Monday, December 8, 2014

10 Facts About the Milky Way

10 Facts About the Milky Way:



This annotated artist's conception illustrates our current understanding of the structure of the Milky Way galaxy. Image Credit: NASA


This annotated artist’s conception illustrates our current understanding of the structure of the Milky Way galaxy. Image Credit: NASA
The Milky Way Galaxy is an immense and very interesting place. Not only does it measure some 100,000–120,000 light-years in diameter, it is home to planet Earth, the birthplace of humanity. Our Solar System resides roughly 27,000 light-years away from the Galactic Center, on the inner edge of one of the spiral-shaped concentrations of gas and dust particles called the Orion Arm.

But within these facts about the Milky Way lie some additional tidbits of information, all of which are sure to impress and inspire. Here are ten such facts, listed in no particular order:


1. It’s warped.For starters, the Milky Way is a disk about 120,000 light years across with a central bulge that has a diameter of 12,000 light years (see the Guide to Space article for more information). The disk is far from perfectly flat though, as can be seen in the picture below. In fact, it is warped in shape, a fact which astronomers attribute to the our galaxy’s two neighbors -the Large and Small Magellanic clouds.

These two dwarf galaxies — which are part of our “Local Group” of galaxies and may be orbiting the Milky Way — are believed to have been pulling on the dark matter in our galaxy like in a game of galactic tug-of-war. The tugging creates a sort of oscillating frequency that pulls on the galaxy’s hydrogen gas, of which the Milky Way has lots of (for more information, check out How the Milky Way got its Warp).



The Spiral Galaxy ESO 510-13 is warped similar to our own. Credit: NASA/Hubble Heritage Team (STScI / AURA), C. Conselice (U. Wisconsin / STScI/ NASA


The warp of Spiral Galaxy ESO 510-13 is similar to that of our own. Credit: NASA/Hubble
2. It has a halo, but you can’t directly see it.Scientists believe that 90% of our galaxy’s mass consists of dark matter, which gives it a mysterious halo. That means that all of the “luminous matter” – i.e. that which we can see with the naked eye or a telescopes – makes up less than 10% of the mass of the Milky Way. Its halo is not the conventional glowing sort we tend to think of when picturing angels or observing comets.

In this case, the halo is actually invisible, but its existence has been demonstrated by running simulations of how the Milky Way would appear without this invisible mass, and how fast the stars inside our galaxy’s disk orbit the center.

The heavier the galaxy, the faster they should be orbiting. If one were to assume that the galaxy is made up only of matter that we can see, then the rotation rate would be significantly less than what we observe. Hence, the rest of that mass must be made up of an elusive, invisible mass – aka. “dark matter” – or matter that only interacts gravitationally with “normal matter”.

To see some images of the probable distribution and density of dark matter in our galaxy, check out The Via Lactea Project.

3. It has over 200 billion starsAs galaxies go, the Milky Way is a middleweight. The largest galaxy we know of, which is designated IC 1101, has over 100 trillion stars, and other large galaxies can have as many as a trillion. Dwarf galaxies such as the aforementioned Large Magellanic Cloud have about 10 billion stars. The Milky Way has between 100-400 billion stars; but when you look up into the night sky, the most you can see from any one point on the globe is about 2,500. This number is not fixed, however, because the Milky Way is constantly losing stars through supernovae, and producing new ones all the time (about seven per year).



These images taken by the Spitzer Space Telescope show the dust and gas concentrations around a supernova. Credit: NASA/JPL-Caltech


These images taken by the Spitzer Space Telescope show dust and gas concentrations around a distant supernova. Credit: NASA/JPL-Caltech
4. It’s really dusty and gassy.Though it may not look like it to the casual observer, the Milky Way is full of dust and gas. This matter makes up a whopping 10-15% of the luminous/visible matter in our galaxy, with the remainder being the stars. Our galaxy is roughly 100,000 light years across, and we can only see about 6,000 light years into the disk in the visible spectrum. Still, when light pollution is not significant, the dusty ring of the Milky Way can be discerned in the night sky.

The thickness of the dust deflects visible light (as is explained here) but infrared light can pass through the dust, which makes infrared telescopes like the Spitzer Space Telescope extremely valuable tools in mapping and studying the galaxy. Spitzer can peer through the dust to give us extraordinarily clear views of what is going on at the heart of the galaxy and in star-forming regions.

5. It was made from other galaxies.The Milky Way wasn’t always as it is today – a beautiful, warped spiral. It became its current size and shape by eating up other galaxies, and is still doing so today. In fact, the Canis Major Dwarf Galaxy is the closest galaxy to the Milky Way because its stars are currently being added to the Milky Way’s disk. And our galaxy has consumed others in its long history, such as the Sagittarius Dwarf Galaxy.

6. Every picture you’ve seen of the Milky Way from above is either another galaxy or an artist’s interpretation.Currently, we can’t take a picture of the Milky Way from above. This is due to the fact that we are inside the galactic disk, about 26,000 light years from the galactic center. It would be like trying to take a picture of your own house from the inside. This means that any of the beautiful pictures you’ve ever seen of a spiral galaxy that is supposedly the Milky Way is either a picture of another spiral galaxy, or the rendering of a talented artist.

Imaging the Milky Way from above is a long, long way off. However, this doesn’t mean that we can’t take breathtaking images of the Milky Way from our vantage point!



Artist's concept of Sagittarius A, the supermassive black hole at the center of our galaxy. Credit: NASA/JPL


Artist’s concept of Sagittarius A, the supermassive black hole at the center of our galaxy. Credit: NASA/JPL-Caltech
7. There is a black hole at the center.Most larger galaxies have a supermassive black hole (SMBH) at the center, and the Milky Way is no exception. The center of our galaxy is called Sagittarius A*, a massive source of radio waves that is believed to be a black hole that measures 22,500 kilometers (14 million miles) across – about the size of Mercury’s orbit. But this is just the black hole itself.

All of the mass trying to get into the black hole – called the accretion disk – forms a disk that has 4.6 million times the mass of our Sun and would fit inside the orbit of the Earth. Though like other black holes, Sgr A* tries to consume anything that happens to be nearby, star formation has been detected near this behemoth astronomical phenomenon.

8. It’s almost as old as the Universe itself.The most recent estimates place the age of the Universe at about 13.7 billion years. Our Milky Way has been around for about 13.6 billion of those years, give or take another 800 million. The oldest stars in our the Milky Way are found in globular clusters, and the age of our galaxy is determined by measuring the age of these stars, and then extrapolating the age of what preceded them.

Though some of the constituents of the Milky Way have been around for a long time, the disk and bulge themselves didn’t form until about 10-12 billion years ago. And that bulge may have formed earlier than the rest of the galaxy.

9. It’s part of the Virgo Supercluster, a group of galaxies within 150 million light years.As big as it is, the Milky Way is part of an even larger galactic structures. Our closest neighbors include the Large and Small Magellanic Clouds, and the Andromeda Galaxy – the closest spiral galaxy to the Milky Way. Along with some 50 other galaxies, the Milky Way and its immediate surroundings make up a cluster known as the Local Group.

And yet, this is still just a small fraction of our stellar neighborhood. Father out, we find that the Milky Way is part of an even larger grouping of galaxies known as the Virgo Supercluster. Superclusters are groupings of galaxies on very large scales that measure in the hundreds of millions of light years in diameter. In between these superclusters are large stretches of open space where intrepid explorers or space probes would encounter very little in the way of galaxies or matter.

In the case of the Virgo Supercluster, at least 100 galaxy groups and clusters are located within it massive 33 megaparsec (110 million light-year) diameter. And a 2014 study indicates that the Virgo Supercluster is only a lobe of a greater supercluster, Laniakea, which is centered on the Great Attractor.

10. It’s on the moveThe Milky Way, along with everything else in the Universe, is moving through space. The Earth moves around the Sun, the Sun around the Milky Way, and the Milky Way as part of the Local Group, which is moving relative to the Cosmic Microwave Background (CMB) radiation – the radiation left over from the Big Bang.

The CMB is a convenient reference point to use when determining the velocity of things in the universe. Relative to the CMB, the Local Group is calculated to be moving at a speed of about 600 km/s, which works out to about 2.2 million km/h. Such speeds stagger the mind and squash any notions of moving fast within our humble, terrestrial frame of reference!

For many more facts about the Milky Way, visit the Guide to Space, listen to the Astronomy Cast episode on the Milky Way, or visit the Students for the Exploration and Development of Space at seds.org..

Further Reading: SEDS.org



About 

Author, freelance writer, educator, Taekwon-Do instructor, and loving hubby, son and Island boy!

Earth May Have Lost Some Primoridial Atmosphere to Meteors

Earth May Have Lost Some Primoridial Atmosphere to Meteors:



4.5 billion years ago, during the Hadean Eon, Earth was bombarded regularly by meteorites. Credit: NASA


4.5 billion years ago, during the Hadean Eon, Earth was bombarded regularly by meteorites. Credit: NASA
During the Hadean Eon, some 4.5 billion years ago, the world was a much different place than it is today. As the name Hades would suggest (Greek for “underworld”), it was a hellish period for Earth, marked by intense volcanism and intense meteoric impacts. It was also during this time that outgassing and volcanic activity produced the primordial atmosphere composed of carbon dioxide, hydrogen and water vapor.

Little of this primordial atmosphere remains, and geothermal evidence suggests that the Earth’s atmosphere may have been completely obliterated at least twice since its formation more than 4 billion years ago. Until recently, scientists were uncertain as to what could have caused this loss.

But a new study from MIT, Hebrew Univeristy, and Caltech indicates that the intense bombardment of meteorites in this period may have been responsible.

This meteoric bombardment would have taken place at around the same time that the Moon was formed. The intense bombardment of space rocks would have kicked up clouds of gas with enough force to permanent eject the atmosphere into space. Such impacts may have also blasted other planets, and even peeled away the atmospheres of Venus and Mars.

In fact, the researchers found that small planetesimals may be much more effective than large impactors –  such as Theia, whose collision with Earth is believed to have formed the Moon – in driving atmospheric loss. Based on their calculations, it would take a giant impact to disperse most of the atmosphere; but taken together, many small impacts would have the same effect.



Artist's concept of a collision between proto-Earth and Theia, believed to happened 4.5 billion years ago. Credit: NASA


Artist’s concept of a collision between proto-Earth and Theia, believed to happened 4.5 billion years ago. Credit: NASA
Hilke Schlichting, an assistant professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences, says understanding the drivers of Earth’s ancient atmosphere may help scientists to identify the early planetary conditions that encouraged life to form.

“[This finding] sets a very different initial condition for what the early Earth’s atmosphere was most likely like,” Schlichting says. “It gives us a new starting point for trying to understand what was the composition of the atmosphere, and what were the conditions for developing life.”

What’s more, the group examined how much atmosphere was retained and lost following impacts with giant, Mars-sized and larger bodies and with smaller impactors measuring 25 kilometers or less.

What they found was that a collision with an impactor as massive as Mars would have the necessary effect of generating a massive a shockwave through the Earth’s interior and potentially ejecting a significant fraction of the planet’s atmosphere.

However, the researchers determined that such an impact was not likely to have occurred, since it would have turned Earth’s interior into a homogenous slurry. Given the appearance of diverse elements observed within the Earth’s interior, such an event does not appear to have happened in the past.

A series of smaller impactors, by contrast, would generate an explosion of sorts, releasing a plume of debris and gas. The largest of these impactors would be forceful enough to eject all gas from the atmosphere immediately above the impact zone. Only a fraction of this atmosphere would be lost following smaller impacts, but the team estimates that tens of thousands of small impactors could have pulled it off.



An artistic conception of the early Earth, showing a surface pummeled by large impact, resulting in extrusion of deep seated magma onto the surface. At the same time, distal portion of the surface could have retained liquid water. Credit: Simone Marchi


Artist’s concept of the early Earth, showing a surface pummeled by large impacts. Credit: Simone Marchi
Such a scenario did likely occur 4.5 billion years ago during the Hadean Eon. This period was one of galactic chaos, as hundreds of thousands of space rocks whirled around the solar system and many are believed to have collided with Earth.

“For sure, we did have all these smaller impactors back then,” Schlichting says. “One small impact cannot get rid of most of the atmosphere, but collectively, they’re much more efficient than giant impacts, and could easily eject all the Earth’s atmosphere.”

However, Schlichting and her team realized that the sum effect of small impacts may be too efficient at driving atmospheric loss. Other scientists have measured the atmospheric composition of Earth compared with Venus and Mars; and compared to Venus, Earth’s noble gases have been depleted 100-fold. If these planets had been exposed to the same blitz of small impactors in their early history, then Venus would have no atmosphere today.

She and her colleagues went back over the small-impactor scenario to try and account for this difference in planetary atmospheres. Based on further calculations, the team identified an interesting effect: Once half a planet’s atmosphere has been lost, it becomes much easier for small impactors to eject the rest of the gas.

The researchers calculated that Venus’ atmosphere would only have to start out slightly more massive than Earth’s in order for small impactors to erode the first half of the Earth’s atmosphere, while keeping Venus’ intact. From that point, Schlichting describes the phenomenon as a “runaway process — once you manage to get rid of the first half, the second half is even easier.”

This gave rise to another important question: What eventually replaced Earth’s atmosphere? Upon further calculations, Schlichting and her team found the same impactors that ejected gas also may have introduced new gases, or volatiles.

“When an impact happens, it melts the planetesimal, and its volatiles can go into the atmosphere,” Schlichting says. “They not only can deplete, but replenish part of the atmosphere.”



The "impact farm:, an area on Venus marked by impact craters and volcanic activity. Credit: NASA/JPL


The “impact farm:, an area on Venus marked by impact craters and volcanic activity. Credit: NASA/JPL
The group calculated the amount of volatiles that may be released by a rock of a given composition and mass, and found that a significant portion of the atmosphere may have been replenished by the impact of tens of thousands of space rocks.

“Our numbers are realistic, given what we know about the volatile content of the different rocks we have,” Schlichting notes.

Jay Melosh, a professor of earth, atmospheric, and planetary sciences at Purdue University, says Schlichting’s conclusion is a surprising one, as most scientists have assumed the Earth’s atmosphere was obliterated by a single, giant impact. Other theories, he says, invoke a strong flux of ultraviolet radiation from the sun, as well as an “unusually active solar wind.”

“How the Earth lost its primordial atmosphere has been a longstanding problem, and this paper goes a long way toward solving this enigma,” says Melosh, who did not contribute to the research. “Life got started on Earth about this time, and so answering the question about how the atmosphere was lost tells us about what might have kicked off the origin of life.”

Going forward, Schlichting hopes to examine more closely the conditions underlying Earth’s early formation, including the interplay between the release of volatiles from small impactors and from Earth’s ancient magma ocean.

“We want to connect these geophysical processes to determine what was the most likely composition of the atmosphere at time zero, when the Earth just formed, and hopefully identify conditions for the evolution of life,” Schlichting says.

Schlichting and her colleagues have published their results in the February edition of the journal Icarus.

Further Reading: MIT News



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Author, freelance writer, educator, Taekwon-Do instructor, and loving hubby, son and Island boy!

Venus Express May Be Out Of Fuel After Death-Duelling Maneuvers

Venus Express May Be Out Of Fuel After Death-Duelling Maneuvers:

by Elizabeth Howell on December 5, 2014


Artist's concept of Venus Express. Credit: ESA


Artist’s concept of Venus Express. Credit: ESA
After more than eight years orbiting a hellish planet, Venus Express is showing its age. The spacecraft made some risky maneuvers this summer, dipping down into the atmosphere as it nears the end of its mission. Now, the European Space Agency reports it has mostly lost contact with the probe. The reason could be lack of fuel.

The “anomaly” started Nov. 28 when the agency’s operations center lost touch with the spacecraft. Since then, ground stations at ESA and NASA have been trying to hail the probe. All they’ve received since then is a little bit of telemetry showing that the spacecraft has it solar panels pointing towards the Sun, and it’s slowly rotating.



Artist's conception of Venus Express doing an aerobraking maneuver in the atmosphere in 2014. Credit: ESA–C. Carreau


Artist’s conception of Venus Express doing an aerobraking maneuver in the atmosphere in 2014. Credit: ESA–C. Carreau
“It is possible that the remaining fuel on board VEX was exhausted,” ESA wrote in a blog post, pointing out that in recent weeks it has been trying to raise the spacecraft’s altitude for more science observations. But with the spacecraft spinning, its high-gain antenna is likely out of contact with Earth and it’s hard to reach it.

“The operations team is currently attempting to downlink the table of critical events that is stored in protected memory on board, which may give details of the sequence of events which occurred over the past few days,” ESA added. “The root cause of the anomaly (fuel situation or otherwise) remains to be established.”

We’ll keep you posted as events arise.

Source: European Space Agency



About 

Elizabeth Howell is the senior writer at Universe Today. She also works for Space.com, Space Exploration Network, the NASA Lunar Science Institute, NASA Astrobiology Magazine and LiveScience, among others. Career highlights include watching three shuttle launches, and going on a two-week simulated Mars expedition in rural Utah. You can follow her on Twitter @howellspace or contact her at her website.

Pluto Spacecraft Wakes Up For An Exciting Close Encounter Next Year

Pluto Spacecraft Wakes Up For An Exciting Close Encounter Next Year:



Artist's conception of the New Horizons spacecraft at Pluto. Credit: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI)


Artist’s conception of the New Horizons spacecraft at Pluto. Credit: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI)
Pluto, humanity is getting ready to change your image. The New Horizons spacecraft is awake once more after emerging from hibernation as planned yesterday (Dec. 6). And after a decade of sailing through space, there will be a historic first encounter with the dwarf planet in July.

The story may not end there, either. Mission managers are working hard to make the case that since New Horizons is way “out there” anyway, it would be a great idea to put the spacecraft past another object later in the mission. That hope rides heavily on the success of the Pluto encounter July 14.

“Technically, this was routine, since the wake-up was a procedure that we’d done many times before,” said Glen Fountain, New Horizons project manager at the Johns Hopkins Applied Physics Laboratory, in a statement. “Symbolically, however, this is a big deal. It means the start of our pre-encounter operations.”



The New Horizons spacecraft takes off on Jan. 19, 2006 from the Kennedy Space Center for its planned close encounter with Pluto. Credit: NIKON/Scott Andrews/NASA


The New Horizons spacecraft takes off on Jan. 19, 2006 from the Kennedy Space Center for its planned close encounter with Pluto. Credit: NIKON/Scott Andrews/NASA
It’s been a neat few years for the mighty machine, even before getting to the main event. New Horizons launched from the Kennedy Space Center in 2006 and made a close pass by Jupiter and its moons in 2007, doing some science en route — including catching a huge explosion from Io, a volcanic moon.

Since then, the spacecraft has dutifully been sending back pictures from across the Solar System, including a picture of Neptune’s moon Triton, and several of Pluto — the first time a spacecraft will venture that far. In between the science work and checking out systems, New Horizons spent two-thirds of the journey sleeping to conserve energy for the big show.

Up next for the spacecraft will be several weeks of checkouts and also putting together the commands to make sure New Horizons is successfully guided past Pluto and its moons (a process that got complicated over the years as more moons were discovered.) After that, if the spacecraft holds out and the budget is approved, managers want to swing it past a Kuiper Belt Object.



Two potential targets for the New Horizons mission emerge in these Hubble Space Telescope multiple-exposure images. Both are about four billion miles (6.4 billion kilometers) away. NASA, ESA, SwRI, JHU/APL, and the New Horizons KBO Search Team


Two potential targets for the New Horizons mission emerge in these Hubble Space Telescope multiple-exposure images. Both are about four billion miles (6.4 billion kilometers) away. NASA, ESA, SwRI, JHU/APL, and the New Horizons KBO Search Team
The Kuiper Belt is a collection of icy bodies past Neptune’s orbit. These small worlds are believed to be building blocks of the Solar System, showing off a time billions of years ago when there were no planets or moons — just chunks of rocks and ice, which slowly collided and coalesced over millions of years to form the familiar landscape we see today.

New Horizons team members plan to ask for more money for this mission in late 2016, as they gather information via the Hubble Space Telescope and other sources to make their case. (They already have some targets in mind.) But the focus will definitely be on Pluto in the coming months.

Next year, by the way, will see another planned close encounter with a dwarf planet when NASA’s Dawn spacecraft gets to Ceres in the spring.



About 

Elizabeth Howell is the senior writer at Universe Today. She also works for Space.com, Space Exploration Network, the NASA Lunar Science Institute, NASA Astrobiology Magazine and LiveScience, among others. Career highlights include watching three shuttle launches, and going on a two-week simulated Mars expedition in rural Utah. You can follow her on Twitter @howellspace or contact her at her website.

Workaholic Hubble Telescope Will Eventually Burn To Death: Report

Workaholic Hubble Telescope Will Eventually Burn To Death: Report:



The Hubble Space Telescope viewed by the STS-125 shuttle repair crew in 2009. Credit: NASA


The Hubble Space Telescope viewed by the STS-125 shuttle repair crew in 2009. Credit: NASA
The Hubble Space Telescope has delivered an amazing near quarter-century of science from all over the universe. Even this year, it’s delivered results to think about: the shrinking Great Red Spot on Jupiter (see picture below), helping New Horizons hunt for flyby targets after Pluto, and enhancing our view of deep space.

But that didn’t come cheap. Four astronaut servicing missions (including one to fix a mirror that was launched with myopia) were required to keep the telescope going since 1990. Hubble has never been more scientifically productive, according to a recent NASA review, but a new article asks if Hubble is destined to die a fiery death when its orbit decays in the next eight to 10 years.

“NASA doesn’t have any official plans for upgrading the telescope, meaning its hardware will grow old and out-of-date in the coming years,” reads the article in Popular Science. “Without assistance, Hubble can’t maintain its orbit forever, and eventually Earth’s gravity will pull the telescope to a fiery death.”

That’s not to say NASA is going to abandon the cosmos — far from it. Besides NASA’s other space telescopes, the successor James Webb Space Telescope is planned to launch in 2018 to chart the universe in other wavelengths. But a review from April warns that ceasing operations of Hubble would not be prudent until James Webb is up, running, and doing its own work productively. That’s a narrow window of time considering Hubble is expected to work well until about 2020.



The Hubble Space Telescope shows the shrinking size of Jupiter's Great Red Spot in this series of images taken between 1995 and 2014. Credit: NASA, ESA, and A. Simon (Goddard Space Flight Center)


The Hubble Space Telescope shows the shrinking size of Jupiter’s Great Red Spot in this series of images taken between 1995 and 2014. Credit: NASA, ESA, and A. Simon (Goddard Space Flight Center)
The Hubble Space Telescope senior review panel submitted a report on March that overall praised the observatory’s work, and which also talked about its potential longevity. As is, Hubble is expected to work until at least 2020, the review stated. The four science instruments are expected to be more than 85% reliable until 2021, and most “critical subsystems” should exceed 80% until that same year.

The report urges that experienced hands are kept around as the telescope degrades in the coming years, but points out that Hubble has backups that should keep the observatory as a whole going for a while.

There are no single-point failure modes on Hubble that could take down the entire observatory. It has ample redundancy. Planned mitigations for numerous possible sub-system failures or degraded performance have been developed in advance via the project’s Life-Extension Initiatives campaign. Hubble will likely degrade gracefully, with loss or degradation of individual science instrument modes and individual sub-system components.
In NASA’s response to the Senior Review for several missions (including Hubble), the agency said that the telescope has been approved (budgetarily speaking) until 2016, when an incremental review will take place. Further in the future, things get murky.



The Hubble Ultra Deep Field seen in ultraviolet, visible, and infrared light. Image Credit: NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R. Windhorst (Arizona State University), and Z. Levay (STScI)


The Hubble Ultra Deep Field seen in ultraviolet, visible, and infrared light. Image Credit: NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R. Windhorst (Arizona State University), and Z. Levay (STScI)
The just-tested Orion spacecraft won’t be ready to take crews until the mid-2020s, and so far (according to the Popular Science article) the commercial crew program isn’t expected to include a servicing mission.

According to STS-125 astronaut Michael Good, who currently serves in the Commercial Crew Program, the space agency isn’t looking into the possibility of using private companies to fix Hubble, but he says there’s always a chance that could happen. “One of the reasons we’re doing Commercial Crew is to enable this capability to get into lower Earth orbit,” says Good. “But it’s certainly in the realm of possibility.”
Much can happen in a decade — maybe a surge in robotic intelligence would make an automated mission more possible — but then there is the question of priorities. If NASA chooses to rescue Hubble, are there other science goals the agency would need to push aside to accomplish it? What is best? Feel free to leave your feedback in the comments.



About 

Elizabeth Howell is the senior writer at Universe Today. She also works for Space.com, Space Exploration Network, the NASA Lunar Science Institute, NASA Astrobiology Magazine and LiveScience, among others. Career highlights include watching three shuttle launches, and going on a two-week simulated Mars expedition in rural Utah. You can follow her on Twitter @howellspace or contact her at her website.

C/2014 Q2 Lovejoy – A Binocular Comet in Time for Christmas

C/2014 Q2 Lovejoy – A Binocular Comet in Time for Christmas:



Like a Christmas ornament dangling from string, Comet Lovejoy Q2 is headed north and coming into good view for northern hemisphere observers in the next two weeks. This photo was taken on November 26th. Credit: Rolando Ligustri


Like a Christmas ornament dangling from string, Comet Lovejoy Q2 is just now coming into good view for northern hemisphere observers. This photo was taken on November 26th and shows a bright coma and long, delicate ion tail. Credit: Rolando Ligustri
Hmmm. Something with a long white beard is making an appearance in northern skies this week. Could it be Santa Claus? No, a bit early for the jolly guy yet, but comet watchers will soon find a special present under the tree this season.  Get ready to unwrap Comet Lovejoy Q2, now bright enough to spot in a pair of 10×50 binoculars.



Comet Lovejoy Q2 starts out low in the southern sky below Canis Major this week but quickly zooms northward. Visibility improves with each passing night. Source: Chris Marriott's SkyMap software


Comet Lovejoy Q2 starts out low in the southern sky in Puppis this week (6° max. altitude on Dec. 9) but quickly zooms north and west with each passing night. On the night of December 28-29, the comet will pass 1/3° from the bright globular cluster M79 in Lepus. This map shows the sky and comet’s position facing south from 42° north latitude around 1:30 a.m. CST. Source: Chris Marriott’s SkyMap software
Following a rocket-like trajectory into the northern sky, this visitor from deep space is no longer reserved for southern skywatchers alone. If you live in the central U.S., Lovejoy Q2 pokes its head from Puppis in the early morning hours this week. Glowing at magnitude +7.0-7.5, it’s a faint, fuzzy cotton ball in binoculars from a dark sky and visible in telescopes as small as 3-inches (7.5 cm). With the Moon past full and phasing out of the picture, comet viewing will continue to improve in the coming nights. What fun to watch Lovejoy gradually accelerate from its present turtle-like amble to agile cheetah as it leaps from Lepus to Taurus at the rate of 3° a day later this month. Why the hurry? The comet is approaching Earth and will pass nearest our planet on January 7th at a distance of 43.6 million miles (70.2 million km). Perihelion follows some three weeks later on January 30th.



Image triplet taken by Terry Lovejoy on which he discovered the comet. The comet moves slightly counterclockwise around the larger fuzzy spot. Credit: Terry Lovejoy


Terry Lovejoy discovered the comet in this triplet of images taken on August 17th. The comet moves slightly counterclockwise around the larger fuzzy spot during the sequence. Credit: Terry Lovejoy
The new object is Australian amateur Terry Lovejoy’s 5th comet discovery. He captured images of the faint, 15th magnitude wisp on August 17th with a Celestron C-8 fitted with a CCD camera at his roll-off roof observatory in Brisbane, Australia. Comet Lovejoy Q2 has a period of about 11,500 years with an orbit steeply inclined to the plane of the Solar System (80.3°), the reason for its sharp northern climb. As December gives way to January the comet crosses from below to above the plane of the planets.



Another awesome shot of Comet Lovejoy Q2 taken on November 26, 2014. Gases in the coma fluoresce green in the Sun's ultraviolet light. Credit: Damian Peach


Another awesome shot of Comet Lovejoy Q2 taken on November 26, 2014. Gases in the coma including carbon and cyanogen fluoresce green in the Sun’s ultraviolet light. The comet’s moderately condensed coma currently measures about 8 arc minutes across or 1/4 the size of the full Moon. Credit: Damian Peach
Comet Lovejoy is expected to brighten to perhaps 5th magnitude as it approaches Earth, making it faintly visible with the naked eye from a dark sky site. Now that’s what I call a great way to start the new year!

To help you find it, use the top map to get oriented; the detailed charts (below) show stars to magnitude +8.0. Click each to enlarge and then print out a copy for use at night. Bonus! Comet Lovejoy will pass only 10 arc minutes (1/3°) south of the 8th magnitude globular cluster M79 on December 28-29 – a great opportunity for astrophotographers and observers alike. Both comet and cluster will pose side by side in the same binocular and telescopic field of view. In early January I’ll post fresh maps to help you track the comet all through next month, too.



Detailed map showing the comet tomorrow morning through December 27th in the early morning hours (CST). Stars shown to magnitude +8.0. Source: Chris Marriott's SkyMap software


Detailed map showing the comet tomorrow December 9th through December 27th in the early morning hours (CST). Stars shown to magnitude +8.0. Source: Chris Marriott’s SkyMap software


Because Comet Lovejoy rapidly moves into the evening sky by mid-late December, its position on this detailed map is shown at 10 p.m. (CST) nightly. Credit:


Because Comet Lovejoy moves rapidly into the evening sky by mid-late December, its position on this detailed map is shown for 10 p.m. (CST) nightly. Credit: Chris Marriott’s SkyMap software


About 

I'm a long-time amateur astronomer and member of the American Association of Variable Star Observers (AAVSO). My observing passions include everything from auroras to Z Cam stars. Every day the universe offers up something both beautiful and thought-provoking. I also write a daily astronomy blog called Astro Bob.

New Research Suggests Better Ways To Seek Out Pale Blue Dots

New Research Suggests Better Ways To Seek Out Pale Blue Dots:



Artist’s impression of how an infant earth might look. Credit: ESO.


Artist’s impression of how an infant earth might look. Credit: ESO.
The search for worlds beyond our own is one of humankind’s greatest quests. Scientists have found thousands of exoplanets orbiting other stars in the Milky Way, but are still ironing out the details of what factors truly make a planet habitable. But thanks to researchers at Cornell University, their search may become a little easier. A team at the Institute for Pale Blue Dots has zeroed in on the range of habitable orbits for very young Earth-like planets, giving astronomers a better target to aim at when searching for rocky worlds that contain liquid water and could support the evolution of life.

The Habitable Zone (HZ) of a star is its so-called “Goldilocks region,” the not-too-hot, not-too-cold belt within which liquid water could exist on orbiting rocky planets. Isolating planets in the HZ is the primary objective for scientists hoping to find evidence of life. Until now, astronomers have mainly been searching for worlds that lie in the HZ of stars that are in the prime of their lives: those that are on the Main Sequence, the cosmic growth chart for stellar evolution. According to the group at Cornell, however, scientists should also be looking at cooler, younger stars that have not yet reached such maturity.



The increased distance of the Habitable Zone from pre-main sequence stars makes it easier to spot infant Earths. Credit: Astrophysical Journal Letters.


The increased distance of the Habitable Zone from pre-main sequence stars makes it easier to spot infant Earths. Credit: Astrophysical Journal Letters.
As shown in the figure above, cool stars in classes F, G, K, and M are more luminous in their pre-Main Sequence stage than they are once they mature. Planets that circle around such bright stars tend to have more distant orbits than those that accompany dimmer stars, making transits more visible and providing a larger HZ for astronomers to probe. In addition, the researchers found that fledgling planets can spend up to 2.5 billion years in the HZ of a young M-class star, a period of time that would allow ample time for life to flourish.

But just because liquid water could exist on a planet doesn’t mean that it does. A rocky planet must first acquire water, and then retain it long enough for life to develop. The Cornell group found that a watery world could lose its aqueous environment to a runaway greenhouse effect if if forms too close to a cool parent star, even if the planet was on course to eventually stray into the star’s HZ. These seemingly habitable planets would have to receive a second supply of water later on in order to truly support life. “Our own planet gained additional water after this early runaway phase from a late, heavy bombardment of water-rich asteroids,” offered Ramses Ramirez, one author of the study. “Planets at a distance corresponding to modern Earth or Venus orbiting these cool stars could be similarly replenished later on.”

Estimations for the HZs of cool, young stars and probable amounts of water loss for exoplanets orbiting at various distances are provided in a preprint of the paper, available here. The research will be published in the January 1, 2015 issue of The Astrophysical Journal.



About 

Vanessa earned her bachelor's degree in Astronomy and Physics in 2009 from Wheaton College in Massachusetts. Her credits in astronomy include observing and analyzing eclipsing binary star systems and taking a walk on the theory side as a NSF REU intern, investigating the impact of type 1a supernovae on the expansion of the Universe. In her spare time she enjoys writing about astrophysics and cosmology, making delicious vegetarian meals, taking adventures with her husband and/or Nikon D50, and saving the world.

Wednesday, December 3, 2014

Communicating Across the Cosmos, Part 3: Bridging the Vast Gulf

Communicating Across the Cosmos, Part 3: Bridging the Vast Gulf:



The cover of the phonograph record on the Voyager 1 and 2 spacecraft, which contains an interstellar message encoded on a phonographic record. The encoded instructions attempt to explain to extraterrestrials how to play the record. Credit: NASA JPL


The cover of the phonograph record on the Voyager 1 and 2 spacecraft, which contains an interstellar message encoded on a phonographic record. The encoded instructions attempt to explain to extraterrestrials how to play the record, and the location of the Earth. Credit: NASA JPL
If extraterrestrial civilizations exist, the nearest is probably at least hundreds or thousands of light years away. Still, the greatest gulf that we will have to bridge to communicate with extraterrestrials is not such distances, but the gulf between human and alien minds.

In mid-November, the SETI Institute in Mountain View, California sponsored an academic conference on interstellar communication, “Communicating across the Cosmos“. The conference drew 17 speakers from a variety of disciplines, including linguistics, anthropology, archeology, mathematics, cognitive science, radio astronomy, and art. In this installment we will explore some of the formidable difficulties that humans and extraterrestrials might face in constructing mutually comprehensible interstellar messages.



Optical PAyload for Lasercomm Science (OPALS) Flight System, the first laser communication from space. Credit: NASA/JPL-Caltech.


Optical PAyload for Lasercomm Science (OPALS) Flight System, the first laser communication from space. Credit: NASA/JPL-Caltech.
If we knew where they were, and we wanted to, the information revolution has given us the capability to send an extraterrestrial civilization a truly vast amount of information. According to SETI Institute radio astronomer Seth Shostak, with broadband microwave radio we could transmit the Library of Congress, or the contents of the World Wide Web in 3 days; with broadband optical (a laser beam for space transmission) we could transmit this same amount of information in 20 minutes. This transmission would, of course, take decades or centuries to cross the light years and reach its destination. These truly remarkable capabilities give us the ability to send almost any message we want to the extraterrestrials. But transmitting capabilities aren’t the hard part of the problem. If the aliens can’t interpret it, the entire content of the World Wide Web is just a mountain of gibberish.

Many conference participants felt that the problems involved in devising a message that could be understood by a non-human mind were extremely formidable, and quite possibly insurmountable.

Having its own separate origin, extraterrestrial life could be different from Earthly life all the way down to its biochemical foundations. The vast diversity of life on Earth gives us little reason to think that aliens will look like us. Given the different conditions of another planet, and the contingencies of a different history, evolution will have produced a different set of results. For interstellar messaging to be possible at all, these results must include an alien creature capable of language, culture, and tool-making. But if these abilities are founded on a different biology and different perceptual systems, they might differ from their human counterparts in ways that we would find hard to even imagine. Looking to our own possible future development, we can’t even be sure that extraterrestrials will be biological creatures. They might be intelligent machines.

According to cognitive scientist Dominique Lestel, who presented at the conference, understanding extraterrestrials poses an unprecedented set of problems. We face all of the problems that ethologists (scientists who study animal behavior) face when they study perception and signaling in other animal species. These are compounded with all of the problems that ethnologists face when they study other human cultures. Lestel worries that humans might not be smart enough to do it. He wasn’t alone in that opinion.



Explanation of the symbols on the cover of the Voyager record Credit: NASA JPL


Explanation of the symbols on the cover of the Voyager record. Credit: NASA JPL
Linguist and conference presenter Sheri-Wells Jensen said that humans have created more than 7,000 different spoken and signed languages. No one knows whether all human languages sprung from a single instance of the invention of language or whether several human groups invented language independently. Given the ease with which children learn a language, many linguists think that our brain has a specialized language “module” underlying the “universal” grammar of human languages. These special features of the human brain might pose a formidable barrier to learning the language of a creature with a different brain produced by a different evolutionary history. An alien language might make demands on our short term memory or other cognitive abilities that humans would find impossible to meet.

When human beings talk to one another, they rely on a system of mutually understood conventions. Often gestures and body language are essential to conveying meaning. Conference presenter Klara Anna Capova, a cultural anthropologist, noted that interstellar messaging poses unique problems because the conventions to be followed in the message can’t be mutually arranged. We must formulate them ourselves, without knowing anything about the recipients. The intended recipients are distant in both time and space. The finite speed of light ensures that query and response will be separated by decades or centuries. With so little to go on, the message will inevitably reflect our cultural biases and motives. In 1962, the Soviet Union transmitted a message towards the planet Venus. It was in Morse code, and consisted of the Cyrillic characters “Lenin”, “CCCP” (USSR), and “MIR” (the Russian word for “peace”). But the posited Venusians couldn’t possibly have known the conventions of Morse code, the Cyrillic alphabet, human names, countries, or possible relationships between them, no matter how intimately familiar these things would have seemed to the Soviets. Whether they are meant to build national prestige, sell a product, or cause humans to think deeply about their place in the universe, interstellar messages play to a human audience.

Given the long timescales involved in interstellar messaging, many conference participants noted the parallels with archeology. Archeologists have learned quite a lot about past human cultures by studying the artifacts and symbols they have left for us. Still, archeological methodologies have their limits. According to conference presenter and archeologist Paul Wason, these limits have much to teach us about interstellar messaging. Certain meanings are accessible to archeological analysis and others aren’t, because we lack the contextual knowledge needed to interpret them. Neolithic cave paintings speak to modern investigators about the skill and abilities of the painters. But, because we don’t have the needed contextual knowledge, they don’t tell us what the paintings meant to their creators.

To interpret symbols used in the past, we need to know the conventions that related the symbols to the things they symbolized. Linguistic symbols pose special problems. To understand them, we need to know two different sets of conventions. First, we need to know the conventions that relate the script to the words of the spoken language. Second, we need to know how the words of the spoken language relate to the things and situations it refers to. It is a sobering thought for would-be exolinguists that no one has ever succeeded in deciphering an ancient script without knowing the language it was written in.

What does all this tell us about our fledgling attempts to devise messages for aliens? The phonograph record carried on the Voyager 1 and 2 spacecraft includes a moving message from then President Carter, encoded as English text. It reads in part: “We hope someday, having solved the problems we face, to join a community of galactic civilizations. This record represents our hope and our determination, and our good will in a vast and awesome universe.”

Human archeologists have never deciphered linear A, the writing system of the ancient Minoan civilization, due to its apparent lack of association with any known language. Unfortunately, since extraterrestrials likewise lack contextual knowledge of any human language, it is almost certain that they could never discern the meaning of President Carter’s text. The team that developed the Voyager message, which included astronomers and SETI pioneers Carl Sagan and Frank Drake, were well aware of the problem. Carter was, most likely, made aware. Interstellar messages play to a human audience.



An inscription written around the inner surface of a cup in Linear A, a script used by the Minoan civilization that has never been deciphered. Credit: Sir Arthur Evans, Scripta Minoa: The Written Documents of Minoan Crete


An inscription written around the inner surface of a cup in Linear A, a script used by the Minoan civilization that has never been deciphered. Credit: Sir Arthur Evans, Scripta Minoa: The Written Documents of Minoan Crete
Is it possible for us to do better? Some off-beat ideas were proposed. Both astronomer Seth Shostak and designer Marek Kultys thought we might consider sending the sequence of the human genome. This idea was quickly shot down by a comment from the audience. Why send them a key, they said, if the aliens don’t have a lock. The metaphor is apt. DNA can only do its job as a constituent part of a living cell. Reading and implementing the genetic code involves numerous highly specialized enzymes and other cellular parts. Even if alien biochemistry and cell structure are generally similar to their Earthly counterparts, there are many features of Earthly biochemistry that appear to be quirky products of the history of life on Earth. The probability that they would repeat themselves precisely on another world are, for all practical purposes, nil. Without the context of an Earthly cell, the sequence of the human genome would be meaningless gibberish.

In the twenty first century, our ability to transmit and process information has become astounding, but we still don’t know how information conveys meaning. Is there even a glimmering of a hope that we can reach beyond the limitations of our humanity to convey meaning to an alien mind? In the final installment of this report, we’ll consider some possibilities.

Previous articles in this series:
Part 1: Shouting into the Darkness
Part 2: Petabytes from the Stars

References and further reading:

Communicating across the Cosmos, How can we make ourselves understood by other civilizations in the galaxy?, SETI Institute

E. Howell (2014) How Do Aliens Think? We Need to Learn About Their Biology First, Analyst Argues. Universe Today.

J. Minor (2014) Will We Find Alien Life in 20 Years? You can bet on it. Universe Today.

C. Sagan, F. D. Drake, A. Druyan, T. Ferris, J. Lomberg, L. S. Sagan, (1978) Murmurs of Earth: The Voyager Interstellar Record. Random House, New York.



About 

Paul Patton is a freelance science writer. He holds a Bachelor's degree in physics from the University of Wisconsin Green Bay, a Master's degree in the history and philosophy of science from Indiana University, and a Doctorate in neuroscience from the University of Chicago. He has been interested in space, astronomy, and extraterrestrial life since early childhood.

New Analysis Sets a Space & Time Zone for Complex Life

New Analysis Sets a Space & Time Zone for Complex Life:



A new research paper reveals more details of the effect gamma ray bursts (GRB) have had on the development of complex life throughout the cosmos. Illustration depicts a beam from a GRB as might have been directed toward early life on Earth during the Cambrian or Ordovician periods, ~500 million years ago. (Illustration Credit: T. Reyes)


A new research paper reveals more details of the effect gamma ray bursts (GRB) have had on the development of complex life throughout the cosmos. Illustration depicts a beam from a GRB as might have been directed toward early life on Earth during the Cambrian or Ordovician periods, ~500 million years ago. (Illustration Credit: T. Reyes)
If too close to an environment harboring complex life, a gamma ray burst could spell doom for that life. But could GRBs be the reason we haven’t yet found evidence of other civilizations in the cosmos? To help answer the big question of “where is everybody?” physicists from Spain and Israel have narrowed the time period and the regions of space in which complex life could persist with a low risk of extinction by a GRB.


GRBs are some of the most cataclysmic events in the Universe. Astrophysicists are astounded by their intensity, some of which can outshine the whole Universe for brief moments. So far, they have remained incredible far-off events. But in a new paper, physicists have weighed how GRBs could limit where and when life could persist and evolve, potentially into intelligent life.

In their paper, “On the role of GRBs on life extinctions in the Universe”, published in the journal Science, Dr. Piran from Hebrew University and Dr. Jimenez from University of Barcelona consider first what is known about gamma ray bursts. The metallicity of stars and galaxies as a whole are directly related to the frequency of GRBs. Metallicity is the abundance of elements beyond hydrogen and helium in the content of stars or whole galaxies. More metals reduce the frequency of GRBs. Galaxies that have a low metal content are prone to a higher frequency of GRBs. The researchers, referencing their previous work, state that observational data has shown that GRBs are not generally related to a galaxy’s star formation rate; forming stars, including massive ones is not the most significant factor for increased frequency of GRBs.

As fate would have it, we live in a high metal content galaxy – the Milky Way. Piran and Jimenez show that the frequency of GRBs in the Milky Way is lower based on the latest data available. That is the good news. More significant is the placement of a solar system within the Milky Way or any galaxy.



The brightest gamma-ray burst ever seen in X-rays temporarily blinded Swift's X-ray Telescope on 21 June 2010. This image merges the X-rays (red to yellow) with the same view from Swift's Ultraviolet/Optical Telescope, which showed nothing extraordinary. Credit: NASA/Swift/Stefan Immler


The brightest gamma-ray burst ever seen in X-rays temporarily blinded Swift’s X-ray Telescope on 21 June 2010. This image merges the X-rays (red to yellow) with the same view from Swift’s Ultraviolet/Optical Telescope, which showed nothing extraordinary. Credit: NASA/Swift/Stefan Immler
The paper states that there is a 50% chance of a lethal GRB’s having occurred near Earth within the last 500 million years. If a stellar system is within 13,000 light years (4 kilo-parsecs) of the galactic center, the odds rise to 95%. Effectively, this makes the densest regions of all galaxies too prone to GRBs to permit complex life to persist.

The Earth lies at 8.3 kilo-parsecs (27,000 light years) from the galactic center and the astrophysicists’ work also concludes that the chances of a lethal GRB in a 500 million year span does not drop below 50% until beyond 10 kilo-parsecs (32,000 light years). So Earth’s odds have not been most favorable, but obviously adequate. Star systems further out from the center are safer places for life to progress and evolve. Only the outlying low star density regions of large galaxies keep life out of harm’s way of gamma ray bursts.

The paper continues by describing their assessment of the effect of GRBs throughout the Universe. They state that only approximately 10% of galaxies have environments conducive to life when GRB events are a concern. Based on previous work and new data, galaxies (their stars) had to reach a metallicity content of 30% of the Sun’s, and the galaxies needed to be at least 4 kilo-parsecs (13,000 light years) in diameter to lower the risk of lethal GRBs. Simple life could survive repeated GRBs. Evolving to higher life forms would be repeatedly set back by mass extinctions.

Piran’s and Jimenez’s work also reveals a relation to a cosmological constant. Further back in time, metallicity within stars was lower. Only after generations of star formation – billions of years – have heavier elements built up within galaxies. They conclude that complex life such as on Earth – from jelly fish to humans – could not have developed in the early Universe before Z > 0.5, a cosmological red-shift equal to ~5 billion years ago or longer ago. Analysis also shows that there is a 95% chance that Earth experienced a lethal GRB within the last 5 billion years.

The question of what effect a nearby GRB could have on life has been raised for decades. In 1974, Dr. Malvin Ruderman of Columbia University considered the consequences of a nearby supernova on the ozone layer of the Earth and on terrestrial life. His and subsequent work has determined that cosmic rays would lead to the depletion of the ozone layer, a doubling of the solar ultraviolet radiation reaching the surface, cooling of the Earth’s climate, and an increase in NOx and rainout that effects biological systems. Not a pretty picture. The loss of the ozone layer would lead to a domino effect of atmospheric changes and radiation exposure leading to the collapse of ecosystems. A GRB is considered the most likely cause of the mass extinction at the end of the Ordovician period, 450 million years ago; there remains considerable debate on the causes of this and several other mass extinction events in Earth’s history.

The paper focuses on what are deemed long GRBs – lGRBs – lasting several seconds in contrast to short GRBs which last only a second or less. Long GRBs are believed to be due to the collapse of massive stars such as seen in supernovas, while sGRBs are from the collision of neutron stars or black holes. There remains uncertainty as to the causes, but the longer GRBs release far greater amounts of energy and are most dangerous to ecosystems harboring complex life.

The paper narrows the time and space available for complex life to develop within our Universe. Over the age of the Universe, approximately 14 billion years, only the last 5 billion years have been conducive to the creation of complex life. Furthermore, only 10% of the galaxies within the last 5 billion years provided such environments. And within only larger galaxies, only the outlying areas provided the safe distances needed to evade lethal exposure to a gamma ray burst.

This work reveals how well our Solar System fits within the ideal conditions for permitting complex life to develop. We stand at a fairly good distance from the Milky Way’s galactic center. The age of our Solar System, at approximately 4.6 billion years, lies within the 5 billion year safe zone in time. However, for many other stellar systems, despite how many are now considered to exist throughout the Universe – 100s of billions in the Milky Way, trillions throughout the Universe – simple is probably a way of life due to GRBs. This work indicates that complex life, including intelligent life, is likely less common when just taking the effect of gamma ray bursts into consideration.

References:

On the role of GRBs on life extinction in the Universe, Tsvi Piran, Raul Jimenez, Science, Nov 2014, pre-print



About 

Contributing writer Tim Reyes is a former NASA software engineer and analyst who has supported development of orbital and lander missions to the planet Mars since 1992. He has an M.S. in Space Plasma Physics from University of Alabama, Huntsville.

Live Discussion: How Good is the Science of “Interstellar?”

Live Discussion: How Good is the Science of “Interstellar?”:

by Nancy Atkinson on November 26, 2014
Kip Thorne’s concept for a black hole in 'Interstellar.' Image Credit: Paramount Pictures


Kip Thorne’s concept for a black hole in ‘Interstellar.’ Image Credit: Paramount Pictures
The highly anticipated film “Interstellar” is based on science and theory; from wormholes, to the push-pull of gravity on a planet, to the way a black hole might re-adjust your concept of time. But just how much of the movie is really true to what we know about the Universe? There has also been some discussion whether the physics used for the visual effects in the movie actually was good enough to produce some science. But how much of it is just creative license?

Today, (Wed. November 26) at 19:00 UTC (3 pm EDT, 12:00 pm PDT), the Kavli foundation hosts a live discussion with three astrophysicists who will answer viewers’ questions about black holes, relativity and gravity, to separate the movie’s science facts from its science fiction.


According to the Kavli twitter feed, the Hangout will even help you understand what in the world happened at the end of the movie!

Scientists Mandeep Gill, Eric Miller and Hardip Sanghera will answer your questions in the live Google Hangout.

Submit questions ahead of and during the webcast by emailing info@kavlifoundation.org or by using the hashtag #KavliSciBlog on Twitter or Google+.

You can watch today’s hangout here:



Also, you can enjoy the “Interstellar” trailer: