Posted on by Nancy Atkinson

Falcon 9 Experienced Engine Anomaly But Kept Going to Orbit

During last night’s launch of the Dragon capsule by SpaceX’s Falcon 9 rocket, there was an anomaly on one of the rocket’s nine engines and it was shut down. But Dragon still made it to orbit – just a little bit later than originally expected. At about 1:20 into the flight, there was a bright flash and a shower of debris. SpaceX’s CEO Elon Musk issued a statement about the anomaly saying:

“Falcon 9 detected an anomaly on one of the nine engines and shut it down. As designed, the flight computer then recomputed a new ascent profile in realtime to reach the target orbit, which is why the burn times were a bit longer. Like Saturn V, which experienced engine loss on two flights, the Falcon 9 is designed to handle an engine flameout and still complete its mission. I believe F9 is the only rocket flying today that, like a modern airliner, is capable of completing a flight successfully even after losing an engine. There was no effect on Dragon or the Space Station resupply mission.”

UPDATE (2 pm EDT 8/10): SpaceX has now provided an update and more information: the engine didn’t explode, but (now updated from a previous update), “panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines.” Here’s their statement:

Approximately one minute and 19 seconds into last night’s launch, the Falcon 9 rocket detected an anomaly on one first stage engine. Initial data suggests that one of the rocket’s nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued. We know the engine did not explode, because we continued to receive data from it. Panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines. Our review of flight data indicates that neither the rocket stage nor any of the other eight engines were negatively affected by this event.

As designed, the flight computer then recomputed a new ascent profile in real time to ensure Dragon’s entry into orbit for subsequent rendezvous and berthing with the ISS. This was achieved, and there was no effect on Dragon or the cargo resupply mission.

Falcon 9 did exactly what it was designed to do. Like the Saturn V (which experienced engine loss on two flights) and modern airliners, Falcon 9 is designed to handle an engine out situation and still complete its mission. No other rocket currently flying has this ability.

It is worth noting that Falcon 9 shuts down two of its engines to limit acceleration to 5 g’s even on a fully nominal flight. The rocket could therefore have lost another engine and still completed its mission.

We will continue to review all flight data in order to understand the cause of the anomaly, and will devote the resources necessary to identify the problem and apply those lessons to future flights. We will provide additional information as it becomes available.

In their initial press release following the launch SpaceX had originally described the performance of Falcon 9 as nominal “during every phase of its approach to orbit.”

During the press briefing following the launch SpaceX President Gwynne Shotwell replied to a question about the flash and said “I do know we had an anomaly on Engine 1, but I have no data on it. But Falcon 9 was designed to lose engines and still make mission, so it did what it was supposed to do. If you do end up with issues, you burn longer to end up where you need to go.”

SpaceX’s website also mentions this capability, saying, “”This vehicle will be capable of sustaining an engine failure at any point in flight and still successfully completing its mission. This actually results in an even higher level of reliability than a single engine stage.”

Dragon made it to orbit about 30 seconds later than originally planned, but Shotwell said it made it into the correct orbit, “within two or three kilometers in both apogee and perigee and Dragon is now on its way to Station.” The anomaly happened right at the time of Max-Q, just as the vehicle went supersonic.

The Space Shuttle was also designed to make it into orbit even if one of its three engines failed – after a certain point in the flight – and did so at least once to this reporter’s knowledge, on STS-51-F which resulted in an Abort To Orbit trajectory, where the shuttle achieved a lower-than-planned orbital altitude.

This was the first time SpaceX made lift-off at their originally planned “T-0” launch time, Shotwell noted. And they also deployed a tag-along, secondary payload in addition to the Dragon capsule, a prototype commercial communications satellite for New Jersey-based Orbcomm Inc. However, A report by Jonathan McDowell indicates the Orbcomm satellite is being tracked in low orbit instead of its elliptical target orbit because the Falcon 9 upper stage failed its second burn. (More info here from Jonathan’s Space Report).

SpaceX will undoubtedly review the anomaly, and we’ll provide more information about it when available.

SpaceX Launches to the International Space Station. Credit: NASA

Posted on by Nancy Atkinson

Liftoff! SpaceX Launches First Official Commercial Resupply Mission to ISS

The launch of SpaceX’s Falcon 9 rocket sending the Dragon capsule to orbit. Credit: KSC Twitter Feed

SpaceX has successfully launched the first official Cargo Resupply Services (CRS) mission to the International Space Station. The commercial company’s Falcon 9 rumbled rocket to life at 8:35 EDT on Oct 7 (00:35 UTC Oct. 8) in a picture perfect launch, sending the Dragon capsule on its way in the first of a dozen operational missions to deliver supplies to the orbiting laboratory. The launch took place at Launch Complex 40 at Cape Canaveral Air Force Station in Florida, just a few miles south of the space shuttle launch pads.

“This was a critical event for NASA and the nation tonight,” said NASA Administrator Charlie Bolden after the launch. “We are once again launching spacecraft from American soil with supplies that the ISS astronauts need.”

Watch the launch video below:

All the major milestones of the launch ticked off in perfect timing and execution, and the Dragon capsule is now in orbit with its solar arrays deployed. The Dragon capsule separated from the Falcon 9 about 10 minutes and 24 seconds after liftoff. Dragon should arrive at the ISS on Oct. 10 and the crew will begin berthing operations after everything checks out.

All three members of the current ISS crew were able to watch the launch live via a NASA uplink to the ISS, and Commander Suni Williams passed on her congratulations to the SpaceX team, saying “We are ready to grab Dragon!”

Williams and astronaut Akihiko Hoshide will use the CanadArm 2 to grapple the Dragon capsule around 7:22 a.m. EDT (11:22 UTC) Wednesday, moving it to a berthing at the Earth-facing port of the forward Harmony module.

Even though SpaceX sent the Dragon to the ISS in May, that was considered a demonstration flight and this flight is considered the first operational mission.

“No question, we are very excited,” said SpaceX President Gwynne Shotwell just before the launch. “Everyone was very excited in May and we are very much looking forward to moving forward with the operational missions.”

Dragon is carrying approximately 450 kg (1,000 pounds) of supplies, including food, water, scientific experiments and Space Station parts. There are also 23 student experiments from the Student Spaceflight Experiments Program (SSEP) involving 7,420 pre-college students engaged in formal microgravity experiment design, according to SSEP director Dr. Jeff Goldstein.

SpaceX and NASA revealed this weekend a special treat is on board a new freezer called GLACIER (General Laboratory Active Cryogenic ISS Experiment Refrigerator): Blue Bell ice cream, a brand that is a favorite of astronauts training at the Johnson Space Center in Houston. The freezer will be used to return frozen science experiments to Earth.

In the next three days, Dragon will perform systems checks, and start a series of Draco thruster firings to reach the International Space Station.

Dragon will return a total of 750 kg (1,673 pounds) of supplies and hardware to the ground. NASA says Dragon’s capability to return cargo from the station “is critical for supporting scientific research in the orbiting laboratory’s unique microgravity environment, which enables important benefits for humanity and vastly increases understanding of how humans can safely work, live and thrive in space for long periods. The ability to return frozen samples is a first for this flight and will be tremendously beneficial to the station’s research community. Not since the space shuttle have NASA and its international partners been able to return considerable amounts of research and samples for analysis.”

Dragon is currently scheduled to return to Earth at the end of the month, splashing down in the Pacific Ocean on October 29.

1000 SpaceX employees watch Falcon 9 and Dragon launch, at the Hawthorne, California headquarter. Credit: SpaceX

Taking a cue from the Mars Science Laboratory “Mohawk Guy” this SpaceX employee watching from Hawthorne sports a blue mohawk with a SpaceX logo shaved on her head. Credit: SpaceX.

Here’s a shorter video version of the launch from SpaceX:

Posted on by Jason Major

Minute Physics: Real World Telekinesis

How do magnets affect things at a distance? How does the Sun heat our planet from 93 million miles away? How can we send messages across the world with our cell phones? We take these seemingly simple things for granted, but in fact there was a time not too long ago when the processes behind them were poorly understood, if at all… and, to the uninformed, there could seem to be a certain sense of “magic” about them.

This video from MinutePhysics, featuring director of the Perimeter Institute for Theoretical Physics Neil Turok, illustrates how our understanding of electromagnetic fields was developed and why there’s nothing magic about it… except, perhaps, how they pack all that excellent info into 5 minutes. Enjoy!

Video: MinutePhysics (Created by Henry Reich.) In conjunction with The CBC Massey Lectures.

Posted on by Nancy Atkinson

Surreal Photos: CubeSats Launched from the Space Station

Three small CubeSats are deployed from the International Space Station on October 4, 2012. Credit: NASA

Five tiny CubeSats were deployed from the International Space Station on Thursday and astronaut Chris Hadfield called the image above “surreal” on Twitter. And rightly so, as they look like a cross between Star Wars training droids and mini Borg Cubes from Star Trek. The Cubesats measure about 10 centimeters (4 inches) on a side and each will conduct a range of scientific missions, ranging from Earth observation and photography to technology demonstrations to sending LED pulses in Morse Code (which should be visible from Earth) to test out a potential type of optical communication system.

These are low-cost satellites that could be the wave of the future to enable students and smaller companies to send equipment into space. If you’re worried about these tiny sats creating more space junk, Hadfield assured that since they are very light and in such a low orbit, the Cubesat orbits will decay within a few months.

The Rubic-cube-sized Cubesats were deployed from the new Japanese Small Satellite Orbital Deployer that was brought to the space station in July by the Japanese HTV cargo carrier.

The Japanese FITSAT-1 will investigate the potential for new kinds of optical communication by transmitting text information to the ground via pulses of light set to Morse code. The message was originally intended to be seen just in Japan, but people around the world have asked for the satellite to communicate when it overflies them, said Takushi Tanaka, professor at The Fukuoka Institute of Technology.

Observers, ideally with binoculars, will be able to see flashes of light — green in the northern hemisphere, where people will see the “front” of the satellite, and red in the southern hemisphere, where the “back” will be visible.

The message it will send is “Hi this is Niwaka Japan.” Niwaka is the satellite’s nickname and reflects a play on words in the local dialect of southwestern Japan, according to an article on Discovery Space. To see the Morse Code message, the Cubesat will be near the ISS, so find out when you can see the ISS from NASA or Heaven’s Above. Find out more about the FITSAT at this website.

The other Cubesats include NASA’s TechEdSat which carries a ham radio transmitter and was developed by a group of student interns from San Jose State University (SJSU) in California with mentoring and support from staff at NASA’s Ames Research Center.

“TechEdSat will evaluate plug-and-play technologies, like avionics designed by commercial providers, and will allow a group of very talented aerospace engineering students from San Jose State University to experience a spaceflight project from formulation through decommission of a small spacecraft,” said Ames Director S. Pete Worden.

The other Cubesats include RAIKO, which will do photography from space, We Wish, an infrared camera for environmental studies, and and the F-1 Vietnam Student CubeSat which has an on-board camera for Earth observation.

See more cool-looking images and video of the deployement below (all images credit the Expedition 32 crew from the ISS/NASA):

Posted on by Jason Major

How to Steal a Space Shuttle

For two days, from October 12 to 13, the shuttle Endeavour will be transported along 12 miles of road on the final leg of its journey to the California Science Center. During that time the orbiter will be the most publicly exposed as it’s ever been, a national treasure on the streets of LA. While this will of course be a well-orchestrated undertaking with the security of not only Endeavour but citizens and spectators being of utmost priority, one might be prompted to speculate: what if someone tried to steal the space shuttle?

And that one, in this instance, was Jalopnik.com‘s Jason Torchinsky. In his latest article, Jason describes in detail a method for snatching a spaceship — and a rather dramatic one at that, worthy of a Bondian supervillian (and requiring a similarly cinematic amount of funds.) However nefarious, fictitious, and unlikely, it’s nevertheless intriguing.

Now while we don’t encourage the theft of a space shuttle (or any federal property, for that matter) it’s a fun read… check it out.

Just keep an eye out for any suspicious Swiss skulking along Endeavour’s route…

(Image: NASA/Bill Ingalls)

Posted on by Ken Kremer

Curiosity Set for 1st Martian Scooping at ‘Rocknest’ Ripple

Image caption: Context view of Curiosity working at ‘Rocknest’ Ripple. Curiosity’s maneuvers robotic arm for close- up examination of ‘Rocknest’ ripple site and inspects sandy material at “bootlike” wheel scuff mark with the APXS (Alpha Particle X-Ray Spectrometer) and MAHLI (Mars Hand Lens Imager) instruments positioned on the rotatable turret at the arm’s terminus. Mosaic was stitched together from Sol 57 & 58 Navcam raw images and shows the arm extended to fine grained sand ripple in context with the surrounding terrain and eroded rim of Gale Crater rim on the horizon. Rocknest patch measures about 8 feet by 16 feet (2.5 meters by 5 meters).See NASA JPL test scooping video below. Credit: NASA/JPL-Caltech/Ken Kremer/Marco Di Lorenzo

NASA’s Curiosity rover is set to scoop up her 1st sample of Martian soil this weekend at a soil patch nicknamed ‘Rocknest’ -see our context mosaic above – and will funtion as a sort of circulatory system cleanser for all the critical samples to follow. This marks a major milestone on the path to delivering Mars material to the sample acquisition and processing system for high powered analysis by the robots chemistry labs and looking for the ingredients of life, said the science and engineering team leading the mission at a media briefing on Thursday, Oct 4.

Since landing on the Red Planet two months ago on Aug. 5/6, Curiosity has trekked over 500 yards eastwards across Gale crater towards an intriguing area named “Glenelg” where three different types of geologic terrain intersect.

This week on Oct. 2 (Sol 56), the rover finally found a wind driven patch of dunes at ‘Rocknest’ with exactly the type of fine grained sand that the team was looking for and that’s best suited as the first soil to scoop and injest into the sample acquisition system.

See NASA JPL earthly test scooping video below to visualize how it works:

“We now have reached an important phase that will get the first solid samples into the analytical instruments in about two weeks,” said Mission Manager Michael Watkins of NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

The rover used its wheels to purposely scuff the sand and expose fresh soil – and it sure looked like the first human “bootprint” left on the Moon by Apollo 11 astronauts Neil Armstrong and Buzz Aldrin.

Curiosity will remain at the “Rocknest” location for the next two to three weeks as the team fully tests and cleans the walls of most of the sample collection, handling and analysis hardware – except for the drilling equipment – specifically to remove residual contaminants from Earth.

Image caption: ‘Rocknest’ From Sol 52 Location on Sept. 28, 2012, four sols before the rover arrived at Rocknest. The Rocknest patch is about 8 feet by 16 feet (1.5 meters by 5 meters). Credit: NASA/JPL-Caltech/MSSS

The purpose of this initial scoop is to use the sandy material to thoroughly clean out, rinse and scrub all the plumbing pipes, chambers, labyrinths and interfaces housed inside the complex CHIMRA sampling system and the SAM and CheMin chemistry labs of an accumulation of a very thin and fine oily layer that could cause spurious, interfering readings when the truly important samples of Martian soil and rocks are collected for analysis starting in the near future.

The scientists especially do not want any false signals of organic compounds or other inorganic materials and minerals stemming from Earthly contamination while the rover and its instruments were assembled together and processed for launch.

“Even though we make this hardware super squeaky clean when it’s delivered and assembled at the Jet Propulsion Laboratory, by virtue of its just being on Earth you get a kind of residual oily film that is impossible to avoid,” said Daniel Limonadi of JPL, lead systems engineer for Curiosity’s surface sampling and science system. “And the Sample Analysis at Mars instrument is so sensitive we really have to scrub away this layer of oils that accumulates on Earth.”

The team plans to conduct three scoop and rinse trials – dubbed rinse and discard – of the sample acquisition systems. So it won’t be until the 3rd and 4th soil scooping at Rocknest that a Martian sample would actually be delivered for entry into the SAM and CheMin analytical chemistry instruments located on the rover deck.

“What we’re doing at the site is we take the sand sample, this fine-grained material and we effectively use it to rinse our mouth three times and then kind of spit out,” Limonadi said. “We will take a scoop, we will vibrate that sand on all the different surfaces inside CHIMRA to effectively sand-blast those surfaces, then we dump that material out and we rinse and repeat three times to finish cleaning everything out. Our Earth-based testing has found that to be super effective at cleaning.”

Limondi said the first scooping is likely to be run this Saturday (Oct 6) on Sol 61, if things proceed as planned. Scoop samples will be vibrated at 8 G’s to break them down to a very fine particle size that can be easily passed through a 150 micron sieve before entering the analytical instruments.

The team is being cautious, allowing plenty of margin time and will not proceed forward with undue haste.

“We’re being deliberately slow and incredibly careful,” said Watkins. “We’re taking a lot of extra steps here to make sure we understand exactly what’s going on, that we won’t have to do every time we do a scoop in the future.”

Curiosity’s motorized, clamshell-shaped scoop measures 1.8 inches (4.5 centimeters) wide, 2.8 inches (7 centimeters) long, and can sample to a depth of about 1.4 inches (3.5 centimeters). It is part of the CHIMRA collection and handling device located on the tool turret at the end of the rover’s arm.

“The scoop is about the size of an oversized table spoon,” said Limonadi.

Image caption: Curiosity extends 7 foot long arm to investigate ‘Bathurst Inlet’ rock outcrop with the MAHLI camera and APXS chemical element spectrometer in this mosaic of Navcam images assembled from Sols 53 & 54 (Sept. 29 & 30, 2012). Mount Sharp, the rover’s eventual destination is visible on the horizon. Thereafter the rover drove more than 77 feet (23 meters) eastwards to reach the ‘Rocknest’ sand ripple. Credit: NASA/JPL-Caltech/Ken Kremer/Marco Di Lorenzo

During the lengthy stay at Rocknest, the rover will conduct extensive investigations of the surrounding rocks and terrain with the cameras, ChemCam laser, DAN, RAD as well as weather monitoring with the REMS instrument.

After finishing her work at Rocknest, Curiosity will resume driving eastward to Glenelg, some 100 meters (yards) away where the team will select the first targets and rock outcrops to drill, sample and analyze.

At Glenelg and elsewhere, researchers hope to find more evidence for the ancient Martian stream bed they discovered at rock outcrops at three different locations that Curiosity has already visited.

Curiosity is searching for organic molecules and evidence of potential habitable environments to determine whether Mars could have supported Martian microbial life forms, past or present.

Ken Kremer

Image caption: Curiosity’s Travels Through Sol 56 – Oct. 2, 2012

Posted on by Fraser Cain

Weekly Space Hangout – Oct. 4, 2012

It was a slow week on Space news except for the massive announcement that an ancient riverbed was discovered on the surface of Mars. We took a look at this as well as the historic 55th anniversary of Sputnik, a precise measurement of the expansion of the Universe, and more!

Stories:

Panel: Amy Shira Teitel, Nicole Gugliucci, Nancy Atkinson

Host: Fraser Cain

We record the Weekly Space Hangout every Thursday at 10am PDT / 1 pm EDT. You can watch us live on Google+, Cosmoquest, or at the Universe Today YouTube channel, or listen after as part of the Astronomy Cast podcast feed (audio only).

Click here to put the next event right into your calendar.

Posted on by Nancy Atkinson

Rare X-Ray Nova Reveals a New Black Hole in the Milky Way

Swift J1745-26, with a scale of the moon as it would appear in the field of view from Earth. This image is from September 18, 2012 when the source peaked in hard X-rays. Credit: NASA/Goddard Space Flight Center/S. Immler and H. Krimm

Back in mid-September, the Swift satellite was going about its multi-wavelength business of watching for bursts of bright gamma-ray, X-ray, ultraviolet, or optical events in the sky, when it detected a rising tide of high-energy X-rays from a source toward the center of our Milky Way galaxy. But this was different from any other burst the satellite had detected, and after observing the event for a few days, astronomers knew this had to be a rare X-ray nova. What it meant was that Swift had detected the presence of a previously unknown stellar-mass black hole.

“Bright X-ray novae are so rare that they’re essentially once-a-mission events and this is the first one Swift has seen,” said Neil Gehrels from Goddard Space Flight Center, the mission’s principal investigator. “This is really something we’ve been waiting for.”

The object was named Swift J1745-26 after the coordinates of its sky position, the nova is located a few degrees from the center of our galaxy toward the constellation Sagittarius. While astronomers do not know its precise distance, they think the object resides about 20,000 to 30,000 light-years away in the galaxy’s inner region.

An X-ray nova is a short-lived X-ray source that appears suddenly in the sky and dramatically increases in strength over a period of a few days and then decreases, fading out over a few months. Unlike a conventional nova, where the compact component is a white dwarf, an X-ray nova is caused by material – usually gas — falling onto a neutron star or a black hole.

The rapidly brightening source triggered Swift’s Burst Alert Telescope twice on the morning of Sept. 16, and once again the next day.

Ground-based observatories detected infrared and radio emissions, but thick clouds of obscuring dust have prevented astronomers from catching Swift J1745-26 in visible light.

The nova peaked in hard X-rays — energies above 10,000 electron volts, or several thousand times that of visible light — on Sept. 18, when it reached an intensity equivalent to that of the famous Crab Nebula, a supernova remnant that serves as a calibration target for high-energy observatories and is considered one of the brightest sources beyond the solar system at these energies.

Even as it dimmed at higher energies, the nova brightened in the lower-energy, or softer, emissions detected by Swift’s X-ray Telescope, a behavior typical of X-ray novae. By Wednesday, Swift J1745-26 was 30 times brighter in soft X-rays than when it was discovered and it continued to brighten.

“The pattern we’re seeing is observed in X-ray novae where the central object is a black hole. Once the X-rays fade away, we hope to measure its mass and confirm its black hole status,” said Boris Sbarufatti, an astrophysicist at Brera Observatory in Milan, Italy, who currently is working with other Swift team members at Penn State in University Park, Pa.

Here’s usually happens in events like this: The black hole is part of a binary system with a normal Sun-like star. A stream of material flows into an accretion disk around the black hole. Usually, the disk of gas spirals in steadily to the black hole, heats up and produces a steady X-ray glow. But sometimes, for reasons unknown, the material is held up in the outer regions, held back by some mechanism, almost like a dam. Once enough gas accumulates, the dam breaks and a flood of gas surges towards the black hole, creating the X-ray nova outburst.

“Each outburst clears out the inner disk, and with little or no matter falling toward the black hole, the system ceases to be a bright source of X-rays,” said John Cannizzo, a Goddard astrophysicist. “Decades later, after enough gas has accumulated in the outer disk, it switches again to its hot state and sends a deluge of gas toward the black hole, resulting in a new X-ray outburst.”

This phenomenon, called the thermal-viscous limit cycle, helps astronomers explain transient outbursts across a wide range of systems, from protoplanetary disks around young stars, to dwarf novae — where the central object is a white dwarf star — and even bright emission from supermassive black holes in the hearts of distant galaxies.

It is estimated that our galaxy must harbor some 100 million stellar-mass black holes. Most of these are invisible to us, and only about a dozen have been identified.

Swift discovers about 100 bursts per year. The Burst Alert Telescope detects GRBs and other events and accurately determines their positions on the sky. Swift then relays a 3 arcminute position estimate to the ground within 20 seconds of the initial detection, enabling ground-based observatories and other space observatories the chance to observe the event as well. The Swift spacecraft itself “swiftly” –in less than approximately 90 seconds — and autonomously repoints itself to bring the burst location within the field of view of the sensitive narrow-field X-ray and UV/optical telescopes to observe the afterglow and gather data.

Source: NASA

Posted on by Nancy Atkinson

Once in a Lifetime Image: Emperor Penguins Under the Aurora Australis

Emperor Penguins on the Antarctic Sea Ice Under the Aurora Australis. Credit and copyright: Stefan Christmann. Used by permission.

Photographer Stefan Christmann called this incredible Antarctic view a once in a lifetime experience.

“It was the most impressive experience to sit on the sea-ice and watch the Aurora Australis dance above the penguin colony with the sounds of the chicks and the adult penguins. I feel truly blessed for having had the opportunity to witness this once in a lifetime experience,” he told Universe Today.

Christmann is currently based in Antarctica, working at the German Antarctic research station Neumayer III. He is an “overwinterer” — scientific and technical staff who stay at the base for the entire southern winter — and will stay in Antarctica for an uninterrupted 14 months. “As a physicist, my duty is to maintain the data acquisition of our seismological and geomagnetic observatories as well as the analysis of the collected data,” Christmann said.

But he is also an accomplished photographer. His website and Facebook page are filled with beautiful nature images from around the world, and recently feature the Emperor penguins and their adorable chicks, as well as the stark beauty of the Antarctic landscape.

Originally from Germany, he studied photography in the US, and his work has now brought him to an extended stay in Antarctica.

Christmann explained the conditions and the difficulties in obtaining this shot, one he had long hoped for, the planning of it always in the back of his mind.

“The picture was taken at Atka-Bay on the sea-ice. The bay is roughly 8 km away from our station so the penguin colony is a popular destination for free-time trips. The idea of a photo of the Aurora Australis above the penguin colony had been in my head for a long time, but the conditions have to be just right –which usually never happens. You need a full Moon, high magnetic activity and a cloudless sky. Also the penguins should be standing close enough to the ice-berg. I made multiple attempts to get the photo, but we either had incoming clouds, low activity or had to cancel our stay because of wind picking up (which can be really dangerous out on the sea-ice).”

And time was short, as after he had been outside for a few hours the wind picked up and he and his accomplices had to leave the ice for safety reasons. “Otherwise we probably would have sat there all night!” Christmann said. The image was taken on October 1, 2012.

Christmann shared what equipment he uses as well as a few tips for Antarctic and cold weather photography.

“I used a Nikon D700 Fullframe DSLR with an AF-S G-Nikkor 14-24mm f/2.8. ISO settings varied with the intensity of the aurora from ISO 500-800,” he said. “F-Stops in the range of 4.0-5.6 and Exposure times from 20s to 30s. I try to keep ISO as low as possible for noise reasons and also try to limit the exposure time in order not to get star trails. It’s either super long star trails or almost star-dots, but I don’t really like the in between. A full battery charge (in my case around 2500mAh) lasts around 1h in the cold, so I had to switch batteries twice during our stay out on the ice!”

Asked what other details he felt was important to share about this image, Christmann said, “Antarctica is an incredible place where nature dwarfs anything made by humans. Hopefully people will gain even more interest in this continent and help to protect it as well as its inhabitants.”

To see more of Christmann’s work visit his website, Nature in Focus or his Facebook page, where he shares many pictures of his Antarctic adventure.

Please note: This image may not be re-posted, used or copied without the express permission of Stefan Christmann.

Posted on by Nancy Atkinson

Two Stars Do a Short-Orbit Tango Around the Milky Way’s Black Hole

Astronomers have known for some time there was one star orbiting fairly close to the black hole at the center of our galaxy. But now another star has been found dipping close and orbiting even faster around the Milky Way’s central black hole. Astronomer Andrea Ghez from UCLA says the ability to watch these two stars in a short-period ‘tango’ around the black hole will help scientist measure the effects of space-time curvature, and they should be able to determine whether Albert Einstein was right in his prediction of how black holes could warp space and time.

“I’m extremely pleased to find two stars that orbit our galaxy’s supermassive black hole in much less than a human lifetime,” said Ghez. “It is the tango of [these stars] that will reveal the true geometry of space and time near a black hole for the first time. This measurement cannot be done with one star alone.”

There are nearly 3,000 stars that orbit somewhat close to the black hole, and most of them have orbits of 60 years or longer.
The previously known close-in star, S0-2, orbits the black hole every 15.5 years. And now, the newly found star, called S0-102, orbits the black hole in a blazing 11.5 years, the shortest known orbit of any star near this black hole.

Reconstruction of the orbits of two stars—S0-2 and S0-102—near the black hole at the Milky Way’s center. (Other stars’ orbits are also depicted by fainter lines.) The background is a real high-resolution infrared image of the region. Credit: Andrea Ghez et al./UCLA/Keck

In the same way that planets orbit around the sun, S0-102 and S0-2 are each in an elliptical orbit around the central black hole. Ghez said that the planetary motion in our solar system was the ultimate test for Newton’s gravitational theory 300 years ago, and now the motion of S0-102 and S0-2 will be the ultimate test for Einstein’s theory of general relativity, which describes gravity as a consequence of the curvature of space and time.

“The exciting thing about seeing stars go through their complete orbit is not only that you can prove that a black hole exists but you have the first opportunity to test fundamental physics using the motions of these stars,” Ghez said. “Showing that it goes around in an ellipse provides the mass of the supermassive black hole, but if we can improve the precision of the measurements, we can see deviations from a perfect ellipse — which is the signature of general relativity.”

As the stars come to their closest approach, their motion will be affected by the curvature of spacetime, and the light traveling from the stars to us will be distorted, Ghez said.

S0-2, which is 15 times brighter than S0-102, will go through its closest approach to the black hole in 2018. S0-102 makes its closest approach in 2021, so the team will be keeping an eye on these stars as they get tantalizingly close, but not close enough to get sucked in, Ghez said.

Ghez and her colleagues have been observing S0-2 since 1995. In 2000, she and her team reported — for the first time – that astronomers had seen stars accelerate around the supermassive black hole. Their research demonstrated that three stars had accelerated by more than 250,000 mph a year as they orbited the black hole. The speed of S0-102 and S0-2 should also accelerate by more than 250,000 mph at their closest approach, Ghez said.

“The fact that we can find stars that are so close to the black hole is phenomenal,” said Ghez. “Now it’s a whole new ballgame, in terms of the kinds of experiments we can do to understand how black holes grow over time, the role supermassive black holes play in the center of galaxies, and whether Einstein’s theory of general relativity is valid near a black hole, where this theory has never been tested before. It’s exciting to now have a means to open up this window.”

The research was done using the Keck Telescopes. The team’s paper was published Oct. 5 in the journal Science.

Source: UCLA

Lead image caption: The Keck I and Keck II telescopes focus on two stars orbiting Milky Way’s black hole. Background photo credit: Dan Birchall/Subaru Telescope on Mauna Kea, Hawaii. Overlay created by Professor Andrea Ghez and her research team at UCLA and are from data sets obtained with the W. M. Keck Telescopes.