Astronomy Archives

October 19, 2014December 23, 2015 by Tim Reyes

A Compendium of Universe Today Comet Siding Spring Articles: January 2013 – October 2014

Comet C/2013 A1 Siding Spring passed between the Small Magellanic Cloud (left) and the rich globular cluster NGC 130 on August 29, 2014. Credit: Rolando Ligustri

We present here a compendium of Universe Today articles on comet Siding Spring. Altogether 18 Universe Today stories and counting have represented our on-going coverage of a once in a lifetime event. The articles beginning in February 2013, just days after its discovery, lead to the comet’s penultimate event – the flyby of Mars, October 19, 2014. While comet Siding Spring will reach perihelion just 6 days later, October 25, 2014, it will hardly have sensed the true power and impact that our Sun can have on a comet.

Siding Spring’s Oort Cloud cousin, Comet ISON in November 2013 encountered the Sun at a mere 1.86 million km. The intensity of the Sun’s glare was 12,600 times greater than what Siding Spring will experience in a few days. Comet ISON did not survive its passage around the Sun but Comet Siding Spring will soon turn back and begin a very long journey to its place of origin, the Oort Cloud far beyond Pluto.

An animation of comet Siding Springs passage through the inner Solar System. The scale size of its place of origin would dwarf the orbits of the Solar System to little more than a small dot. (Illustration Credit: Near-Earth Object (NEO) office, NASA/JPL)

The closest approach for comet Siding Spring with the Sun – perihelion is at a distance of 1.39875 Astronomical Units (1 AU being the distance between the Earth and Sun), still 209 million km (130 million miles). The exact period of the comet is not exactly known but it is measured in millions of years. In my childhood astronomy book, it stated that comet Halley, when it is at its furthest distance from the Sun, is moving no faster than a galloping horse. This has also been all that comet Siding Spring could muster for millions of years – the slightest of movement in the direction of the Sun.

It is only in the last 3 years, out all the millions spent on its journey, that it has felt the heat of the Sun and been in proximity to the planetary bodies of our Solar System. This is story of all long period comets. A video camera on Siding Spring would have recorded the emergence and evolution of one primate out of several, one that left the trees to stand on two legs, whose brain grew in size and complexity and has achieved all the technological wonders (and horrors) we know of today.

Now with its close encounter with Mars, the planet’s gravity will bend the trajectory of the comet and reduce its orbital period to approximately one million years. No one will be waiting up late for its next return to the inner Solar System.

It is also unknown what force in the depths of the Oort cloud nudged the comet into its encounter with Mars and the Sun. Like the millions of other Oort cloud objects, Siding Spring has spent its existence – 4.5 Billion years, in the darkness of deep space, with its parent star, the Sun, nothing more than a point of light, the brightest star in its sky. The gravitational force that nudged it may have been a passing star, another cometary body or possibly a larger trans-Neptunian object the size of Pluto and even as large as Mars or the Earth.

The forces of nature on Earth cause a constant turning over geological features. Our oceans and atmosphere are constantly recycling water and gases. The comets that we receive from the Oort Cloud are objects as old as our Solar System. Yet it is the close encounter with Mars that has raised the specter of an otherwise small ordinary comet. All these comets from deep space are fascinating gems nearly unaltered for 1/3rd of the time span of the known Universe.

Universe Today’s Siding Spring Compendium

2014/10/17: Here’s A Look At Comet Siding Spring Two Days Before Its Encounter With Mars

2014/10/17: Weekly Space Hangout Oct 17 2014

2014/10/15: Comet A1 Siding Spring vs Mars Views In Space And Time

2014/10/10: How To See Comet Siding Spring As It Encounters Mars

2014/10/08: Comet Siding Spring Close Call For Mars Wake Up Call For Earth

2014/09/19: How NASA’s Next Mars Spacecraft Will Greet The Red Planet On Sunday

2014/09/09: Tales Tails Of Three Comets

2014/09/05: Maven Mars Orbiter Ideally Poised To Uniquely Map Comet Siding Spring Composition Exclusive Interview With Principal Investigator Bruce Jakosky

2014/08/30: Caterpillar Comet Poses For Pictures En Route To Mars

2014/07/26: NASA Preps For Nail Biting Comet Flyby Of Mars

2014/05/08: Interesting Prospects For Comet A1 Siding Spring Versus The Martian Atmosphere

2014/03/27: Mars Bound Comet Siding Spring Sprouts Multiple Jets

2014/01/29: Neowise Spots Mars Crossing Comet

2014/01/02: Comets Prospects For 2014 A Look Into The Crystal Ball

2013/04/12: New Calculations Effectively Rule Out Comet Impacting Mars In 2014

2013/03/28: NASA Scientists Discuss Potential Comet Impact On Mars

2013/03/05: Update On The Comet That Might Hit Mars

2013/02/26: Is A Comet On A Collision Course With Mars

October 17, 2014December 23, 2015 by Tim Reyes

Balloon launcher Zero2Infinity Sets Its Sights to the Stars

Zero2Infinity announced on October 15, their plans to begin micro-satellite launches to low-earth orbit by 2017. (Credit: OIIOO)

Clearly, the sky is not the limit for balloon launcher Zero2Infinity. Based in Barcelona, Spain, the company announced this week their plans to launch payloads to orbit using a balloon launch system. The Rockoon is a portmanteau, as Lewis Carroll would have said: the blend of the words rocket and balloon.

The launch system announced by the company is called Bloostar. The Rockoon system begins with a balloon launch to stratospheric altitudes followed by the igniting of a 3 stage rocket to achieve orbit. The Rockoon concept is not new. Dr. James Van Allen with support from the US Navy developed and launched the first Rockoons in 1949. Those were just sounding rockets, Bloostar will take payloads to low-earth orbit and potentially beyond.

The Zero2Infinity Bloostar launch vehicle. Three stages will use a set of liquid fuel engines clustered as concentric toroids. (Photo Credit: 0II00)

The advantage of rocket launch from a balloon is that it takes the Earth’s atmosphere out as a factor in design and as a impediment to reaching orbit. The first phase of the Bloostar system takes out 99% of the Earth’s atmosphere by reaching an altitude of over 20 km (>65,000 feet). Aerodynamics is not a factor so the stages are built out rather than up. The stages of the Bloostar design are a set of concentric rings which are sequentially expended as it ascends to orbit.

Zero2Infinity is developing a liquid fuel engine that they emphasize is environmentally friendly. The first stage firing of Bloostar will last 160 seconds, reach 250 km of altitude and an inertial speed of 3.7 km/s. This is about half the velocity necessary for reach a stable low earth orbit. The second stage will fire for 230 seconds and achieve an altitude of 530 km with velocity of 5.4 km/s. The 3rd and final stage motor will fire at least twice with a coast period to achieve the final orbit. Zero2Infinity states that their Bloostar system will be capable of placing a 75kg (165 lbs) payload into a 600 km (372 mi) sun-synchronous orbit. In contrast, the International Space Station orbits at 420 km (260 mi) altitude.

The Bloostar launch phases. Zero2Infinity intends to de-orbit the final stage to minimize their contribution to the growing debris field in low-earth orbit. Their plans are to launch from a ship at sea. (Photo Credit: 0II00)

For the developing cubesat space industry, a 75 kg payload to orbit is huge. A single cubesat 10x10x10 cm (1U) will typically weigh about 1 kg so Bloostar would be capable of launching literally a constellation of cubesats or in the other extreme, a single micro-satellite with potentially its own propulsion system to go beyond low-earth orbit.

The Rockoon concept is not unlike what Scaled Composites undertakes with a plane and rocket. Their Whiteknight planes lift the SpaceShips to 50,000 feet for takeoff whereas the Zero2Infinity balloon will loft Bloostar to 65,000 feet or higher. The increased altitude of the balloon launch reduces the atmospheric density to half of what it is at 50,000 feet and altogether about 8% of the density at sea level.

The act of building and launching a stratospheric balloon to 30 km (100,000 feet) altitude with >100 kg instrument payloads is a considerable accomplishment. This is just not the releasing of a balloon but involves plenty of logistics and telecommunications with instrumentation and also the returning of payloads safely to Earth. This is clearly half of what is necessary to reach orbit.

Bloostar is blazing new ground in Spain. The ground tests of their liquid fuel rocket engine are the first of its kinds in the country. Zero2Infinity began launching balloons in 2009. The founder and CEO, Jose Mariano Lopez-Urdiales is an aeronautical engineer educated in Spain with R&D experience involving ESA, MIT and Boeing. He has speerheaded organizations and activities in his native Spain. In 2002 he presented to the World Space Congress in Houston, the paper “The Role of Balloons in the Future Development of Space Tourism”.

References:

Zero2Infinity Press Release

Bloostar Launch Cycle

October 17, 2014December 23, 2015 by Tim Reyes

Hawking Radiation Replicated in a Laboratory?

In honor of Dr. Stephen Hawking, the COSMOS center will be creating the most detailed 3D mapping effort of the Universe to date. Credit: BBC, Illus.: T.Reyes

Dr. Stephen Hawking delivered a disturbing theory in 1974 that claimed black holes evaporate. He said black holes are not absolutely black and cold but rather radiate energy and do not last forever. So-called “Hawking radiation” became one of the physicist’s most famous theoretical predictions. Now, 40 years later, a researcher has announced the creation of a simulation of Hawking radiation in a laboratory setting.

The possibility of a black hole came from Einstein’s theory of General Relativity. Karl Schwarzchild in 1916 was the first to realize the possibility of a gravitational singularity with a boundary surrounding it at which light or matter entering cannot escape.

This month, Jeff Steinhauer from the Technion – Israel Institute of Technology, describes in his paper, “Observation of self-amplifying Hawking radiation in an analogue black-hole laser” in the journal Nature, how he created an analogue event horizon using a substance cooled to near absolute zero and using lasers was able to detect the emission of Hawking radiation. Could this be the first valid evidence of the existence of Hawking radiation and consequently seal the fate of all black holes?

This is not the first attempt at creating a Hawking radiation analogue in a laboratory. In 2010, an analogue was created from a block of glass, a laser, mirrors and a chilled detector (Phys. Rev. Letter, Sept 2010); no smoke accompanied the mirrors. The ultra-short pulse of intense laser light passing through the glass induced a refractive index perturbation (RIP) which functioned as an event horizon. Light was seen emitting from the RIP. Nevertheless, the results by F. Belgiorno et al. remain controversial. More experiments were still warranted.

The latest attempt at replicating Hawking radiation by Steinhauer takes a more high tech approach. He creates a Bose-Einstein condensate, an exotic state of matter at very near absolute zero temperature. Boundaries created within the condensate functioned as an event horizon. However, before going into further details, let us take a step back and consider what Steinhauer and others are trying to replicate.

Artists illustrations of black holes are guided by descriptions given from theorists. There are many illustrations. A black hole has never been seen up close. However, to have Hawking radiation all the theatrics of accretion disks and matter being funneled off a companion star are unnecessary. One just needs a black hole in the darkness of space. (Illustration: public domain) — Artists illustrations of black holes are guided by descriptions given to them by theorists. There are many illustrations. A black hole has never been seen up close. However, to have Hawking radiation, all the theatrics of accretion disks and matter being funneled off a companion star are unnecessary. Just a black hole in the darkness of space will do. (Illustration: public domain)

The recipe for the making Hawking radiation begins with a black hole. Any size black hole will do. Hawking’s theory states that smaller black holes will more rapidly radiate than larger ones and in the absence of matter falling into them – accretion, will “evaporate” much faster. Giant black holes can take longer than a million times the present age of the Universe to evaporate by way of Hawking radiation. Like a tire with a slow leak, most black holes would get you to the nearest repair station.

So you have a black hole. It has an event horizon. This horizon is also known as the Schwarzchild radius; light or matter checking into the event horizon can never check out. Or so this was the accepted understanding until Dr. Hawking’s theory upended it. And outside the event horizon is ordinary space with some caveats; consider it with some spices added. At the event horizon the force of gravity from the black hole is so extreme that it induces and magnifies quantum effects.

All of space – within us and surrounding us to the ends of the Universe includes a quantum vacuum. Everywhere in space’s quantum vacuum, virtual particle pairs are appearing and disappearing; immediately annihilating each other on extremely short time scales. With the extreme conditions at the event horizon, virtual particle and anti-particles pairs, such as, an electron and positron, are materializing. The ones that appear close enough to an event horizon can have one or the other virtual particle zapped up by the black holes gravity leaving only one particle which consequently is now free to add to the radiation emanating from around the black hole; the radiation that as a whole is what astronomers can use to detect the presence of a black hole but not directly observe it. It is the unpairing of virtual particles by the black hole at its event horizon that causes the Hawking radiation which by itself represents a net loss of mass from the black hole.

So why don’t astronomers just search in space for Hawking radiation? The problem is that the radiation is very weak and is overwhelmed by radiation produced by many other physical processes surrounding the black hole with an accretion disk. The radiation is drowned out by the chorus of energetic processes. So the most immediate possibility is to replicate Hawking radiation by using an analogue. While Hawking radiation is weak in comparison to the mass and energy of a black hole, the radiation has essentially all the time in the Universe to chip away at its parent body.

This is where the convergence of the growing understanding of black holes led to Dr. Hawking’s seminal work. Theorists including Hawking realized that despite the Quantum and Gravitational theory that is necessary to describe a black hole, black holes also behave like black bodies. They are governed by thermodynamics and are slaves to entropy. The production of Hawking radiation can be characterized as a thermodynamic process and this is what leads us back to the experimentalists. Other thermodynamic processes could be used to replicate the emission of this type of radiation.

Using the Bose-Einstein condensate in a vessel, Steinhauer directed laser beams into the delicate condensate to create an event horizon. Furthermore, his experiment creates sound waves that become trapped between two boundaries that define the event horizon. Steinhauer found that the sound waves at his analogue event horizon were amplified as happens to light in a common laser cavity but also as predicted by Dr. Hawking’s theory of black holes. Light escapes from the laser present at the analogue event horizon. Steinhauer explains that this escaping light represents the long sought Hawking radiation.

Publication of this work in Nature underwent considerable peer review to be accepted but that alone does not validate his findings. Steinhauer’s work will now withstand even greater scrutiny. Others will attempt to duplicate his work. His lab setup is an analogue and it remains to be verified that what he is observing truly represents Hawking radiation.

References:

“Observation of self-amplifying Hawking radiation in an analogue black-hole laser“, Nature Physics, 12 October 2014

“Hawking Radiation from Ultrashort Laser Pulse Filaments”, F. Belgiorno, et al., Phys. Rev. Letter, Sept 2010

“Black hole explosions?”, S. W. Hawking, et al., Nature, 01 March 1974

“The Quantum Mechanics of Black Holes”, S. W. Hawking, Scientific American, January 1977

October 17, 2014December 23, 2015 by Elizabeth Howell

A Ghastly Green Shade On The Space Station Evokes Hallowe’en Spirit

The International Space Station is bathed in a green laser as part of a communications test at the European Space Agency's optical ground station in Spain. Credit: ESA (screenshot)

Woah, is that home to six people in space now some sort of a ghoul? Here is a video of the International Space Station in an odd shade of … green. And no, it’s not because astronauts secretly painted the hull during their spacewalk this week.

What you’re actually seeing is a green laser shining on the space station as part of a test of next-generation communications technologies. Lasers have been used in successful tests to the Moon and the space station in the past year, hinting that perhaps there’s a faster way to transmit data than over traditional radio.

The clip was filmed at the European Space Agency’s optical ground station in Tenerife, Spain, on Oct. 8 as part of a social media event. Below, you can see a shot of the laser in action, aiming at the sky. More photos are here.

A green laser shines out into space at an October 2014 social media event at the European Space Agency's optical ground station in Spain. Credit: Daniel Lopez/IAC — A green laser shines out into space at an October 2014 social media event at the European Space Agency’s optical ground station in Spain. Credit: Daniel Lopez/IAC

October 16, 2014December 23, 2015 by Shannon Hall

Distant Galaxies Reveal 3D Cosmic Web for the First Time

3D map of the cosmic web at a distance of 10.8 billion light years from Earth. The map was generated from imprints of hydrogen gas observed in the spectrum of 24 background galaxies, which are located behind the volume being mapped. This is the first time that large-scale structures in such a distant part of the Universe have been mapped directly. The coloring represents the density of hydrogen gas tracing the cosmic web, with brighter colors representing higher density. Credit: Casey Stark (UC Berkeley) and Khee-Gan Lee (MPIA)

On the largest scales, networks of gaseous filaments span hundreds of millions of light-years, connecting massive galaxy clusters. But this gas is so rarified, it’s impossible to see directly.

For years, astronomers have used quasars — brilliant galactic centers fueled by supermassive black holes rapidly accreting material — to map the otherwise invisible matter.

But now, for the first time, a team of astronomers led by Khee-Gan Lee, a post-doc at the Max Planck Institute for Astronomy, has managed to create a three-dimensional map of the large-scale structure of the Universe using distant galaxies. And the advantages are numerous.

The science has always gone a little something like this: as the bright light from a distant quasar travels toward Earth, it encounters the intervening clouds of hydrogen gas and is partially absorbed. This leaves dark absorption lines in the quasar’s spectrum.

Artist's impression illustrating the technique of Lyman-alpha tomography: as light from distant background galaxies (yellow arrows) travels through the Universe towards Earth, hydrogen gas in the foreground leaves a characteristic imprint ("absorption signature"). From this imprint, astronomers can reconstruct which clouds the light has encountered as it traverses the "cosmic web" of dark matter and gas that accounts for the biggest structures in our universe. By observing a number of background galaxies in a small patch of the sky, astronomers were able to create a 3D map of the cosmic web using a technique similar to medical computer tomography (CT) scans. The coloring represents the density of hydrogen gas tracing the cosmic web, with brighter colors representing higher density. The rendition of the cosmic web in this image is based on a supercomputer simulation of cosmic structure formation. Credit: Khee-Gan Lee (MPIA) and Casey Stark (UC Berkeley) — Artist’s impression illustrating how a distant quasar’s or galaxy’s spectrum becomes clouded with absorption lines from intervening hydrogen gas. Credit: Khee-Gan Lee (MPIA) and Casey Stark (UC Berkeley)

If the Universe were static, the dark absorption lines would always be located at the same spot (121 nanometers for the so-called Lyman-alpha line) in the quasar’s spectrum. But because the Universe is expanding, the distant quasar is flying away from the Earth at a rapid speed. This stretches the quasar’s light, such that each intervening hydrogen gas cloud imprints its absorption signature on a different region of the quasar’s spectrum, leaving a forest of lines.

Therefore detailed measurements of multiple quasars’ spectra close together can actually reveal the three-dimensional nature of the intervening hydrogen clouds. But galaxies are nearly 100 times more numerous than quasars. So in theory they should provide a much more detailed map.

The only problem is that galaxies are also about 15 times fainter than quasars. So astronomers thought they were simply not bright enough to see well in the distant universe. But Lee carried out calculations that suggested otherwise.

“I was surprised to find that existing large telescopes should already be able to collect sufficient light from these faint galaxies to map the foreground absorption, albeit at a lower resolution than would be feasible with future telescopes,” said Lee in a news release. “Still, this would provide an unprecedented view of the cosmic web which has never been mapped at such vast distances.”

Lee and his colleagues used the 10-meter Keck I telescope on Mauna Kea, Hawaii to take a look a closer look at the distant galaxies and the forest of hydrogen absorption embedded in their spectra. But even the weather in Hawaii can turn ugly.

“We were pretty disappointed as the weather was terrible and we only managed to collect a few hours of good data,” said coauthor Joseph Hennawi, also from the Max Planck Institute for Astronomy. “But judging by the data quality as it came off the telescope, it was already clear to me that the experiment was going to work.”

The team was only able to collect data for four hours. But it was still unprecedented. They looked at 24 distant galaxies, which provided sufficient coverage of a small patch of the sky and allowed them to combine the information into a three-dimensional map.

The map reveals the large-scale structure of the Universe when it was only a quarter of its current age. But the team hopes to soon parse the map for more information about the structure’s function — following the flows of cosmic gas as it funneled away from voids and onto distant galaxies. It will provide a unique historical record on how the galaxy clusters and voids grew from inhomogeneities in the Big Bang.

The results have been published in the Astrophysical Journal and are available online.

October 16, 2014December 23, 2015 by Paul Patton

Moons of Confusion: Why Finding Extraterrestrial Life may be Harder than we Thought

NASA's James Webb Space Telescope, scheduled for launch in Dec. 2021, will be capable of measuring the spectrum of the atmospheres of Earthlike exoplanets orbiting small stars. Credit: NASA, Northrop Grumman

Astronomers and planetary scientists thought they knew how to find evidence of life on planets beyond our Solar System. But, a new study indicates that the moons of extrasolar planets may produce “false positives” adding an inconvenient element of uncertainty to the search.

More than 1,800 exoplanets have been confirmed to exist so far, with the count rising rapidly. About 20 of these are deemed potentially habitable. This is because they are only somewhat more massive than Earth, and orbit their parent stars at distances that might allow liquid water to exist.

Astronomers soon hope to be able to determine the composition of the atmospheres of such promising alien worlds. They can do this by analyzing the spectrum of light absorbed by them. For Earth-like worlds circling small stars, this challenging feat can be accomplished using NASA’s James Webb Space Telescope, scheduled for launch in 2018.

They thought they knew how to look for the signature of life. There are certain gases which shouldn’t exist together in an atmosphere that is in chemical equilibrium. Earth’s atmosphere contains lots of oxygen and trace amounts of methane. Oxygen shouldn’t exist in a stable atmosphere. As anyone with rust spots on their car knows, it has a strong tendency to combine chemically with many other substances. Methane shouldn’t exist in the presence of oxygen. When mixed, the two gases quickly react to form carbon dioxide and water. Without some process to replace it, methane would be gone from our air in a decade.

On Earth, both oxygen and methane remain present together because the supply is constantly replenished by living things. Bacteria and plants harvest the energy of sunlight in the process of photosynthesis. As part of this process water molecules are broken into hydrogen and oxygen, releasing free oxygen as a waste product. About half of the methane in Earth’s atmosphere comes from bacteria. The rest is from human activities, including the growing of rice, the burning of biomass, and the flatulence produced by the vast herds of cows and other ruminants maintained by our species.

By itself, finding methane in a planet’s atmosphere isn’t surprising. Many purely chemical processes can make it, and it is abundant in the atmospheres of the gas giant planets Jupiter, Saturn, Uranus, and Neptune, and on Saturn’s large moon Titan. Although oxygen alone is sometimes touted as a possible biomarker; its presence, by itself, isn’t rock solid evidence of life either. There are purely chemical processes that might make it on an alien planet, and we don’t yet know how to rule them out. Finding these two gases together, though, seems as close as one could get to “smoking gun” evidence for the activities of life.

A monkey wrench was thrown into this whole argument by an international team of investigators led by Dr. Hanno Rein of the Department of Environmental and Physical Sciences at the University of Toronto in Canada. Their results were published in the May, 2014 edition of the Proceedings of the National Academy of Sciences USA.

Suppose, they posited, that oxygen is present in the atmosphere of a planet, and methane is present separately in the atmosphere of a moon orbiting the planet. The team used a mathematical model to predict the light spectrum that might be measured by a space telescope near Earth for plausible planet-moon pairs. They found that the resulting spectra closely mimicked that of a single object whose atmosphere contained both gasses.

Unless the planet orbits one of the very nearest stars, they showed it wasn’t possible to distinguish a planet-moon pair from a single object using technology that will be available anytime soon. The team termed their results “inconvenient, but unavoidable…It will be possible to obtain suggestive clues indicative of possible inhabitation, but ruling out alternative explanations of these clues will probably be impossible for the foreseeable future.”

References and further reading:

The Habitable Exoplanets Catalog, Planetary Habitability Laboratory, University of Puerto Rico at Arecibo

Kaltenegger L., Selsis F., Fridlund M. et al. (2010) Deciphering spectral fingerprints of habitable exoplanets. Astrobiology, 10(1) p. 89-102.

Major J. (2013) Earthlike exoplanets are all around us. Universe Today

Rein H., Fujii Y., and Spiegel D. S. (2014) Some inconvenient truths about biosignatures involving two chemical species on Earth-like exoplanets. Proceedings of the National Academy of Sciences, 111(19) p. 6871-6875.

Sagan C., Thompson W. R., Carlson R., Gurnett, D., Hord, C. (1993) A search for life on Earth from the Galileo spacecraft. Nature, 365 p. 715-721.

October 16, 2014December 23, 2015 by Shannon Hall

MAVEN Spacecraft’s First Look at Mars Hints at Promising Results

Three views of an escaping atmosphere, obtained by MAVEN’s Imaging Ultraviolet Spectrograph. By observing all of the products of water and carbon dioxide breakdown, MAVEN's remote sensing team can characterize the processes that drive atmospheric loss on Mars. Image Credit: University of Colorado/NASA

It’s been less than a month since NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft slipped into orbit. But it’s already provided mission scientists their first look at Mars’ tenuous atmosphere.

“Everything is performing well so far,” said Bruce Jakosky, the mission’s principle investigator, in a news release. “All the instruments are showing data quality that is better than anticipated at this early stage of the mission. The spacecraft is performing beautifully. It’s turning out to be an easy and straightforward spacecraft to fly, at least so far. It really looks as if we’re headed for an exciting science mission.”

Data collected by MAVEN will answer a longstanding puzzle among planetary scientists. There’s ample evidence that early in the Red Planet’s history it had a much denser atmosphere. Rain fell from the sky and water carved its surface. But then the atmosphere vanished, and scientists are unsure why.

One leading theory is that the gas escaped to space, stripped away by the solar wind rushing past. (Click here to see a cool animation of that process.) Here on Earth, our magnetosphere helps protect our atmosphere from the solar wind. But once Mars lost its own magnetosphere, billions of years ago, its atmosphere became vulnerable.

MAVEN’s spectrometers will attempt to determine if hydrogen atoms, torn from water molecules by ultraviolet sunlight, are escaping to space and at what rate. Already, the spacecraft has observed the edges of the Martian atmosphere using its Imaging Ultraviolet Spectrograph (IUVS) camera, which is sensitive to the sunlight reflected by the atoms.

“With these observations, MAVEN’s IUVS has obtained the most complete picture of the extended Martian upper atmosphere ever made,” said team member Mike Chaffin from Colorado University at Boulder.

So far scientists have used IUVS to create a map of Mars’ ozone. “With these maps we have the kind of complete and simultaneous coverage of Mars that is usually only possible for Earth,” said team member Justin Deighan, also from CU-Boulder.

There will be about two weeks of additional instrument calibration and testing before MAVEN starts its primary science mission in early to mid-November. It will then likely take a few additional months to build up enough measurements to have a clear sense of what’s going on. But the initial results are promising.

October 15, 2014December 23, 2015 by Tim Reyes

Old Equations Shed New Light on Quasars

An artists illustration of the early Universe. Image Credit: NASA

There’s nothing more out of this world than quasi-stellar objects or more simply – quasars. These are the most powerful and among the most distant objects in the Universe. At their center is a black hole with the mass of a million or more Suns. And these powerhouses are fairly compact – about the size of our Solar System. Understanding how they came to be and how — or if — they evolve into the galaxies that surround us today are some of the big questions driving astronomers.

Now, a new paper by Yue Shen and Luis C. Ho – “The diversity of quasars unified by accretion and orientation” in the journal Nature confirms the importance of a mathematical derivation by the famous astrophysicist Sir Arthur Eddington during the first half of the 20th Century, in understanding not just stars but the properties of quasars, too. Ironically, Eddington did not believe black holes existed, but now his derivation, the Eddington Luminosity, can be used more reliably to determine important properties of quasars across vast stretches of space and time.

A quasar is recognized as an accreting (meaning- matter falling upon) super massive black hole at the center of an “active galaxy”. Most known quasars exist at distances that place them very early in the Universe; the most distant is at 13.9 billion light years, a mere 770 million years after the Big Bang. Somehow, quasars and the nascent galaxies surrounding them evolved into the galaxies present in the Universe today. At their extreme distances, they are point-like, indistinguishable from a star except that the spectra of their light differ greatly from a star’s. Some would be as bright as our Sun if they were placed 33 light years away meaning that they are over a trillion times more luminous than our star.

An artists illustration of the central engine of a Quasar. These "Quasi-stellar Objects" QSOs are now recognized as the super massive black holes at the center of emerging galaxies in the early Universe. (Photo Credit: NASA) — An artists illustration of the central engine of a quasar. These “Quasi-stellar Objects” QSOs are now recognized as the super massive black holes at the center of emerging galaxies in the early Universe. (Photo Credit: NASA)

The Eddington luminosity defines the maximum luminosity that a star can exhibit that is in equilibrium; specifically, hydrostatic equilibrium. Extremely massive stars and black holes can exceed this limit but stars, to remain stable for long periods, are in hydrostatic equilibrium between their inward forces – gravity – and the outward electromagnetic forces. Such is the case of our star, the Sun, otherwise it would collapse or expand which in either case, would not have provided the stable source of light that has nourished life on Earth for billions of years.

Generally, scientific models often start simple, such as Bohr’s model of the hydrogen atom, and later observations can reveal intricacies that require more complex theory to explain, such as Quantum Mechanics for the atom. The Eddington luminosity and ratio could be compared to knowing the thermal efficiency and compression ratio of an internal combustion engine; by knowing such values, other properties follow.

Several other factors regarding the Eddington Luminosity are now known which are necessary to define the “modified Eddington luminosity” used today.

The new paper in Nature shows how the Eddington Luminosity helps understand the driving force behind the main sequence of quasars, and Shen and Ho call their work the missing definitive proof that quantifies the correlation of a quasar properties to a quasar’s Eddington ratio.

They used archival observational data to uncover the relationship between the strength of the optical Iron [Fe] and Oxygen[O III] emissions – strongly tied to the physical properties of the quasar’s central engine – a super-massive black hole, and the Eddington ratio. Their work provides the confidence and the correlations needed to move forward in our understanding of quasars and their relationship to the evolution of galaxies in the early Universe and up to our present epoch.

Astronomers have been studying quasars for a little over 50 years. Beginning in 1960, quasar discoveries began to accumulate but only through radio telescope observations. Then, a very accurate radio telescope measurement of Quasar 3C 273 was completed using a Lunar occultation. With this in hand, Dr. Maarten Schmidt of California Institute of Technology was able to identify the object in visible light using the 200 inch Palomar Telescope. Reviewing the strange spectral lines in its light, Schmidt reached the right conclusion that quasar spectra exhibit an extreme redshift and it was due to cosmological effects. The cosmological redshift of quasars meant that they are at a great distance from us in space and time. It also spelled the demise of the Steady-State theory of the Universe and gave further support to an expanding Universe that emanated from a singularity – the Big Bang.

Dr. Maarten Schmidt, Caltech University, with Donald Lynden-Bell, were the first recipients of the Kavli Prize in Astrophysics, “for their seminal contributions to understanding the nature of quasars”. While in high school, this author had the privilege to meet Dr. Schmidt at the Los Angeles Museum of Natural History after his presentation to a group of students. (Photo Credit: Caltech) — Dr. Maarten Schmidt, Caltech, with Donald Lynden-Bell, were the first recipients of the Kavli Prize in Astrophysics, “for their seminal contributions to understanding the nature of quasars”. While in high school, this author had the privilege to meet Dr. Schmidt at the Los Angeles Museum of Natural History after his presentation to a group of students. (Photo Credit: Caltech)

The researchers, Yue Shen and Luis C. Ho are from the Institute for Astronomy and Astrophysics at Peking University working with the Carnegie Observatories, Pasadena, California.

References and further reading:

“The diversity of quasars unified by accretion and orientation”, Yue Shen, Luis C. Ho, Sept 11, 2014, Nature

“What is a Quasar?”, Universe Today, Fraser Cain, August 12, 2013

“Interview with Maarten Schmidt”, Caltech Oral Histories, 1999

“Fifty Years of Quasars, a Symposium in honor of Maarten Schmidt”, Caltech, Sept 9, 2013

October 15, 2014December 23, 2015 by Shannon Hall

Retired Astronaut Chris Hadfield Releases Stunning Space Photos

On a clear day, astronauts aboard the ISS can see over 1,000 miles from Havana to Washington D.C. Image Credit: Chris Hadfield / NASA

Orbiting 200 miles above the Earth, Retired Astronaut Chris Hadfield could easily photograph the ridges of the Himalayan Mountains, the textures of the Sahara Desert and the shadows cast by the tallest buildings in Manhattan.

The Richat Structure in Mauritania, also known as the Eye of the Sahara, is a landmark for astronauts. It’s hard to know where you are, especially if you’re over a vast 3,600,000-square-mile desert, but this bull’s-eye orients you, instantly. Oddly, it appears not to be the scar of a meteorite but a deeply eroded dome, with a rainbow-inspired color scheme. Image Credit: Chris Hadfield / NASA — Mauritania, also known as the Eye of the Sahara, is a landmark in the vast 3,600,000-square-mile desert. Credit: Chris Hadfield / NASA

“The view of the world when you have it just right there through the visor of your helmet is overpoweringly gorgeous,” said Hadfield, speaking Oct. 14 at the American Museum of Natural History in New York City. “It is phenomenal. The world is pouring by with all its colors and textures so fast.”

Although Hadfield has already shared many of his photos via social media, he unveiled another 150 images in his latest book, “You Are Here: Around The World in 92 Minutes.” The photographs open a rare window onto the Earth, illuminating our planet’s beauty and the consequences of human settlement.

The book is designed to replicate a single 92-minute orbit aboard the International Space Station. “It’s as if you and I are sitting at the window of the space station, and I said, ‘let’s go around the world once. I want to show you the really cool stuff,’ ” said Hadfield.

The astronaut, famed for his zero-gravity rendition of David Bowie’s “Space Oddity,” took approximately 45,000 photos during his 146-day stint on the space station in 2013. That’s roughly 300 photos per day every day. Since NASA does not set aside specific time slots for astronauts to take photos, Hadfield did so while he should have been asleep or serenading millions with his guitar.

The Himalayan mountain range in South Asia. Credit: Chris Hadfield / NASA

Why? Beauty triggers an unexplained emotional reaction, explained Hadfield. It also provides the best means of communication. Although the space station is an incredible scientific laboratory, art is equally important, he added, because it’s a way to reach people who might not otherwise be interested in the scientific nitty-gritty.

Hadfield is often attributed for humanizing space travel in a way that others before him had not. His use of social media, videos designed to quench our curiosity about living in space, and music, demonstrate a sheer passion that has inspired millions.

Manhattan awake at 9:23 a.m. local time, and Manhattan at rest at 3:45 a.m. local time. Image Credit: Chris Hadfield / NASA — Manhattan awake at 9:23 a.m. local time, and Manhattan at rest at 3:45 a.m. local time. Credit: Chris Hadfield / NASA

His photos not only share the natural beauty of our home planet, but also many signs of humanity, from bright city lights to the devastations of climate change as lakes dry up and disappear. “There’s so much information in just one glimpse out the window of human decision making and geology,” said Hadfield.

Hadfield’s remote yet vivid photos stand as a reminder of both the magnificence and fragility of life on our planet. “To have the world on one side, like this huge kaleidoscope, and then the bottomlessness of the Universe right there beside you,” said Hadfield, trailing off in awe. “You’re not on the world looking at it. You’re in the Universe with the world.”

October 15, 2014December 23, 2015 by Elizabeth Howell

Mars One Dustup: Founder Says Mission Won’t Fail As MIT Study Predicts

Artist's conception of Mars One human settlement. Credit: Mars One/Brian Versteeg

How possible is it to land humans on Mars? And can Mars One, the organization proposing to start with sending four astronauts one way, capable of doing it by 2025 as it promises?

A new study says that the Mars One concept could fail on several points: oxygen levels could skyrocket unsafely. Using the local resources to generate habitability is unproven. The technology is expensive. But the founder of Mars One says the Massachusetts Institute of Technology (MIT) student study is based on the wrong assumptions.

“It’s based on technology available on the ISS [International Space Station],” said Bas Landorp in an interview with Universe Today. “So you end up with a completely different Mars mission than Mars One. So their analysis has nothing to do with our mission.”

The mission has sparked a debate about sending humans on a trip with no promise for a return, but thousands of applicants vied for the chance to do it. After two cuts, the interim shortlist is now at 700 people. Those folks are awaiting interviews (more news is coming shortly, Landorp says) and no date has yet been announced for the next “cut.”

ISRO's Mars Orbiter Mission captures spectacular portrait of the Red Planet and swirling dust storms with the on-board Mars Color Camera from an altitude of 74500 km on Sept. 28, 2014. Credit: ISRO — ISRO’s Mars Orbiter Mission captures spectacular portrait of the Red Planet and swirling dust storms with the on-board Mars Color Camera from an altitude of 74500 km on Sept. 28, 2014. Credit: ISRO

A couple of weeks ago, MIT students presented a technical feasibility analysis of Mars One at the International Astronautical Congress in Toronto, Canada. The study is 35 pages long, so we recommend you read it to get the whole picture. The students’ main concerns are that crops (if they are responsible for 100% of the food) would send oxygen levels to unsafe margins, with no way to remove it. There are concerns with how well the in-situ resource utilization (using the resources on Mars to live off of) would perform. And the mission would cost $4.5 billion at a minimum — for the first crew only.

Cost: To get to Mars, the students say it will cost $4.5 billion and take 15 Falcon Heavy launches (a proposed next-generation rocket from SpaceX). Landorp says he can do it for $1.625 billion (since he doesn’t require constant Earth resupply) and as few as 13 launches (assuming $125 million per launch, a figure Landrop says is from SpaceX) by taking advantage of a few quirks of physics. If Mars One chooses a landing site that is four kilometers (2.5 miles) below the average Martian surface height, they will have both a thicker atmosphere and more time to land the payloads than, say, the Curiosity rover that landed about two kilometers (1.24 miles) above the average surface height. Mars One’s numbers show they could carry a payload of 2,500 kilograms (5,512 pounds) per mission, which they say is well within reach of what spacecraft can do today. The 13 launches would be divided into 11 robotic launches to send equipment to the surface, and two for humans (one to head to Earth orbit for assembly, and the other for the colonists to head to the in-orbit spacecraft and fly to Mars. The assembly crew would then fly back to Earth on the launch vehicle.)

Life support: While many of the technologies planned for use in life support are similar to those on the ISS — such as a trace gas system for air revitalization — Landorp says there will be some crucial differences. They are in talks with Paragon Space Systems Corp. (which describes itself as an environmental control firm for extreme environments, and whose customers include NASA and Bigelow.) As for the unsafe oxygen levels, Landorp points out there are plenty of oxygen removal systems available and that are used in hospitals and militaries. All that is needed is more testing in space. Landorp also points out these systems will be tested for two years robotically before humans land. “If that is not successful, then obviously we will not send humans,” he said.

The proposed Falcon Heavy rocket. Credit: SpaceX

In-situ resource utilization: Landorp acknowledges this requires more study, but says the robotic missions will be an important precursor for the human landings. Technologies needing to be developed will include nitrogen extraction from the Martian atmosphere. Oxygen production from water is well-studied in space, but water from the Martian surface (through vaporizing water in the soil) will require more work.

Another concern raised in media from time to time is where the money is coming from to fund Mars One. Landorp says right now funds are flowing from private investors. Mars One representatives are also in serious talks with a United Kingdom-based listed investment fund willing to finance the mission. In the long run, Landorp is confident money will come from broadcast deals similar to what partially fund the Olympics and the Fédération Internationale de Football Association (FIFA) competitions. Associated sponsorships would also help. But these won’t kick in until the colonists launch and land, since that’s when the world’s eyeballs will be on the mission.

Another stream of revenue, which may take five to seven years to kick in, will be intellectual property deals Mars One one representatives are working on closing now with potential suppliers, such as Lockheed Martin and Paragon. These agreements, should they go through as planned, would give Mars One a share of future revenue from any technologies flowing from the IP. “In the short term it’s not that interesting, it takes time to mature, but in the long term that will be interesting,” Landorp said.