When Did the First Stars Form?

When Did the First Stars Form?

Shortly after the Big Bang, the Universe had cooled to the point that the first stars could form out of the primordial hydrogen. How long did it take, and what did these first stars like?

Hydrogen soup. Doesn’t that sound delicious? Perhaps not for humans, but certainly for the first stars!

Early in the Universe, in a spectacular show of stellar soupification, clouds of hydrogen atoms gathered together. They combined with one another. The collected mass got bigger and bigger, and after a time, ignition. The first stars were alive!

Well, alive in the sense that they were burning – not that they had feelings or knew what was going on, or had opinions, or were beginning to write would what would eventually become the first Onion article or anything.

But where did all that gas come from, and can we spot the evidence of those long-ago stars today? As you know, the Big Bang got our Universe off to a speedy start of expansion. It then took 400,000 years for us to see any light at all. Protons and electrons and other small particles were floating around, but it was far too hot for them to interact.

Once the power of the Big Bang finally faded, those protons and electrons paired up and created hydrogen. This is called, rather uninventively, “recombination”. I’d rather just call it hydrogen soup. We’ve got energy. But what is the secret ingredient that sparked these stars? It was just that soup clumping together over time.

A map of the faint microwave radiation left over after the big bang shows superclusters (red circles) and supervoids (blue circles). Credit: B. Granett, M. Neyrinck, I. Szapudi
A map of the faint microwave radiation left over after the big bang shows superclusters (red circles) and supervoids (blue circles). Credit: B. Granett, M. Neyrinck, I. Szapudi

We can’t say to the minute when the first stars formed, but we have a pretty good idea. The Wilkinson Microwave Anisotropy Probe, aka WMAP examined what happened when these clouds of hydrogen molecules got together, creating tiny temperature differences of only a millionth of a degree.

Over time, gravity began to yank matter from spots of lower density into the higher-density regions, making the clumps even bigger. Fantastically bigger. So big that about 200 million years after the clumps were formed, it was possible for these hydrogen molecules to ram into each other at very high speeds.

This process is called nuclear fusion. On Earth, it’s a way to produce energy. Same goes for a star. With enough nuclear reactions happening, the cloud of gas compresses and creates a glow. And these stars weren’t tiny – they were monsters! NASA says the first stars were 30 to 300 times as massive as the sun, shining millions of times brighter.

The supernova that produced the Crab Nebula was detected by naked-eye observers around the world in 1054 A.D. This composite image uses data from NASA’s Great Observatories, Chandra, Hubble, and Spitzer, to show that a superdense neutron star is energizing the expanding Nebula by spewing out magnetic fields and a blizzard of extremely high-energy particles. The Chandra X-ray image is shown in light blue, the Hubble Space Telescope optical images are in green and dark blue, and the Spitzer Space Telescope’s infrared image is in red. The size of the X-ray image is smaller than the others because ultrahigh-energy X-ray emitting electrons radiate away their energy more quickly than the lower-energy electrons emitting optical and infrared light. The neutron star is the bright white dot in the center of the image.
The supernova that produced the Crab Nebula was detected by naked-eye observers around the world in 1054 A.D. This composite image uses data from NASA’s Great Observatories, Chandra, Hubble, and Spitzer.

But this flashy behavior came at a price, because in only a few million years, the stars grew unstable and exploded into supernovae. These stars weren’t only exploding. They were also altering the soup around them. They were big emitters of ultraviolet light. It’s a very energetic wavelength, best known for causing skin cancer.

So, this UV light struck the hydrogen surrounding the stars. This split the atoms apart into electrons and protons again, leaving quite the mess in space. But it’s through this process that we can learn more about these earliest stars.The stars are long gone, but like a criminal fleeing the scene, they left a pile of evidence behind for their existence. Splitting these atoms was their evidence. This re-ionization is one key piece of understanding how these stars came to be.

So it was an action-packed time for the universe, with the Big Bang, then the emergence of soup and then the first stars. It’s quite an exciting start for our galactic history.

What do you think the first stars looked like?

And if you like what you see, come check out our Patreon page and find out how you can get these videos early while helping us bring you more great content!

ALMA Shows Off Baby Pictures… Baby Planets, That Is!

This is the sharpest image ever taken by ALMA — sharper than is routinely achieved in visible light with the NASA/ESA Hubble Space Telescope. It shows the protoplanetary disc surrounding the young star HL Tauri. These new ALMA observations reveal substructures within the disc that have never been seen before and even show the possible positions of planets forming in the dark patches within the system. Credit: ALMA (ESO/NAOJ/NRAO)

In a test of its new high resolution capabilities, the Atacama Large Millimeter/submillimeter Array (ALMA) is happily sharing some family snapshots with us. Astronomers manning the cameras have captured one of the best images so far of a newly-forming planet system gathering itself around a recently ignited star. Located about 450 light years from us in the constellation of Taurus, young HL Tau gathers material around it to hatch its planets and fascinate researchers.

Thanks to ALMA images, scientists have been able to witness stages of planetary formation which have been suspected, but never visually confirmed. This very young star is surrounded by several concentric rings of material which have neatly defined spacings. Is it possible these clearly marked gaps in the solar rubble disc could be where planets have started to gel?

“These features are almost certainly the result of young planet-like bodies that are being formed in the disk. This is surprising since HL Tau is no more than a million years old and such young stars are not expected to have large planetary bodies capable of producing the structures we see in this image,” said ALMA Deputy Director Stuartt Corder.

“When we first saw this image we were astounded at the spectacular level of detail. HL Tauri is no more than a million years old, yet already its disc appears to be full of forming planets. This one image alone will revolutionize theories of planet formation,” explained Catherine Vlahakis, ALMA Deputy Program Scientist and Lead Program Scientist for the ALMA Long Baseline Campaign.

Let’s take a look at what we understand about solar system formation…

Through repeated research, astronomers suspect that all stars are created when clouds of dust and gas succumb to gravity and collapse on themselves. As the star begins to evolve, the dust binds together – turning into “solar system soup” consisting of an array of different sized sand and rocks. This rubble eventually congeals into a thin disc surrounding the parent star and becomes home to newly formed asteroids, comets, and planets. As the planets collect material into themselves, their gravity re-shapes to structure of the disc which formed them. Like dragging a lawn sweeper over fallen leaves, these planets clear a path in their orbit and form gaps. Eventually their progress pulls the gas and dust into an even tighter and more clearly defined structure. Now ALMA has shown us what was once only a computer model. Everything we thought we knew about planetary formation is true and ALMA has proven it.

This is the sharpest image ever taken by ALMA — sharper than is routinely achieved in visible light with the NASA/ESA Hubble Space Telescope. It shows the protoplanetary disc surrounding the young star HL Tauri. The observations reveal substructures within the disc that have never been seen before and even show the possible positions of planets forming in the dark patches within the system. In this picture the features seen in the HL Tauri system are labelled.  Credit: ALMA (ESO/NAOJ/NRAO)
This is the sharpest image ever taken by ALMA — sharper than is routinely achieved in visible light with the NASA/ESA Hubble Space Telescope. It shows the protoplanetary disc surrounding the young star HL Tauri. The observations reveal substructures within the disc that have never been seen before and even show the possible positions of planets forming in the dark patches within the system. In this picture the features seen in the HL Tauri system are labelled. Credit: ALMA (ESO/NAOJ/NRAO)

“This new and unexpected result provides an incredible view of the process of planet formation. Such clarity is essential to understand how our own solar system came to be and how planets form throughout the universe,” said Tony Beasley, director of the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, which manages ALMA operations for astronomers in North America.

“Most of what we know about planet formation today is based on theory. Images with this level of detail have up to now been relegated to computer simulations or artist’s impressions. This high resolution image of HL Tauri demonstrates what ALMA can achieve when it operates in its largest configuration and starts a new era in our exploration of the formation of stars and planets,” says Tim de Zeeuw, Director General of ESO.

The major reason astronomers have never seen this type of structure before is easy to envision. The very dust which creates the planetary disc around HL Tau also conceals it to visible light. Thanks to ALMA’s ability to “see” at much longer wavelengths, it can image what’s going on at the very heart of the cloud. “This is truly one of the most remarkable images ever seen at these wavelengths. The level of detail is so exquisite that it’s even more impressive than many optical images. The fact that we can see planets being born will help us understand not only how planets form around other stars but also the origin of our own solar system,” said NRAO astronomer Crystal Brogan.

How does ALMA do it? According to the research staff, its new high-resolution capabilities were achieved by spacing the antennas up to 15 kilometers apart. This baseline at millimeter wavelengths enabled a resolution of 35 milliarcseconds, which is equivalent to a penny as seen from more than 110 kilometers away. “Such a resolution can only be achieved with the long baseline capabilities of ALMA and provides astronomers with new information that is impossible to collect with any other facility, including the best optical observatories,” noted ALMA Director Pierre Cox.

This is a composite image of the young star HL Tauri and its surroundings using data from ALMA (enlarged in box at upper right) and the NASA/ESA Hubble Space Telescope (rest of the picture). This is the first ALMA image where the image sharpness exceeds that normally attained with Hubble.  Credit: ALMA (ESO/NAOJ/NRAO)
This is a composite image of the young star HL Tauri and its surroundings using data from ALMA (enlarged in box at upper right) and the NASA/ESA Hubble Space Telescope (rest of the picture). This is the first ALMA image where the image sharpness exceeds that normally attained with Hubble. Credit: ALMA (ESO/NAOJ/NRAO)

The long baselines spell success for the ALMA observations and are a tribute to all the technology and engineering that went into its construction. Future observations at ALMA’s longest possible baseline of 16 kilometers will mean even more detailed images – and an opportunity to further expand our knowledge of the Cosmos and its workings. “This observation illustrates the dramatic and important results that come from NSF supporting world-class instrumentation such as ALMA,” said Fleming Crim, the National Science Foundation assistant director for Mathematical and Physical Sciences. “ALMA is delivering on its enormous potential for revealing the distant universe and is playing a unique and transformational role in astronomy.”

Pass them baby pictures our way, Mama ALMA… We’re delighted to take a look!

Original Story Source: “Revolutionary ALMA Image Reveals Planetary Genesis” – ESO Press Release

Watch Universe Today’s Fraser Cain School the Cast of ‘Interstellar’ on Black Holes

Interstellar poster
Interstellar poster, courtesy Paramount.

Space fans have been waiting for the movie “Interstellar” which opens in theaters this Friday, November 7. Today, the cast and crew of Interstellar did a special Google+ Hangout on Air at the Smithsonian’s National Air and Space Museum. Host Kevin Frazier and the cast had their chance to throw a few space-related questions to the astronauts and scientists assembled for the Hangout. Our own publisher, Fraser Cain, was the unfortunate target for the question, “can you explain what a black hole is?” You can watch the entire Hangout above; Fraser schools them at about 35:33.

Soviet Era Engines Likely Caused Antares Catastrophic Rocket Failure

Soviet era NK-33 engines refurbished as the AJ26 exactly like pictured here probably caused Antares’ rocket failure on Oct. 28, 2014. Orbital Sciences technicians at work on two AJ26 first stage engines at the base of an Antares rocket during exclusive visit by Ken Kremer/Universe Today at NASA Wallaps. These engines powered the successful Antares liftoff on Jan. 9, 2014 at NASA Wallops, Virginia bound for the ISS. Credit: Ken Kremer – kenkremer.com

NASA WALLOPS FLIGHT FACILITY, VA – Investigators probing last week’s catastrophic failure of an Antares commercial rocket moments after liftoff, are pointing the finger at the rocket’s Soviet-era built engines as the probable cause of the huge explosion that destroyed the booster and its NASA payload in a raging fireball after liftoff from NASA’s Wallops Flight Facility, VA, according to Orbital Sciences managers.

The Orbital Sciences privately developed Antares rocket was doomed by a sudden mid-air explosion some 15 seconds after liftoff from NASA’s Wallops Flight Facility, VA, at 6:22 p.m. EDT on Tuesday, October 28.

Antares’ first stage is powered by a pair of refurbished Aerojet Rocketdyne AJ26 engines originally manufactured some 40 years ago in the then Soviet Union and originally designated as the NK-33. Overall this was the 5th Antares launch using the AJ26 engines.

See my exclusive photos above and below showing the AJ26 engines with their original NK-33 stencil, during prelaunch processing and mating to the first stage inside Orbital’s Horizontal Integration Facility (HIF) at NASA Wallops.

The NK-33 was originally designed and manufactured in the 1960s by the Kuznetsov Design Bureau for the Soviet Union’s planned N1 rocket to propel cosmonauts to the moon during the space race with NASA’s hugely successful Apollo Moon Landing program.

First stage propulsion system at base of Orbital Sciences Antares rocket appears to explode moments after blastoff from NASA’s Wallops Flight Facility, VA, on Oct. 28, 2014, at 6:22 p.m. Credit: Ken Kremer – kenkremer.com
First stage propulsion system at base of Orbital Sciences’ Antares rocket appears to explode moments after blastoff from NASA’s Wallops Flight Facility, VA, on Oct. 28, 2014, at 6:22 p.m. Credit: Ken Kremer – kenkremer.com

Rocket developer Orbital Sciences Corp. said today, Nov. 5, that the launch mishap was probably due to “a failure in one of the two Aerojet Rocketdyne AJ26 stage one main engines.”

Engineers assisting Orbital’s Accident Investigation Board (AIB) say that failure in the AJ26 turbopump is the likely cause. The AIB is chaired by David Steffy, Chief Engineer of Orbital’s Advanced Programs Group.

“While the work of the AIB continues, preliminary evidence and analysis conducted to date points to a probable turbopump-related failure in one of the two Aerojet Rocketdyne AJ26 stage one main engines,” Orbital said in a statement.

“As a result, the use of these engines for the Antares vehicle likely will be discontinued,” said Orbital.

“We will likely discontinue the use of AJ26 rocket engines that had been used on the first five Antares launch vehicles unless and until those engines can be conclusively shown to be flight worthy,” noted David Thompson, Orbital’s Chairman and Chief Executive Officer, during an investor conference call.

Orbital’s options for the way forward will be outlined in a separate story.

Side view of two AJ26 first stage engines at the base of an Antares rocket during exclusive visit by Ken Kremer/Universe Today.  These engines powered the successful Antares  liftoff on Jan. 9, 2014 at NASA Wallops, Virginia.  Credit: Ken Kremer - kenkremer.com
Side view of two AJ26 first stage engines at the base of an Antares rocket during exclusive visit by Ken Kremer/Universe Today. These engines powered the successful Antares liftoff on Jan. 9, 2014, at NASA Wallops, Virginia. Credit: Ken Kremer – kenkremer.com

The Oct. 28 launch disaster was just the latest in a string of serious problems with the AJ-26/NK-33 engines.

Earlier this year an AJ26 engine failed and exploded during pre launch acceptance testing on a test stand on May 22, 2014, at NASA’s Stennis Space Center in Mississippi.

Besides completely destroying the AJ26 engine, the explosion during engine testing also severely damaged the Stennis test stand. It has taken months of hard work to rebuild and restore the test stand and place it back into service.

An extensive engine analysis, recheck and test stand firings by Aerojet Rocketdyne and Orbital Sciences engineers was conducted to clear this new pair of engines for flight.

Aerojet Rocketdyne purchased approximately 40 NK-33 engines in the mid-1990s and ‘Americanized’ them with multiple modifications including a gimbal steering mechanism.

AJ26 engine failure was immediately suspected, though by no means certain, based on an inspection of numerous photos and videos from myself and many others that clearly showed a violent explosion emanating from the base of the two stage rocket.

Up close view of two AJ26 first stage engines at the base of an Antares rocket during exclusive visit by Universe Today.  These engines powered the successful Antares  liftoff on Jan. 9, 2014 at NASA Wallops, Virginia.  Credit: Ken Kremer - kenkremer.com
Up close view of two AJ26 first stage engines at the base of an Antares rocket during exclusive visit by Universe Today. These engines powered the successful Antares liftoff on Jan. 9, 2014, at NASA Wallops, Virginia. Credit: Ken Kremer – kenkremer.com

The remainder of the first stage and Antares entire upper stage was clearly intact at the moment of the explosion in all the imagery.

Antares was carrying the unmanned Cygnus cargo freighter on a mission dubbed Orb-3 to resupply the six person crew living aboard the International Space Station (ISS) with science experiments and needed equipment.

The AIB is making rapid progress in assessing the accident’s cause based on an analysis of the rocket’s telemetry as well as the substantial amounts of debris collected from the rocket and the Cygnus cargo freighter at the Wallops launch site.

A preliminary review of telemetry and video data has been conducted and substantial debris from the Antares rocket and its Cygnus payload has been collected and examined.

Antares rocket begins rollout atop transporter erector to Launch Pad 0A at NASA Wallops Island Facility, VA., on Sept. 13, 2013.  Credit: Ken Kremer (kenkremer.com)
Antares rocket begins rollout atop transporter erector to Launch Pad 0A at NASA Wallops Island Facility, VA., on Sept. 13, 2013. Credit: Ken Kremer (kenkremer.com)

The 14 story Antares rocket is a two stage vehicle.

The liquid fueled first stage is filled with about 550,000 pounds (250,000 kg) of Liquid Oxygen and Refined Petroleum (LOX/RP) and powered by a pair of AJ26 engines that generate a combined 734,000 pounds (3,265kN) of sea level thrust.

The doomed mission was bound for the International Space Station (ISS) on a flight to bring up some 5000 pounds of (2200 kg) of science experiments, research instruments, crew provisions, spare parts, spacewalk and computer equipment and gear on a critical resupply mission in the Cygnus resupply ship.

Antares rocket stand erect, reflecting off the calm waters the night before their first night launch from NASA’s Wallops Flight Facility, VA, targeted for Oct. 27 at 6:45 p.m.  Credit: Ken Kremer – kenkremer.com
Antares rocket stands erect, reflecting off the calm waters the night before the first night launch planned from NASA’s Wallops Flight Facility, VA, on Oct. 28, which ended in disaster. Credit: Ken Kremer – kenkremer.com

The Orbital-3, or Orb-3, mission was to be the third of eight cargo resupply missions to the ISS through 2016 under the NASA Commercial Resupply Services (CRS) contract award valued at $1.9 Billion.

Orbital Sciences is under contract to deliver 20,000 kilograms of research experiments, crew provisions, spare parts, and hardware for the eight ISS flights.

I was an eyewitness to the awful devastation suffered by the Orb-3 mission from the press viewing site at NASA Wallops located at a distance of about 1.8 miles away from the launch complex.

I was interviewed by NBC News and you can watch the entire story and see my Antares explosion photos featured at NBC Nightly News on Oct. 29 here.

Watch the Antares launch disaster unfold into a raging inferno in this dramatic sequence of my photos shot on site here.

Check out my raw video of the launch here.

Read my first hand account here.

Watch my interview at Universe Today’s Weekly Space Hangout on Oct 31, 2014, here.

Watch here for Ken’s onsite reporting direct from NASA Wallops.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

Orbital Sciences Antares rocket explodes violently and is consumed in a gigantic aerial fireball seconds after blastoff from NASA’s Wallops Flight Facility, VA, on Oct. 28, 2014 at 6:22 p.m.  Credit: Ken Kremer – kenkremer.com
Orbital Sciences’ Antares rocket explodes violently and is consumed in a gigantic aerial fireball seconds after blastoff from NASA’s Wallops Flight Facility, VA, on Oct. 28, 2014, at 6:22 p.m. Credit: Ken Kremer – kenkremer.com

Building A Space Base, Part 3: Making Remote Robots Smart

An astronaut retrieves a sample from an asteroid in this artist's conception. Credit: NASA

We’re still a few years away from the cute robots in Moon or Interstellar that help their human explorers. But if we want to build a base off of Earth, robotic intelligence will be essential to lower the cost and pave the way for astronauts, argues Philip Metzger, a former senior research physicist at NASA’s Kennedy Space Center.

In the last of a three-part series on getting a base ready on the moon or an asteroid, Metzger talks about the steps to get robots ready for the work and what barriers are standing in the way of accomplishing this.

UT: A table in your 2012 paper talks about the steps of lunar industry, starting with tele-operation and an “insect-like” robotic intelligence and then progressing through a few steps to “closely supervised autonomy” (mouse-like) and eventually “nearly full autonomy” (monkey-like) and “autonomous robotics” (human-like). What sorts of developments and how much time/resources would it take to progress through these steps?

Most of the advances in robotic artificial intelligence are being made in software, but they also require advances in computing power. We mentioned in the paper that really only “mouse-like” robotics is needed for it to become successful in a near-Earth environment. We will need robots that can pick up a nut and screw it on a bolt without every motion being commanded from Earth. I believe we are on a trajectory to achieve these levels of autonomy already for robotics here on Earth.  I am more concerned about developing robots that can be made easily in space without an extensive supply chain. For example, we need to invent a simple way to manufacture functional motors for the robots, minimizing the assembly tasks for robots making the same motors that are in themselves.

It is very difficult to estimate how long this will take. Here are some guiding ideas. First, robotics and manufacturing technologies are already on an explosive growth curve for terrestrial application, so we can ride on the coattails of that growth as we re-purpose the technologies for space.  Second, we are not talking about inventing new capabilities. Everything we are talking about doing in space is already being done on Earth. All we need to do is discover what sets of equipment will function together as partial supply chains using space resources. We need to develop a sequence of partial supply chains, each more sophisticated than the last, each one capable of making a significant portion of the mass of the next. It will require innovation, but it is lower-risk innovation because we already have Earth’s more sophisticated industry to copy.

R2 and D2? NASA and General Motors have come together to develop the next generation dexterous humanoid robot. The robots – called Robonaut2 – were designed to use the same tools as humans, which allows them to work safely side-by-side humans on Earth and in space. Credit: NASA
R2 and D2? NASA and General Motors have come together to develop the next generation dexterous humanoid robot. The robots – called Robonaut2 – were designed to use the same tools as humans, which allows them to work safely side-by-side humans on Earth and in space. Credit: NASA

Third, we tend to estimate things will happen faster than they do in the near term, but slower than they do in the long term. Consider how much technology has changed in the past 200 years, and you will agree that it won’t take another 200 years to get this done. I think it will be much less than 100 years. I am betting it will be done within 50 years, and if we try hard we could do it in 20. In fact, if we really wanted to, and if we put up the money, I think we could do it in 10. But I’m telling people 20 to 50 years.  Don’t worry if you think that’s too slow, because the fun of doing it can start immediately, and we will be doing really cool things in space long before the supply chain is complete.

UT: Is it really cheaper and scientifically viable to have a robotic fleet of spacecraft than humans, given development costs and the difficulties of making the robots as efficient to do work as humans?

Biological life needs a place like planet Earth.  Humans need more than that; we also need a food chain, and in the final analysis we need an entire ecology of networked organisms interdependent on each other. And if we want to be more than hunters and gatherers, then civilization requires even more than that. We require the industrial supply chain: all the tools and machines and energy sources that we have developed over the past 10,000 years.

When we leave Earth, we need to take not just a canister of air to breath to replicate the physical conditions of our planet. We need the benefit of the entire ecosystem and the entire industrial base to support us. So far we have stayed close to Earth so we have never really “cut the surly bonds of Earth.” We take a consumable supply of food and spare parts from Earth with us, and we send up rockets to the space station when we need more. Even schemes to colonize Mars are depending on regular shipments of things from Earth. These are the things that make it expensive to put humans in space.

Robots, on the other hand, can be adapted to living in the space environment with nothing more from Earth. They can become the ecosphere and the supply chain in space that we humans require. Under our guidance, they can transform any environment analogously to how life has transformed the Earth. They can make air, purify water, and build the habitats and landing pads. Then, when we arrive, it will be vastly less expensive, and it will be safer, too.  And this will free us up to spend our time in space doing the things that make us uniquely human. In the long term, robots will make space vastly cheaper for humans.

Canada’s Dextre robot (highlight) and NASA’s Robotic Refueling Experiment jointly performed groundbreaking robotics research aboard the ISS in March 2012.  Dextre used its hands to grasp specialized work tools on the RRM for experiments to repair and refuel orbiting satellites. Credit: NASA
Canada’s Dextre robot (highlight) and NASA’s Robotic Refueling Experiment jointly performed groundbreaking robotics research aboard the ISS in March 2012. Dextre used its hands to grasp specialized work tools on the RRM for experiments to repair and refuel orbiting satellites. Credit: NASA

But yes, in the near-term there are things we can do more affordably in space by skipping development of robotic industry. We can shoot off sortie missions to various places, and when we are done we can zip back home before everyone dies. But that doesn’t fulfill our great potential as a species. It doesn’t take civilization to the next level. It doesn’t enable scientific research with a billion times the budget we have today. It doesn’t save our planet from overuse and industrial pollution. It doesn’t bring all humanity up to the standard of living many of us are enjoying in the west. It doesn’t make our existence safe in the galaxy.  It doesn’t terraform new worlds.  It doesn’t take us to other stars.  All these things will be possible for almost no additional investment once we pay the tiny cost of bootstrapping industry in our solar system.  It’s worth the cost.

UT: We’re seeing a 3-D printer going on the International Space Station, and the European Space Agency has seriously talked about using this technology on the Moon. How close are we to actually doing this?

I know of several other groups also developing 3D printers that could work on the Moon or Mars to print things directly out of regolith. The KSC Swamp Works is pursuing one technological approach and has built a prototype, and Professor Behrokh Khoshnevis at the University of Southern California is pursing another approach and has printed many things already. My friend Jason Dunn who founded Made In Space, which put the 3D printer into the ISS, has another concept they are pursuing. My friends at NASA have told me that this is healthy, having a portfolio of technologies to pursue rather than just one.

To be ready for missions in space you have to do more than test things in a lab. You need to do testing in reduced gravity aircraft to see if the materials like regolith will flow properly, in vacuum chambers to make sure nothing overheats or jams, and in rugged field locations like a desert or on a volcano to check for dust problems or other unexpected effects. After that, you are ready to start designing the actual version that is going into space, to do the final qualification testing where you shake it and bake it half to death, to assemble and test the flight version, and to launch it.

Deputy Program Manager Matthew Napoli examines a 3D printed piece at Marshall Space Flight Center. Image courtesy Made In Space.
Deputy Program Manager Matthew Napoli examines a 3D printed piece at Marshall Space Flight Center. Image courtesy Made In Space.

So there are years of work ahead before all that is done. NASA’s direction is to put humans on Mars by the mid-2030’s, so we also have time and there is no rush. If we start to bootstrap space industry in the near-Earth region of space in parallel with getting ready for a Mars campaign then we will probably start testing regolith printers at field sites and making them interoperable with other equipment sooner than NASA presently needs them.

UT: What are the main barriers to robotic exploration on the Moon and beyond?

Budget is the only barrier. But taking a step back we might say a lack of vision is the only barrier because if enough of us understand what is now possible in space and how revolutionary it will be for humanity then there will be no lack of budget.

UT: Is there anything else you would like to add that I haven’t brought up yet?

We live in a very exciting time when these possibilities are being opened to us. It is exciting to think about the world our grandchildren will see, and it is exciting to think of what we can do to bring it about.

Whenever I speak on this topic, afterward the young people in the audience come up and start asking what they can do to get involved in space industry. They tell me that this is how they want to spend their lives. It gets that response because it is so compelling, so logical, and so right.

This is the third in a three-part series about building a space base. Two days ago: Why mine on the moon or an asteroid? Yesterday: How much money would it take?

Satellite Debris Forces Space Station To Evade Threat Hours Before Collision Risk

The International Space Station as seen by the departing STS-134 crew on May 29, 2011. Credit: NASA

A spacecraft attached to the International Space Station did an “emergency maneuver” to push the complex, which now houses six people, away from a threatening piece of space debris Oct. 27, the European Space Agency said in a statement.

A hand-sized shard of the Russian Cosmos-2251 satellite, which collided with a U.S. Iridium satellite in 2009, would have come within at least four kilometers (2.5 miles) of the orbiting outpost. This was close enough for the space station partners to agree to a move six hours before the potential impact.

“This is the first time the station’s international partners have avoided space debris with such urgency,” the European Space Agency wrote. The push to a safer orbit took place using the agency’s automated transfer vehicle Georges Lemaître, which docked with the space station in August.

The International Space Station in October 2014, with the European automated transfer vehicle Georges Lemaître attached. Credit: Alexander Gerst/ESA/NASA
The International Space Station in October 2014, with the European automated transfer vehicle Georges Lemaître attached. Credit: Alexander Gerst/ESA/NASA

While many collision threats are spotted at least days before impact, occasionally ground networks aren’t able to see a piece until 24 hours or less before the potential impact. Since 2012, the space station has normally done last-minute maneuvers using Russian cargo Progress vehicles, but this time around none were docked there. This is where the ATV came in.

Controllers at the ATV control center in France then did a four-minute preprogrammed move that raised the station’s orbit by one kilometer (0.6 miles), enough to get out of the way.

The ATV is expected to remain at the station until February, when it will undock and burn up in the atmosphere. This is the last of the series of ATVs that Europe agreed to make as a part of its space station agreement.

Where Have All the Pulsars Gone? The Mystery at the Center of Our Galaxy

The galactic core, observed using infrared light and X-ray light. Credit: NASA, ESA, SSC, CXC, and STScI

The galactic center is a happening place, with lots of gas, dust, stars, and surprising binary stars orbiting a supermassive black hole about three million times the size of our sun. With so many stars, astronomers estimate that there should be hundreds of dead ones. But to date, scientists have found only a single young pulsar at the galactic center where there should be as many as 50.

The question thus arises: where are all those rapidly spinning, dense stellar corpses known as pulsars? Joseph Bramante of Notre Dame University and astrophysicist Tim Linden of the University of Chicago have a possible solution to this missing-pulsar problem, which they describe in a paper accepted for publication in the journal Physical Review Letters.

Maybe those pulsars are absent because dark matter, which is plentiful in the galactic center, gloms onto the pulsars, accumulating until the pulsars become so dense they collapse into a black hole. Basically, they disappeared into the fabric of space and time by becoming so massive that they punched a hole right through it.

Dark matter, as you may know, is the theoretical mass that astrophysicists believe fills roughly a quarter of our universe. Alas, it is invisible and undetectable by conventional means, making its presence known only in how its gravitational pull interacts with other stellar objects.

One of the more popular candidates for dark matter is Weakly Interacting Massive Particles, otherwise known as WIMPs. Underground detectors are currently hunting for WIMPs and debate has raged over whether gamma rays streaming from the galactic center come from WIMPs annihilating one another.

In general, any particle and its antimatter partner will annihilate each other in a flurry of energy. But WIMPs don’t have an antimatter counterpart. Instead, they’re thought to be their own antiparticles, meaning that one WIMP can annihilate another.

But over the last few years, physicists have considered another class of dark matter called asymmetric dark matter. Unlike WIMPs, this type of dark matter does have an antimatter counterpart.

Numerical simulation of the density of matter when the universe was one billion years old. Cosmic Infrared Background ExpeRIment (CIBER) Credit: Caltech/Jamie Bock
 Cosmic Infrared Background ExpeRIment (CIBER) simulation of the density of matter when the universe was one billion years old, as produced by large-scale structures from dark matter. Credit: Caltech/Jamie Bock

Asymmetric dark matter appeals to physicists because it’s intrinsically linked to the imbalance of matter and antimatter. Basically, there’s a lot more matter in the universe than antimatter – which is good considering anything less than an imbalance would lead to our annihilation. Likewise, according to the theory, there’s much more dark matter than anti-dark-matter.

Physicists think that in the beginning, the Big Bang should’ve created as much matter as antimatter, but something altered this balance. No one’s sure what this mechanism was, but it might have triggered an imbalance in dark matter as well – hence it is “asymmetric”.

Dark matter is concentrated at the galactic center, and if it’s asymmetric, then it could collect at the center of pulsars, pulled in by their extremely strong gravity. Eventually, the pulsar would accumulate so much mass from dark matter that it would collapse into a black hole.

The idea that dark matter can cause pulsars to implode isn’t new.  But the new research is the first to apply this possibility to the missing-pulsar problem.

If the hypothesis is correct, then pulsars around the galactic center could only get so old before grabbing so much dark matter that they turn into black holes. Because the density of dark matter drops the farther you go from the center, the researchers predict that the maximum age of pulsars will increase with distance from the center. Observing this distinct pattern would be strong evidence that dark matter is not only causing pulsars to implode, but also that it’s asymmetric.

“The most exciting part about this is just from looking at pulsars, you can perhaps say what dark matter is made of,” Bramante said. Measuring this pattern would also help physicists narrow down the mass of the dark matter particle.

    Artist's illustration of a pulsar that was found to be an ultraluminous X-ray source. Credit: NASA, Caltech-JPL
Artist’s illustration of a pulsar that was found to be an ultraluminous X-ray source.
Credit: NASA, Caltech-JPL

But as Bramante admits, it won’t be easy to detect this signature. Astronomers will need to collect much more data about the galactic center’s pulsars by searching for radio signals, he claims. The hope is that as astronomers explore the galactic center with a wider range of radio frequencies, they will uncover more pulsars.

But of course, the idea that dark matter is behind the missing pulsar problem is still highly speculative, and the likelihood of it is being called into question.

“I think it’s unlikely—or at least it is too early to say anything definitive,” said Zurek, who was one of the first to revive the notion of asymmetric dark matter in 2009. The tricky part is being able to know for sure that any measurable pattern in the pulsar population is due to dark-matter-induced collapse and not something else.

Even if astronomers find this pulsar signature, it’s still far from being definitive evidence for asymmetric dark matter. As Kathryn Zurek of the Lawrence Berkeley National Laboratory explained: “Realistically, when dark matter is detected, we are going to need multiple, complementary probes to begin to be convinced that we have a handle on the theory of dark matter.”

And asymmetric dark matter may not have anything to do with the missing pulsar problem at all. The problem is relatively new, so astronomers may find more plausible, conventional explanations.

“I’d say give them some time and maybe they come up with some competing explanation that’s more fleshed out,” Bramante said.

Nevertheless, the idea is worth pursuing, says Haibo Yu of the University of California, Riverside. If anything, this analysis is a good example of how scientists can understand dark matter by exploring how it may influence astrophysical objects. “This tells us there are ways to explore dark matter that we’ve never thought of before,” he said. “We should have an open mind to see all possible effects that dark matter can have.”

There’s one other way to determine if dark matter can cause pulsars to implode: To catch them in the act. No one knows what a collapsing pulsar might look like. It might even blow up.

“While the idea of an explosion is really fun to think about, what would be even cooler is if it didn’t explode when it collapsed,” Bramante said. A pulsar emits a powerful beam of radiation, and as it spins, it appears to blink like a lighthouse with a frequency as high as several hundred times per second. As it implodes into a black hole, its gravity gets stronger, increasingly warping the surrounding space and time.

Studying this scenario would be a great way to test Einstein’s theory of general relativity, Bramante says. According to theory, the pulse rate would get slower and slower until the time between pulses becomes infinitely long. At that point, the pulses would stop entirely and the pulsar would be no more.

Further Reading: APS Physics, WIRED

VLTI Detects Exozodiacal Light Around Exoplanets

Artist's impression of zodiacal light viewed from the surface of an exoplanet. Credit: ESO/L. Calçada

If you’ve ever stood outside after twilight has passed, or a few hours before the sun rises at dawn,  then chances are you’ve witnessed the phenomenon known as zodiacal light. This effect, which looks like a faint, diffuse white glow in the night sky, is what happens when sunlight is reflected off of tiny particles and appears to extend up from the vicinity of the Sun. This reflected light is not just observed from Earth but can be observed from everywhere in the Solar System.

Using the full power of the Very Large Telescopic Interferometer (VLTI), an international team of astronomers recently discovered that the exozodiacal light – i.e., zodiacal light around other star systems – close to the habitable zones around nine nearby stars was far more extreme. The presence of such large amounts of dust in the inner regions around some stars may pose an obstacle to the direct imaging of Earth-like planets.

The reason for this is simple: even at low levels, exozodiacal dust causes light to become amplified intensely. For example, the light detected in this survey was roughly 1000 times brighter than the zodiacal light seen around the Sun. While this exozodiacal light had been previously detected, this is the first large systematic study of this phenomenon around nearby stars.

The team used the VLTI visitor instrument PIONIER which is able to interferometrically connect all four Auxiliary Telescopes or all four Unit Telescopes of the VLTI at the Paranal Observatory. This led to not only extremely high resolution of the targets but also allowed for a high observing efficiency.

The Very Large Telescoping Interferometer firing it's adaptive optics laser.  Credit: ESO/G. Hüdepohl
The Very Large Telescoping Interferometer firing its adaptive optics laser.
Credit: ESO/G. Hüdepohl

In total, the team observed exozodiacal light from hot dust close to the habitable zones of 92 nearby stars and combined the new data with their earlier observations.

In contrast to these earlier observations – which were made with the Center for High Angular Resolution Astronomy (CHARA) array at Georgia State University – the team did not observe dust that will later form into planets, but dust created in collisions between small planets of a few kilometers in size – objects called planetesimals that are similar to the asteroids and comets of the Solar System. Dust of this kind is also the origin of the zodiacal light in the Solar System.

As a by-product, these observations have also led to the discovery of new, unexpected stellar companions orbiting around some of the most massive stars in the sample. “These new companions suggest that we should revise our current understanding of how many of this type of star are actually double,” says Lindsay Marion, lead author of an additional paper dedicated to this complementary work using the same data.

“If we want to study the evolution of Earth-like planets close to the habitable zone, we need to observe the zodiacal dust in this region around other stars,” said Steve Ertel, lead author of the paper, from ESO and the University of Grenoble in France. “Detecting and characterizing this kind of dust around other stars is a way to study the architecture and evolution of planetary systems.”

A portrait of the HR8799 planetary system as imaged by the Hale Telescope. Credit: NASA/JPL-Caltech/Palomar Observatory.
A portrait of the HR8799 planetary system as imaged by the Hale Telescope.
Credit: NASA/JPL-Caltech/Palomar Observatory.

However, the good news is that the number of stars containing zodiacal light at the level of our Solar System is most likely much higher than the numbers found in the survey.

“The high detection rate found at this bright level suggests that there must be a significant number of systems containing fainter dust, undetectable in our survey, but still much brighter than the Solar System’s zodiacal dust,” explains Olivier Absil, co-author of the paper, from the University of Liège. “The presence of such dust in so many systems could therefore become an obstacle for future observations, which aim to make direct images of Earth-like exoplanets.”

Therefore, these observations are only a first step towards more detailed studies of exozodiacal light, and need not dampen our spirits about discovering more Earth-like exoplanets in the near future.

Further Reading: ESO

Update: NTSB Confirms SpaceShipTwo feathering was Prematurely Unlocked

NTSB Acting Chairman Christopher Hart shown explaining details of the investigation during a Monday Press Conference at Mojave Air & Space Port. (Photo Credit: NTSB)

In a Monday afternoon press conference, acting NTSB chairman Christopher Hart confirmed that the safety lock on Virgin Galactic’s SpaceShipTwo feathering mechanism was prematurely unlocked moments before breakup. Hart also quickly stated that this would be the last on-site press conference. The NTSB is nearing the completion of data gathering and the team will be returning to Washington DC with the data to undertake the facts compilation followed by the analysis.

Hart reiterated that the test flight was rich in telemetry. He said that the supply of data could expedite the analysis but he cautioned that they still expect the investigation to take 12 months to conclude and release a final report. He also added that as analysis proceeds, the NTSB would provide updates and he encouraged interested parties including the public at-large to undertake analysis of the available data; however, he emphasized that the conclusions drawn would be based on NTSB analysis alone.

From the data released and statements by Hart during the press conference, it is now clear that the NTSB recognizes that the feathering was not to be deployed until SpaceShipTwo achieved mach 1.4. The statement that acting chairman Hart made appeared to be explicitly referencing the Flight Card – the plan of actions and constraints for the flight. If this was the specific wording on the Flight Card, then it would have permitted a pilot to interpret it in various ways.

Sunday, it was reported that SpaceShipTwo was flying at about Mach 1.2 when break up occurred. As a private pilot familiar with the impact that flight conditions have on operations of an aircraft, I would add that the SpaceShipTwo constraint of mach 1.4 for executing feathering is likely intended to be viewed by the pilots-in-control as the descent speed after SpaceShipTwo had achieved maximum altitude during a flight to the edge of the atmosphere. During descent, mach 1.4 would be achieved at a much higher altitude where the air density is much lower and stresses from the feathering would also be much lower; SpaceShipTwo is designed to feather with those environmental conditions. During previous tests of SpaceShipTwo when feathering was tested at low altitude, the vehicle was flying far below mach 1, i.e., subsonic. The vehicle in that flight regime had no difficulty withstanding stresses during the test of feathering. It should be emphasized that the strict rules under which the NTSB proceeds with an investigation do not allow the investigators to inject assumptions based on their past experience.

A timeline of events leading up to catastrophic breakup of SpaceShipTwo was stated by the NTSB acting chairman:

10:07:19: SpaceShipTwo is released from the carrier craft, WhiteKnightTwo
10:07:21  SpaceShipTwo’s engine starts
10:07:29  SpaceShipTwo reaches mach 0.94
10:07:31: SpaceShipTwo exceeds the speed of sound – mach 1.02. Between 10:07:29 and 10:07:31, the feathering safety was unlocked.

10:0 7:34: All telemetry was lost

The NTSB has also created a new team responsible for evaluating the Human-Machine Interface (HMI) on SpaceShipTwo. HMI is a discipline that has gained increased interest within several manufacturing sectors, particularly in aircraft cockpit design. The performance of modern aircraft, places greater demand on human performance. The formulation of a Human performance team evaluating the HMI of SpaceShipTwo indicates that the NTSB wants to assess the quality of the cockpit control panels and whether the configuration of switches contributed to pilot error.

While most of the debris is confined to a 5 mile swath of desert, Hart stated that debris has now been found as far as 30 to 35 miles from the immediate debris field.

Besides the apparent focus by the NTSB on the unplanned feathering, Hart stated that they are checking the subsystems of the spacecraft for integrity – pneumatics, flight control, electrical, and so on.

Hart concluded the press conference by taking questions from reporters.

Q. Had the pilot been interviewed?
A. Not yet and not until he is fit to be interviewed.

Q. Was the Flight Card reviewed?
A. The NTSB has reviewed the flight card for procedures and constraints.
According to Hart, the card stated not to release the safety lock of the feathering mechanism until mach 1.4. The Flight Card describes the steps that a flight crew is to take to complete a successful mission.
Q/A. Hart confirmed that 2 pilot actions were necessary for feathering. 1) Unlock the safety, and 2) engage feathering lever. U.T. – Hart could not say if both pilots were necessary, that is, shared the two step process.
Q/A. A reporter contentiously asked Hart who was in the right seat. Hart stated that he did not know and also was unwilling to assume that it was the co-pilot, Alsbury. The reporter probing him further asked about his statements from Sunday. Hart agreed that he was mistaken to have assumed on Sunday that it was the copilot.

Finally, a review of the NTSB press conference video, placed on YouTube, presented a clarification as text on video. It stated that the co-pilot was residing in the right seat and was responsible for unlocking the feathering. At this preliminary stage of the investigation, it would appear that Alsbury’s death in the accident was due to his premature unlocking of the feathering mechanism. Hart did not state this but the circumstantial evidence so far is pointing in that direction.

Reference:

NTSB Press Conference Video, November 3, 2014

Join the Cast of Interstellar Movie for a Live Google+ Hangout

Interstellar poster
Interstellar poster, courtesy Paramount.

We’re just a few days away from the official release of Paramount’s new Interstellar movie, directed by Christopher Nolan and starring Matthew McConaughey, Anne Hathaway, and Jessica Chastain.

To celebrate the movie, the cast and crew of Interstellar will be doing a special Google+ Hangout on Air at the Smithsonian’s National Air and Space Museum. They’ll broadcast for about an hour, talk about what it took to make the movie, and answer your questions… LIVE.

Wednesday, November 5th at 2:30 PM PST

And for Universe Today fans, I’m pleased to announce that I’m going to be involved in the broadcast. I’ll be participating in the Hangout, and passing along your questions to the creators.

So, if you want to participate live, and maybe even get your questions answered by the cast and crew of Interstellar, here’s what you have to do:

  1. Click here and go to the Live Interstellar Hangout Event page.
  2. Choose “Yes”, you’re going to watch. That will put the event right into your Google calendar, so you’ll get a reminder.
  3. Post a question. If you click the video on the Event page, you’ll be able to post a question which we’ll see when the broadcast goes live on Wednesday.
  4. Join the conversation using the hashtag #InterstellarHangout. You can post comments and questions on Google+ or Twitter.

See you on Wednesday!