Earth has been menaced by a couple of asteroids and meteorites of late. Hopefully we’ve seen the last of these threats for a while, but it raises the question of how to deal with such objects, especially if there is some sort of advance warning that they are on the way.
Thankfully there are a couple of options on the table. Scientists in California for instance say it is possible to use laser beams to evaporate asteroids, or failing that, move them into less threatening orbits:
Described as a “directed energy orbital defense system,” DE-STAR is designed to harness some of the power of the sun and convert it into a massive phased array of laser beams that can destroy, or evaporate, asteroids posing a potential threat to Earth. It is equally capable of changing an asteroid’s orbit – deflecting it away from Earth, or into the Sun – and may also prove to be a valuable tool for assessing an asteroid’s composition, enabling lucrative, rare-element mining. And it’s entirely based on current essential technology.
Meanwhile, Sung Wook Paek, a MIT graduate, says splattering white paint on the surface of asteroids would also help alter their course:
Paintballs themselves could impart a slight momentum change to the asteroid, diverting it only slightly, but not enough to avoid Earth. The main effect would come from the paint’s increase in reflectivity on the asteroid. Thus, the pressure of photons coming from the sun, acting over enough time, could result in a large shift in course. Paek concluded that the course of asteroid Apophis, a 27-gigaton rock that is expected to pass close to Earth in 2029 and in 2036, could be changed enough to miss Earth. He estimated that 5 tons of paint would be sufficient to cover the 1,480-foot-diameter asteroid.
Climate change, peak oil, rising sea levels, we have more than a few challenges ahead of us if the world our grand children will be living in is to be anywhere near habitable. Now I read topsoil, where crops and the like, or the sources of much of the food we eat, looks to be running out:
A rough calculation of current rates of soil degradation suggests we have about 60 years of topsoil left. Some 40% of soil used for agriculture around the world is classed as either degraded or seriously degraded – the latter means that 70% of the topsoil, the layer allowing plants to grow, is gone. Because of various farming methods that strip the soil of carbon and make it less robust as well as weaker in nutrients, soil is being lost at between 10 and 40 times the rate at which it can be naturally replenished. Even the well-maintained farming land in Europe, which may look idyllic, is being lost at unsustainable rates.
The world isn’t going to end on 21 December as per misguided understandings, or otherwise, of the Maya Calendar, but I can tell you that I will be suspending posting here at disassociated.com while I take a two-week break from writing over the year-end holiday.
And even though – barring some unknown, totally left-of-field happening beforehand – we’ll still be here on 22 December, it has to be said the ways some people saw the world ending were colourful to say the least… if nothing else there’s likely some sound inspiration for sci-fi writers amongst it all:
However, if we (wrongly) assume that 12/12/2012 is the end of the world, then how will it supposedly happen? Most of the “theories” I’ve seen involve a lot of nonsense about (1) alignment of planets and the galactic center; (2) the close pass of some dark star or large planet to Earth (e.g., Nibiru); (3) complete random rubbish. So, as to try to quell some of the rumors out there, I thought I’d do a brief Q & A about the Maya Apocalypse because a lot of the ways the world ends involves earthquakes and volcanoes.
The broad spectrum sounds recorded in the summer of 1997 are consistent with icequakes generated by large icebergs as they crack and fracture. NOAA hydrophones deployed in the Scotia Sea detected numerous icequakes with spectrograms very similar to “Bloop”. The icequakes were used to acoustically track iceberg A53a as it disintegrated near South Georgia Island in early 2008. Icequakes are of sufficient amplitude to be detected on multiple sensors at a range of over 5000 km. Based on the arrival azimuth, the iceberg(s) generating “Bloop” most likely were between Bransfield Straits and the Ross Sea, or possibly at Cape Adare, a well know source of cryogenic signals.
What if the Earth had two, or more, moons? While the prospect may appeal to science fiction writers and romantics, life on the surface, to put it mildly, would be far less stable than it is now. If there were life on the surface in the first place, that is.
If we had a second moon show up, things would change in a hurry. Our tides would go haywire and cause massive storms, volcanoes and earthquakes to pop up from the added forces put on the Earth’s crust. Unfortunately for most things alive on Earth at the time, this would mean chaos, death and possible extinction. That includes us, but maybe not the bacteria or cockroaches. The second moon would also cause chaos on our first moon, causing similar geologic changes, although not as severe since Moon #1 is a lot more dormant on the inside.
And here’s another reason to be thankful Earth has only the one natural satellite. Like many of the other planets in the solar system, Uranus has several (27 actually) moons, or at least it does for now. At some point the future though a number of them are slated to collide with each other, events that will cause all sorts of chaos:
In the first act, Cupid smacks into the larger moon Belinda sometime between 1000 and 10 million years from now, depending on initial conditions. What happens next depends a lot on the moons’ as-yet-unknown compositions. They could bounce off each other, stick together or break apart into tiny pieces. In some settings, French and Showalter assume Cupid and Belinda will merge to form a single moon called CupBel. From there, the next pair of doomed moons is Cressida and Desdemona, fated to crash in 100,000 to 10 million years. If those moons merge, the resulting body, Cresdemona, takes out the moon Juliet, and CupBel collides with Perdita.
Since 1972 seven orbiting Landsat satellites have taken turns to photograph the Earth’s surface. Needless to say if they could talk they’d be able to tell a few stories, as seen by this series of then and now photos, showing how cities such as Tokyo, Chicago, Istanbul, and Santiago have changed over the last forty years.
The image of Santiago (move the centre dividing slider back and forth to see the contrasts) is especially interesting. Note the presence of what looks to be snow/ice in the bottom right-hand corner of the 1985 image and then compare the same region with the 2010 photo.
Place a satellite into a geosynchronous orbit above the Earth, being 36,000 kilometres or so up, and it will, all things remaining equal (a big ask at the best of times, but that’s another story), remain there perpetually. As it is there are hundreds of such probes, many no longer functioning, floating in this zone, giving rise to the term “graveyard orbit”.
What better place then to store a record of artworks created on Earth that will still be about long, long, after life on the surface has disappeared?
That’s the thinking of behind US artist Trevor Paglen’s “The Last Pictures” project, that will see trillions of images depicting artworks from across the globe, stored on very long life discs, aboard a satellite that will be launched into a permanent graveyard orbit this September.