We are all made of stars

Discovery by Stardust probe in Wild 2 comet suggests life on Earth began in space.

(C) www.timesonline.co.uk

A fundamental building block of biology has been discovered in wisps of stardust from the tail of a comet, offering fresh evidence that life on Earth could have begun from matter that arrived on our planet from space.

New analysis of tiny particles captured by the Stardust comet-chasing probe has revealed for the first time the presence of traces of an amino acid called glycine, a basic component of proteins without which life as we know it could not exist.

The discovery, by Nasa scientists, supports a theory that the raw material from which life began first formed in space, and was carried to Earth by comets that crashed into the planet. It also means that other planets are likely to have been seeded with amino acids from comets in a similar fashion, suggesting that extraterrestrial life may well have evolved elsewhere in the Universe and could even be common.

“Glycine is an amino acid used by living organisms to make proteins, and this is the first time an amino acid has been found in a comet,” said Jamie Elsila, of Nasa’s Goddard Space Flight Centre in Maryland, who led the research. “Our discovery supports the theory that some of life’s ingredients formed in space and were delivered to Earth long ago by meteorite and comet impacts.”

Carl Pilcher, director of the Nasa Astrobiology Institute, said: “The discovery of glycine in a comet supports the idea that the fundamental building blocks of life are prevalent in space, and strengthens the argument that life in the Universe may be common rather than rare.”

The discovery is the latest to come from Nasa’s unmanned Stardust mission, which flew through the cloud of dust and debris trailing the Wild 2 comet on January 2, 2004.

Millions of tiny particles from the comet’s tail were captured by a grid filled with aerogel, a super-light, sponge-like material sometimes nicknamed “frozen smoke” because 99 per cent of its volume is empty space.

A capsule containing the collection grid detached from the spacecraft soon after its close encounter with Wild 2 and returned to Earth, where it parachuted to the surface on January 15, 2006. Scientists have since been examining the contents of the capsule for clues about the early solar system.

All forms of life on Earth rely on proteins, which drive chemical reactions in their cells and form many of the structural elements around which organisms are built. This huge variety of proteins are all made up of chains of 20 amino acids.

The origin of amino acids has long been debated among scientists, with some favouring the view that they emerged in the primordial soup of the planet’s youth, and others proposing that they formed in space and came here on comets and meteorites.

The discovery of glycine in the Stardust samples points towards an extraterrestrial origin for at least one of the 20 amino acids.

Dr Elsila’s team first identified traces of glycine last year, in particles removed both from the aerogel and aluminium foil around it. As glycine is also present on Earth, however, the scientists had to confirm that it originated from space. The team used isotopic analysis to examine the chemical composition of the glycine. Many elements occur in different isotopes, or versions, which have different masses.

“We discovered that the Stardust-returned glycine has an extraterrestrial carbon isotope signature, indicating that it originated on the comet,” Dr Elsisa said.

The Stardust probe will fly past the comet Tempel 1 in 2011.

There's no place like home

túrána hott kurdís by hasta la otra méxico! from Till Credner on Vimeo.

Large Impact Simulation

I watched last night one of the best clips I have ever seen on Youtube. I don't know if it was because I was a wee bit tipsy lol, or because the clip uses the music of the brillaint Great Gig In The Sky, written by Richard Wright of Pink Floyd who sadly died yesterday, but I was left stunned by watching it.

Either way this clip, created by the Discovery Channel, is a stunning piece of animation, set to incredibly evokative music, and is both beautiful and terrifying at the same time.

I hope you enjoy this half as much as I did.

Earth from 31 Million miles

This cracking photo is of our Home.

Taken from the Deep Impact probe, whose cameras were trained back on Earth at a distance of 31,000,000 Miles.

Cool as!

Perseids

We are currently passing through the Perseid meteor shower. Something the Earth does every year. Here are a couple of cool shots from the year and previous years shows. Niiiice!

Astronomy Picture of the Day

You might occasionally wonder where I get all the cool photos from space and beyond. NASA have a daily website called (funnily enough) Astronomy Picture of the Day. http://apod.nasa.gov/apod/astropix.html. They have been busy in the last few days. Enjoy! :)



1. The Echus chasm on Mars
2. Jupiter over Hadrians temple in Ephesus
3. Rhea and Saturn
4. The moon over the temple of Posiedon in Greece
5. Soyuz docking with the International Space Station

Southern skies

I've just been chatting with my mate Nick in Australia by the wondrous invention known as Skype. Free voice and video calls with anyone in the world as long as they have a Skype account and a broadband connection. Barely a seconds lag on the line and I'm chatting in real time with Harrogate boy, nee Downunder Insurance demi-god, Nick. Them's some cool beans!

So to honour our boy in the Antipodes, a beautiful picture of the Southern Cross and the sky over the Southern Hemisphere - widely agreed by astronomers to be the more beautiful and interesting of our planets two hemispheres. Boo!

Plus a rather snazzy false-colour image from the surface of Mercury.

"The sprawling Caloris basin on Mercury is one of the solar system's largest impact basins. Created during the early history of the solar system by the impact of a large asteroid-sized body, the basin spans about 1,500 kilometers and is seen in yellowish hues in this enhanced color mosaic. The image data is from the January 14th flyby of the MESSENGER spacecraft, captured with the MDIS instrument. Orange splotches around the basin's perimeter are now thought to be volcanic vents, new evidence that Mercury's smooth plains are indeed lava flows. Other discoveries at Mercury by NASA's MESSENGER mission include evidence that Mercury, like planet Earth, has a global magnetic field generated by a dynamo process in its large core, and that Mercury's surface has contracted significantly as its core cooled."

Sundogs and Pyramid Ice Halos

Eh?

What if the atmosphere above you became one gigantic lens? This actually happens when a nearly transparent sheet of pyramid shaped ice crystals falls from the sky in a common orientation. These ice-crystals act together like millions of miniature ice mirrors, with external and internal reflections from different faces creating arcs and halos of different radii. An amazing display of pyramid ice crystal halos was captured on June 5 above Tampere, Finland. Visible above are very unusual sun halos of 9, 18, 20, 23, and 24 degrees. In contrast, thin and flat falling ice crystals will produce a halo of 22 degrees only. The high clouds containing the ice crystals are faintly visible, as are some sundogs. The usual Sun image was covered behind a light post, and the above image was significantly digitally sharpened. It is not currently known how large areas of nearly uniform pyramidal ice crystals form.

What if you woke up one morning and saw more than one Sun in the sky? Most probably, you would be seeing sundogs, extra-images of the Sun created by falling ice-crystals in the Earth's atmosphere. As water freezes in the atmosphere, small, flat, six-sided, ice crystals might be formed. As these crystals flutter to the ground, much time is spent with their faces flat, parallel to the ground. An observer may pass through the same plane as many of the falling ice crystals near sunrise or sunset. During this alignment, each crystal can act like a miniature lens, refracting sunlight into our view and creating parhelia, the technical term for sundogs. Sundogs were photographed here in a cloudy sky above the Very Large Array of radio telescopes. The real Sun is near the center above the train tracks. A bright sundog is visible on the far right, and a dim one on the far left. Ice-crystals can create other strange illusions of the Sun and Moon including halos and pillars

Nighttime

How to destroy the Earth, parts 10 & 11

10. Hurled into the Sun

You will need: Earthmoving equipment.

Method: Hurl the Earth into the Sun, where it will be rapidly melted and then vaporized by the Sun's heat.

Sending Earth on a collision course with the Sun is not as easy as one might think. Contrary to popular opinion, Earth's orbit is not "unstable" and Earth will not begin to spiral into the Sun if we give it the slightest of nudges (otherwise, you can bet it would have happened already). It's surprisingly easy to end up with Earth in a loopy elliptical orbit which merely roasts it for four months in every eight. Careful planning will be needed to avoid this.

Earth's final resting place: a small globule of vaporized iron sinking slowly into the heart of the Sun.

Comments: As far as energy changes are concerned, this method is inferior to the next one.

This method is essentially a variation on the Solar Oven method listed above, wherein you bring the Sun to the Earth (in a manner of speaking).

Feasibility rating: 9/10. Impossible at our current technological level, but will be possible one day, I'm certain. In the meantime, may happen by freak accident if something comes out of nowhere and randomly knocks Earth in precisely the right direction.

Source: Infinity Welcomes Careful Drivers, by Grant Naylor

11. Ripped apart by tidal forces

You will need: Earthmoving equipment.

Method: When something (like a planet) orbits something else (like the Sun), the closer in it is, the faster it orbits. Mercury, the closest planet to the Sun, moves faster along its path than Earth, which in turn moves faster than Neptune, the furthest planet.

Now, if you move Earth close enough to the Sun, you'll find that it's close enough that the side of the Earth facing the Sun wants to orbit the Sun faster than the side pointing away from it. That causes a strain. Move Earth close enough, within an imaginary boundary called the Roche Limit, and the strain will be great enough to literally tear the planet Earth apart. It'll form one or more rings, much like the rings around Saturn (in fact this may be exactly where Saturn's rings came from). So our method? Move the Earth to within the Sun's Roche limit. Or, better, move it out, to Jupiter.

Moving the Earth out to Jupiter is much the same as moving the Earth in towards the Sun, the most obvious difference being your choice of vectors. However, there is another important consideration, and that is energy. It takes energy to raise or lower an object through a gravity field; it would take energy to propel the Earth into the Sun and it would take energy to propel it into Jupiter. When you do the calculations, Jupiter is actually rather preferable; it takes about 38% less energy.

Alternatively, it may be simpler to move Jupiter to Earth. The theory works like this: build a massive free-standing tower or "candle", with its lower end deep inside Jupiter's depths and its upper end pointing into space. Put machinery inside the tower to pull hydrogen and helium gases in as fuel, through ports in the middle section, and vent these elements out through fusion thrusters at the top and bottom. The tower is called a "candle" because it burns at both ends, see? Now: the flame directed downwards into Jupiter serves to keep the tower afloat (although some secondary thrusters would be needed to also keep it stable and upright). But this lower flame has no direct effect on the Jupiter/candle system as a whole, because all the thrust from the flame is absorbed by Jupiter itself. The two objects are locked together, as if the candle is balanced on a spring or something. The top flame, therefore, can be used to push both the candle and Jupiter along. The top flame pushes the candle which pushes the planet. This is a little unorthodox, and it only works on gas giants, but as means for moving planets it's at least as plausible as the mass-driver and gravity-assist methods described on the earthmoving page.

Earth's final resting place: lumps of heavy elements, torn apart, sinking into the massive cloud layers of Jupiter, never to be seen again.

Feasibility rating: 9/10. As before, impossible at our current technological level, but will be possible one day, and in the meantime, may happen by freak accident if something comes out of nowhere and randomly knocks Earth in precisely the right direction.

Source: Mitchell Porter suggested this method. Daniel T. Staal clued me in on the fusion candle technique, which he got from this Shlock Mercenary comic, which in turn was inspired by the novel "A World Out Of Time" by Larry Niven.

How to destroy the Earth, parts 8 & 9

8. Meticulously and systematically deconstructed

You will need: a mass driver. A mass driver is a sort of oversized electromagnetic railgun, which was once proposed as a way of getting mined materials back from the Moon to Earth - basically, you just load it into the driver and fire it upwards in roughly the right direction. Your design should be powerful enough to hit escape velocity of 11 kilometres per second.

At a million tonnes of mass driven out of the Earth's gravity well per second, this would take 189,000,000 years. One mass driver would suffice, but ideally, lots (i.e. trillions) would be employed simultaneously. Alternatively you could use space elevators or conventional rockets.

Method: Basically, what we're going to do here is dig up the Earth, a big chunk at a time, and boost the whole lot of it into orbit. Yes. All six sextillion tonnes of it.

We will ignore atmospheric considerations. Compared with the extra energy needed to overcome air friction, it would be a relatively trivial step to completely burn away the Earth's atmosphere before beginning the process. Even with this done, however, this method would require a - let me emphasize this - titanic quantity of energy to carry out. Building a Dyson sphere ain't gonna cut it here. (Note: Actually, it would. But if you have the technology to build a Dyson sphere, why are you reading this?)

Earth's final resting place: Many tiny pieces, some dropped into the Sun, the remainder scattered across the rest of the Solar System.

Feasibility rating: 6/10. If we wanted to and were willing to devote resources to it, we could start this process RIGHT NOW. Indeed, what with all the gunk left in orbit, on the Moon and heading out into space, we already have done.

Source: this method arose when Joe Baldwin and I knocked our heads together by accident.


9. Pulverized by impact with blunt instrument

You will need: a big heavy rock, something with a bit of a swing to it... perhaps Mars.

Method: Essentially, anything can be destroyed if you hit it hard enough. ANYTHING. The concept is simple: find a really, really big asteroid or planet, accelerate it up to some dazzling speed, and smash it into Earth, preferably head-on but whatever you can manage. The result: an absolutely spectacular collision, resulting hopefully in Earth (and, most likely, our "cue ball" too) being pulverized out of existence - smashed into any number of large pieces which if the collision is hard enough should have enough energy to overcome their mutual gravity and drift away forever, never to coagulate back into a planet again.

A brief analysis of the size of the object required can be found here. Falling at the minimal impact velocity of 11 kilometres per second and assuming zero energy loss to heat and other energy forms, the cue ball would have to have roughly 60% of the mass of the Earth. Mars, the next planet out, "weighs" in at about 11% of Earth's mass, while Venus, the next planet in and also the nearest to Earth, has about 81%. Assuming that we would fire our cue ball into Earth at much greater than 11km/s (I'm thinking more like 50km/s), either of these would make great possibilities.

Obviously a smaller rock would do the job, you just need to fire it faster. Taking mass dilation into account, a 5,000,000,000,000-tonne asteroid at 90% of light speed would do just as well. See the Guide to moving Earth for useful information on manoeuvring big hunks of rock across interplanetary distances. For smaller chunks, there are more options - a Bussard Ramjet (scoop up interstellar hydrogen at the front and fire it out the back as propellant) is one of the most technically feasible as of right now. Of course, a run-up would be needed...

Earth's final resting place: a variety of roughly Moon-sized chunks of rock, scattered haphazardly across the greater Solar System.

Feasibility rating: 7/10. Pretty plausible.

Source: This method suggested by Andy Kirkpatrick

Comments: Earth is believed to have been hit by an object the size of Mars at some point in the distant past before its surface cooled. This titanic collision resulted in... the Moon.

How to destroy the Earth, part 7

7. Sucked into a giant black hole

You will need: a black hole, extremely powerful rocket engines, and, optionally, a large rocky planetary body. The nearest black hole to our planet is 1600 light years from Earth in the direction of Sagittarius, orbiting V4641.

Method: after locating your black hole, you need get it and the Earth together. This is likely to be the most time-consuming part of this plan. There are two methods, moving Earth or moving the black hole, though for best results you'd most likely move both at once. See the Guide to moving Earth for details on how to move the Earth. Several of the methods listed can be applied to the black hole too, though obviously not all of them, since it is impossible to physically touch the black hole, let along build rockets on it.

Earth's final resting place: part of the mass of the black hole.

Feasibility rating: 6/10. Very difficult, but definitely possible.

Sources: The Hitch Hiker's Guide To The Galaxy, by Douglas Adams; space.com.


Comments: It's clear that dropping the Earth into a singularity is massive overkill. A reasonably strong gravitational field, such as might be associated with any body between Jupiter and a neutron star, would be sufficient to rip the Earth apart via tidal forces. These possibilities are dealt with further down.

How to destroy the Earth, part 6

6.
Blown up

You will need: 25,000,000,000,000 tonnes of antimatter.

Method: This method involves detonating a bomb so big that it blasts the Earth to pieces.

This, to say the least, requires a big bomb. All the explosives mankind has ever created, nuclear or non-, gathered together and detonated simultaneously, would make a significant crater and wreck the planet's ecosystem, but barely scratch the surface of the planet. There is evidence that in the past, asteroids have hit the Earth with the explosive yield of five billion Hiroshima bombs - and such evidence is difficult to find. It is, in short, insanely difficult to significantly alter the Earth's structure with explosives. This is not to mention the gravity problem. Just because you blasted the Earth apart doesn't mean you blasted it apart for good. If you don't blast it hard enough, the pieces will fall back together again under mutual gravitational attraction, and Earth, like the liquid metal Terminator, will reform from its shattered shards. You have to blow the Earth up hard enough to overcome that attraction.

How hard is that?

If you do the lengthy calculations you find that to liberate that much energy is equivalent to the complete annihilation of around 1,246,400,000,000 tonnes of antimatter. That's assuming zero energy loss to heat, neutrinos and radiation, which is unlikely to be the case in reality: You'll probably need to up the dose by at least a factor of twenty. Once you've generated your antimatter, probably in space, just launch it en masse towards Earth. The resulting release of energy (obeying Einstein's famous mass-energy equation, E=mc2) should be sufficient to split the Earth into a thousand pieces.

Greg Bear's novel, "The Forge Of God", contains an interesting refinement of this technique. Here, the antagonist instead generates antimatter in the form of a "slug" of anti-neutronium - superdense material massing a billion kilograms per cubic centimetre. This is fired into the Earth's core. Neutronium passes through ordinary matter as easily as a ball flies through the air, so the anti-neutronium slug doesn't annihilate immediately; rather, it builds up a protective sheath of plasma around it as it plunges downwards towards the Earth's core. It's then followed up by a slug of regular neutronium, which also falls into the core, at a time calculated to meet the first slug head-on at the exact centre of the Earth, where they annihilate themselves, and soon afterwards, the Earth itself. Highly space-efficient, and with the added bonus of all the energy being released at the Earth's core, where it can do the most damage. In the book, the antagonists simultaneously detonate nuclear warheads in certain oceanic trenches, to weaken the crust and allow the planet to be blown apart more easily.


Rearranging Earth into two planets - which, provisionally, is sufficient according to my current criteria - would take slightly less energy, but considerably more finesse.

Earth's final resting place: A second asteroid belt around the Sun.


Comments: trembling writes, "I still think that antimatter is crazy s**t, i.e. wouldn't want it on my flapjacks"

Feasibility rating: 4/10. Just about slightly possible.

How to destroy the Earth, part 4

4.
Cooked in a solar oven

You will need: Means for focusing a good few percent of the Sun's energy output directly on the Earth.

What I'm talking about here is: mirrors, and lots of them. Intercept several decent sized asteroids for raw materials and start cranking out kilometre-square sheets of lightweight reflective material (aluminised mylar, aluminium foil, nickel foil, iron foil or whatever you can scrape together). They need to be capable of changing focus direction at will because it is generally impossible to place things stationary in space and the relative positions of the Earth and Sun will be shifting as time passes, so attach a few manoeuvering thrusters and a communications and navigation system to each sheet.

Preliminary calculations suggest you would need roughly two trillion square kilometres of mirror.

Method: Command your focusing array to concentrate as much solar energy as you can directly on the Earth - perhaps on its core, perhaps at a point on its surface. So the theory goes, this will cause the Earth to generally increase in temperature until it completely boils away, becoming a gas cloud.

A variation on this method involves turning the Sun into a gigantic hydrogen gas laser.

Earth's final resting place: A gas cloud.

Feasibility rating: 3/10. The major problem here is: What's to stop the matter cooling and becoming a planet again? In fact, once the top layer of planet becomes gaseous, what would compel it to vent into space rather than remaining on the surface, absorbing more heat and preventing the lower layers from even being heated? Unless the amount of heat put in was really immense, all you'd get is a gas planet at best, and a temporary one at that. Moving the Earth towards the Sun (see later) is likely to be a far more viable method.

Source: This method suggested by Sean Timpa.

Twilight

"No sudden, sharp boundary marks the passage of day into night in this gorgeous view of ocean and clouds over our fair planet Earth. Instead, the shadow line or terminator is diffuse and shows the gradual transition to darkness we experience as twilight. With the Sun illuminating the scene from the right, the cloud tops reflect gently reddened sunlight filtered through the dusty troposphere, the lowest layer of the planet's nurturing atmosphere. A clear high altitude layer, visible along the dayside's upper edge, scatters blue sunlight and fades into the blackness of space. This picture actually is a single digital photograph taken in June of 2001 from the International Space Station orbiting at an altitude of 211 nautical miles."

Space, above and beyond

There's been some fantastic astronomy pictures published in my absence. Here's just a few of them. (Please) click to enlarge.

1. My favourite moon Europa

2. The International Space Station

3. Alborz Mountains in Moonlight

4. Comet McNaught at dawn

5. Saturns rings and its moon Tethys.

Lighthouse in fog

This fantastic picture is of an lighthouse on a foggy night

"This spectacular sky is mostly human-made. Once a year, the Light Station at Pigeon Point near San Francisco, California, USA is lit as it was over 100 years ago. During this time, light generated by five kerosene lamps pours through 24 rotating Fresnel lenses, warning approaching ships to stay away. Early last week, light emanating from the Pigeon Point Lighthouse was particularly picturesque because of a thin fog, also blurring the distant Moon"