The popular story we tell ourselves whenever the subject of alien life comes up is that the universe is nearly infinite, so how could there not be more life in it than just us? Surely, we think, that life exists on Earth proves that it can exist at all, and it’s just a case of finding that right combination of factors that give rise to another form of life.

There’s nothing really wrong with this theory, in a bubble. Our galaxy alone has an approximate 100 billion stars. The universe is estimated to have about 100 billion galaxies. That’s as close to infinite as humans have the capacity to behold, so given the sheer repetition of star making, planet making and life making, we cannot be the only case of life evolving into intelligence.

But time plays a crucial role in deciding these things, and whether or not we ever actually encounter intelligent life at all. Yet we almost never factor time into our popular mythology. Here are five good reasons to suspect that we may never find life in the universe, at all. Sorry.

5. Time, Itself.

Most of us are only thinking in three dimensions when we talk about life in the universe. But time is the critical forth dimension. Yes, the universe is really big. But the universe is also extremely old, and according to our best understanding, due to stay cohesive for billions more years. With this in mind, we’re confronted with the possibility that even if life can exist elsewhere in the universe, it may already have been and gone by now. Or that life may still be “coming soon” to a planet near us. For the moment, it’s out of our reach. Speaking of which…

4. Extinction

Life has only existed on our own Earth for about 3.5 billion years. And in that time, 99.9% of the species that have ever lived here have gone extinct. No more stromatolites, eurypterids, diplodocus. No more sabre tooth tigers. Our time is coming, as well. Will we have extinguished ourselves before we get a chance to find what we’re looking for? Maybe.

How long does it take an intelligent species to become extinct? Here, again, we simply don’t know the answer. If we allow that our species will exist for another 100 million years – a very generous assumption – that is merely a blink of an eye to our vast universe. Which lends itself to another question..

3. Limits on Evolutionary Intelligence

One constant refrain in exobiology is that we may encounter species of vasty more evolved intellect. This is a humble thought, as indeed centuries of space exploration have taught us that our world is rarely the extreme. We are neither the biggest nor the smallest planet in the Solar System. Our Solar System is but one of a sea of star systems. The smallest-known galaxy contains only a few thousand stars, while the IC 1101 mega-galaxy could fit thousands of Milky Way galaxies within it’s expanse without burping.

It makes sense to leave open the possibility that we might not be the smartest, either. But just how smart does life get? We now know a limit must exist for intelligence just as surely as it does for everything else. What are the brackets for most and least-intelligent forms of life? One more answer we do not have.

The idea that we might find life that is vastly more evolved than us may actually be hubristic, from the perspective of intelligent life. How do we know we’re not depressingly close to our own maximum? Or that of intelligent life, itself? What if we really are the very tippy-top of what intelligence can achieve in this universe? We’ve not yet discovered extraterrestrial life. Perhaps all forms of intelligence are doomed to live in isolation?

2. Planetary Orbit Degradation

The vaunted “Goldilocks Zone.” It is the distance a planet must orbit from it’s parent star in order for liquid water to exist. To the best of our knowledge, life requires liquid water, therefore planets that exist within this zone are the ones most likely to harbor life. We’ve even discovered a few candidates.

However, orbits are not fixed things. An orbit is simply the delicate balance of an object falling towards a gravitational field, missing, and sling-shotting around it. Those delicate balances, like all things in the universe, degrade over time.

What this means is that planets can either drift away from or closer to their parent stars. The Earth is getting ever so slightly closer to the Sun every year. Don’t worry: the Earth will not be in any danger for billions of years, by which time, the Sun will have become a white dwarf and we’ll all be cinders in the solar wind anyway. Buck up, explorers!

But it is entirely possible to have a planet that exists within the Goldilocks Zone long enough to get life started, but either drift away from or get pulled into it’s parent star’s gravity well and right out of the Zone altogether. Whatever are the limits on intelligence in the universe may be, this hypothetical form of life will never see them.

1. So many star systems, so very little time.

If this list proves nothing else, it certainly makes clear that time may not be on our side, in this search for extraterrestrial life. And while the fantasy of a near-infinite universe may give hope to those of us hungry to learn about extraterrestrial life, it’s not very comforting to the men and women tasked to find it. Because an infinite number of options means that even if the chances of finding extraterrestrial life are pretty good, the odds are still enormous.

In other words, it’s a bit like hurling someone’s keys into Lake Ontario and then telling them, “well, they gotta be in there, somewhere.” I Want to Believe, indeed.

Truthfully, exploring galaxies other than our own is not practical. We can barely observe stars and planets in our own galaxy with any specificity. We’re only just now able to view Pluto, a planet in our own galaxy. We are able to observe distant star systems and their planets based on tricks of physics and statistics, but we have no idea what they look like, much less what they’re composed of. Much less what may live on them.

Dude. Why ya gotta harsh my buzz?

None of the challenges to finding extraterrestrial life are unknown to science, obviously. They’re not new revelations or road blocks. But colloquially, at least, we don’t discuss them. This is because we all – and especially media outlets – enjoy a bias in favour of speculative science.

Because we all want to believe the next big thing is out there. And it is. But finding that next thing is a non-trivial exercise that’s a lot less sexy. In order for Science to advance, you need the theorist to push our ideas forward. But you also need the practical scientist to spend his or her days grinding away at experiments to prove that the theorist’s ideas match with reality’s sometimes stark truths. And personally, I find that struggle fascinating.

After a trip of 3 billion miles, the NASA spacecraft New Horizons has finally reached it’s closest orbit of the much-beloved planetesimal Pluto today at 8:45am. Powered by Pluto’s namesake element, Plutonium, New Horizons is Humanity’s first meet-and-greet with the famed body. What it saw in those fateful moments, only a few at NASA know about for now. It may be until 9pm before we get new images, but those images may also be the first-ever full-color images of the mini planet.

“This is real exploration,” intoned NASA Associate Administrator for Science John Grunsfeld. And indeed, we will still be waiting some time to find out if the spacecraft survives the full experience of flying by Pluto.

This is largely due to the fact that space missions have to run on shoestring-and-less resources in order to be able to make the journeys they do make. New Horizons has to split it’s time between taking measurements, then turning, and sending it’s data payload back to Earth.

In fact,  one interesting observation that helps us understand just how far the New Horizons spacecraft has traveled, it takes 8 minutes for light from our sun to reach the Earth, but speed-of-light communications from the New Horizon craft will take about 4.5 hours to reach Earth.

Still, Principle Investigator Alan Stern doesn’t think New Horizons is in much danger of failing. NASA calculates that there’s about 2 chances in 10,000 that the mission will fail. After that, New Horizons has enough power to continue it’s mission until as late as 2030. By that time, New Horizons may even have passed out of the heliosphere – the region of space affected by solar radiation – just as Voyager 1 and 2 have done. But this time, it will be with much more sophisticated technology.

Pluto: a world of surprises

We’ve yet to find a planet in our solar system that’s a snoozefest. And if it was going to happen, most predicted it might be Pluto. After all, it’s just a hunk of rock in the distant Solar System that has even been stripped of it’s planet status. Many of us still bristle at the prospect of Pluto the “Planetesimal,” yet that’s exactly what it is.

Still, early indications predict a much more active planet than we’d thought. Alan Stern points out that the dichotomy of Pluto and it’s moon Charon could not be more striking. Since Pluto’s surface looks much less crater-ridden than it’s neighbor, indications are good that there might have been or may still be geological activity on the planet. There are also striations on the surface that suggest more seismic or tectonic activity.

A planet that gets regular quakes, volcanic activity or other geological processes tend to cover up their asteroid strikes. That Charon has these marks but Pluto does not seems to suggest that it’s been at least that active.

We’ve known for a while that Pluto has a very thin nitrogenous atmosphere. The idea that this atmosphere might obscure surface features has been a real worry for scientists embarking on this mission. But on close inspection, this atmosphere seems to be extremely thin with almost no differentiation. Thinning and thickening clouds would indicate weather patterns, but none are present. Still, when asked if it snows on Pluto, scientists seemed confident.

“It sure looks that way,” exclaimed Stern.

So, there may not be an active atmosphere on Pluto, but like Madison Square Garden, you can still occasionally get some precipitation.

We will be spending months and years analyzing the data brought back to us by New Horizons, but for now, we will need to wait on a lot of it. It’s not just distance alone that makes the wait: it’s also the technology. To say the least, transmitting data through 3 billion miles of space is “lossy.” Thus the transfer rate from New Horizons is in the range of about 1000 to 4000 bits per second. Literally fractions of the speed that your old dialup modem enjoyed.

On top of that, NASA’s means of transferring data is based on the already successful model put forth by the Apollo missions. Namely, that data is sent twice, first as a “contingent data” stream, in case the mission goes south later. Then again as fully-fleshed out data. We’ll get full-color pictures tonight, but they won’t be full-resolution for some time.

What’s next for the New Horizons probe? Well, it’s currently traveling on the night side (opposite the sun) of Pluto. Boffins were able to plan the trip to coincide with Charon’s travel across the same night side, so that reflections from Charon will illuminate the surface of Pluto in much the same way that our Earth’s Luna does. After that, it’s off to interstellar space, perhaps with another flyby of one of our outer Solar System’s many mysterious planetesimals.

It’s been a few months since Comet ISON has been in the news again, but fear not: the hurtling pile of ice and gas is still on its trajectory inside the Solar System. Boffins at JPL tell us today that the “soda pop comet” has just begun shedding carbon dioxide and dust, turning on something akin to a fog machine as it gets closer to the sun:

“We estimate ISON is emitting about 2.2 million pounds (1 million kilograms) of what is most likely carbon dioxide gas and about 120 million pounds (54.4 million kilograms) of dust every day,” said Carey Lisse, leader of NASA’s Comet ISON Observation Campaign and a senior research scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. “Previous observations made by NASA’s Hubble Space Telescope and the Swift Gamma-Ray Burst Mission and Deep Impact spacecraft gave us only upper limits for any gas emission from ISON. Thanks to Spitzer, we now know for sure the comet’s distant activity has been powered by gas.”

As comets get closer to stars, they begin to warm up. “Warm,” in this case, being a relative term. Carbon dioxide freezes at -78C and its much, much colder than that in space. But as ISON gets closer to the sun, the sun’s energy begins warming the flying snowball, creating the signature tail, which is a trail of debris being shed from the comet.

This explains why the tail doesn’t necessarily trail out behind the comet: the tail points in the same direction as the solar wind that is creating it, pushing debris off the comet.

In ISON’s case, once it arrives in the inner atmosphere, scientists think it could become extremely bright. Brighter, in fact, than the moon. That’s because it is both large and made of chemicals known to cause nice, bright tails. But that’s only one possibility. Another is that the comet breaks apart from the heat.

We won’t know what will happen until it happens. For now, scientists are busy gathering data they believe will “help explain how and when the solar system first formed.” But then, let’s be honest: they always say that.

We’ve seen images of Saturn from Cassini that also captured the Earth, but this is the first time that NASA has made the deliberate effort to take such a photo. Not to mention that this is the first time we’ve been given advanced notice of the pic here on Earth.

In fact, JPL even invited us all to “Say cheese!” for the image. This image also captures the moon as well as the Earth.

As often as we get images from space these days, it might be easy for some to get jaded by the whole affair. But even in the span of my short lifetime, we have gone from Saturn being a remote and unreachable object of scientific inquiry to a neighbor. That is not an inconsequential change.

See more images here

New findings from researchers at @NASA and other international teams has discovered a link between the bombardment history of our moon and that of the asteroid Vesta. It appears that the same set of projectiles that hit our moon – and presumably other objects in the inner Solar System – 4 billion years ago also impacted Vesta.

Vesta is an asteroid in our Solar System’s main asteroid belt, between the orbits of Jupiter and Mars. Researchers studying this asteroid have compared moon rocks brought back from the Apollo missions to the findings on Vesta and determined that the same set of projectiles were responsible for both sets of bombardments. And they point to a 4-billion year old disruption of the Solar System:

The findings support the theory that the repositioning of gas giant planets like Jupiter and Saturn from their original orbits to their current location destabilized portions of the asteroid belt and triggered a solar system-wide bombardment of asteroids billions of years ago, called the lunar cataclysm.

The research provides new constraints on the start and duration of the lunar cataclysm, and demonstrates that the cataclysm was an event that affected not only the inner solar system planets, but the asteroid belt as well.

It is nearly impossible to stop paying attention to scary things, once they’re revealed. And in a click-hungry Internet media landscape (hey: guilty as charged), it is even harder not to want to write articles that you know are going to get clicks, even if they aren’t the most reputable or useful content.

So now that we’ve had our meteor visit in Russia and lots of “near misses” by other space debris – including one that came closer to us than our own satellites – it is easy to spend a lot of time and energy on these types of things. Why not? It is both scary and awe-inspiring to think of things unknown to us floating in space on a collision course with our Earth:

Scott Hubbard, a consulting professor of aeronautics and astronautics at Stanford, thinks we can do something about that. Hubbard, a former director of NASA Ames Research Center, is also the program architect for the B612 Foundation, which aims to track down the hundreds of thousands of unknown asteroids that could pose a threat to Earth.

But the uncomfortable truth is that the Big Bang never stopped and the placid, gently floating galaxy you saw in Discovery Channel documentaries simply doesn’t exist. The universe is a dynamic, ongoing explosion, filled with lots of gas, lots of planets, lots of stars and yes, lots and lots of debris. The Earth itself is orbiting the Sun at a rate of approximately 67k miles an hour, which is itself rotating around the Milky Way at an estimated 8,700 miles per hour.

Basically, you’ve got a lot of crap spinning at a super-high rate of speed around a lot of other crap. And with more than a little regularity, some crap collides with other crap and you get a giant, intergalactic crap explosion. Bigger the crap, bigger the explosion.

And as pitifully expendable sacs of protoplasm stuck on Earth, we worry that even a small bit of debris could end us.

Galactically speaking, not an unreasonable concern. But what happened in Russia – and the media frenzy that ensued – is evidence not of our vulnerability, but of the extraordinary rareness of such events on a human scale. Debris hits our planet with perhaps disconcerting regularity, but does so completely unnoticed most of the time. That’s because not all space debris is measured in bus or football field lengths. And those large objects that do occasionally hit our planet happen on a regular albeit slow schedule, without wiping out life on Earth, let alone the Earth herself.

Sure. A city the size of San Francisco could suddenly cease to be. But hey! As long as you’re not there, you can say you “remember them when.”

The truth is that as dynamic and violent as our universe is, it is also quite big. And collisions with our Earth of the type we worry about are extremely rare. So I would hold off on that shooting spree you’ve been contemplating: there’s every reason to believe you’ll still be here to pay the piper.

No matter how many images you see of the surfaces of planetoids and planets, the brilliant illumination dust clouds and galaxies, nothing brings space home quite like seeing it with your own two eyes in real-time. That’s what makes the arrival of two comets in the year 2013 especially exciting for all of those who love space porn like I know we here at DFE do.

Comet PANSTARRS has been visible in the Southern Hemisphere for while, but starting Friday night, the comet makes its Northern debut.. for those with the right conditions to see it.

Courtesy of Universe Today, a graph showing the predicted brightness curves for the PANSTARRS comet. Peak will be Sunday, but weather here looks to be a bit cloudy.

Here in Rochester, conditions look to be strictly catch-as-catch-can, with all the major networks in town and The Weather Channel predicting breaks in the clouds by the afternoon. But you’ll need to be out-of-town – probably out of the ‘burbs, too – with a decent set of binoculars to really appreciate this relatively dim comet. According to @NASA JPL:

By March 8, comet PANSTARRS may be viewable for those with a totally unobstructed view of the western horizon for about 15 minutes after twilight. On March 10, it will make its closest approach to the sun about 28 million miles (45 million kilometers) away. As it continues its nightly trek across the sky, the comet may get lost in the sun’s glare but should return and be visible to the naked eye by March 12. As time marches on in the month of March, the comet will begin to fade away slowly, becoming difficult to view (even with binoculars or small telescopes) by month’s end. The comet will appear as a bright point of light with its diffuse tail pointing nearly straight up from the horizon like an exclamation point.

The key as always with spotting a comet is to get out somewhere flat with as little artificial light as possible. This time of year, if you can find someone with a farm whose willing to let you and your weird friends hang out in the middle of a field, that would be just about perfect. If you do, this blog would greatly appreciate any photos you can snap of the event! By all means, please contact us and share your photos!

Star Trek fans will be familiar with the term “positron,” if not necessarily what a positron is. I’ll admit that, before researching this article, I certainly did not. But it now appears that the colossally powerful energy bursts that we call lightning are only part of the amazing energy interaction happening in our skies every day. And the other one includes a blast of.. positrons.

The Fermi Gamma Radiation Telescope is a satellite telescope run by NASA whose job it is to detect the presence of antimatter, which scientists expected to see streaming out of distant stars or black holes. When the satellite was hit by a blast of positron particles, a type of antimatter, the were surprised to find that the source was actually here on our own Earth:

Researchers studying thunderstorms have made a surprising discovery: The lightning we see with our eyes has a dark competitor that discharges storm clouds and flings antimatter into space. Astrophysicists and meteorologists are scrambling to understand “dark lightning.”

This “Dark Lightning” is yet another chain reaction that happens when electromagnetic energy builds up in clouds. Whereas electrons in lightning zap from one charged area to another, causing the brilliant bolts of energy we are familiar with, another reaction causes nearly-invisible (dark) bursts of electrons directly up and out of the cloud. This “avalanche,” as the video below describes it, causes a chain reaction that creates a short-term particle collider that shoots gamma radiation, and now we discover, positrons out into the universe.

So, what is a positron and what is antimatter? Particle physicists discovered long ago that, in order for the math of particle dynamics to work out right, every type of particle needed to have a nearly exact opposite version. Nearly, that is, in that the “Bizarro Particle” must have the same mass and an opposite value such as electrical charge. Neutrons can only exist if antineutrons can also exist; protons can only exist if antiprotons exist. And electrons can only exist if positrons – positively charged particles of the same mass as electrons – also exist. The confusing bit in this case is that we tend to think of electrons and protons as being opposite – and they are oppositely charged, but have different masses and are fundamentally different particles.

Collectively, all these antiparticles are known as antimatter. And far from being hypothetical as so much of modern quantum physics is, positrons have been detected regularly as early as 1932. For a much more in-depth primer on antimatter, read this excellent piece from Scientific American. Now, the video:

[youtube]http://www.youtube.com/watch?v=hN0wGga5e0I&feature=youtube_gdata[/youtube]

.. but be warned: the commute to most any job besides astronaut is kind of prohibitive.

NASA ( @NASA ) announced on Friday that they have awarded a $17.8 million dollar contract to Bigelow Aerospace to create new expandable habitat areas that will be used to expand the current size of the International Space Station. Based on the limited and somewhat vague information given in the press release, it looks like Bigelow plans to design and implement light-weight, collapsible habitat systems that can be shipped to the Space Station and installed to accommodate a larger crew. Moar astronauts means moar science!

“The International Space Station is a unique laboratory that enables important discoveries that benefit humanity and vastly increase understanding of how humans can live and work in space for long periods,” NASA Deputy Administrator Lori Garver said. “This partnership agreement for the use of expandable habitats represents a step forward in cutting-edge technology that can allow humans to thrive in space safely and affordably, and heralds important progress in U.S. commercial space innovation.”

After Space-X Dragon’s successful docking maneuvers to the Space Station and Felix Baumgartner’s successful stratospheric parachute ride (which successfully demonstrated the utility of a commercial flight suit in emergency bail-out situations), this is yet another example of commercial innovation in the space program.

Our solar system includes our sun at the center; four rocky planets surrounding that; an asteroid belt; four gas giants; the icy Kuiper Belt of still more rock and snow. The appearance of two similar belts of debris, one warmer and one colder, happens in at least two very near-by star systems as well. Vega and Fomalhaut, both a relatively-neighborly 25 light-years away from us. New insights into these systems, aided by observations from the Spitzer Space Telescope and Herschel Space Observatory are leaving scientists with the impression that there must also be planets around those systems. In fact, the existence of the belts may actually depend on the existence of the planets.

When star systems form, they begin with clouds of dust. Once enough of the dust has been compacted into the center of the cloud by gravity, the sudden and rapid fusion of hydrogen atoms creates a huge nuclear furnace: the star is born. The rest of the dust begins to accrete into larger and larger rocks. Dust becomes asteroid. Asteroid becomes planetesimal. And if they eat their peas and clean their rooms, planetesimals become planets. All of this happens because gravity requires them to cling together.

But the heat of the sun also plays a role. Closer to our sun, large masses of gas were not allowed to form around planets, and thus the inner most orbits are rocky. Outer worlds become gas giants like Jupiter and Neptune, playing interplanetary Dust Buster to the surrounding material. What material stretched between these two temperature zones – and everything outside the gas giants’ reach – became asteroid belts.

That similar conditions exist within these other nearby star systems suggests strongly to scientists in both NASA and the ESA (European Space Agency, whose project the Herschel SO largely is) that similar planets must also exist. What is even more compelling about the evidence is that, while the parent stars Vega and Fomalhaut are both double the size of our sun:

The gap between the inner and outer debris belts for Vega and Fomalhaut also proportionally corresponds to the distance between our sun’s asteroid and Kuiper belts. This distance works out to a ratio of about 1:10, with the outer belt 10 times farther from its host star than the inner belt.

While much of the research into extra-Solar planets has been done by observing the wobbling movement of the parent star or observing the blink of transiting planets (see this kinda weird vid for a good explainer), more new technology is on the way in the form of the James Webb Space Telescope, among other projects. How many planets will we find? How many moons?

Just yesterday, we reported on NASA’s use of “Solar Grazing Comets” to study the magnetic field of our Sun. But today, I want to talk about another SGC that has a lot of people in the space community very, very excited.

No, it doesn’t look like much right now. But that’s because ISON is very far away from the Sun. Once it gets closer and the Sun’s heat begins to create the atmosphere around the comet that creates the glow and tail we all generally know comets to have, then we’re going to see something amazing. We will hopefully see a comet that outshines the moon for at least an evening or two.

Because astronomers believe that ISON’s composition is similar to that of a comet that passed in 1680 and was reported to have been as bright. How do they know what the composition of the comet from 1680 was? Well, I don’t have the foggiest notion, and neither do most of the reports I’m reading.

However, most comets including this one are believed to come from the Oort Cloud, a hypothesized haze of ice and rock nearly a lightyear away from our Sun and a quarter of the distance between our Sun and our nearest neighboring star, Alpha Centauri. It is believed to be composed of the last snowy bits of material that formed our solar system and exists at the hypothetical edge of our Sun’s gravitational pull.

Astronomers predict that ISON will make its presence known in the night sky around October of this year. The moon-dimming display depends on a couple of things, however. Since heating up a ball of space snow has about as much chance of breaking it apart in space as it would on Earth, there’s every chance that ISON may just fracture into a bunch of smaller comets. Secondly, the comet has to come close enough to the Sun to create a tail, but not so close that it just gets disintegrated altogether. The current estimate is that ISON will pass within 800,000 miles of the Sun. That’s about 100 times closer to the Sun than the Earth. Mercury, by contrast, is about 36,000,000 miles from the Sun.

One interesting and unique ripple in this story is the fact that our Mars Curiosity and Mars Orbiter should be in a position to give us close up views of ISON’s passage before we get good views here on Earth. Imagine that? Pictures of a comet passing another world, then seeing it pass ours.

NASA’s SDO YouTube channel has released some amazing new video, showing comets as they pass close by the sun. When they do, the deformation of the comet’s tail shows where magnetic field lines are pulling at the material in the tail. As the video explains, this process is not unlike meteorologists releasing barium tracers into the upper atmosphere of our Earth to study the wind currents there.

The video goes on to note that we are “in a period of high solar-grazing comet activity,” and NASA will continue to be using these comets to study the mysteries of how the sun works, as well as answering some questions about the solar wind as they track the path of comet tail dust back out into the Solar System. The next SGC expected to make its way around the Sun will be in November of the upcoming year. So… mark your calendars, space fans!

[youtube]http://www.youtube.com/watch?v=MZfD8dpBk4U&feature=youtube_gdata[/youtube]