Universe Today

March 14, 2013December 23, 2015 by Nancy Atkinson

Breaks in Jupiter’s Clouds are Swirling Hot Spots

The dark hot spot in this false-color image from NASA's Cassini spacecraft is a window deep into Jupiter's atmosphere. All around it are layers of higher clouds, with colors indicating which layer of the atmosphere the clouds are in. Image credit: NASA/JPL-Caltech/SSI/GSFC

In the swirling canopy of Jupiter’s atmosphere, cloudless patches are so exceptional that the big ones get the special name “hot spots.” Exactly how these clearings form and why they’re only found near the planet’s equator have long been mysteries. Now, using images from NASA’s Cassini spacecraft, scientists have found new evidence that hot spots in Jupiter’s atmosphere are created by a Rossby wave, a pattern also seen in Earth’s atmosphere and oceans. The team found the wave responsible for the hot spots glides up and down through layers of the atmosphere like a carousel horse on a merry-go-round.

“This is the first time anybody has closely tracked the shape of multiple hot spots over a period of time, which is the best way to appreciate the dynamic nature of these features,” said the study’s lead author, David Choi, a NASA Postdoctoral Fellow working at NASA’s Goddard Space Flight Center in Greenbelt, Md. The paper is published online in the April issue of the journal Icarus.

Choi and his colleagues made time-lapse movies from hundreds of observations taken by Cassini during its flyby of Jupiter in late 2000, when the spacecraft made its closest approach to the planet. The movies zoom in on a line of hot spots between one of Jupiter’s dark belts and bright white zones, roughly 7 degrees north of the equator. Covering about two months (in Earth time), the study examines the daily and weekly changes in the sizes and shapes of the hot spots, each of which covers more area than North America, on average.

Much of what scientists know about hot spots came from NASA’s Galileo mission, which released an atmospheric probe that descended into a hot spot in 1995. This was the first, and so far only, in-situ investigation of Jupiter’s atmosphere.

“Galileo’s probe data and a handful of orbiter images hinted at the complex winds swirling around and through these hot spots, and raised questions about whether they fundamentally were waves, cyclones or something in between,” said Ashwin Vasavada, a paper co-author who is based at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and who was a member of the Cassini imaging team during the Jupiter flyby. “Cassini’s fantastic movies now show the entire life cycle and evolution of hot spots in great detail.”

Because hot spots are breaks in the clouds, they provide windows into a normally unseen layer of Jupiter’s atmosphere, possibly all the way down to the level where water clouds can form. In pictures, hot spots appear shadowy, but because the deeper layers are warmer, hot spots are very bright at the infrared wavelengths where heat is sensed; in fact, this is how they got their name.

One hypothesis is that hot spots occur when big drafts of air sink in the atmosphere and get heated or dried out in the process. But the surprising regularity of hot spots has led some researchers to suspect there is an atmospheric wave involved. Typically, eight to 10 hot spots line up, roughly evenly spaced, with dense white plumes of cloud in between. This pattern could be explained by a wave that pushes cold air down, breaking up any clouds, and then carries warm air up, causing the heavy cloud cover seen in the plumes. Computer modeling has strengthened this line of reasoning.

In this series of images from NASA's Cassini spacecraft, a dark, rectangular hot spot (top) interacts with a line of vortices that approaches from on the upper-right side (second panel). Image credit: NASA/JPL-Caltech/SSI/GSFC — In this series of images from NASA’s Cassini spacecraft, a dark, rectangular hot spot (top) interacts with a line of vortices that approaches from on the upper-right side (second panel). Image credit: NASA/JPL-Caltech/SSI/GSFC

From the Cassini movies, the researchers mapped the winds in and around each hot spot and plume, and examined interactions with vortices that pass by, in addition to wind gyres, or spiraling vortices, that merge with the hot spots. To separate these motions from the jet stream in which the hot spots reside, the scientists also tracked the movements of small “scooter” clouds, similar to cirrus clouds on Earth. This provided what may be the first direct measurement of the true wind speed of the jet stream, which was clocked at about 300 to 450 mph (500 to 720 kilometers per hour) — much faster than anyone previously thought. The hot spots amble at the more leisurely pace of about 225 mph (362 kilometers per hour).

By teasing out these individual movements, the researchers saw that the motions of the hot spots fit the pattern of a Rossby wave in the atmosphere. On Earth, Rossby waves play a major role in weather. For example, when a blast of frigid Arctic air suddenly dips down and freezes Florida’s crops, a Rossby wave is interacting with the polar jet stream and sending it off its typical course. The wave travels around our planet but periodically wanders north and south as it goes.

The wave responsible for the hot spots also circles the planet west to east, but instead of wandering north and south, it glides up and down in the atmosphere. The researchers estimate this wave may rise and fall 15 to 30 miles (24 to 50 kilometers) in altitude.

The new findings should help researchers understand how well the observations returned by the Galileo probe extend to the rest of Jupiter’s atmosphere. “And that is another step in answering more of the questions that still surround hot spots on Jupiter,” said Choi.

March 14, 2013December 30, 2015 by Jason Major

A Tribute to MESSENGER

If you’re reading this then you probably love space exploration, and if you love space exploration then you know how awesome the MESSENGER mission is — the incredibly successful venture by NASA, Johns Hopkins University Applied Physics Laboratory, and the Carnegie Institution of Washington to orbit and study the first rock from the Sun in unprecedented detail. Since entering orbit around Mercury on March 18, 2011, MESSENGER has mapped nearly 100% of the planet’s surface, found unique landforms called hollows residing in many of its craters, and even discovered evidence of water ice at its poles! That’s a lot to get accomplished in just two years!

The video above, assembled by Mark ‘Indy’ Kochte, is a tribute to the many impressive achievements of the MESSENGER mission, featuring orbital animations (love that MESSENGER shimmy!), surface photos, and the approach to the planet. Enjoy!

Images and animation stills courtesy NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington. Music: “Mercury Ridge” by Simon Wilkinson. Video creation and time-lapse animations by Mark ‘Indy’ Kochte.

March 14, 2013December 23, 2015 by Elizabeth Howell

Former Navy SEAL Survived ‘Hell Week’ En Route to Space

Astronaut Chris Cassidy training for a spacewalk in NASA's Neutral Buoyancy Laboratory. Credit: Robert Markowitz

If a meteor hit the station, or a fire suddenly broke out, you’d want some pretty quick-thinking people on board to solve the problem. Thankfully, Chris Cassidy — a former Navy SEAL — is on his way to station in just a couple of weeks as a part of Expedition 35/36.

SEAL training is perhaps the most vigorous military program in the world. Even a quick look at the tests candidates must pass makes us feel exhausted. You need to master a suite of skills that range from demolition to navigation to, of course, fast swimming. There’s something called “combat diving”, which is supposed to test how well these Navy people “perform in stressful and often uncomfortable environments.”

And don’t forget “hell week.” Candidates only get to sleep four hours in 5.5 days. They rack up 200 miles of running through physically training for 20 hours a day. (No, those numbers are not typos. It’s real.)

Cassidy — who by the way, passed that gruelling SEAL training on the first try without getting hurt or going crazy — told Universe Today last week about what he would do should he be faced with an emergency in space.

I think just the training that I got in the field, training in the early part of my Navy career, and during my time being an astronaut will all combine together. What I know from combat in the Navy, there’s a sort of calmness that comes over people who are well-trained and know what to do. Muscle memory kicks in, and it’s not until after the thing is over that you realize what you went through.

I kind of think that’s how me as an individual, and we as a crew, will respond to any dicey dynamic event like that. Just work through the procedures that we’ve been trained, make the place safe if we can, and if we can’t, we are trained to evacuate. And the procedures all get us to that point.

Cassidy further joked that some of the humor SEALs use might not be appropriate in his most recent job title; former SEAL and International Space Station Expedition 1 commander William Shepherd once told Cassidy he might be “kicked out of a NASA meeting” if he used some of the language.

More seriously, though, Cassidy said he is particularly looking forward to doing experiments measuring bone mass on the International Space Station. Since that research has applications for people on Earth (particularly those facing osteoporosis he said it’s a demonstration of how spaceflight can help further health work on the ground.

His ultimate goal? “To be called back [to station] a second time.” Let’s hope he makes it.

Cassidy and his crewmates Pavel Vinogradov and Alexander Misurkin are scheduled to launch from the Baikonur Cosmodrome in Kazakhstan on March 29. Here a look at some of the final training the crew received at the Gagarin Cosmonaut Training Center in Star City, Russia:

March 13, 2013December 23, 2015 by Nancy Atkinson

O Canada! Hadfield Becomes First Canadian Commander of ISS

The change of command ceremony on the ISS. Via NASA TV.

With the Canadian national anthem playing, astronaut Chris Hadfield accepted the “keys” to the International Space Station from outgoing Expedition 34 commander Kevin Ford, as Hadfield became the first Canadian commander of the space station.

“Thank you very much for giving me the keys to the family car… we’re going to put some miles on it,” Hadfield said during the change of command ceremonies held on the ISS today, marking the start of the Hadfield-led Expedition 35.

“It is a tremendous honour to assume command of the ISS,” Hadfield said in a statement issued by the Canadian Space Agency. “I will do my best to acquit myself well, accomplish the utmost as a crew for all the International Partners, and fully live and share the experience on behalf of so many around our world”.

“It’s a first for our country,” Hadfield continued, “but is really just the culmination of a lot of other firsts. I stand on the shoulders of so many that have made this possible, and now take my turn to try and add to that solid foundation for the Canadians that follow.”

Ford and Russian cosmonauts Oleg Novitskiy and Evgeny Tarelkin arrived at the station on October 25, 2012 and leave the ISS on Friday, March 15, 2013, making a landing on the steppe of Kazakhstan in their Soyuz TMA-06M spacecraft. Remaining on board with Hadfield are NASA astronaut Tom Marshburn and Russian Flight Engineer Roman Romanenko. They will be joined on March 29 by Expedition 35/36 crew members Pavel Vinogradov, NASA Flight Engineer Chris Cassidy and Flight Engineer Alexander Misurkin.

March 13, 2013March 14, 2013 by Nancy Atkinson

We Live in a Cosmic Shooting Gallery

In this new video from Big Think, astrophysicist Neil deGrasse Tyson says he’s almost embarrassed for our species that it takes a warning shot across our bow before legislators take seriously the advice they’ve been receiving from astronomers about getting serious about asteroid detection and deflection; that it’s a matter of when not if Earth will get smacked by an asteroid. “But it took an actual meteor over Russia exploding with 25 times the power of the atom bomb in Hiroshima to convince people that maybe we should start doing something about it.”

March 13, 2013December 23, 2015 by Nancy Atkinson

ALMA Now a Full-Fledged Observatory

This image shows an aerial view of the Chajnantor Plateau, located at an altitude of 5000 meters in the Chilean Andes, where the array of ALMA antennas is located. Credit: Clem & Adri Bacri-Normier (wingsforscience.com)/ESO.

Today, in a remote part of the Chilean Andes, the Atacama Large Millimeter/submillimeter Array (ALMA), was inaugurated at an official ceremony. This event marks the completion of all the major systems of the giant telescope and the formal transition from a construction project to a fully fledged observatory. ALMA is a partnership between Europe, North America and East Asia in cooperation with the Republic of Chile.

ALMA is able to observe the Universe by detecting light that is invisible to the human eye, and will show us never-before-seen details about the birth of stars, infant galaxies in the early Universe, and planets coalescing around distant suns. It also will discover and measure the distribution of molecules — many essential for life — that form in the space between the stars.

ALMA’s three international partners today welcomed more than 500 people to the ALMA Observatory in the Chilean Atacama Desert to celebrate the success of the project. The guest of honour was the President of Chile, Sebastián Piñera.

In honor of the official inauguration of ALMA, this movie, called ALMA — In Search of Our Cosmic Origins, has been released:

The President of Chile, Sebastián Piñera, said: “One of our many natural resources is Chile’s spectacular night sky. I believe that science has been a vital contributor to the development of Chile in recent years. I am very proud of our international collaborations in astronomy, of which ALMA is the latest, and biggest outcome.”

The Director of ALMA, Thijs de Graauw, expressed his expectations for ALMA. “Thanks to the efforts and countless hours of work by scientists and technicians in the ALMA community around the world, ALMA has already shown that it’s the most advanced millimetre/submillimetre telescope in existence, dwarfing anything else we had before. We are eager for astronomers to exploit the full power of this amazing tool.”

The observatory was conceived as three separate projects in Europe, USA and Japan in the 1980s, and merged to one in the 1990s. Construction started in 2003. The total construction cost of ALMA is approximately US$ 1.4 billion.

The antennas of the ALMA array, fifty-four 12-metre and twelve smaller 7-meter dish antennas, work together as a single telescope. Each antenna collects radiation coming from space and focuses it onto a receiver. The signals from the antennas are then brought together and processed by a specialized supercomputer: the ALMA correlator. The 66 ALMA antennas can be arranged in different configurations, where the maximum distance between antennas can vary from 150 meters to 16 kilometers.

Source: ESO

March 13, 2013December 23, 2015 by Elizabeth Howell

How the Space Shuttle Killed an American Halley’s Comet Mission

Halley's Comet, as seen by the European Giotto probe. Credit: Halley Multicolor Camera Team, Giotto Project, ESA

NASA missed the chance to visit Halley’s Comet in 1986 when the famed sentinel swung close to Earth, as it does every 76 years. Luckily for history, the Europeans flew Giotto past it on this day (March 13) in 1986, and some other nations sent their own probes.

The full story of NASA’s withdrawal is in Bruce Murray’s Journey Into Space: The First Three Decades of Space Exploration. Murray, the former director of the Jet Propulsion Laboratory, has chapters upon chapters on Halley, but here are some notable highlights.

First of all, there were at least three initiatives for NASA to send a mission to the famed comet. The missions below are in chronological order, and it appears it was only when the preceding one was killed that the next was envisioned:

– Solar sail. This mission would use the power of the solar wind — bits streaming from the sun — to bring a spacecraft within Halley’s gravitational influence. In fact, the spacecraft would stay with Halley as it whisked out of the solar system and would return (long dead) when Halley came back in 2061.

– A rendezvous with Comet Tempel 2. Another idea would see a spacecraft swing close to Comet Tempel 2 but also have a probe that would take a picture of Halley from a distance. NASA also considered splitting the mission in two to meet annual budgetary requirements, but the Comet Science Working Group was cool to the idea. There also was some thought about bringing the Europeans into this mission, but that never worked out.

– Galileo-type hardware. A third initiative had the Jet Propulsion Laboratory envisioning a distant flyby of Halley, basically using similar types of parts that flew in a spacecraft (called Galileo) to Jupiter.

All three of these initiatives fell to budget cuts during the 1970s and 1980s. What caused the budget cuts? In large part, the space shuttle program. To be sure, the shuttle was an impressive piece of hardware, and we are not doubting what it contributed to the construction of the International Space Station and to human spaceflight in general. But it was a large project and in those tight times, something had to give.

Perhaps the most interesting cancellation came in 1979, when NASA administrator Robert Frosch and his deputy went to President Jimmy Carter’s office to plead for the case of two projects: a solar electric propulsion system that would eventually power the Halley-Tempel 2 mission, and the Compton Gamma Ray Observatory (which flew into space, after many delays, in 1991).

Carter, according to Murray, was reading a book on black holes penned by Walter Sullivan of the New York Times. (We’re assuming it’s the 1979 book Black Holes: The Edge of Space, the End of Time.) When presented with the options, Carter said he was “partial to the gamma-ray thing because of this connection with the black-hole problem.”

That signaled the beginning of the end for NASA’s Halley-Tempel 2 mission.

March 13, 2013December 23, 2015 by Nancy Atkinson

Habitable Earth-Like Exoplanets Might Be Closer Than We Think

The graphic shows optimistic and conservative habitable zone boundaries around cool, low mass stars. The numbers indicate the names of known Kepler planet candidates. Yellow color represents candidates with less than 1.4 times Earth-radius. Green color represents planet candidates between 1.4 and 2 Earth radius. Credit: Penn State.

Size might matter when it comes to stars having habitable environments for planets, and in this case smaller might be better, as well as closer to Earth. A new study indicates that low mass stars may be the most abundant planet hosts in our galaxy. And since these smaller stars like M-dwarfs are plentiful, the number of potentially habitable planets could be greater than previously thought.

“We now estimate that if we were to look at 10 of the nearest small stars we would find about four potentially habitable planets, give or take,” said Ravi Kopparapu from Penn State University. “That is a conservative estimate,” he added. “There could be more.”

Kopparapu has published a new paper where he recalculated how common Earth-sized planets in the habitable zones of low-mass stars, also known as cool stars or M-dwarfs. Since the orbit of planets around M-dwarfs is very short, this allows scientists to gather data on a greater number of orbits in a shorter period of time than can be gathered on Sun-like stars, which have larger habitable zones.

Additionally, since M-dwarfs are more common than Sun-like stars, it means more of them can be observed.

Moreover, there are M-dwarfs located relatively close to Earth, which makes it easier to study any planet that may be orbiting these stars.

“The average distance to the nearest potentially habitable planet is about seven light-years,” Kopparapu said. “That is about half the distance of previous estimates.”

Kopparapu said there are about eight of these cool stars within 10 light-years of Earth, and the thinks, conservatively, we should expect to find about three Earth-size planets in the habitable zones.

His paper follows up on a recent study by researchers at the Harvard-Smithsonian Center for Astrophysics which analyzed 3,987 M-dwarf stars to calculate the number of Earth-sized planet candidates in cool stars’ habitable zones. That study used habitable zone limits calculated in 1993, but recently, a group of astronomers that included Kopparapu developed a new model for identifying habitable zones around stars based on water and carbon dioxide absorption (see the Habitable Zone Calculator here). Now Kopparapu has applied the new model to the Harvard team’s study, and found that there are additional planets in the newly determined habitable zones.

“I used our new habitable zone calculations and found that there are nearly three times as many Earth-sized planets in the habitable zones around these low mass stars as in previous estimates,” Kopparapu said. “This means Earth-sized planets are more common than we thought, and that is a good sign for detecting extraterrestrial life.”

Read Kopparapu’s paper.

Source: Penn State

March 13, 2013December 23, 2015 by Tammy Plotner

ALMA Eyes Most Distant Star-forming Galaxy

This schematic image represents how light from a distant galaxy is distorted by the gravitational effects of a nearer foreground galaxy, which acts like a lens and makes the distant source appear distorted, but brighter, forming characteristic rings of light, known as Einstein rings. An analysis of the distortion has revealed that some of the distant star-forming galaxies are as bright as 40 trillion Suns, and have been magnified by the gravitational lens by up to 22 times. Credit: ALMA (ESO/NRAO/NAOJ), L. Calçada (ESO), Y. Hezaveh et al.

Let’s turn down the lights and set the stage… We’re moving off through space, looking not only at distant galaxies, but the incredibly distant past. Once upon a time astronomers assumed that star formation began in massive, bright galaxies as a concentrated surge. Now, new observations taken with the Atacama Large Millimeter/submillimeter Array (ALMA) are showing us that these deluges of stellar creation may have begun much earlier than they thought.

According to the latest research published in today’s edition of the journal, Nature, and in the Astrophysical Journal, researchers have revealed fascinating discoveries taken with the new international ALMA observatory – which celebrates its inauguration today. Among its many achievements, ALMA has given us a look even deeper into space – showing us ancient galaxies which may be billions of light years distant. The observations of these starburst galaxies show us that stars were created in a frenzy out of huge deposits of cosmic gas and dust.

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“The more distant the galaxy, the further back in time one is looking, so by measuring their distances we can piece together a timeline of how vigorously the Universe was making new stars at different stages of its 13.7 billion year history,” said Joaquin Vieira (California Institute of Technology, USA), who led the team and is lead author of the paper in the journal Nature.

Just how did these observations come about? Before ALMA, an international team of researchers employed the US National Science Foundation’s 10-metre South Pole Telescope (SPT ) to locate these distant denizens and then homed in on them to take a closer look at the “stellar baby boom” during the Universe’s beginning epoch. What they found surprised them. Apparently star forming galaxies are even more distant than previously suspected… their onslaught of stellar creation beginning some 12 billion years ago. This time frame places the Universe at just under 2 billion years old and the star formation explosion occurring some billion years sooner than astronomers assumed. The ALMA observations included two galaxies – the “most distant of their kind ever seen” – that contained an additional revelation. Not only did their distance break astronomical records, but water molecules have been detected within them.

However, two galaxies aren’t the only score for ALMA. The research team took on 26 galaxies at wavelengths of around three millimetres. The extreme sensitivity of this cutting edge technology utilizes the measurement of light wavelengths – wavelengths produced by the galaxy’s gas molecules and stretched by the expansion of the Universe. By carefully measuring the “stretch”, astronomers are able to gauge the amount of time the light has taken to reach us and refine its point in time.

“ALMA’s sensitivity and wide wavelength range mean we could make our measurements in just a few minutes per galaxy – about one hundred times faster than before,” said Axel Weiss (Max-Planck-Institut für Radioastronomie in Bonn, Germany), who led the work to measure the distances to the galaxies. “Previously, a measurement like this would have been a laborious process of combining data from both visible-light and radio telescopes.”

For the most part, ALMA’s observations would be sufficient to determine the distance, but the team also included ALMA’s data with the Atacama Pathfinder Experiment (APEX) and ESO’s Very Large Telescope for a select few galaxies. At the present time, astronomers are only employing a small segment of ALMA’s capabilities – just 16 of the 66 massive antennae – and focusing on brighter galaxies. When ALMA is fully functional, it will be able to zero in on even fainter targets. However, the researchers weren’t about to miss any opportunities and utilized gravitational lensing to aid in their findings.

This montage combines data from ALMA with images from the NASA/ESA Hubble Space Telescope, for five distant galaxies. The ALMA images, represented in red, show the distant, background galaxies, being distorted by the gravitational lens effect produced by the galaxies in the foreground, depicted in the Hubble data in blue. The background galaxies appear warped into rings of light known as Einstein rings, which encircle the foreground galaxies. Credit:ALMA (ESO/NRAO/NAOJ), J. Vieira et al.

“These beautiful pictures from ALMA show the background galaxies warped into multiple arcs of light known as Einstein rings, which encircle the foreground galaxies,” said Yashar Hezaveh (McGill University, Montreal, Canada), who led the study of the gravitational lensing. “We are using the massive amounts of dark matter surrounding galaxies half-way across the Universe as cosmic telescopes to make even more distant galaxies appear bigger and brighter.”

Just how bright is bright? According to the news release, the analysis of the distortion has shown that a portion of these far-flung, star-forming galaxies could be as bright as 40 trillion Suns… then magnified up to 22 times more through the aid of gravitational lensing.

“Only a few gravitationally lensed galaxies have been found before at these submillimetre wavelengths, but now SPT and ALMA have uncovered dozens of them.” said Carlos De Breuck (ESO), a member of the team. “This kind of science was previously done mostly at visible-light wavelengths with the Hubble Space Telescope, but our results show that ALMA is a very powerful new player in the field.”

“This is an great example of astronomers from around the world collaborating to make an amazing discovery with a state-of-the-art facility,” said team member Daniel Marrone (University of Arizona, USA). “This is just the beginning for ALMA and for the study of these starburst galaxies. Our next step is to study these objects in greater detail and figure out exactly how and why they are forming stars at such prodigious rates.”

Bring the house lights back up, please. As ALMA peers ever further into the past, maybe one day we’ll catch our own selves… looking back.

March 13, 2013December 23, 2015 by Nancy Atkinson

Live from 1969: Apollo 9 Returns Home

The crew of Apollo 9: Commander James McDivitt, Command Module Pilot Dave Scott and Lunar Module Pilot Rusty Schweickart. Credit: NASA

“On the success of Apollo 9 mission hangs the hope for future manned missions to the Moon,” said famous CBS newsman Walter Cronkite. HD TV it’s not, but this is a fun look back at actual news footage from the Apollo 9 mission, which landed back on Earth on March 13, 1969, forty-four years ago today.

The ten-day Apollo 9 mission was the first manned flight of the lunar module and while in Earth orbit the crew tested the spacecraft for lunar operations. The crew included Commander Jim McDivitt, Command Module pilot Dave Scott and one of our favorite astronauts, the Lunar Module pilot Rusty Schweickart.

They successfully demonstrated the complete rendezvous and docking operations and conducted an EVA during their 151 Earth orbits. The mission carried the largest payload at that point in time to Earth orbit.