Universe Today

December 17, 2014May 8, 2017 by Shannon Hall

The Universe’s Tour Guide

A number companies are deploying satellites this year to create space-based internet services. Credit: AMNH.

The hazy, white horizon lifts away slowly, giving way to the blue and green, cloud-swept marble we call home. I take in a deep breath, astonished by the Earth’s staggering beauty in stark contrast to the sprinkled backdrop.

People are still shuffling into the 429-seat Hayden Planetarium at the American Museum of Natural History, their shadows projected onto the arched ceiling. A voice resonates in the dome’s spacious cavity. Brian Abbott, the planetarium’s assistant director, is welcoming everyone to the show. It’s a “highlights tour,” he says, covering most of the known universe in one fell swoop.

As we leave Earth further behind, the satellites appear, swarming above our planet like bees around a hive. Soon the curved orbits of other planets become visible and we fly toward Mars.

In minutes we are hovering above Valles Marineris, a canyon so massive it would stretch from Manhattan to Los Angeles. The projectors display six-meter resolution data from the Mars Global Surveyor. We see the canyon ridges in such incredible, 3D detail it seems we could reach out and touch the tallest peaks with our fingers.

Abbott’s voice is slow and soothing. He speaks with authority, mindful of every inflection he makes and every word he uses. He carefully constructs his sentences, but also takes the time to crack a few jokes along the way. It’s just another day at the office, and yet it sounds like he’s having the time of his life.

Abbott in his office at AMNH. Credit: Shannon Hall

Abbott never dreamed of becoming an astronomer. In high school he was on a very different path, headed toward a career in art. Then, in 1985, Halley’s comet was scheduled to appear in the night sky. “For some reason I needed to find it,” he said. So, from his backyard outside Philadelphia, he learned how to pinpoint the constellations and spot distant objects, like galaxies, nebulae and star clusters. When the comet finally came, he was able to spot it, a tiny target in the vast sky. It was a revelation that pumped him full of adrenalin on that long, dark night.

Yet while Abbott left art as a career choice behind, he has been able to integrate art with astronomy, as his planetarium show demonstrates. “I admire the niche he has created for himself in the intersection between art, visualization and science,” said colleague Jana Grcevich, a postdoctoral researcher at AMNH.

Just before starting work at the museum in 1999, however, Abbott was an unhappy graduate student in the astronomy department at the University of Toledo. “Who can explain what gets you out of bed in the morning,” he said. “It just wasn’t what moved me.” Frustrated with his lot in life, he had plans to drive his car across the country, Jack Kerouac style. But first, he attended one last meeting: the American Astronomical Society’s annual conference in Chicago.

There, among all the job listings, he saw only one that wasn’t a research or a faculty position. The AMNH needed someone to create the world’s first interactive atlas of the Universe. So Abbott started sniffing around and coincidentally ran into the planetarium’s famed director, Neil DeGrasse Tyson, in the hallway of their hotel. Yet “Neil wasn’t Neil back then,” Abbott recalled. “He was somewhat known but he wasn’t mobbed with people.”

The duo started talking, and in two weeks Abbott found himself living in New York City with a new job. But he doesn’t regret it for a second. “I feel like I’m almost divorced from the night sky living here. I’m not able to just go out in my backyard and set up a telescope and see stuff. But we have this great dome. And I can go in there and see the entire Universe far better than I can see in the night sky.”

Now, Abbott spends his days visualizing large data sets. For the past 14 years, he has been creating a three-dimensional map of the Universe. He’s constantly updating the atlas with recent data hot off the world’s biggest telescopes and best satellites. And in the planetarium, he turns this abstract data into the planets, stars and galaxies that visitors flock to see. “What we want to do is focus on the scientific story of the universe,” said Abbott. “And we want that reflected in our dome.”

As the Hayden Planetarium’s popularity suggests, there’s a surprising public appetite for such strict scientific cartography. “There’s always at least one time in the show when the air comes out of the room,” said Abbott, referring to the moment when the audience takes a collective breath, in awe of the universe above them.

I can recall easily when that moment came for me. We had just left the Milky Way galaxy. Looking back on our home galaxy, the bright yellow core was surrounded by gorgeous blue spiral arms and sweeping dust lanes. Swarms of smaller galaxies began to appear. In minutes, we saw the Tully Catalogue, which covers an astonishing 30,000 galaxies in total.

The audience gasped in awe at the sheer number of galaxies in our local neighborhood. It’s impossible not to feel small at a moment like that.

But we were nowhere near the farthest reaches of the Universe yet. In moments, we saw the total number of galaxies ever recorded in the Sloan Digital Sky Survey. A chill ran down my spine. There were over one million galaxies projected onto the dome. Each one has over 100 billion stars. And each one of those likely has 5 or even ten planets. There are so many opportunities for life in our vast Universe.

We continued to zoom out, until we reached the edges of the 46.6 billion-light-year-wide observable Universe. In just over an hour, the tour had grossly violated the speed of light. “So that’s the Universe,” Abbott said. “Any questions?”

December 17, 2014December 23, 2015 by Tim Reyes

NASA’s Curiosity Rover detects Methane, Organics on Mars

After a 20 month trek across Mars and careful analysis of data, NASA scientists have announced two separate detection of organics - in the surface and the air of Mars. (Photo Credit: NASA/JPL, Illustration - T. Reyes)

On Tuesday, December 16, 2014, NASA scientists attending the American Geophysical Union Fall Meeting in San Francisco announced the detection of organic compounds on Mars. The announcement represents the discovery of the missing “ingredient” that is necessary for the existence – past or present – of life on Mars.

Indeed, the extraordinary claim required extraordinary evidence – the famous assertion of Dr. Carl Sagan. The scientists, members of the Mars Science Lab – Curiosity Rover – mission, worked over a period of 20 months to sample and analyze Martian atmospheric and surface samples to arrive at their conclusions. The announcement stems from two separate detections of organics: 1) ten-fold spikes in atmospheric Methane levels, and 2) drill samples from a rock called Cumberland which included complex organic compounds.

The Tunable Laser Spectrometer, one of the tools within the Sample Analysis at Mars (SAM) laboratory on NASA's Curiosity Mars rover. By measuring absorption of light at specific wavelengths, it measures concentrations of methane, carbon dioxide and water vapor in Mars' atmosphere. (Image Credit: NASA/JPL-Caltech) — The Tunable Laser Spectrometer, one of the tools within the Sample Analysis at Mars (SAM) laboratory on NASA’s Curiosity Mars rover. By measuring absorption of light at specific wavelengths, it measures concentrations of methane, carbon dioxide and water vapor in Mars’ atmosphere. (Image Credit: NASA/JPL-Caltech)

Methane, of the simplest organic compounds, was detected using the Sample Analysis at Mars instrument (SAM). This is one of two compact laboratory instruments embedded inside the compact car-sized rover, Curiosity. Very soon after landing on Mars, the scientists began to use SAM to periodically measure the chemical content of the Martian atmosphere. Over many samples, the level of Methane was very low, ~0.9 parts per billion. However, that suddenly changed and, as scientists stated in the press conference, it was a “wow” moment that took them aback. Brief daily spikes in Methane levels averaging 7 parts per billion were detected.

The detection of methane at Mars has been claimed for decades, but more recently, in 2003 and 2004, independent research teams using sensitive spectrometers on Earth detected methane in the atmosphere of Mars. One group led by Vladimir Krasnopolsky of Catholic University, and another led by Dr. Michael Mumma from NASA Goddard Space Flight Center, detected broad regional and temporal levels of Methane as high as 30 parts per billion. Those announcements met with considerable skepticism from the scientific community. And the first atmospheric measurements by Curiosity were negative. However, neither group backed down from their claims.

Regions where methane appears notably localized in Northern Summer (A, B1, B2), andtheir relationship to mineralogical and geo-morphological domains. (A.) Observations of methane near the Syrtis Major volcanic district. (B.) Geologic map of Greeley and Guest (41) superimposed on the topographic shaded-relief from MOLA (42). The most ancient terrain (Npld, Nple) is Noachian in age (~3.6 - 4.5 billion years old, when Mars was wet), and is overlain by volcanic deposits from Syrtis Major of Hesperian (Hs) age (~3.1 - 3.6 billion yrs old). (Credit: Mumma, et al., 2009, Figure 3) — Regions where methane appears notably localized in Northern Summer (A, B1, B2), and their relationship to mineralogical and geo-morphological domains. (A.) Observations of methane near the Syrtis Major volcanic district. (B.) Geologic map of Greeley and Guest (41) superimposed on the topographic shaded-relief from MOLA (42). The most ancient terrain (Npld, Nple) is Noachian in age (~3.6 – 4.5 billion years old, when Mars was wet), and is overlain by volcanic deposits from Syrtis Major of Hesperian (Hs) age (~3.1 – 3.6 billion yrs old). (Credit: Mumma, et al., 2009, Figure 3)

The sudden detection of ten-fold spikes in methane levels in Gale crater is not inconsistent with the earlier remote measurements from Earth. The high seasonal concentrations were in regions that do not include Gale Crater, and it remains possible that the Curiosity measurements are of a similar nature but due to some less active process than exists at the regions identified by Dr. Mumma’s team.

This graphic shows tenfold spiking in the abundance of methane in the Martian atmosphere surrounding NASA's Curiosity Mars rover, as detected by a series of measurements made with the Tunable Laser Spectrometer instrument in the rover's Sample Analysis at Mars laboratory suite. (Image Credit: NASA/JPL-Caltech) — This graphic shows tenfold spiking in the abundance of methane in the Martian atmosphere surrounding NASA’s Curiosity Mars rover, as detected by a series of measurements made with the Tunable Laser Spectrometer instrument in the rover’s Sample Analysis at Mars laboratory suite. (Image Credit: NASA/JPL-Caltech)

The NASA scientists at AGU led by MSL project scientist Dr. John Grotzinger emphasized that they do not yet know how the methane is being generated. The process could be biological or not. There are abiotic chemical processes that could produce methane. However, the MSL SAM detections were daily spikes and represent an active real on-going process on the red planet. This alone is a very exciting aspect of the detection.

The team presented slides to describe how methane could be generated. With the known low background levels of methane at ~ 1 part per billion, an external cosmic source, for example micro-meteoroids entering the atmosphere and releasing organics which is then reduced by sunlight to methane, could be ruled out. The methane source must be of local origin.

This image illustrates possible ways methane might be added to Mars' atmosphere (sources) and removed from the atmosphere (sinks). NASA's Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur on modern Mars. A longer caption discusses which are sources and which are sinks. (Image Credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan) — This image illustrates possible ways methane might be added to Mars’ atmosphere (sources) and removed from the atmosphere (sinks). NASA’s Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur on modern Mars. A longer caption discusses which are sources and which are sinks. (Image Credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan)

The scientists illustrated two means of production. In both instances, there is some daily – or at least periodic – activity that is releasing methane from the subsurface of Mars. The source could be biological which is accumulated in subsurface rocks then suddenly released. Or an abiotic chemistry, such as a reaction between the mineral olivine and water, could be the generator.

The subsurface storage mechanism of methane proposed and illustrated is called clathrate storage. Clathrate storage involves lattice compounds that can trap molecules such as methane which can subsequently be released by physical changes in the clathrate, such as solar heating or mechanical stresses. Through press Q&A, the NASA scientists stated that such clathrates could be preserved for millions and billions of years underground.

The second discovery of organics involved more complex compounds in surface materials. Also since arriving at Mars, Curiosity has utilized a drilling tool to probe the interiors of rocks. Grotzinger emphasized how material immediately at the surface of Mars has experienced the effects of radiation and the ubiquitous soil compound perchlorate reducing and destroying organics both now and over millions of years. The detection of no organics in loose and exposed surface material had not diminished NASA scientists’ hopes of detecting organics in the rocks of Mars.

Comparisons between the amount of an organic chemical named chlorobenzene detected in the "Cumberland" rock sample and amounts of it in samples from three other Martian surface targets analyzed by NASA's Curiosity Mars rover. (Image Credit: NASA/JPL-Caltech) — Comparisons between the amount of an organic chemical named chlorobenzene detected in the “Cumberland” rock sample and amounts of it in samples from three other Martian surface targets analyzed by NASA’s Curiosity Mars rover. (Image Credit: NASA/JPL-Caltech)

Drilling was performed on several selected rocks and it was finally a mud rock called Cumberland that revealed the presence of organic compounds more complex than simple methane. The scientists did emphasize that what exactly these organic compounds are remains a mystery because of the confounding presence of the active chemical perchlorate which can quickly breakdown organics to simpler forms.

Examples from the Sample Analysis at Mars (SAM) laboratory's detection of Martian organics in a sample of powder that the drill on NASA's Curiosity Mars rover collected from a rock target called "Cumberland." (Image Credit: NASA/JPL-Caltech) — Examples from the Sample Analysis at Mars (SAM) laboratory’s detection of Martian organics in a sample of powder that the drill on NASA’s Curiosity Mars rover collected from a rock target called “Cumberland.”
(Image Credit: NASA/JPL-Caltech)

The detection of organics in the mud rock Cumberland required the drilling tool and also the scoop on the multifaceted robotic arm to deliver the sample into the SAM laboratory for analysis. To detect methane, SAM has an intake valve to receive atmospheric samples.

Dr. Grotzinger described how Cumberland was chosen as a sample source. The rock is called a mud stone which has undergone a process called digenesis – the metamorphosis of sediment to rock. Grotzinger emphasized that fluids will move through such rock during digenesis and perchlorate can destroy organics in the process. Such might be the case for many metamorphic rocks on the Martian surface. The panel of scientists showed a comparison between rock samples measured by SAM. Two in particular – from the rock “John Klein” and the Cumberland rock — were compared. The former showed no organics as well as other rocks that were sampled; but Cumberland’s drill sample from its interior did reveal organics.

Illustration of some of the reasons why finding organic chemicals on Mars is challenging. Whatever organic chemicals may be produced on Mars or delivered to Mars face several possible modes of being transformed or destroyed. (Image Credit: NASA/JPL-Caltech)

The analysis of the work was painstaking – harking back to the Sagan statement. The importance of discovering organics on Mars could not be understated by the panel of scientists and Grotzinger called these two discoveries as the lasting legacy of the Mars Curiosity Rover. Furthermore, he stated that the discovery and analysis methods will go far to guide the choice of instruments and their use during the Mars 2020 rover mission.

The discovery of organics completes the necessary set of “ingredients” for past or present life on Mars: 1) an energy source, 2) water, and 3) organics. These are the basic requirements for the existence of life as we know it. The search for life on Mars is still just beginning and the new discoveries of organics is still not a clear sign that life existed or is present today. Nevertheless, Dr. Jim Green, introducing the panel of scientists, and Dr. Grotzinger both emphasized the magnitude of these discoveries and how they are tied into the objectives of the NASA Mars program — particularly now with the emphasis on sending humans to Mars. For the Mars Curiosity rover, the journey up the slopes of Mount Sharp continues and now with greater earnestness and a continued search for rocks similar to Cumberland.

References:

Curiosity detects methane spike on Mars

NASA Rover Finds Active, Ancient Organic Chemistry on Mars

Research Papers, AGU Press Conerence via Ustream

Strong Release of Methane on Mars in Northern Summer 2003

Non-Detection of Methane in the Mars Atmosphere by the Curiosity Rover

Detection of methane in the martian atmosphere: evidence for life?

December 17, 2014December 23, 2015 by Elizabeth Howell

How To Experience ‘Zero Gravity’ Without Leaving Home: Virtual Reality

Still from a video short previewing "Weightless", a virtual-reality experience showing how to play with objects in a microgravity environment. Credit: Martin Schubert/YouTube (screenshot)

If you don’t have a few thousand dollars to spend on a “Vomit Comet” ride, and especially if you can’t afford to buy a ticket for a future weightless joyride in a spacecraft, virtual reality remains the best option to “experience” weightlessness.

There’s a new game available for the virtual-reality headset Oculus Rift that lets people play with objects in microgravity to see what happens next.

Called “Weightless”, the game appears to have a person zooming around a sort of space station and playing with things including pill bottles and cubes, seeing how they spin and soar without gravity’s pull weighing them down. (Note that the author does not have an Oculus Rift and could not test the game out for this article.)

“I wanted the player to have an experience that’s only possible in VR [virtual reality],” wrote creator Martin Schubert on the game’s webpage. “That means taking advantage of the ability to look around in any direction and having good spatial awareness. This led to investigating a weightless environment that allowed freedom of movement in any direction.”

Schubert wrote that the game is available in prototype form for the Oculus Rift DK2, and is best used with a head-mounted Leap Motion finger-tracking sensor. Bear in mind that the Oculus is still very much a prototype gaming platform, but that being said, the experience looks like a lot of fun for those of us lucky to have one. You can learn more about the hardware requirements and download information here.

December 17, 2014December 23, 2015 by Elizabeth Howell

Morning Star, We Hardly Knew Ya: Venus Express’ Best Discoveries In 8 Years

Artist's impression of Venus Express entering orbit in 2006. Credit: ESA - AOES Medialab

Venus Express is mostly dead. The spacecraft spent more than eight years faithfully relaying information from the Morning Star/Evening Star planet, but it’s now out of fuel, out of control and within weeks of burning up in the atmosphere.

While we mourn the end of the productive mission, the European Space Agency spacecraft showed us a lot about the planet that we once considered a twin to Earth. Some of the surprises, as you can see below, including a possibly slowing-down rotation, and the realization that volcanoes may still be active on the hellish planet.

False colour composite of a rainbow-like feature known as a ‘glory’, seen on Venus on 24 July 2011. The image is composed of three images at ultraviolet, visible, and near-infrared wavelengths from the Venus Monitoring Camera. The images were taken 10 seconds apart and, due to the motion of the spacecraft, do not overlap perfectly. The glory is 1200 km across, as seen from the spacecraft, 6000 km away. It's the only glory ever seen on another planet. Credit: ESA/MPS/DLR/IDA. — False color composite of a rainbow-like feature known as a ‘glory’, seen on Venus on 24 July 2011. The image is composed of three images at ultraviolet, visible, and near-infrared wavelengths from the Venus Monitoring Camera. The images were taken 10 seconds apart and, due to the motion of the spacecraft, do not overlap perfectly. The glory is 1200 km across, as seen from the spacecraft, 6000 km away. It’s the only glory ever seen on another planet. Credit: ESA/MPS/DLR/IDA.

Quick video summary: Venus Express found that the spacecraft’s rotation may have slowed down by 6.5 minutes between 1996 (when the Magellan spacecraft was in orbit) and 2012. The surprising information emerged when scientists discovered surface features weren’t in the expected areas, and couldn’t find any calculation errors between the data.

Animation of Venus’ southern polar vortex made from VIRTIS thermal infrared images; white is cooler clouds at higher altitudes. Credit: ESA/VIRTIS-VenusX/INAF-IASF/LESIA-Obs. de Paris (G. Piccioni, INAF-IASF)

Quick video summary: Volcanic flows may still be active on Venus’ surface, according to 2010 data from the mission. Scientists looked at surface areas that had not been “weathered” very much (indicating that they are relatively young) and detected at least nine spots where the heat in those zones is much higher than the areas around it.

Venus Express picture of clouds on the planet. Despite the planet being extremely hot, the spacecraft found a cold layer in the atmosphere at temperatures of about -175 degrees Celsius (-283 Fahrenheit) that is colder than anything on Earth. It's so chilling that carbon dioxide may freeze and fall as snow or ice. Credit: ESA/MPS/DLR/IDA — A picture of Venus’ clouds. Despite the planet being extremely hot, Venus Express found a cold layer in the atmosphere at temperatures of about -175 degrees Celsius (-283 Fahrenheit) that is colder than anything on Earth. It’s so chilling that carbon dioxide may freeze and fall as snow or ice. Credit: ESA/MPS/DLR/IDA

Artist's impression of Venus with the solar wind flowing around the planet, which has little magnetic protection. Venus Express found that a lot of water has bled into space over the years from the planet, which happens when the sun's ultraviolet radiation breaks oxygen and hydrogen molecules apart and pushes them into space. Credit: ESA - C. Carreau — Artist’s impression of Venus with the solar wind flowing around the planet, which has little magnetic protection. Venus Express found that a lot of water has bled into space over the years from the planet, which happens when the sun’s ultraviolet radiation breaks oxygen and hydrogen molecules apart and pushes them into space. Credit: ESA – C. Carreau

December 17, 2014December 23, 2015 by Elizabeth Howell

Gallery: Saturn Moons Show How Not To Be Seen In Cassini Images

Tethys is mostly obscured behind Rhea as the moons orbit Saturn. The picture was captured by the Cassini spacecraft in April 2012 and highlighted in December 2014. Credit: NASA/JPL-Caltech/Space Science Institute

Peekaboo! Tethys makes a (mostly in vain) attempt to hide behind Rhea in this picture taken by the Cassini spacecraft a couple of years ago, but highlighted by NASA in a recent picture essay. Besides the neat view of the orbital dance, one thing that is clearly visible between the two moons is the different colors — a product of their different surfaces. It turns out that Tethys’ bright surface is due to geysers from another moon.

“Scientists believe that Tethys’ surprisingly high albedo is due to the water ice jets emerging from its neighbor, Enceladus,” NASA stated. “The fresh water ice becomes the E ring [of Saturn] and can eventually arrive at Tethys, giving it a fresh surface layer of clean ice.”

Saturn has an astounding number of moons — 62 moons discovered so far, and 53 of them named, if you don’t count the spectacular ring that surrounds the planet. The collection of celestial bodies includes Titan, the second-biggest moon in the Solar System. It’s so big that it includes a thick atmosphere. (Ganymede, around Jupiter, is the biggest.)

Below are some other pictures of moons dancing around Saturn — some harder to spot than others. All images were taken by the Cassini spacecraft since it arrived at the planet in 2004.

Titan peeks from behind two of Saturn's rings. Another small moon Epimetheus, appears just above the rings. Credit: NASA/JPL/Space Science Institute — Titan peeks from behind two of Saturn’s rings. Another small moon Epimetheus, appears just above the rings. Credit: NASA/JPL/Space Science Institute

Saturn's moons Dione and Rhea appear conjoined in this optical illusion-like image taken by the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute — Saturn’s moons Dione and Rhea appear conjoined in this optical illusion-like image taken by the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute

Saturn's rings, made dark in part as the planet casts its shadow across them, cut a striking figure before Saturn's largest moon, Titan. Credit: NASA/JPL/Space Science Institute — Saturn’s rings, made dark in part as the planet casts its shadow across them, cut a striking figure before Saturn’s largest moon, Titan. Credit: NASA/JPL/Space Science Institute

Three of Saturn's moons bunch together in this image by Cassini. Credit: NASA/JPL/Space Science Institute. Click for larger image. — Three of Saturn’s moons bunch together in this image by Cassini. Credit: NASA/JPL/Space Science Institute. Click for larger image.

Saturns rings with Saturns moon Mimas in the foreground (credit: NASA) — Saturn’s rings with Saturn’s moon Mimas in the foreground (credit: NASA)

Titan and Tethys line up for a portrait of 'sibling' moons. Credit: NASA/JPL/Space Science Institute — Titan and Tethys line up for a portrait of ‘sibling’ moons. Credit: NASA/JPL/Space Science Institute

December 17, 2014December 23, 2015 by David Dickinson

Astro-Challenge: Taming the Pup-Can You Glimpse Sirius B?

White dwarf and companion star resolved.

Astronomy is all about thinking big, both in time and space.

The Earth turns on its axis, the Moon passes through its phases, and the planets come into opposition and solar conjunction on a routine basis.

Of course, on the other end of the spectrum, there are some events which traverse such colossal spans of time that the mere mortal life span of measly homo sapiens such as ourselves can never expect to cover them. Many comets have periods measured in centuries, or thousands of years. The axis of the Earth wobbles like a top, completing one turn every 26,000 years in what’s known as the Precession of the Equinoxes. Our solar system completes one revolution about the galactic center every quarter billion years…

Feeling puny yet? Sure, astronomy is also about humility. But among these stupendous cycles, there are some astronomical events that you just might be able to live through. One such instance is the orbits of double stars. And as 2015 approaches, we challenge you to see of the most famous white dwarf of them all, as it reaches a favorable viewing position over the next few years: Sirius B.

Sirius A and B in x-rays courtesy of Chandra. Credit: NASA/SAO/CXC.

Sirius itself is easy to find, as it’s the brightest star in Earth’s sky shining at magnitude -1.42. In fact, you can spot Sirius in the daytime sky if you know exactly where to look.

But it is one of the ultimate in cosmic ironies that the most conspicuous of stars in our sky also hosts such an elusive companion. The discovery of Sirius B awaited the invention of optics capable of resolving it next to its dazzling host. Alvan Clark Jr. and Sr. first spied the enigmatic companion on January 31^st, 1862 while testing their newly constructed 18.5 inch refractor, which was the largest at the time. The discovery was soon verified from the Harvard College Observatory, adding Sirius A and B to the growing list of multiple stars.

A 19th century refractor similar to the one used to discover Sirius B. Photo by the author.

And what a strange companion it turned out to be. Today, we know that Sirius B is a white dwarf, the cooling dense ember of a main sequence star at the end of its life. We call the matter in such a star degenerate, not as a commentary on its moral stature, but the state the electrons and the closely packed nuclei within under extreme pressure. Our Sun will share the same ultimate fate as Sirius B, about six billion years from now.

The challenge, should you choose to accept it, is to spot Sirius B in the glare of its host. The contrast in brightness between the pair is daunting: shining at magnitude +11, the B companion is more than 63,000 times fainter than -1.46 magnitude Sirius A.

The changing position angle of Sirius B. Note that the graphic is inverted, with north at the bottom. Created by the author.

A feat of visual athletics, indeed. Still, Sirius B breaks 10” in separation from its primary in 2015, as it heads towards apastron — its most distant point from its primary, at just over 11” in separation — in 2019. Sirius B varies from 8.2 and 31.5 AUs from its primary. Sirius B is on a 50.1 year orbit, meaning the time to cross this one off of your life list is over the upcoming decade. Perhaps making an animation showing the motion of Sirius B from 2015-2025 would present a supreme challenge as well.

Sirius culminates at local midnight right around New Year’s Eve, shining at its highest to the south as the “ball drops” ushering in 2015. Of course, this is only a fortuitous circumstance that is possible in our current epoch, and precession and the proper motions of both Sirius and Sol will make this less so millennia hence.

Sirius crossing the meridian at local midnight on New Year’s Eve. Credit: Stellarium.

Newsflash: there’s a very special visual treat in the offing next week, as comet C/2014 Q2 Lovejoy is currently hovering around +6^th magnitude and passes 19 degrees south of Sirius on Christmas Day… more to come!

Magnification and good seeing are your friends in the hunt for Sirius B. Two factors describe the position of a secondary star in a binary pair: its position angle in degrees, and separation in arc seconds. When it comes to stars that are a tough split, I find its better to estimate the position angle first before looking it up. A close match can often confirm the observation. Does a friend see the same thing at the eyepiece? A good star to “warm up” on is the +6.8 magnitude companion to Rigel in the foot of Orion, with a separation of 9”.

Nudging Sirius just out of view might allow the B companion to become apparent. Another nifty star-spliting tool is what’s known as an occulting bar eyepiece. Making an occultation bar eyepiece is easy: we’ve used everything from a small strip of foil to a piece of guitar string (heavy E gauge works nicely) for the central bar. An occulting bar eyepiece is also handy for hunting down the moons of Mars near opposition.

Sirius B also works its way into cultural myths and lore, not the least of which are the curious tales of the Dogon people of Mali. At the outset, it seems that these ancient people have knowledge of a small dense hidden companion star to Sirius, knowledge that requires modern technology to reproduce. Carl Sagan noted, however, that cultural contamination may have resulted in the late 19^th century discovery of Sirius B making its way into the Dogon pantheon. The science of anthropology is rife with anecdotes that have been carefully fed to credulous anthropologists only to be reported later as fact, all in the name of a good story.

All amazing things to ponder as you begin your 2015 quest for Sirius B, a bashful but fascinating star.

– Read more on the curious case of the Dogon and Sirius B.

-Want more white dwarfs? Here’s a handy list of white dwarfs of backyard telescopes.

December 17, 2014December 23, 2015 by Nancy Atkinson

Astrophotos: Views of the Geminid Meteor Shower from Around the World

A stunning moment captured as a Geminid meteor over Mt. Fuji is reflected in Lake Saiko on December 14, 2014. Credit and copyright: Yuga Kurita.

It’s nice to know that not everyone around the world was plagued by clouds, dense fog, driving rain and snowstorms like we had in Minnesota during this year’s Geminid Meteor Shower (and all that weather was within one 24-hour period!) In fact, some astrophotographers were able to capture some stunning views of the Geminids, like this absolutely gorgeous shot of a meteor over Mt. Fuji in Japan.

“I’ve captured Fuji with meteors many times in the past,” said photographer Yuga Kurita. “So I went ambitious this time. I tried to capture Fuji and a meteor reflected in Lake Saiko with a standard focal length lens. When I saw this meteor, I was absolutely stunned.”

See more Geminids from around the world, below:

Geminid meteors over Beijing, China. A stacked image of more than 20 meteors, taken in just 140 minutes. Credit and copyright: Steed Yu.

Geminid Meteor on 12-15-2014 .Captured cutting through the winter Milkyway in the constellation of Auriga, you can see the very colorful trail of the meteor in this image, the trail stretched more than 15 degrees of sky. Taken near Warrenton, Virginia. Credit and copyright: John Chumack.

Four different Geminid meteors as seen from Oxfordshire, England with a Canon 1100D with standard lens. The time of the meteor is marked on the photo. Credit and copyright: Mary Spicer.

Astrophotographer Mary Spicer shared these four meteor shots, and added, “Over about 90 minutes we saw a total of 61 meteors, 57 of which were Geminids and 6 were fireballs.”

In a 3.5 hour period on Dec. 13/14, 2014, the photographer managed to capture 38 Geminid meteors. This composite contains just 11 of those meteors. Credit and copyright: Paul Andrew.

A timelapse movie taken by Michael Mauldin of the clouds and stars over Liberty Hill, Texas on Saturday, December 13, 2014. Two Geminid meteors are captured (each frame is frozen for a few seconds so you can see them):

Geminid meteors caught over Connaught Dome, at the Norman Lockyer Observatory in Devon, England. Credit and copyright: David Strange.

Two Geminid meteors — one especially bright — streak through the sky on Sunday, December 14, 2014. This photo is a composite of two separate frames, taken a few minutes apart, to capture both meteors. Credit and copyright: David Murr.

A Geminid fireball captured on Dec. 13, 2014 near Cabo Rojo, Puerto Rico. Credit and copyright: Frankie Lucena.

A faint green Geminid meteor joined in the sky scene with On display are : M44, Jupiter , the Moon, and Procyon in Canis Minor. Credit and copyright: Carsten Pauer.

A unique view of the 2014 Geminid Meteor Shower, taken on Dec. 14. 5 images stacked. Credit and copyright: Jason Asplin.

A Geminid Meteor taken on Dec. 14, 2014 from a garden in the middle of Worthing, West Sussex England. Credit and copyright: BiteYourBum.com Photography. — A Geminid Meteor
taken on Dec. 14, 2014 from a garden in the middle of Worthing, West Sussex England. Credit and copyright: BiteYourBum.com Photography.

A bright Geminid meteor on Dec. 14, 2014. Credit and copyright: Slave Stojanoski.

Waiting for Geminids: a self portrait of the photographer waiting for the meteor shower to peak. Credit and copyright: Sergio Garcia Rill.

While the above photo doesn’t have any meteors, it still garners a place in this post because astrophotographer Sergio Garcia Rill was waiting and hoping to capture some. Alas, writes Rill on Flickr, “While I had good enough luck to get some relatively clear skies for the Geminids meteor shower I think I wasn’t fortunate enough to catch any meteors on camera. I saw about a dozen meteors with my eyes, and a couple in the direction my cameras were pointing, but they probably weren’t strong enough to get captured with the settings I had.”

December 17, 2014December 23, 2015 by Elizabeth Howell

How Many Horses Can A Rocket Carry? Cool Comic Comparison

An xkcd comic from December 2014 showing spacecraft mass and launch vehicle capacity in terms of horses. The full comic is at http://xkcd.com/1461/large/. Credit: xkcd

The challenge with thinking about space is putting it into terms that we can understand. How far is a light-year? Just how powerful is NASA’s next-generation Space Launch System, which the agency hopes will bring astronauts out into the solar system?

Luckily for us, the comic xkcd is a regular contributor to making space understandable, and the latest comic from Randall Munroe is a gem — explaining launch vehicle capacity and spacecraft mass in terms of horses.

So now comparisons are fairly easy. At the left of the diagram, for example, you can see the Saturn V — that rocket that was the first stage of bringing astronauts to the moon in the 1960s — carried the equivalent of 262 horses. The SLS Block 2, if it is ever developed, will have a slightly larger capacity of 289 horses.

Blastoff of NASA’s Space Launch System (SLS) rocket and Orion crew vehicle from the Kennedy Space Center, Florida. Credit: NASA/MSFC

Meanwhile, the spacecraft mass of the International Space Station is an astounding 932 horses, the total shuttle mass was 206 horses, and Apollo was 67 horses. There also are a few robotic spacecraft in there, such as Voyager, Vanguard 1, the Keyhole 3 spy satellite, and the upcoming James Webb Space Telescope.

Check out the entire diagram in large here, and the original comic here. (For those unfamiliar with xkcd, make sure to mouse over the comic for an extra joke.)

December 16, 2014December 28, 2015 by Susie Murph

Carnival of Space #384

Carnival of Space. Image by Jason Major.

This week’s Carnival of Space is hosted by Gadi Eidelheit at his The Venus Transit blog.

Click here to read Carnival of Space #384.

And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.

December 16, 2014December 23, 2015 by Shannon Hall

What’s Next for the Large Hadron Collider?

A section of the LHC. Image Credit: CERN

The world’s most powerful particle collider is waking up from a well-earned rest. After roughly two years of heavy maintenance, scientists have nearly doubled the power of the Large Hadron Collider (LHC) in preparation for its next run. Now, it’s being cooled to just 1.9 degrees above absolute zero.

“We have unfinished business with understanding the universe,” said Tara Shears from the University of Liverpool in a news release. Shears and other LHC physicists will work to better understand the Higgs Boson and hopefully unravel some of the secrets of supersymmetry and dark matter.

On February 11, 2013 the LHC shut down for roughly two years. The break, known as LS1 for “long stop one,” was needed to correct several flaws in the original design of the collider.

The LHC’s first run got off to a rough start in 2008. Shortly after it was fired up, a single electrical connection triggered an explosion, damaging an entire sector (one-eighth) of the accelerator. To protect the accelerator from further disaster, scientists decided to run it at half power until all 10,000 copper connections could be repaired.

So over the last two years, scientists have worked around the clock to rework every single connection in the accelerator.

Now that the step (along with many others) is complete, the collider will operate at almost double its previous power. This was tested early last week, when scientists powered up the magnets of one sector to the level needed to reach the high energy expected in its second run.

“The machine that’s now being started up is almost a new LHC,” said John Womersley, the Chief Executive Officer of the Science and Technology Facilities Council.

With such a powerful new tool, scientists will look for deviations from their initial detection of the Higgs boson, potentially revealing a deeper level of physics that goes well beyond the Standard Model of particle physics.

Many theorists have turned to supersymmetry — the idea that for every known fundamental particle there exists a “supersymmetric” partner particle. If true, the enhanced LHC could be powerful enough to create supersymmetric particles themselves or prove their existence in subtler ways.

“The higher energy and more frequent proton collisions in Run 2 will allow us to investigate the Higgs particle in much more detail,” said Victoria Martin from Edinburgh University. “Higher energy may also allow the mysterious “dark matter” observed in galaxies to be made and studied in the lab for the first time.”

It’s possible that the Higgs could interact with — or even decay into — dark matter particles. If the latter occurs, then the dark matter particles would fly out of the LHC without ever being detected. But their absence would be evident.

So stay turned because these issues might be resolved in the spring of 2015 when the particle accelerator roars back to life.