Universe Today

March 29, 2012December 23, 2015 by Nancy Atkinson

Huge ‘Tornado’ on the Sun

Spectacular rotation of material from solar prominences and the coronal cavities on September 25, 2011. Credit: NASA/Dr. Xing Li, Dr. Huw Morgan and Mr. Drew Leonard.

[/caption]

The Solar Dynamics Observatory captured images and video of a spectacular rotation of material from the Sun in a solar prominence. The whirling, dancing prominence created a massive tornado-like feature on the Sun, five times bigger than the Earth. “This is perhaps the first time that such a huge solar tornado is filmed by an imager,” said Dr. Xing Li of Aberystwyth University, presenting his team’s work at the National Astronomy Meeting this week in the UK. “The superb spatial and temporal resolution of SDO allows us to observe the solar atmosphere in great detail.”

The solar tornado was discovered using the Atmospheric Imaging Assembly (AIA) telescope on board SDO. On September 25, 2011, the AIA saw superheated gases as hot as 50,000 – 2,000,000 Kelvin sucked from the origin of a solar prominence, and spiral up into the high atmosphere. It traveled about 200,000 kilometers (124,000 miles) along the Sun for a period of at least three hours.

The hot gases in the tornadoes have speeds as high as 300,000 km per hour (186,000 mph) as opposed to terrestrial tornadoes, which can reach 150 km/h (90 mph).

Li and his team said that these tornadoes often occur at the root of huge coronal mass ejections. The solar tornadoes drag winding magnetic field and electric currents into the high atmosphere. It is possible that the magnetic field and currents play a key role in driving the coronal mass ejections.

A smaller solar tornado was captured in February of 2012:

The team’s work has been submitted for publication in the Astrophysical Journal. See more of the images and animations here.

March 29, 2012January 11, 2016 by Nancy Atkinson

20-Ton Cargo Freighter Arrives at Space Station

The heaviest cargo ship ever has arrived and docked to the International Space Station, laden with 7 tons of supplies for the 6-member ISS crew. The 20-ton European ATV-3 cargo ship, named “Edoardo Amaldi” after the Italian physicist and spaceflight pioneer, made a “smooth and gentle” docking on March 28, 2012, the European Space Agency said. The supplies delivered included food, drinking water, clothing, oxygen, spare parts and fuel.

The ATV launched from Kourou, French Guiana last Friday. It will use its engines to boost the space station during its 5-month stay on orbit. It is scheduled to undock on August 27 and perform an “orbital cremation” of trash from the space station.

March 28, 2012December 23, 2015 by Nancy Atkinson

Apollo 11’s Rocket Engines Found on the Bottom of the Ocean

[/caption]

Amazon.com founder Jeff Bezos has located the Apollo 11 F-1 rocket engines and plans to recover them. “I’m excited to report that, using state-of-the-art deep sea sonar, the team has found the Apollo 11 engines lying 14,000 feet below the surface, and we’re making plans to attempt to raise one or more of them from the ocean floor,” Bezos wrote on the Bezos Expeditions website. “We don’t know yet what condition these engines might be in – they hit the ocean at high velocity and have been in salt water for more than 40 years. On the other hand, they’re made of tough stuff, so we’ll see.”

Bezos said that about a year ago he was thinking of the 1969 Apollo 11 mission and wondered if the F-1 engines that started the seminal mission to the Moon could be located.

The Saturn V used five F-1 engines in the first stage. The F-1 is still the most powerful single-chamber liquid-fueled rocket engine ever developed, producing one and a half million pounds of thrust, burning 6,000 pounds of rocket grade kerosene and liquid oxygen every second. On July 16, 1969, Apollo 11 was launched and the five F-1s burned for just a few minutes, and then plunged back to Earth into the Atlantic Ocean.

Even though the engines remain the property of NASA, Bezos hopes that the space agency would allow the recovered engines to be displayed at the Smithsonian or another museum.

“If we’re able to raise more than one engine, I’ve asked NASA if they would consider making it available to the excellent Museum of Flight here in Seattle,” he said. “NASA is one of the few institutions I know that can inspire five-year-olds. It sure inspired me, and with this endeavor, maybe we can inspire a few more youth to invent and explore.”

Bezos pointed out that no public funding will be used to attempt to raise and recover the engines, as it’s being undertaken by him privately.

Bezos said he’ll keep everyone posted on the progress of the recovery of these engines.

March 28, 2012December 23, 2015 by Jason Major

“Tidal Venuses” May Have Been Wrung Out To Dry

Extreme heating from tidal stresses may render a "Tidal Venus" planet inhabitable

[/caption]

Earth-sized exoplanets within a distant star’s habitable zone could still be very much uninhabitable, depending on potential tidal stresses — either past or present — that could have “squeezed out” all the water, leaving behind a bone-dry ball of rock.

New research by an international team of scientists suggests that even a moderately eccentric orbit within a star’s habitable zone could exert tidal stress on an Earth-sized planet, enough that the increased surface heating due to friction would boil off any liquid water via extreme greenhouse effect.

Such planets are dubbed “Tidal Venuses”, due to their resemblance to our own super-heated planetary neighbor. This evolutionary possibility could be a factor in determining the actual habitability of an exoplanet, regardless of how much solar heating (insolation) it receives from its star.

The research, led by Dr. Rory Barnes of the University of Washington in Seattle, states that even an exoplanet currently in a circular, stable orbit could have formed with a much more eccentric orbit, thus subjecting it to tidal forces. Any liquid water present after formation would then have been slowly but steadily evaporated and the necessary hydrogen atoms lost to space.

The risk of such a “desiccating greenhouse” effect would be much greater on exoplanets orbiting lower-luminosity stars, since any potential habitable zone would be closer in to the star and thus prone to stronger tidal forces.

And as far as such an effect working to create habitable zones further out in orbit than otherwise permissible by stellar radiation alone… well, that wouldn’t necessarily be the case.

Even if an exoplanetary version of, say, Europa, could be heated through tidal forces to maintain liquid water on or below its surface, a rocky world the size of Earth (or larger) would still likely end up being rather inhospitable.

“One couldn’t do it for an Earthlike planet — the tidal heating of the interior would likely make the surface covered by super-volcanoes,” Dr. Barnes told Universe Today.

So even though the right-sized exoplanets may be found in the so-called “Goldilocks zone” of their star, they may still not be “just right” for life as we know it.

The team’s full paper can be found here.

March 28, 2012December 23, 2015 by Nancy Atkinson

Astronomers Discover Ancient Planetary System

Artist’s impression of HIP 11952 and its two Jupiter-like planets. Image credit: Timotheos Samartzidis

[/caption]

From a press release from the Max Planck Institute for Astronomy:

A group of European astronomers has discovered an ancient planetary system that is likely to be a survivor from one of the earliest cosmic eras, 13 billion years ago. The system consists of the star HIP 11952 and two planets, which have orbital periods of 290 and 7 days, respectively. Whereas planets usually form within clouds that include heavier chemical elements, the star HIP 11952 contains very little other than hydrogen and helium. The system promises to shed light on planet formation in the early universe – under conditions quite different from those of later planetary systems, such as our own.

It is widely accepted that planets are formed in disks of gas and dust that swirl around young stars. But look into the details, and many open questions remain – including the question of what it actually takes to make a planet. With a sample of, by now, more than 750 confirmed planets orbiting stars other than the Sun, astronomers have some idea of the diversity among planetary systems. But also, certain trends have emerged: Statistically, a star that contains more “metals” – in astronomical parlance, the term includes all chemical elements other than hydrogen and helium – is more likely to have planets.

This suggests a key question: Originally, the universe contained almost no chemical elements other than hydrogen and helium. Almost all heavier elements have been produced, over time inside stars, and then flung into space as massive stars end their lives in giant explosions (supernovae). So what about planet formation under conditions like those of the very early universe, say: 13 billion years ago? If metal-rich stars are more likely to form planets, are there, conversely, stars with a metal content so low that they cannot form planets at all? And if the answer is yes, then when, throughout cosmic history, should we expect the very first planets to form?

Now a group of astronomers, including researchers from the Max-Planck-Institute for Astronomy in Heidelberg, Germany, has discovered a planetary system that could help provide answers to those questions. As part of a survey targeting especially metal-poor stars, they identified two giant planets around a star known by its catalogue number as HIP 11952, a star in the constellation Cetus (“the whale” or “the sea monster”) at a distance of about 375 light-years from Earth. By themselves, these planets, HIP 11952b and HIP 11952c, are not unusual. What is unusual is the fact that they orbit such an extremely metal-poor and, in particular, such a very old star!

For classical models of planet formation, which favor metal-rich stars when it comes to forming planets, planets around such a star should be extremely rare. Veronica Roccatagliata (University Observatory Munich), the principal investigator of the planet survey around metal-poor stars that led to the discovery, explains: “In 2010 we found the first example of such a metal-poor system, HIP 13044. Back then, we thought it might be a unique case; now, it seems as if there might be more planets around metal-poor stars than expected.”

HIP 13044 became famous as the “exoplanet from another galaxy” – the star is very likely part of a so-called stellar stream, the remnant of another galaxy swallowed by our own billions of years ago.

Compared to other exoplanetary systems, HIP 11952 is not only one that is extremely metal-poor, but, at an estimated age of 12.8 billion years, also one of the oldest systems known so far. “This is an archaeological find in our own backyard,” adds Johny Setiawan of the Max Planck Institute for Astronomy, who led the study of HIP 11952: “These planets probably formed when our Galaxy itself was still a baby.”

“We would like to discover and study more planetary systems of this kind. That would allow us to refine our theories of planet formation. The discovery of the planets of HIP 11952 shows that planets have been forming throughout the life of our Universe”, adds Anna Pasquali from the Center for Astronomy at Heidelberg University (ZAH), a co-author of the paper.

March 28, 2012December 23, 2015 by Nancy Atkinson

Billions of Habitable Worlds Likely in the Milky Way

Artist’s impression of sunset on the super-Earth world Gliese 667 Cc. Credit: ESO

[/caption]

Could there be ‘tens of billions’ of habitable worlds in our own galaxy? That’s the results from a new study that searched for rocky planets in the habitable zones around red dwarf stars. An international team of astronomers using ESO’s HARPS spectrograph now estimates that there are tens of billions of such planets in the Milky Way galaxy, with probably about one hundred in the Sun’s immediate neighborhood, less than 30 light years away.

“Our new observations with HARPS mean that about 40% of all red dwarf stars have a super-Earth orbiting in the habitable zone where liquid water can exist on the surface of the planet,” said Xavier Bonfils, from IPAG, Observatoire des Sciences de l’Univers de Grenoble, France, and the leader of the team. “Because red dwarfs are so common — there are about 160 billion of them in the Milky Way — this leads us to the astonishing result that there are tens of billions of these planets in our galaxy alone.”

This is the first direct estimate of the number of smaller, rocky planets around red dwarf stars. Add this to another recent finding which suggested that every star in our night sky has at least one planet circling it — which didn’t include red dwarf stars – and our galaxy could be teeming with worlds.

This team used the HARPS spectrograph on the 3.6-metre telescope at ESO’s La Silla Observatory in Chile to search for exoplanets orbiting the most common kind of star in the Milky Way — red dwarf stars (also known as M dwarfs). These stars are faint and cool compared to the Sun, but very common and long-lived, and therefore account for 80% of all the stars in the Milky Way.

eso-3m60_milky-way-cc — The Milky Way over the ESO 3.6-metre Telescope, a photo submitted via Your ESO Pictures Flickr Group. Credit: ESO/A. Santerne

The HARPS team surveyed a carefully chosen sample of 102 red dwarf stars in the southern skies over a six-year period. A total of nine super-Earths (planets with masses between one and ten times that of Earth) were found, including two inside the habitable zones of Gliese 581 and Gliese 667 C respectively.

By combining all the data, including observations of stars that did not have planets, and looking at the fraction of existing planets that could be discovered, the team has been able to work out how common different sorts of planets are around red dwarfs. They find that the frequency of occurrence of super-Earths in the habitable zone is 41% with a range from 28% to 95%.

Bonfils and his team also found that rocky planets were far more common than massive gas giants like Jupiter and Saturn. Less than 12% of red dwarfs are expected to have giant planets (with masses between 100 and 1000 times that of the Earth).

However, the rocky worlds orbiting red dwarfs wouldn’t necessarily be a good place to spend your first exo-vacation – or for harboring life.

“The habitable zone around a red dwarf, where the temperature is suitable for liquid water to exist on the surface, is much closer to the star than the Earth is to the Sun,” said Stéphane Udry from the Geneva Observatory and member of the team. “But red dwarfs are known to be subject to stellar eruptions or flares, which may bathe the planet in X-rays or ultraviolet radiation, and which may make life there less likely.”

New Exoplanet Discovered

A new exoplanet was discovered in this HARPS survey of red dwarfs: Gliese 667 Cc. This is the second planet in this triple star system and seems to be situated close to the center of the habitable zone. Although this planet is more than four times heavier than the Earth it is the closest twin to Earth found so far and almost certainly has the right conditions for the existence of liquid water on its surface. This is the second super-Earth planet inside the habitable zone of a red dwarf discovered during this HARPS survey, after Gliese 581d was announced in 2007 and confirmed in 2009.

“Now that we know that there are many super-Earths around nearby red dwarfs we need to identify more of them using both HARPS and future instruments,” said Xavier Delfosse, another member of the team. “Some of these planets are expected to pass in front of their parent star as they orbit — this will open up the exciting possibility of studying the planet’s atmosphere and searching for signs of life.”

Research papers: Bonfils et al. and Delfosse et al.

Source: ESO

March 28, 2012December 23, 2015 by Jason Major

“Snowing Microbes” On Saturn’s Moon?

Cassini image of Enceladus from Dec. 2010 (NASA/JPL/SSI)

[/caption]

Enceladus, Saturn’s 318-mile-wide moon that’s become famous for its ice-spraying southern jets, is on astronomers’ short list of places in our own solar system where extraterrestrial life could be hiding — and NASA’s Cassini spacecraft is in just the right place to try and sniff it out.

On March 27, Cassini came within 46 miles (74 km) of Enceladus’ south pole, the region where the moon’s many active water-ice jets originate from. This was Cassini’s closest pass yet over the southern pole, allowing the spacecraft to use its ion and neutral mass spectrometer — as well as its plasma spectrometer, recently returned to service — to taste the icy spray emanating from deep fissures called “tiger stripes” that scar Enceladus’ surface.

(Fly along with Cassini toward Enceladus’ jets here.)

“More than 90 jets of all sizes near Enceladus’s south pole are spraying water vapor, icy particles, and organic compounds all over the place,” said Carolyn Porco, planetary scientist and Cassini Imaging science team leader. “Cassini has flown several times now through this spray and has tasted it. And we have found that aside from water and organic material, there is salt in the icy particles. The salinity is the same as that of Earth’s oceans.”

In addition to water, salt and organics, there is also a surprising amount of heat — heat generated in part by tidal friction, helping keep Enceladus’ underground water reserves liquid.

“If you add up all the heat, 16 gigawatts of thermal energy are coming out of those cracks,” Porco said.

This creates, in effect, a so-called “Goldilocks zone” of potential habitability orbiting around Saturn… a zone that Cassini has easy access to.

“It’s erupting out into space where we can sample it. It sounds crazy but it could be snowing microbes on the surface of this little world,” Porco said. “In the end, it’s the most promising place I know of for an astrobiology search. We don’t even need to go scratching around on the surface. We can fly through the plume and sample it. Or we can land on the surface, look up and stick our tongues out. And voilà…we have what we came for.”

enceladus_stripe_11-30-10-1 — Cassini's view down into a jetting "tiger stripe" in August 2010

Cassini’s latest results — and images! — from the flyby should be landing on Earth any time now. Stay tuned to Universe Today for more updates on Cassini and Enceladus.

TV Viewing Alert: NASA’s Unexplained Files

About 20 minutes after the first step, Aldrin joined Armstrong on the surface and became the second human to set foot on the Moon. Credit: NASA

Countless mysterious objects have been caught by NASA’s cameras, and usually the events can be explained logically. The Science Channel has a show premiering tonight (10 PM EDT and PDT) called NASA’s Unexplained Files, which is part of the channel’s “Are We Alone” features for the month of March. In this broadcast, NASA’s top ten unexplained encounters are discussed, with original footage and special interviews with astronauts and scientists.

A few of the astronauts and scientists who will be on the show include Story Musgrave, astronaut; Dr. Jack Kasher, Professor of Physics and Astronomy and ET researcher; Jim Oberg, space flight operations specialist; Alan Bean, the fourth man to visit the moon; Franklin Chang Diaz, Astronaut; Bruce Maccabee, Optical analyst and former Navy member; and Edgar Mitchell, Apollo astronaut.

See the Science Channel website for more about this show and also to find out when it will air in your location.
Continue reading “TV Viewing Alert: NASA’s Unexplained Files”

March 27, 2012December 23, 2015 by Nancy Atkinson

Join in the Discussion of the Future of Human Spaceflight, Live from SEDS

What’s the latest on the future of human spaceflight and exploration? Join in on the discussion with a live videostream event from the Students for the Exploration and Development of Space (SEDS) Spring Space Forum, taking place this week at Purdue University on March 29, 2012, starting at 8:30 am EDT.

You’ll hear from the leaders in commercial space endeavors, such as former NASA space shuttle manager Mike Moses, currently VP of Operations at Virgin Galactic and former astronauts now working in commercial space, such as Chris Ferguson now at Boeing and Garrett Reisman from SpaceX.

Every spring, SEDS hosts the Spring Space Forum, inviting prominent members of industry, academia, and other space-related fields to discuss a current relevant issue. This year, representatives from major aerospace companies will be giving short talks on the future of human space flight and exploration. There will also be panel discussions and other events.

The Spring Space Forum can be watched via UStream at this link, and the schedule of events can be seen here.

For more information on SEDS and the Spring Space Forum, see the Purdue SEDS website.

March 27, 2012January 11, 2016 by Nancy Atkinson

Brain Surgery, Fixing the Space Station’s Toilet and Orbital Cremation

“As you can imagine, all works comes to a stop on the Space Station when the toilet breaks,” said astronaut Don Pettit, known as Mr. Fixit among the astronaut corps. In this latest edition of “Inside the International Space Station,” Expedition 30 astronauts Dan Burbank and Don Pettit discuss their glamorous life in space of having to fix the toilet, upgrade their computers, and take out the garbage. This sounds just like living on Earth, but there are a few orbital twists for doing those things in space. And of course Pettit nails it with his vivid descriptions.

It’s a dirty job but somebody’s gotta do it.