The Causes of Earth’s Spin Axis Drift

Did you feel that? Well probably not, but believe it or not, the Earth wobbles all the time as it spins on its axis — that imaginary line that passes through the North and South Poles. That wobble causes that “spin axis” to shift. Over a century it’s moved about 10 cm per year. Scientists now have a new handle on the causes of Earth’s Spin Axis Drift.

The boffins at NASA have been crunching away on data accumulated across the entire 20th century to identify three separate mechanisms that combine to cause the observed drift — 1) loss of mass in the global cryosphere (frozen regions), primarily in Greenland;, 2) glacial rebound, and 3) mantle convection.

Glacial rebound is the shifting of large land masses on the Earth’s surface in response to the loss of ice sheets. Not too long ago, in the last Ice Age, heavy glaciers covered a lot of the Earth’s surface. The whole of England is slowly rising in the west and sinking in the east. This can be observed by looking at castles like Harlech in Wales which were built on the coast, but are now miles inland. The fairy tale Avalon of King Arthur’s tales is speculated to actually have been Glastonbury Tor, which during that Dark Age period was actually an island, yet is now high and dry. This phenomenon can be observed in many places across Europe.

Mantle convection — another mouthful — is the action of the hot magma beneath the Earth’s tectonic plates, causing them to move. This magma heats and circulates like any heated fluid, behaving much like water boiling in a pot. This effect represents another large-scale shift in surface mass that contributes to the overall “wobble”.

If you want to check out an interactive simulation, check on this link.

 

 

Studies like this are invaluable in understanding our own planet. As a SF writer, they provide invaluable insights when it comes to build your own planets! Check out my own world-building in The Tau Ceti Diversion.

With the crew dead, and the starship’s fusion drive held back from a lethal explosion, Karic and the surviving officers reach a habitable planet – the last thing they expected was to find it already occupied . . .

Get it here!

 

 

Evolution, Insects & Oxygen

One of the key elements of my novel the Tau Ceti Diversion was the unique setting I imagined for the story. Specifically, an alien planet where the top evolutionary niche was filled by an intelligent insect race.  So I needed to think about insect evolution, and how that evolution was affected by the amount of oxygen those insects could take in from the planet’s atmosphere to fuel their metabolism.

Now, it wasn’t going to be too much fun to have my human crew menaced by determined ladybugs or extremely intelligent grasshoppers two inches long, so I needed big insects! I needed a world where the entire biosphere – every single evolutionary niche, both large and small – was filled with insectoid life.

You think people shudder when they have to shoo an insect out of the living room window with a rolled up newspaper, how about having to face a three metre tall intelligent being, staring back at you with multi-faceted insect eyes? Creepy? Stay calm space-explorers!

dragonflycaterpllar lifecycle_thumb

On Earth, insects are small, and a variety of other life has evolved to claim the top evolutionary spots in the food chain.

The size of insects on Earth has been constrained by two main factors, the way they take oxygen into their bodies, and the amount of oxygen in the atmosphere. Change those two things, and everything changes. Insects were here first. If not for those two constraints, our little furry ancestors would probably never have made it out of their burrows, let alone up the primate tree.

Earth’s insects don’t actually breathe in the way that mammals do. Our insects take oxygen into their bodies through the process of diffusion, the precious oxygen passing across membranes directly into their cells, with waste gases passing out of the cell walls in the other direction. Our insects have a series of holes in their abdomen, called spiracles, that allow air to enter their bodies. From there, incoming air moves into a network of tiny tubes called tracheae. The biggest bugs have the longest tracheae, to allow them to get the most oxygen into their bodies.

Insects have a very limited ability to use their oxygen absorption equipment. They can open or close the spiracles by muscle contraction, and they can also pump muscles inside their body to try and increase the amount of air passing through the tracheal system, but to limited effect. The amount of oxygen they can extract from the air is always going to be limited by the tracheae shape and the rate of  oxygen diffusion through the cell walls.

In the Tau Ceti Diversion, human explorers come face-to-face with evolved life dominated by insects, thanks in part to the planet’s high oxygen atmosphere, and an evolutionary adaption of the alien insects that has given them true lungs.

That’s not to say Earth didn’t have some big insects. At the moment our atmosphere has around 21% oxygen (by volume). The concentration of oxygen in the air has gone up and down throughout Earth’s history, mostly in response to what was happening in the biosphere. Toward the end of the Carboniferous periods (300 million years ago), oxygen peaked at a maximum of 35%. At this time there were some pretty impressive insects – like dragonflies with wingspans of over a metre in length. That’ s one hell of an insect, and all with basic air diffusion to get the oxygen into its body.

On my fictional planet of Cru, orbiting Tau Ceti, the oxygen concentration in the atmosphere is more than 30 percent, which certainly makes things fun for the explorers. They not only have to deal with huge insect life, but also have to deliberately moderate their breathing to prevent hyperventilation, and they have to be careful how all that extra oxygen makes any sort of combustion in the atmosphere more aggressive.

My novel, The Tau Ceti Diversion, is a story about our search for new planets to colonise outside our solar system. Much of the action takes place on planet tidally locked to Tau Ceti that has some rather unique life forms. The novel is due to be launched on September 1st 2016 – not long now! – and pre-order is available on Amazon! Read more about what happens in the story here!

Stay tuned for a free chapter download, coming soon!

Tau-Ceti-Diversion-severed-ebook-cover (Medium)

 

Capturing our First Planetary Snapshots

 

Kepler has confirmed more than 1000 planets outside our solar system, but so far only a few of Earth-like size and in the habitable zone — rocky planets with just the right temperature for liquid water. And none of those potential Earth-analogues have been observed directly, but through the interpretation of astronomical data, such as the wobble of the star, or the dimming on the star’s light due to planetary transit.

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So far, some pictures of other planets have been taken from ground-based telescopes, but those planets are large, bright and orbit far from their suns — not like potential Earth-twins which will be far smaller and orbit closer to their suns.

NASA scientists and engineers are working on two new technologies to help look for new planets, a starshade and a coronagraph, which will both work to block the light of the star, allowing the telescope to examine the reflected light of the planet itself.

This means we can not only take pictures of prospective Earth-like planets, but also use spectrographic analysis to analyse what in their atmospheres as well. This will give us clues to what might exist there. For example, evidence of plant life and animals similar to those on our Earth would show up as a series of simple signature compounds in the planet’s atmosphere: such as oxygen, ozone, water and methane.

A starshade is a type of spacecraft that actually flies in front of the telescope to block the light of the sun under observation. Despite the fact it will be only tens of metres wide, it will fly quite a bit in front of the telescope — in fact around 50,000 km away — more than four Earth diameters. Getting it into space is a challenge. It will be folded up like a super-origami prior to launch to unfurl in space,  somewhat like an unwinding spring, into to a crazy-sized sunflower. The pointed petals are crucial to its design: they control the light the right way to reduce the glare to levels where planets can be seen. The petal-fringed shape creates a softer edge that causes less bending of the light waves.

Both the starshade and the telescope will be independent spaceships, allowing them to move into just the right position for observations. The petals of the starshade need to be positioned with millimetre accuracy.

Blocking out the starlight while preserving the light emitted from the planet is called starlight suppression.

The light of a sun can be billions of times brighter than the reflected light from the planet. Our own sun is 10 billion times bright than Earth.

Coronagraphs were originally introduced in the early 20th century to study our own sun, blocking out the light from the sun’s disk to allow scientists to study its outer atmosphere, or corona; hence coronagraph. They are much smaller than the starshade, located within the telescope itself.

These starlight-blocking coronagraphs will be more sophisticated.

These new generation coronagraphs uses multiple masks as well as smart mirrors that can deform, to suppress starlight in sequential stages. There are many other challenges in delivering the coronagraph technology, including being able to suppress or compensate for the warping and vibrations that all space telescopes experience.

Back with a Vengeance

Cropped A3 Poster with Red Button

Hey, everyone. After a bit of a hiatus, I’m going to be back with a vengeance:)

Starting from next week I’ll be blogging three times a week – Cosmic Monday with Space, Science and Astronomy news, Writing Thursday with tips and discussions on the Writing Craft, then Giveaway Saturday with special offers and freebies on the Jakiran series and more.

Stay tuned!

 

Geek Jokes

Hi, everyone. Continuing on in the festive spirit. Here are a few clever Geek Jokes. . .

 

Some things Man was never meant to know. For everything else, there’s Google.

 

Black holes are where God divided by zero

 

An infinite crowd of mathematicians enters a bar. The first one orders a pint, the second one a half pint, the third one a quarter pint… “I understand”, says the bartender – and pours two pints

 

The truth is out there. Anybody got the URL?

 

There are three kinds of people: those who can count and those who can’t

 

Two scientists walk into a bar. The first says, “I’ll have some H2O.”

The second says, “I’ll have some H2O too.”

The second scientist dies.

 

Entropy isn’t what it used to be.

 

Have you heard the one about the sick chemist? If you can’t helium, and you can’t curium, you’ll probably have to barium.

 

A Buddhist monk approaches a hotdog stand and says, “Make me one with everything.”

 

Heisenberg was speeding down the highway. Cop pulled him over and says, “Son, do you have any idea how fast your were going back there?”

Heisenberg said, “No, but I knew where I was.”

 

Helium walks into a bar and orders a beer, the bartender says, “Sorry, we can’t serve noble gases here.” He doesn’t react.

 

Did you hear about the man who got cooled to absolute zero?

He’s 0K now.

 

What do you get when you cross a joke with a rhetorical question?

 

Hope you enjoyed these as much as I did. The Heisenberg one cracked me up.

BTW – this is the last day for the Calvanni Book Giveaway. Have to be in it to win it!

Moon Rabbit Breaks Dry Spell

When I read the article today, I could not believe I missed this. I could also not believe the lack of media coverage in general. We’re back on the Moon!

On the 14th December China’s Chang’e 3 lander touched down on the surface of the Moon. This is the first soft landing there since the former Soviet Union’s Luna 24 in 1976 – a 37 year dry spell that followed a previously intense period of space exploration. The recent touchdown follows the Chang’e 1 and Chang’e 2 orbiter missions in 2007 and 2010.

The unmanned Chang’s 3  lander hovered 100m above the surface as it analysed the local features searching for a safe landing spot. Once it was satisfied in its choice of landing pad it throttled down its engine and free-fell to land on its springy legs.

The robotic lander was controlled from the Beijing Aerospace Control Center.

Of course, these days no visit to a celestial neighbour is complete without a robotic rover. A few hours after landing, the Chang’e – named after the Chinese goddess – released its Yutu moon rover. Yutu is named after the pet rabbit the goddess carries with her on her travels. The rover’s wheels were unlocked by the firing of explosive devices, after which the rover unfurled its solar wings and deployed its instrument mast. Twin ramps then inched down to the lunar surface, allowing the rover to roll down them onto the dust.

Yutu is a six-wheeled robot that weighs around 140 kg and has a 10km range. It’s outfitted with navigation and both panoramic cameras and hazard-avoidance cameras fitted to its lower front portion. No reversing cameras though – parking is generally no problem on the Moon.

The solar-powered rover will hibernate through the bitter chill of the Moon’s 14 day night. Once it wakes up it will deploy its nifty Proton X-ray spectrometer, which will be used to examine lunar material, particularly ejecta that will give clues about what lies beneath the lunar surface. The data will also help researchers develop better impact-cratering models.

Yutu is also equipped with ground penetrating radar, which is useful to carrying surveys of the sub-surface up to 100m depth. Variation in the radar wavelength can allow more detailed mapping of the shallower surface areas. Exploration of the deeper areas will be at the trade-off of lower resolution.

I for one am glad the dry spell is over. This is really exciting news.

Was anyone out there following the Chang’e 3 landing?

PS: Don’t forget to enter The Calvanni Book Giveaway.

Need a Laugh? Governmentium has been Discovered!

Here is something I came across a little while ago sure to be enjoyed by all you geeks out there!

The heaviest element yet known to science has been discovered.

The new element is Governmentium (Gv). It has one neutron, 25 assistant neutrons, 88 deputy neutrons and 198 assistant deputy neutrons, giving it an atomic mass of 312.

These 312 particles are held together by forces called morons, which are surrounded by vast quantities of lefton-like particles called peons.
Since Governmentium has no electrons or protons, it is inert. However, it can be detected, because it impedes every reaction with which it comes into contact. A tiny amount of Governmentium can cause a reaction normally taking less than a second to take from four days to four years to complete.

Governmentium has a normal half-life of 2- 6 years. It does not decay but instead undergoes a reorganisation in which a portion of the assistant neutrons and deputy neutrons exchange places.

In fact, Governmentium’s mass will actually increase over time, since each reorganisation will cause more morons to become neutrons, forming isodopes.

This characteristic of moron promotion leads some scientists to believe that Governmentium is formed whenever morons reach a critical concentration. This hypothetical quantity is referred to as critical morass.

When catalysed with money, Governmentium becomes Administratium, an element that radiates just as much energy as Governmentium since it has half as many peons but twice as many morons. All of the money is consumed in the exchange, and no other byproducts are produced.

A classic isn’t it?:)

PS: Don’t forget to enter The Calvanni book giveaway!