the sun in their top stories list. Stunning!

Hubble celebrated its 20^th year in space this year by taking even more beautiful images. Several are included in Bad Astronomy’s “Top 14 Astronomy Pictures of 2010.”

Technology

Electric cars and NASA’s new foray into commercial spacecraft are included in Scientific American’s top ten stories of the year.

The Large Hadron Collider was very busy this year, and topped many lists. Another machine at CERN made news (and also topped Nature’s readers’ choice list) when it was able to capture antimatter for a sixth of a second!

Graphene not only garnered a Nobel Prize this year, the material (and it’s potential) also made news and top science lists of the year.

DiscoveryNews put plastics on their 2010 list—whether its finding new ways of removing plastic from the oceans or engineering smarter plastics.

What was your favorite science story of the year? Share with us by adding it to the comment section below!

Image by Les Stone, International Bird Rescue Research Center/Wikipedia

In broad strokes…  We have dark energy, which makes up 73-74% of the Universe and causes the Universe to accelerate in its expansion. Dark matter, on the other hand, makes up 22-23% of the Universe, accounts for most of the mass and exerts gravitational effects on galaxies—influencing the rotational speed, orbital velocity, and distribution of the remaining 4% of the Universe, namely the stuff we can actually see.

But what if you could see the dark stuff? Would the images match up to the theories describing it?

Scientists at NASA/JPL, working with a West Point mathematician and using the Hubble Space Telescope, have created one of the sharpest maps to date of dark matter.

Focusing on a galaxy cluster called Abell 1689, 2.2 billion light years away, the team was able to create a map of dark matter using gravitational lensing.

Abell 1689 contains about 1,000 galaxies and trillions upon trillions of stars. Its gravitational influence, the majority of which results from dark matter, acts like a cosmic magnifying glass, bending and amplifying light from galaxies much farther away. This effect, called gravitational lensing, produces multiple, warped, and greatly magnified images of those galaxies, like the view in a funhouse mirror. By studying the distorted images, astronomers estimated the amount of dark matter within the cluster. If the cluster’s gravity only came from the visible galaxies, the lensing distortions would be much, much weaker.

Researchers used the observed positions of 135 “lensed” images of 42 background galaxies to calculate the location and amount of dark matter in the cluster. They superimposed a map of these inferred dark matter concentrations, tinted blue here, on a Hubble image of the cluster.

According to team leader Dan Coe, “the lensed images are like a big puzzle. Here we have figured out, for the first time, a way to arrange the mass of Abell 1689 such that it lenses all of these background galaxies to their observed positions.”

The new dark matter observations may yield new insights into the role of dark energy in the Universe’s early formative years.

Will the theories prove correct? From Discover’s Cosmic Variance blog:

We have theoretical predictions about how dark matter should act, and it’s good to compare them to data. Interestingly, the fit to our favorite models is not perfect; this cluster, and a few others like it, are more dense in a central core region than simple theories predict. This is an opportunity to learn something — perhaps clusters started to form earlier in the history of the Universe than we thought, or perhaps there’s something new in the physics of dark matter that we have to start taking into account.

Astronomers will use the new “dark” map to shed light on how the Universe has evolved in the past—and will continue to evolve in the future.

The galaxy was actually revealed in a Hubble photograph in 2009. It was a very faint light among very bold and bright galaxies. 

It might have become irrelevant, but a ground-based telescope took another look. From  ScienceNow:

To measure the distance to the galaxy, lead author Matthew Lehnert of the Paris Observatory, Nicole Nesvadba of the University of Paris, and their colleagues took a spectrum of the object using a spectrograph mounted on the European Southern Observatory’s Very Large Telescope in Chile. By analyzing the spectrum, the researchers determined that the galaxy had a red shift of 8.55, corresponding to a distance of 13.1 billion light-years.

Nesvadba sums up this work in a press release:

Measuring the redshift of the most distant galaxy so far is very exciting in itself, but the astrophysical implications of this detection are even more important. This is the first time we know for sure that we are looking at one of the galaxies that cleared out the fog which had filled the very early Universe.

When the Universe was about 400 million years old, it began to go through what scientists call the reionization era. Universe Today and Bad Astronomy have good descriptions of this era, and a supporting article in Nature puts it most succinctly:

According to astronomers’ best models, the early Universe burst out of the Big Bang around 13 billion years ago as an ionized fireball. This ball of gas gradually cooled, becoming neutral as protons and neutrons combined to form hydrogen. “Then stars and galaxies began to form, lighting up the Universe, heating up the gas and reionizing it,” says Lehnert. “This galaxy allows us to peek at the reionization era.”

We know it’s 153 light years away, that it has water in its atmosphere, and that it orbits its star in three and a half days at a distance 100 times closer than Jupiter is to the sun.

And, last week, University of Colorado scientists using the Hubble Space Telescope confirmed another remarkable fact about the gas giant: the heat of its star and the stellar winds are whipping its atmosphere into a comet-like tail coming off of the planet. The study was published in The Astrophysical Journal.

Hubble’s Cosmic Origins Spectrograph (COS) detected the heavy elements carbon and silicon in the planet’s super-hot, 2,000-degree-Fahrenheit atmosphere. This detection revealed the parent star is heating the entire atmosphere, dredging up the heavier elements and allowing them to escape the planet in the form of gas.

Some of that gas is coming off the planet at pretty fast speeds, heading in the direction toward Earth. Lead author and astronomer Jeffrey Linsky, PhD, said that:

We found gas escaping at high velocities, with a large amount of this gas flowing toward us at 22,000 miles per hour. This large gas flow is likely gas swept up by the stellar wind to form the comet-like tail trailing the planet.

Although this extreme planet is being roasted away by its star, it won’t be destroyed anytime soon. At almost the same mass as Jupiter, “It will take about a trillion years for the planet to evaporate,” according to Linsky.

Image credit: NASA, ESA, and G. Bacon (STScI)

Here’s how it works: When a large nearby object, such as a galaxy, blocks a distant object, such as another galaxy, gravity from the nearby object causes light to detour around it. But instead of taking a single path, light bends around the object sometimes doubling, sometimes quadrupling, sometimes creating an entire ring of light around the nearby galaxy.

Astrophysicist Phil Marshall explains it quite well using a birthday candle and wine glass stem here.

Using the Hubble Space Telescope and WMAP data, the Stanford team could measure the distances light traveled from a bright, active galaxy to the earth along different paths. For example, if the light quadrupled around the nearby object, the scientists could measure it four times, along four separate paths.

Marshall likens it to four cars taking four different routes between places on opposite sides of a large city, such as Stanford University to Lick Observatory, through or around San Jose. And like automobiles facing traffic snarls, light can encounter delays, too.

By understanding the time it took to travel along each path and the effective speeds involved, researchers could infer not just how far away the galaxy lies but also the overall scale of the universe and some details of its expansion.

Using light bent by gravity, astronomers can measure the Universe—a yardstick billions of light years in length!

In 2006, after the International Astronomical Union reclassified Pluto as a “dwarf planet,” the public protested.

But today at a NASA press conference, Pluto took on new importance. Mark Buie, of the Southwest Research Institute in Boulder, Colorado called Pluto “a piece of the puzzle of the solar system.”

The puzzle? What causes the redness of objects within the solar system? The inner solar system has red colored objects (think Mars), and scientists assume it’s carbon-related. But at the same time, if it is carbon-related, why aren’t the objects black, like charcoal? Other objects in the Kuiper Belt, where Pluto resides in the outer solar system, also are red.

The Hubble Space Telescope photographed the planet from 2000 to 2003, and with the data it imaged, Buie and his colleagues found that the planet was redder. 20% redder. As Buie admits, this scared him, “It was so hard to believe– I wondered many times, did I screw up the data?”

Buie was assured that his data were accurate when he noticed Pluto’s moon, Charon, had the same color throughout the images.

Pluto is a planet of extremes because its orbit is very severe. Pluto takes 248 years to circle to the sun– moving dramatically closer to and farther from the Sun. This causes temperatures to fluctuate greatly. Some color change (the increased brightness captured by Hubble) was expected due to nitrogen ice melting as it gets warmer. But some of the color change (regions getting darker, or redder) was not expected.

So, planet or dwarf, don’t count Pluto out! As Mike Brown stated when asked about Pluto’s status, “There’s nothing wrong with being an ice ball– I affectionately call it an ice ball.”

As the New Horizons spacecraft approaches Pluto in 2015, we will discover more about this beloved ice ball.