Low-mass Jupiter-like objects provide planetary formation clues

Astronomers can now better chart the way planetary systems, including our own Solar System, are born and change over time

An artist’s impression of a primordial rotating disc of gas and dust 

from which planets can form surrounding a young, low-mass object

When a star is young, it is often still surrounded by a primordial rotating disc of gas and dust from which planets can form. Astronomers like to find such discs because they might be able to catch the star partway through the planet-formation process, but it’s highly unusual to find such discs around brown dwarfs or stars with very low masses. New work from a team led by Anne Boucher of Université de Montréal, and including Carnegie’s Jonathan Gagné and Jacqueline Faherty, has discovered four new low-mass objects surrounded by discs. Three of the four objects discovered by these researchers are quite small, somewhere between only 13 and 18 times the mass of Jupiter. The fourth has about 120 times Jupiter’s mass. For comparison, the Sun is just over 1,000 times more massive than Jupiter. “Finding discs in low-mass systems is really interesting to us, because objects that exist at the lower limit of what defines a star and that still have discs that indicate planet formation can tell us a lot about both stellar and planetary evolution,” says Boucher, who works at her university’s Institute for Research on Exoplanets (iREx). In a planet-forming disc, the dust grains collide and aggregate to form pebbles, which grow into boulders, and so on, increasing in size through planetesimals, planetary embryos, and finally rocky terrestrial planets – some of which then become the cores for gas giant planets. Astronomers are able to identify these types of planet-birthing discs because the star heats up the surrounding dust, which affects the way it looks using a telescope with an infrared camera.However, some discs indicate that planet formation isn’t ongoing, but has already finished. These discs are made up of the debris left behind by all the collisions during planet formation and by subsequent collisions of the newly formed planets. Eventually, these dusty remains are swept away. But until that happens, a cooler, thinner ring of dust surrounds the star.

Could low-mass objects assist in our understanding of planetary formation. 

Some discs even represent an intermediate stage between the planet-forming and dusty remnant phases.It’s important for astronomers to try to distinguish between these different types of discs, because then they can better chart the way planetary systems, including our own Solar System, are born and change over time.The research team was able to determine that the discs surrounding their four newly discovered low-mass objects were all likely in a phase of planet forming. None were in the dusty aftermath phase.Even more interesting, two of the objects are possibly between 42 and 45 million years old. This would make them the oldest objects surrounded by active disc systems ever found.

സര്‍ജിക്കല്‍ സ്ട്രൈക്കിന് വഴി കാട്ടിയത് കാര്‍ട്ടോസാറ്റ് ചിത്രങ്ങള്‍

ബെംഗലൂരു: നിയന്ത്രണരേഖ മറികടന്ന് ഇന്ത്യന്‍ സൈന്യം നടത്തിയ സര്‍ജിക്കല്‍ ആക്രമണം എളുപ്പമാക്കിയത് ഐഎസ്ആര്‍ഒയുടെ കാര്‍ട്ടോസാറ്റ് ഉപഗ്രഹ ചിത്രങ്ങളാണെന്ന് റിപ്പോര്‍ട്ടുകള്‍. ഉയര്‍ന്ന റെസല്യൂഷനിലുള്ള ചിത്രങ്ങള്‍ നല്‍കുന്ന കാര്‍ട്ടോസാറ്റിന്‍റെ സഹായത്തോടെയാണ് പിഴവില്ലാത്ത ആക്രമണത്തിന് സൈന്യത്തിന് കഴിഞ്ഞതെന്ന് ഐഎസ്ആര്‍ഒ വൃത്തങ്ങള്‍ അറിയിച്ചു.

                      ആകാശത്തിലെ ഇന്ത്യയുടെ കണ്ണ് എന്നാണ് കാര്‍ട്ടോസാറ്റ് അറിയപ്പെടുന്നത്. നിരീക്ഷണങ്ങള്‍ക്കും റിമോട്ട് സെന്‍സിംഗ് സാങ്കേതികവിദ്യക്കും ഉപയോഗിക്കുന്ന ഇവ തദ്ദേശീയമായി നിര്‍മ്മിച്ചതാണ്. 0.65 മീറ്റര്‍ വരെ വലിപ്പമുള്ള വസ്തുക്കളെ കൃത്യമായി തിരിച്ചറിയാന്‍ സഹായിക്കുന്നതാണ് ഏറ്റവും ഒടുവില്‍ ഇന്ത്യ വിക്ഷേപിച്ച കാര്‍ട്ടോസാറ്റ് 2-സി.

                      

                      ചിത്രങ്ങള്‍ മാത്രമല്ല, വീഡിയോകള്‍, പ്രത്യേക പ്രദേശങ്ങള്‍ തിരഞ്ഞെടുത്ത് നിരീക്ഷിക്കാനുള്ള അവസരം എന്നിവയും കാര്‍ട്ടോസാറ്റിനുണ്ട്. കാര്‍ട്ടോസാറ്റ് ചിത്രങ്ങള്‍ സര്‍ജിക്കല്‍ സ്ട്രൈക്കിന് ഉപയോഗിച്ച വിവരം ഔദ്യോഗികമായി പ്രതിരോധമന്ത്രാലയം അംഗീകരിച്ചിട്ടില്ല.

Olympus Mons: The Largest Volcano in the Solar System

                                  Olympus Mons from orbit

The largest volcano in the Solar System and the largest mountain in the Solar System are one in the same: Olympus Mons on Mars. 

                                  Olympus Mons is a shield volcano that towers to an amazing 26 km. That makes it 3 times the height of Mt. Everest. Unlike Everest, Olympus Mons has a very gentle slope. It is up to 550 km at its base. The edge of the volcano’s base is marked by a basal cliff that is 6 km high in some places, but has been eradicated by the overflow of lava in the Martian past. Olympus Mons is the result of many thousands of basaltic lava flows. The extraordinary size of the volcano has been attributed to the lack of tectonic plate movement on the planet. The lack of movement allows the Martian crust to remain fixed in place over a magma hotspot allowing repeated, large lava flows. Many of these flows have levees along their edges. The cooler, outer margins of the flow solidify, forming the levees and leaving a central trough of molten, flowing lava. In images of the volcano you can see partially collapsed lava tubes seen as chains of pit craters. Broad lava fans formed by lava emerging from intact, subsurface tubes are easily visible as well. Some areas along the volcano’s base show lava flows spilling out into the surrounding plains, forming broad aprons, which are burying the basal escarpment. Crater counts taken by the high resolution images returned by the Mars Express spacecraft in 2004 seem to show that flows on the northwestern flank range in age from 2 million years old to 115 million years old. Since these flows are geologically young, it may indicate that the volcano is still active.
                                                        The Olympus Mons caldera complex is made up of at least six overlapping calderas and segments of caldera. Each caldera formed when the roof collapsed following depletion and retreat of the subsurface magma chamber, so each caldera represents a separate eruption. A ‘lake of lava’ seems to have formed the the largest and oldest caldera segment. Using geometric relationships based on caldera dimensions, scientists estimate that the magma chamber associated with this caldera lies about 32 km below the floor of the caldera. Crater size/frequency distributions indicate the calderas range in age from 350 million years ago to about 150 million years ago and may have all formed within 100 million years of each other. 

                                   As the largest volcano in the Solar System, Olympus Mons has been extensively studied. Those studies have been helped by the closeness of Mars. Those studies will continue into the future as will the exploration of the entire planet.

On Jupiter's Moon Europa, More Tantalizing Signs of Giant Water Plumes

By Mike Wall, Space.com Senior Writer

AddA suspected water plume erupts from Jupiter's icy moon Europa (visible at the 7 o'clock position at lower left) in this composite image taken by NASA's Hubble Space Telescope on Jan. 26, 2014. NASA unveiled the image
on Sept. 26, 2016.Credit: NASA/ESA/W. Sparks (STScI)/USGS Astrogeology Science Center caption

Good news on the alien-life-hunting front: The towering plumes emanating from Jupiter's ocean-harboring moon Europa appear to be real.

In late 2012, NASA's Hubble Space Telescope spotted what seemed to be 125-mile-high (200 kilometers) geysers of water vapor erupting from Europa's south polar region. This news was exciting for astrobiologists and space geeks alike, for it suggested that a robotic probe may be able to sample Europa's huge global ocean — which lies beneath the moon's miles-thick icy shell — without even touching down.

The 2012 observation remained a tantalizing outlier for years, however; astronomers failed to find the plume again with Hubble despite repeated attempts. But that long-sought repeat detection has finally been made, scientists announced today (Sept. 26).

Two images of Europa created in 2012 and 2014 by separate research teams using different observation methods reveal activity at a common location on Europa. The transit image on the left shows dark patches of light absorption in the same spot where researchers later found auroral emission from hydrogen and oxygen, the dissociation products of water.

Credit: NASA, ESA, W. Sparks (left image) L. Roth (right image)

A team led by William Sparks of the Space Telescope Science Institute in Baltimore used Hubble to hunt for Europa plumes on 10 separate occasions over a 15-month span. They had success three times, spotting apparent plume activity in January, March and April of 2014.

"They appear to be real," Sparks said during a news conference today. "The statistical significance is pretty good, and I don’t know of any other natural alternative."

Still, Sparks stopped short of calling the repeat detection a definitive confirmation. The newly announced detections were made when Europapassed in front of Jupiter from Hubble's perspective, and plume material seemed to block ultraviolet light coming from the giant planet. The observations Hubble made are right on the edge of the iconic telescope's capabilities, Sparks said.

"We remain cautious," he said. "The problem is that there may be something we don't understand about the instrument, or about our model of the scene, or what Europa looks like in the ultraviolet light."

Analyzing the Hubble data is also a complex process, which explains why the team is revealing the detections now, more than two years after they were made, Sparks added.

The 2012 detection, which was actually announced in December 2013, was made by a different research group, one led by Lorenz Roth of the Southwest Research Institute in San Antonio. Roth and his colleagues used a different method to spot the apparent plume, but the two teams' observations dovetail nicely; both conclude that the plume is about 125 miles high and centered in Europa's southern reaches.

The plume's likely existence should influence the planning of NASA's Europa mission, which the agency aims to launch in the 2020s. This Jupiter-orbiting mission will make multiple flybys of the moon over the course of several years, in an attempt to learn more about Europa's ocean and its potential to support life as we know it.

"Today's results increase our confidence that water and other materials from Europa's ocean — Europa's hidden ocean, hidden under miles of ice — might be on the surface of Europa and available for us to study, without landing and digging through those unknown miles of ice,"said Paul Hertz, director of the Astrophysics Division at NASA Headquarters in Washington, D.C.

This illustration of ridges and fractures on Europa shows one possible way that water could reach Europa’s surface. Chloride salts in the underground ocean bubble up to the moon's frozen surface.

Credit: NASA/JPL-Caltech

The combined Hubble observations also show that the Europa geysers, if they exist, are intermittent phenomena. If scientists learn more about when and why the geysers erupt, it might even be possible for the as-yet-unnamed NASA mission to fly through a Europan plume.

"One of the biggest unknowns we have with these putative plumes is understanding their timing," said Curt Niebur, the Europa program scientist at NASA Headquarters. "And I think the more observations we can get with Hubble and with JWST [the James Webb Space Telescope, which NASA aims to launch in 2018] to better understand that, the better we can use that to construct a schedule for when we search for these plumes at close range from the Europa flyby mission."

Sparks and his team are publishing their results in the Sept. 29 issue of the Astrophysical Journal.

The Universe Is Directionless, Study Finds

By Calla Cofield, Staff Writer

This map, produced using data collected by the Planck satellite, shows a map of the light left over from the big bang. If the universe were not isotropic, scientists think they would find evidence in maps like this one.

Credit: ESA/Planck Collaboration

The universe, it turns out, looks the same in every direction.

Of course, this isn't true on a "small scale" — the stars, galaxies, dark matter and interstellar gas that fill the universe are strewn about and clumped together in unique ways. But on a much size scale encompassing the entire universe, new research shows the cosmic landscape doesn't have any preferred direction — there's no axis of spin like the Earth, no massive asymmetries that would orient a cosmic traveler.

The new study appears to be the most in-depth attempt to answer this question, which confirms a long-held assumption in physics. In addition, it touches on the idea that Earth does not occupy a special place in the universe by showing that not only is no preferred location in the universe, there is no preferred direction. 

Baking the universe

Some things in the universe look different depending on where you're standing when you look at them, or from which direction you view them. For example, the Milky Way galaxy is a disk that rotates around a central axis like a record on a turntable. The galaxy looks different depending on where its viewed from, so observers in different places see different things. But a galaxy is also anisotropic — that is, an observer in one location can look in different directions and will see something different. The stars located far out in the disk move faster as they whip around the center, compared with stars close to the middle. (This is true for an observer inside the galaxy or outside it).

It's that latter kind of variation that's addressed in the new research paper. If the universe looks the same no matter what direction its viewed from, it's isotropic. If it does have a large-scale dependence on direction, it's anisotropic.

If the large-scale structure of the universe is anisotropic — different depending on the direction it is viewed from — that feature would have been present from the get-go. 

A tiny fraction of a second after the universe sprang to life in the Big Bang, scientists think the cosmos underwent a period of rapid inflation, like a loaf of bread expanding in the oven. Very small, random "fluctuations" (like air bubbles in the dough) made it so the matter in the universe didn't spread out evenly, at least on small scales; It clumped together to form stars, galaxies and galaxy clusters, while leaving some areas mostly empty. (This clumping is also observed in dark matter, the mysterious substance that makes up about 80 percent of mass in the universe).

But what if the entire loaf of bread was warped, and not just on small scales? For example, what if space-time, the fabric of the universe, was spinning when inflation began? That would certainly affect how a loaf of bread looked when it finished baking, and it would certainly influence how the universe looks today.

For example, the universe is still expanding, albeit slower than it was during inflation. That means new space is being created between stars and galaxies, so these objects are all moving away from each other. If scientists measured the rate of expansion and found that things were moving a little faster in one direction and a little slower in another direction, that would indicate that something was lopsided in the universal fabric. That would be evidence of anisotropy.

If the universe were anisotropic (did not look the same regardless of direction), it would leave an imprint in the cosmic microwave background. This map shows what one such anisotropy might look like (minus the small-scale fluctuations in the light).

Credit: D. Saadeh, S. M. Feeney, A. Pontzen, H. V. Peiris, J. D. McEwen

The universe expanding at different rates in different directions is the simplest way that anisotropy might play out, according to Daniella Saadeh, a graduate student in physics and astronomy at University College London and the lead author of a new research paper that shows the large-scale universe is, in fact, isotropic.

A map of the cosmos

Saadeh and colleagues looked for signs of anisotropy in data from the European Space Agency's Planck satellite, collected between 2009 and 2013, which maps of the oldest light in the universe — the cosmic microwave background, or the light left over from the Big Bang. If the universe were warped or twisted in some way, that light would likely bear some sign of it, according to the authors.

Mathematicians have already pointed out ways in which the universe could have been warped or twisted or formed in some way as to create a directional dependence. Those variations can be deduced from Einstein's theory of relativity. Saadeh and her colleagues used computer models to simulate all the ways the universe could be anisotropic, and what each of how each of those outcomes would leave an imprint on the light collected by the Planck satellite. In order to pull this off, Saadeh and colleagues needed both the high-quality data provided by Planck, as well as computer programs that could run through all the possible ways those tweaks could influence how the CMB looks over the span of the entire universe.

The left panel shows an anisotropic imprint on the cosmic microwave background; the middle panel shows the small-scale variations in the CMB; the right panel shows the combination of those two.

Credit: D. Saadeh, S. M. Feeney, A. Pontzen, H. V. Peiris, J. D. McEwen

"This is a serious challenge, as we found an enormous number of ways the universe can be anisotropic," said Stephen Feeney, a co-author on the paper, who at the time was a postdoctoral researcher at Imperial College London. "It's extremely easy to become lost in this myriad of possible universes — we need to tune 32 dials to find the correct one."

Because the finding is based on statistical analysis, the conclusion is actually expressed as a likelihood: There is a 1 in 121,000 chance that the universe is not the same in all directions. Saadeh says if anyone wants to improve on that number, they'll likely have to wait for another CMB space observatory that is superior to Planck, and nothing of that nature is under construction.

In a statement from the University College London, Saadeh notes that "universes that spin and stretch are entirely possible, so it’s important that we've shown ours is fair to all its directions."

But in fact, the rule book that modern physics follows ― known as the standard model ― assumes that the universe is isotropic, and has no major variations on large scales.

The standard model describes everything scientists know about the world — all the particles that exist in it, the forces that influence those particles, the laws that govern it all. The model also makes predictions; the discovery of the Higgs boson in 2012 had been predicted by the standard model about four decades prior. If Saadeh and colleagues had found evidence that the universe was anisotropic, that would have thrown a wrench in the standard model.

In some ways, that would have been extremely exciting, but Saadeh said in the release:

"We’re very glad that our work vindicates what most cosmologists assume. For now, cosmology is safe."

Stop Complaining about 'Fake' Colors in NASA Images

By Paul Sutter, The Ohio State University

This gorgeous photo of the famous Crab Nebula combines an infrared view from ESA's Herschel Space Observatory with an optical image from the NASA/ESA Hubble Space Telescope.

Credit: ESA/Herschel/PACS/MESS Key Programme Supernova Remnant Team; NASA, ESA and Allison Loll/Jeff Hester (Arizona State University)

Paul Sutter is an astrophysicist at The Ohio State University and the chief scientist at the COSI science center. Sutter is also host of Ask a Spaceman, RealSpace and COSI Science Now.

We hear it all the time. Well, maybe you don't, but I get this thrown at me a lot. We see beautiful images released by NASA and other space agencies: ghostly nebulas giving tantalizing hints of their inner structures, leftover ruins of long-dead stellar systems, furious supernovae caught in the act of exploding and newborn stars peeking out from their dusty wombs.

Instead of just sitting back, relaxing and enjoying the light show the universe is putting on, some people feel compelled to object: But those colors are fake! You wouldn't see that nebula with your eyes! Binoculars and telescopes wouldn't reveal that supernova structure! Nothing in the universe is that shade of purple! And so on

A light bucket

I think it's first important to describe what a telescope is doing, especially a telescope with a digital camera attached. The telescope itself is an arrangement of tubes, mirrors and/or lenses that enable the instrument to capture as much light as possible. Obviously, it pulls in much more light than the human eye does, or it wouldn't be very good at what it was built to do. So, naturally, telescopes will see really faint things — things you'd never see with your eyes unless you hitched a ride on a wandering rogue exoplanet and settled in for a million-year cruise.

A telescope's second job is to shove all those astronomical photons into a tiny spot that can fit into your iris; otherwise, it would just dump the light on your whole face, which wouldn't be very interesting or useful. That act of focusing also magnifies images, making them appear much larger than in real life. 

So, already, a telescope is giving you an artificial view of the heavens. 

Your retinas have special sensors (aka, rods and cones) that can pick out different colors. But digital sensors — like the one you might use to take a selfie — aren't sensitive to colors at all. They can only measure the total amount of light slamming into them. So to correct for this, they use filters, and either employ multiple sets of sensors or combine multiple readings from the same sensor. 

Either way, the result is the same: an avalanche of data about the properties of the light that hit the device at the same moment you were taking your picture. Fancy software algorithms reconstruct all this data into an image that kinda, sorta approximates what your eyes would've seen without the digital gear.

But as anyone who has had to fiddle with exposure and lighting settings knows, it's far from a one-to-one, human-computer match.

Doing science

If you've ever played with filters before posting a selfie, you're doing it for a reason: You want the picture to look better.

Scientists want pictures to look better, too — for the sake of science. Researchers take pictures of stuff in space to learn about how it works, and some higher contrast here or a little brightening over there can help us understand complex structures and relationships within and between them.

So don't blame NASA for a little photo enhancement touching up; they're doing it for science. [NASA's 10 Greatest Science Missions ]

The colors of the universe 

But what about adding colors? If one had to do a census, perhaps the most common colors in the universe are red and blue. So if you're looking at a gorgeous Hubble Space Telescope image and see lots of those two colors, it's probably close to what your unaided eye would see.

But a broad wash of green? A sprinkling of bright orange? Astrophysical mechanisms don't usually produce colors like that, so what's the deal?

The deal is, again, science. Researchers will often add artificial colors to pick out some element or feature that they're trying to study. Elements when they're heated will glow in very specific wavelengths of light. Sometimes that light is within human perception but will be washed out by other colors in the picture, and sometimes the light's wavelength is altogether beyond the visible.

But in either case, we want to map out where that element is in a particular nebula or disk. So scientists will highlight that feature to get clues to the origins and structure of something complex. "Wow, that oxygen-rich cloud is practically wrapped around the disk! How scientifically fascinating!" You get the idea.[Watch this video where I talk more about colorizing astronomical images.]

Superhero senses 

Ever since William Herschel accidentally discovered infrared radiation, scientists have known that there's more to light than … light. Redder than the deepest reds gives you infrared, microwaves and radio. Violet-er than the deepest violet gives you ultraviolet, plus X-rays and gamma-rays.

Scientists have telescopes to detect every kind of electromagnetic radiation there is, from tiny bullet-like gamma-rays to radio waves that are meters across. The telescope technologies are pretty much always the same, too: collect light in a bucket, and focus it into a central spot.

So, of course, scientists would like to make a map. After all, we did spend quite a bit of money to build the telescope. But what color is a gamma-ray that comes from a distant supernova? What hue is a radio emission from an active galaxy? We need to map all this data onto something palatable to human senses, and we do that by assigning artificial colors to the images.

Without that, we wouldn't be able to actually do science.

Learn more by listening to the episode "How do we see beyond the visible?" on the Ask a Spaceman podcast, available on iTunes and on the Web at http://www.askaspaceman.com. Thanks to Elizabeth M. for the question that led to this piece! Ask your own question on Twitter using #AskASpaceman or by following

Religion May Motivate Humanity's Future Expansion into Space

The Hubble Space Telescope has viewed many heavenly wonders, 

such as the Eagle Nebula’s Pillars of Creation.

Credit: NASA, ESA/Hubble and the Hubble Heritage Team

It's been more than 40 years since a human stepped on another world, and the usual motivators — national pride, scientific discovery and even profit — may not be enough. Instead, people may turn to religion, according to some experts.

At the annual Mars Society convention in Washington, D.C. last week, in a panel called "Cosmos in Cosmoi — Worldview & Visions for the Future of Humanity as a Multi-Planetary Species," four experts discussed the reasons human beings have explored outer space, including religious and social motivators. The panel was moderated by Nicole Willett, education director of the Mars Society.

The group noted that popular notions of the religion-science divide don't often hold up to scrutiny, and that the urge to go to remote places can be rooted in a fundamentally religious impulse.

"Religion has received a sometimes justified, sometimes not justified, rap as being opposed to science and knowledge," said Paul Levinson, a science fiction writer and professor of communications and media studies at Fordham University, during the Sept. 23 panel. "We should take this idea of interrelationship of space travel and religion a little further."

Levinson noted that human spaceflight to other worlds basically stopped in the 1970s, and that the motivations were clearly not powerful enough. "Since we got to the moon and we'd already beaten the Soviets that motive was gone," he said. Science proved insufficient as well. "Science continues to be motivating factor, but it's a weak motivation," he said. "NASA has tried, and it hasn't ignited any real passion."

Profit hasn't proven very helpful, either. "Everybody wants to make a buck," Levinson said. "SpaceX has had some mixed success, and Richard Branson has put some money into it, but I don't see a fleet of spaceships going out beyond the solar system."

That led him to think that some religious motive, based on wonder, might be the way to go. "There's a motivation every sentient being has. Every person and, for all I know, dolphins, has wonder… We ask what is the meaning of our place in the universe. Science doesn't even scratch the deepest parts of that question."

Lance Strate, also a professor of communications at Fordham, said the whole enterprise of space travel was always about more than just the science, or even beating the USSR. "Moses Maimonides came up with idea of planets as intermediary between angels and humans," he said. "All of this suggests we are trying to look for something beyond ourselves."

"The space program is channeling all these resources and labor to send people to our conception of heaven," he added. "Think about the question of what is the reason for doing this."

Beyond motivation, religions are not automatically challenged by space travel, Levinson said. He noted that evangelicals are more likely tobelieve that aliens landed in Roswell, New Mexico. Also, many of the questions that govern ritual and practice would take a different meaning in space. "Where is Mecca if you're on Mars?" he said.

Michael Waltemathe, a theologian at Ruhr-University Bochum in Germany, added that space's challenges to religious observance have already been hashed out. "There was a fatwa put out by Malay Muslim authorities on how to do rituals on the International Space Station — all this has been thought through," he said. (The fatwa says that one can use a "home" time zone to time the prayers, and simply face in any direction.)

Rev. James Heiser, bishop of the Evangelical Lutheran Diocese of North America, noted that Johannes Kepler's speculation on the nature of life on other planets wasn't a direct challenge to his faith.

Asked by Willett about the psychological aspects of long space journeys, Waltemathe added that the religious tradition of setting up monastic communities in remote areas could tie into space travel as well. "The theological idea was that these people were on their own to get a greater connection to transcendence," he said.

Levinson said some forms of religious observance may become less important, because when traveling in space all the celestial markers — moonrise, sunrise, sunset or what phase the moon is in, no longer exist. That could actually have a strengthening effect on religion, he said. "They will see these rituals are not that necessary and religion can then get down to exploring the basis of what religion is — which is what are we doing in this universe." 

Elon Musk Unveils SpaceX Raptor Engine Test for Interplanetary Transport

By Sarah Lewin, Space.com Staff Writer

A photo tweeted by SpaceX CEO Elon Musk Sept. 25, 2016, shows the Raptor rocket engine undergoing testing for the first time. In this tweet, Musk pointed out a wave pattern called "Mach diamonds" that appears in supersonic-speed exhaust plumes.

SpaceX has successfully test-fired the new Raptor rocket engine that will launch the company's planned interplanetary spaceship, according to a series of tweets from the company's CEO, Elon Musk. The engine is being developed to help propel a powerful reusable rocket to Mars and beyond as part of SpaceX's Interplanetary Transport System.

Although Musk revealed some technical details about the engine on Twitter, he promised to reveal more tomorrow (Sept. 27) at his scheduled talk at the International Astronautical Congress event in Guadalajara, Mexico. Musk did not disclose when the test had taken place.

Earlier this month, Musk took to Twitter to announce a name change for the ambitious Mars Colonial Transporter, which can go "well beyond Mars," he said in a series of tweets. The Raptor forms a vital part of the newly named Interplanetary Transport System.

Through Twitter, Musk confirmed that the engine's nozzle is about 14 feet (4.3 meters) in diameter, and that the final version will generate 3 million newtons of force, with a chamber pressure three times that of the Merlin engines that currently propel SpaceX's Falcon 9 rocket.

"Production Raptor goal is specific impulse of 382 seconds and thrust of 3 MN (~310 metric tons) at 300 bar," he wrote on Twitter. "382s is with a 150 area ratio vacuum (or Mars ambient pressure) nozzle. Will go over specs for both versions on Tues.," he clarified in another tweet.

Back in 2012, Musk described the Raptor engine as working similarly to the engines that propelled NASA's space shuttles, with a two-stage cycle that is more efficient than the current Merlin engines used by the company's Falcon 9 rocket. Rather than using liquid oxygen and kerosene as fuel as the Falcon 9's engines do, Raptor will use liquid oxygen and methane to reduce energy costs as well, Musk said at the time.

SpaceX intends to launch an uncrewed Mars mission in 2018, using a Dragon space capsule and a Falcon Heavy rocket. The Interplanetary Transport System could launch humans to Mars as early as 2024 if all goes well, Musk has said.

Pluto's 'Heart' Hints at Deep, Underground Ocean

By Hanneke Weitering, Space.com Staff Writer-Produce

Pluto's heart holds clues about an underwater ocean on the dwarf planet.

Credit: NASA/JHUAPL/SwRI

A new simulation of how Pluto got its "heart" suggests that the dwarf planet most likely has a deep ocean beneath its surface.

Scientists have long suspected that Pluto has liquid water hidden underground. When NASA's New Horizons mission first set sail to the outskirts of the solar system, scientists were already planning to investigate whether the dwarf planet harbors water.

When New Horizons flew past Pluto in July 2015 and beamed its observations back to Earth, scientists found evidence suggesting that Pluto had water at some point. However, they weren't sure whether Pluto's had an existing ocean, or if it had frozen solid over time.

In a new study, scientists have determined that Pluto's subsurface ocean probably does exist, and that liquid water beneath the dwarf planet's icy shell is at least 60 miles (100 kilometers) deep and about as salty as the Dead Sea on Earth. For perspective, the deepest part of Earth's ocean is about 7 miles (11 km) deep, and Earth is about 150 times the size of Pluto.

However, many details about this possible ocean remain elusive.

"Thermal models of Pluto's interior and tectonic evidence found on the surface suggest that an ocean may exist, but it's not easy to infer its size or anything else about it," Brandon Johnson, lead author of the study and an assistant professor at Brown University's Department of Earth, Environmental and Planetary Sciences, said in a statement. "We've been able to put some constraints on its thickness and get some clues about [its] composition."

Johnson and his team discovered this information about Pluto's ocean by simulating the huge asteroid impact that left the flat, icy patch called Sputnik Planum on Pluto's surface, the western half of Pluto's famous heart-shaped feature. But first, they had to look at Charon, Pluto's largest moon. Charon and Pluto are both tidally locked, so they always face each other with the same sides. Sputnik Planum is found on the side of Pluto that constantly faces Charon, and that positioning implies that the area is what scientists call a "positive mass anomaly," meaning it contains more mass than the rest of Pluto's surface, on average.

At first, this doesn't make any sense. The side of Pluto that faces Charon has a gigantic crater, which is "basically a hole in the ground," Johnson said. "You're taking a bunch of material and blasting it out, so you expect it to have negative mass anomaly. But that's not what we see with Sputnik Planum. That got people thinking about how you could get this positive mass anomaly."

That's where the asteroid simulation comes in. Brown and his team ran several simulations of a 200-km (125 miles) asteroid — the appropriate size for Sputnik Planum's 900-km (560 miles) basin — striking Pluto's icy surface with varying depths of liquid water underneath. During this major impact, the asteroid created a huge dent on Pluto. As the asteroid's remains bounced off of the surface, Pluto's interior bounced back, too.

During this rebound, Pluto's interior was pulled toward the surface at the impact site. If the moving material is dense enough, the weight could make up for the missing mass at the impact site and even out Pluto's weight distribution. So the side of the dwarf planet that appears as though it should be lighter actually weighs about the same as the other side. This process is called "isostatic compensation," and it appears to be the reason why Pluto's dented side is so heavy, the researchers said in the new study; after the asteroid took away Pluto's icy crust, denser water from Pluto's interior evened out the missing mass.

But what really tipped the scale for Pluto was the subsequent sea of nitrogen ice that filled Pluto's heart after the impact: The amount of nitrogen ice in Sputnik Planum doesn't weigh enough to explain the tidal locking alone, Johnson said.

"This scenario requires a liquid ocean," Johnson said. "What this tells us is that, if Sputnik Planum is indeed a positive mass anomaly — and it appears as though it is — this ocean layer of at least 100 kilometers has to be there. It's pretty amazing to me that you have this body so far out in the solar system that still may have liquid water."

The new work was detailed Sept. 19 in the journal Geophysical Research Letters

This Is Elon Musk's Plan to Colonize Mars

Is this how we'll get to the Red Planet? 

Elon Musk has some big plans not only to take humans to Mars, but to establish a permanent colony on the planet, and he's about to share the nitty gritty details live in a keynote speech, titled "Making Humans a Multiplanetary Species," that Elon Musk will be in just a few minutes at the 67th International Astronautical Congress in Guadalajara, Mexico. A live feed is embedded above. 

One of the fundamental pillars of Musk's plan is not only to get humans to Mars, but to make it reasonably cheap to do so. By his estimates, sending humans to Mars with traditional tech would take as much as $10 billion per person, not enough to start a real civilization. Musk's goal for a ticket price? The median price of a house in the United States. That is to say, just a few hundred thousand dollars. The key technological milestones to making this happen, according to Musk, are reusable spacecraft, orbital refueling, propellant production on Mars, and some really good propellant, specifically "Deep-cryo methalox" or CH402 because it's relatively cheap and can be made right on Mars. 

The broad strokes of the plan are pretty simple. A rocket ferries tanker after tanker of rocket fuel up into Earth's orbit and then returns for another load. Meanwhile, the spaceship that will actually travel to Mars waits in orbit, being refueled and waiting until Earth and Mars are both in the appropriate places for a trip. 

When it comes to the Mars ship's capacity, Musk thinks that each ship should hold at least 100 people, such that a city of one million could be established on the Red Planet in as few as 10,000 ships. Eventually, if SpaceX has its way, dozens of these ships might depart at once, taking as many as thousands of Earthlings to their new Martian home during the once-every-26-month window when the planets aline. 

One of the key components to this plan is SpaceX's new Raptor engine, which was test fired just yesterday. According to Musk, it's has the highest chamber pressure of any engine ever built, and potentially the highest thrust-to-weight engine as well. The Mars Vehicle would operate using 27 of these engines in a cluster, with the seven in the center able to pivot in order to steer the ship through the void. 

When it comes to funding the project, Musk plans to make a lot of Mars money by launching satellites with the Falcon 9, as well as soliciting investments from private individuals, and potentially money from the U.S. government. For the time being, however, SpaceX is chiefly concerned with moving forward as quickly as it can right now. 

Part of the process of building the first Mars vehicle will be building a carbon fiber fuel tank that can withstand the temperature differentials and pressure required to make a trip between planets. It's the most difficult part of the whole process, according to Musk, which is why SpaceX decided to tackle it first, and has assembled a prototype for testing. 

The timeline for all this is relatively fuzzy, but Musk thinks the earliest possible trip to Mars could be one that would line up with the launch window in 2022. If SpaceX were to miss that, the next chance would be at the end of 2024, and again in early 2027. 

Here's SpaceX's dream of what it will look like if everything goes as planned.

U.S., NATO Already Planning the Next Generation of Fighter Jets

New Russian and Chinese planes are pushing the West to upgrade.

By Kyle Mizokami

The United States and its NATO allies are already looking to the next generation of fighter planes to ensure air superiority, according to the Wall Street Journal. The article cites new fifth-generation Russian and Chinese fighters as the impetus to develop a new round of combat aircraft due in the 2030s.

When we say fifth-gen warplanes, we're talking about aircraft designed to be stealthy, incorporate the latest active electronic scanning array radars, and cruise at supersonic speeds without the use of an afterburner. China's forthcoming Chengdu J-20 and the Russian T-50 (also known as PAK-FA) are expected to be formidable aerial adversaries for the United States and NATO.

The U.S. already fields fifth-generation planes in the form of the F-22 Raptor and the F-35 Joint Strike Fighter. But three-fourths of U.S. planes are fourth-generation designs dating back to the 1970s. The Joint Strike Fighter will replace most of them, but some, such as theF-15E Strike Eagle and the F/A-18 Super Hornet, will need replacing in the 2030-2035 timeframe. So, in addition to the so-called "Penetrating Counter Air" fighter that the Air Force wants to accompany the B-21 Raider bomber deep into enemy territory, the service is already thinking about the next generation of fighter.

France's nEUROn experimental unmanned air combat vehicle. Lessons from the nEUROn program could go into a new generation of European fighters.

European countries, facing a resurgent and aggressive Russia, are also planning on a new generation of planes. After the end of the Cold War, many countries in Europe sought to replace their frontline fighter jets with a single, modern multirole design, such as theEurofighter Typhoon, while allowing secondary fighter and attack jet fleets to age. Now the United Kingdom is buying the F-35 and working on joint research on future sixth-generation fighter designs with France. France, meanwhile, is planning to upgrade theRafale fighter, and Germany wants to replace its Tornado IDS strike jets, which were purchased in the 1980s, with a manned or unmanned design.

Nobody knows what feature set will define sixth-generation fighters. Laser weapons, aircraft skins that act as sensors and antennas, and a lack of a cockpit are two possibilities. But after the soaring costs and development lags that typified the fifth generation F-22 and F-35, affordability and simplicity would be welcome features, too.

Proxima b: scientists discover Earth-like planet that could support life

View of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. Photo: AFP...

Washington: After scanning the vast reaches of the cosmos for Earth-like planets where life might exist, astronomers have found one right next door.

A planet that's rocky like Earth and only slightly bigger has been discovered orbiting Proxima Centauri , the nearest star to our solar system, scientists reported Wednesday. It is probably in the not-too-hot, not-too-cold Goldilocks Zone where liquid water — a key to life — is possible, if the planet has an atmosphere.

And it is a mere 4.22 light-years from Earth or nearly 25 trillion miles.

It is easily the closest potentially habitable planet ever detected outside our solar system — and one that could be reachable by tiny, unmanned space probes before the end of the century, in time for some people alive today to witness it.

The international team of astronomers that announced the discovery did not actually see the planet but deduced its existence indirectly, by using telescopes to spot and precisely calculate the gravitational pull on the star by a possible orbiting body — a tried-and-true method of planet-hunting.

"We hit the jackpot here," said Guillem Anglada-Escude , an astrophysicist at the Queen Mary University of London and lead author of a study on the discovery in the journal Nature . He said the planet is "more or less what we have on Earth."

They're calling it Proxima b, and while it could be like Earth in the important features, it would probably still look very alien.

It is 4.6 million miles from its red dwarf star, or just one-twentieth of the distance between Earth and the sun, creating an incredible orange sky with no blue, so it looks like a perpetual sunset. And if that's not different enough, the planet circles its star so quickly that its year is about 11 days.

The planet doesn't rotate, so one side is always facing its star and the other side is always dark and colder. It is bombarded with X-rays and ultraviolet light, but that wouldn't necessarily be fatal to life, since life can exist underground, scientists said.

Scientists in the past 20 years have found more than 3,000 planets outside our solar system, or "exoplanets." And more than 40 of them seem to be in the habitable zone.

But this one "basically puts a giant flashing neon sign on the nearest star saying: See this right here," said study co-author R. Paul Butler of the Carnegie Institution for Science.

It would take more than eight years for an energy pulse or radio signal traveling at the speed of light to go there and back. NASA's New Horizons probe, the fastest spacecraft launched, left Earth hurtling toward Pluto at about 36,000 mph. At that speed, it would take more than 78,000 years to get there.

Earlier this year, an all-star team of scientists and business leaders including Stephen Hawking announced Breakthrough Starshot , a project to send out hundreds of light-powered space probes that would weigh about a gram, travel at one-fifth the speed of light and send pictures back to Earth.

Breakthrough Starshot executive director Pete Worden, a former top NASA official, said organizers are hoping to include Proxima in their plans. Even at the hoped-for speed, it will take 20 years to get there and four more years for photos to come back. Worden said he hopes they will launch by 2060.

Yet in the vastness of space, Proxima b is practically just over the fence, "like your next-door neighbor," Butler said. Proxima b is more than 50 trillion miles closer than the previous closest potentially habitable exoplanet.

The next step may be for a powerful Earth or space telescope to get an actual image of the planet, Butler said. But even when that comes, and it may be a decade or two away, it will only be a single dot: "You're not going to see espresso bars at the beach. You're not going to see aliens waving at us."

Outside experts praised the finding as rock-solid and thrilling.

"It is inspiring to find a potentially habitable world on our cosmic doorsteps, around our next star," said exoplanet expert Lisa Kaltenegger, director of Cornell University's Carl Sagan Institute . "It is significant because if we needed inspiration to try to reach the next star, now we have it."

Four years ago another group of scientists excited the world with a claim of a planet — not in the habitable zone — around Alpha Centauri, a star a bit farther away. That claim was met with suspicion by other astronomers, who later showed that it was unlikely to be real but a ghost signal from the past.

Xavier Dumusque, an author of the Centauri paper, said it is no longer clear if that was a planet, but in an email he said the team led by Anglada-Escude makes a good case for its own discovery.

Anglada-Escude said there is only a 1-in-10-million chance that what they saw was a false positive, proclaiming "no doubt" that what he found was real. That's because a telescope in Chile that was used to look at Proxima every night for 60 days found a gravitational effect on its star every 11 days or so. Then a close examination of years of data from a different telescope found the same thing, Butler said.

"That cinches it," Butler said. "You've now seen the exact same signal. Two different telescopes, two different techniques."

There are still many questions, especially the crucial one of whether the planet has an atmosphere.

Harvard astronomer Avi Loeb, who isn't part of the discovery team but is advisory board chairman for Breakthrough Starshot, said Proxima might someday prove vital to humanity's future.

"A habitable rocky planet around Proxima would be the most natural location to where our civilization could aspire to move after the sun will die, 5 billion years from now," he said in an email.

(With agency inputs)