Ian O'Neill, Author at Universe Today

February 28, 2008December 26, 2015 by Ian O'Neill

Development Problems May Delay Mars Science Laboratory Mission Until 2011

NASA’s over budget Mars Science Laboratory mission, scheduled for a 2009 launch, may be delayed due to problems with the atmospheric re-entry shield design. A new shield will cost up to $30 million, adding to the $1.8 billion price tag, $165 million more than planned. The mission uses innovative landing technologies and is powered by a mini-nuclear reactor, giving it the ability to travel faster and carry a bigger payload over the Martian terrain. This new setback may postpone the launch until 2011.

As the most advanced part of NASA’s Mars Exploration Program, the Mars Science Laboratory will be the most ambitious mission yet. Powered by a nuclear reactor, the large rover (measuring 9-foot long) will have a greater range and will be able to carry out a massive range of experiments on the planets surface. Complementing missions such as the Mars Exploration Rovers (Spirit and Opportunity, still making history as the longest ever Mars rover mission) and Phoenix (scheduled to arrive on May 25th this year), The Mars Science Laboratory will continue to see whether Mars might be able to sustain microbial life, take samples and analyse rocks plus provide us with detailed information about the landscape, atmosphere and whether water exists in large quantities. This is all in preparation of future manned exploration of the Red Planet.

Due to the adventurous nature of the project, there have been some setbacks and over-spending. The most recent problem focuses on the heat shield protecting the lander from extreme heat as it enters the atmosphere. The original design uses a similar shield to the one that protects the Shuttle’s external fuel tanks, but in tests engineers found that it could suffer catastrophic damage. Now, NASA has switched to a stronger cocoon-like shield similar to the one that protected the Stardust mission returning comet samples to Earth in 2006. But development and construction isn’t cheap, setting NASA back another $30 million.

“It kind of interrupts what has been an incredibly successful sequence of missions.” – John Mustard, Brown University Geologist and head of an advisory group giving scientific input on future Mars projects.

Many scientists believe that such ambitious projects will always stumble across unforeseen problems and expenses, after all, space agencies such as NASA are doing something extraordinary, spearheading mankind’s exploration of space. This is frustrating however, as the Mars Exploration Program has surpassed all expectations so far and it appears that the Mars Science Lab is slowing down progress, prompting worries that costs will soar should the launch date be postponed any longer.

Source: Physorg

February 28, 2008December 26, 2015 by Ian O'Neill

NASA and ESA Orbiters Join Forces to Prepare for Phoenix Arrival on May 25th, 2008

When the Phoenix lander hits the Martian atmosphere at over 20,000 km/h, at least it will feel safe in the knowledge that it has three buddiesÂ looking out for it. NASA’s Mars Reconnaissance Orbiter and Mars Odyssey are already preparing for Phoenixâ€™s arrival, and now ESA’s Mars Express has been asked to assist in watching the lander’s 13-minute descent.

The Phoenix Mars Mission will land on the Red Planet on May 25th of this year to search for evidence of life on Mars and seek out some good regions for future manned settlements. However, before it can begin its work, Phoenix must dive through the Martian atmosphere at high speed and complete a 13-minute entry, decent and landing (EDL phase). This is a critical part of any planetary lander mission. As highlighted by the British Beagle 2 lander when it separated from Mars Express in 2004, nobody should be complacent about atmospheric reentry.

Flight controllers had already begun adjusting Mars Express’ phase in November last year to optimize its orbit so it can get the best possible view of Phoenix’s entry. Orbital adjustments already had to be made, so NASA’s request did not cost too much in additional fuel.

Using instrumentation intended to track the descent of the ill-fated Beagle 2, Mars Express’ adopted lander will be tracked by the Mars Express Lander Communications system (MELACOM). Mars Express will perform a fast (three-times faster than normal operations) turn on one axis to follow Phoenix flying past and down to Mars. Mars Express will be an essential backup system to NASA’s orbiters, allowing NASA to confirm the correct measurements of speed and trajectory of Phoenix.

Having already been tested, ESA scientists are confident Mars Express will perform excellently:

“Last year, we practised relaying commands from NASA to Mars Express and then down to the surface, using NASA’s Mars Rovers as stand-in for Phoenix. It worked fine.” – Michel Denis, Mars Express Spacecraft Operations Manager.

Either way, the 13-minutes from entry to landing will be nerve-wracking for everyone involved, but it’s good to know the NASA and ESA missions already in orbit around Mars will be able to give a helping hand to the Mars rookie.

Source: ESA

February 27, 2008December 26, 2015 by Ian O'Neill

UK Reinstated as Full Member of Gemini Project

It is official: the UK is back as a full member of the Gemini Observatory international partnership. At the beginning of the month, The Science and Technology Facilities Council (STFC) signalled that the UK would partially return to the project after January’s shock announcement that Britain was going to pull all its financial support out of the observatory. Today, the STFC has reinstated the UK as a full member of the Gemini Project. What a rollercoaster ride…

An official joint statement from the Gemini partners reads:

“The Science and Technology Facilities Council has reaffirmed the UK’s position as a full member of the Partnership under the terms of the current Gemini Agreement. The Gemini Board welcomes this statement. The Board acknowledges the STFC’s need to address its budgetary constraints and notes that, under the terms of the Agreement, the UK is entitled to seek to sell some of its telescope time both within the partnership and, subject to the approval of the Board, outside the current partnership.”

This is obviously welcomed news, but the astronomers who were outraged by the initial withdrawal are frustrated as to why selling telescope time wasn’t an option in the first place. Allowing other groups (inside and possibly outside the partnership) to buy campaign time on Gemini is a far better solution to the STFC funding crisis. Wasting the money already invested in the project (over Â£70 million to develop the project alone) and pulling out entirely seemed a very extreme measure, prompting some UK astronomers to say the UK astronomy community was being “sabotaged”.

This debacle resonated with the other partners of Gemini (including the US, Canada, Chile, Australia, Brazil and Argentina) who responded angrily to the news that the UK was suddenly withdrawing funding (understandable really). Any mention of the UK was quickly removed from the Gemini observatory locations and the official website.

Today’s announcement has reinstated the UK as a full partner once more to the Gemini project. According to a source, the UK flag has even been returned to the Gemini Northern Operations Center in Hilo, Hawaii.

But there is still a problem. The situation has not changed, the STFC still has to plug its funding deficit, and government assistance is still not forthcoming. There are concerns for other UK physics and astronomy projects, as the Â£15 million ($30 million) savings from cancelling involvement in Gemini will need to be cut from elsewhere.

It would appear that the outrage caused by the STFC’s initial plans to cancel its subscription to Gemini was instrumental in the funding decision U-turn, so the UK physics and astronomy community will have to fight just as hard when more cutbacks are announced in the future. Keep an eye on the STFC Funding Crisis: Astronomy website for updated news on the problems facing physics and astronomy in the UK.

In case you missed the Universe Today coverage of the funding crisis:

UK Astronomy Community “Deliberately Sabotaged” By Funding Cuts To Gemini Observatories (January 28th, 2008)
Cautious Welcome for UK Research Council U-Turn on Gemini Observatory Funding (February 12th, 2008)

Source: Gemini Observatory

February 26, 2008December 26, 2015 by Ian O'Neill

Pluto’s Moons, Nix and Hydra, may have been Adopted

The discovery images of Nix (and Hydra) obtained by the Hubble Space Telescope. Credit: NASA, ESA, H. Weaver (JHU/APL), A. Stern (SwRI)

How many moons does Pluto have? The mini-moons of Pluto, Nix and Hydra, were discovered in 2005 (but named in 2006) during an observation campaign by the Hubble Space Telescope. The discovery of these mini-moons increase the number of natural satellites orbiting Pluto to three (including larger moon Charon). But where did these satellites come from? The current accepted theory on the formation on the large moon, Charon, is much like the theory supporting the creation of Earth’s Moon. It is thought that a large impact between two Large Kuiper Belt Objects chipped Charon away from a proto-Pluto, putting the chunk of Pluto mass into orbit. Over the years, tidal forces slowed the pair and Charon was allowed to settle into its present-day orbit. Recent theory suggests that Nix and Hydra are a by product of this collision, merely shattered fragments of the huge impact. But there are problems with this idea. Could Nix and Hydra have come from somewhere other than the Pluto-Charon impact?

The small moons that orbit the Large Kuiper Belt Object (formerly classified as a planet) can be found about 48,700 kilometers and 64,800 kilometers from the surface of Pluto. The closest moon is called Nix and the farthest, Hydra. Nix has an orbital resonance of 4:1 with Charons orbit and the larger moon Hydra has a resonance of 6:1 (i.e. Nix will orbit Pluto once for every four of Charons orbits; Hydra will orbit Pluto once for every six of Charons orbits).

The reasons behind these mini-moon orbits are only just beginning to be understood, but it is known that their resonances with Charons orbit is rooted way back during the Pluto-system evolution. If we assume Hydra and Nix were formed from a massive Kuiper Belt Object collision, the easiest explanation is to assume they are whole fragments from the impact caught in the gravity of the Pluto-Charon system. However, due to the highly eccentric orbits that would have resulted from this collision, it is not possible that the two little moons could have evolved into a near-circular orbit, in near-corotational resonance with Charon.

So, could it be possible that the moons may have formed from the dust and debris resulting from the initial collision? If there was enough material produced, and if the material collided frequently, then perhaps Nix and Hydra were born from a cold disk of debris (rather than being whole pieces of rock), eventually coalescing and forming sizeable rocky moons. As there may have been a disk of debris, collisions with the orbiting Nix and Hydra would have also reduced any eccentricity in their orbits.

But there is a big problem with this theory. From impact simulations, the post-impact disk of debris surrounding Pluto would have been very compact. The disk could not have reached as far as the present-day orbits of the moons.

One more theory suggests that perhaps the moons were created in a post-impact disk, but very close to Pluto, and then through gravitational interactions with Charon, the orbits of Nix and Hydra were pulled outward, allowing them to orbit far from the Pluto-Charon post-impact disk. According to recent computer simulations, this doesn’t seem to be possible either.

To find an answer, work by Yoram Lithwick and Yanqin Wu (University of Toronto) suggest we must look beyond the Pluto-Charon system for a source of material for Nix and Hydra. From simulations, the above theories on the creation of the small moons being started by material ejected from a large collision between two Large Kuiper Belt Objects (creating Pluto and Charon) are extremely problematic. They do not correctly answer how the highly eccentric orbits Nix and Hydra would have from a collision could evolve into the near-circular ones they have today.

Lithwick and Wu go on to say that the circular, corotational resonant orbits of the two moons could be created from a Plutocentric disk of small bits of rock scooped up during Plutoâ€™s orbit around the Sun. Therefore Nix and Hydra may have been formed from the rocky debris left over from the development of the Solar System, and not from a collision event creating Charon. This may hold true for the countless other Kuiper Belt Objects in orbit in the far reaches of the Solar System, no impact is necessary for the creation of the tiny moons now thought to be their satellites.

It is hoped that the New Horizons mission (launched January 21st, 2006) to the far reaches of the Solar System will reveal some of the questions that remain unanswered in the depths of our mysterious Kuiper Belt. Hopefully we will also find out whether Nix and Hydra are children of Pluto and Charon… or whether they were adopted.

Source: arXiv

February 26, 2008December 26, 2015 by Ian O'Neill

“Foresight” Wins First Prize in Apophis Asteroid Tagging Competition

The Near Earth Asteroid (NEO) Apophis is expected to flyby the Earth in 2029. However, this flyby will be more of a “fly-very-close” as the lump of rock will miss the Earth by only a few thousand kilometers. This near-miss isn’t worrying scientists too much, but should the asteroid tumble through a 400 meter gravitational “keyhole”, there is concern that the asteroid could swing by and risk another collision in 2036. Although the odds are fairly slim, astronomers need better precision in calculating Apopis’s orbital trajectory.

How can this be done? Why not send a spaceship to shadow the asteroid on its journey? The Planetary Society has announced just that. The winning design of the Apophis Mission Design Competition will send a probe and tag Apophis to gain more details about this interplanetary vagabond, and has been awarded a healthy $25,000 to help the development of the US “Foresight” mission…

99942 Apophis (otherwise known as asteroid 2004 MN4) caused quite a stir back in 2004 when it was discovered. Lacking detailed observation at the time, the probability of the 270 meter long piece of rock hitting the Earth was around 2.7% – a large risk in astronomical terms. Now we are sure the asteroid will fly straight by, albeit rather close. It is estimated that Apophis will pass within the orbit of geostationary satellites located at 35,786 km above Earth, allowing amateur astronomers a great opportunity to observe the NEO (it will be possible to see the asteroid with the naked eye at night), whilst being secure in the knowledge that it’s not going to come any closer.

So, panic over? Not quite. Although Apophis will miss us on its first approach in 2029, we might not be so lucky on one of its return trips in 2036. During its flyby in 2029, should the asteroid pass through a critical gravitational “keyhole” measuring only 400 meters across, the gravitational deflection applied to the Apophis asteroid may adjust its orbit, setting it up for a collision course with Earth seven years later.

This is the reason for events such as the Planetary Society’s Apophis Mission Design Competition, to raise awareness of the risk posed by NEOs. Although the winning entry, designed by SpaceWorks Engineering Inc. (Atlanta, Georgia) in conjunction with SpaceDev Inc. (Poway, California), is in the design phase, it is hoped that the completed project could launch by 2012. “Foresight” is intended to fly to Apophis and tag the rock with tracking equipment. The orbiter will continue to study the asteroid and follow it on its orbit around the Sun, gathering valuable information about its composition, center of mass, surface features and, most importantly, its trajectory.

Missions plans such as Foresight are required by the international community to be used should the threat of an asteroid collision become reality (and not remain in cheesy sci-fi movies like Deep Impact or Armageddon).

“Apophis isn’t science fiction, it isn’t a blockbuster Hollywood movie; it is very real.” – Dan Geraci, the Planetary Society’s board chairman.

For more information on the winning entry and the other award winning designs, see the Planetary Society’s Apophis Mission Design Competition website.

February 25, 2008December 26, 2015 by Ian O'Neill

Nanotechnology and “Electrochromics” Successfully Tested On Board Satellite MidSTAR-1

The zero-gravity of Earth orbit is a massive attraction to developers of new technologies. This highly controlled environment removes one of the key forces acting on experiments here on Earth, therefore allowing new techniques to be tried out. Although it can be great to get a highly sensitive experiment to test new technologies into orbit, the experiments must also be robust enough to cope with the massive forces and vibrations during a rocket launch into space.

The US Naval Academy has announced that two new technologies have succeeded in orbital experiments on board the MidSTAR-1 satellite, signifying these new high-tech methods can indeed be carried out in space, and as an added bonus, they may have revolutionary applications down here on Earth…

The US Naval Academy (USNA) satellite called MidSTAR-1 was launched from Florida’s Cape Canaveral Air Force Station on March 8th, 2007 as a part of the USNA’s Small Satellite Program (SSP). The SSP is intended to send miniature, inexpensive satellites into orbit where experiments and other operations can be carried out. The satellites and experiments are designed, constructed and controlled by officers in the US Navy.

Results from two experiments being carried out on MidSTAR-1 have just been announced, and they appear to be a resounding success. The first experiment uses nanotechnologyÂ to detect dangerous chemicalÂ compounds in the air. Almost like a miniature smoke detector, the new method is designed for use in space environments (on board missions such as the International Space Station) as well as counter-terrorism activities here on Earth. The second experiment tests the response of a radiative film (no thicker than a plastic freezer bag) that could be used to regulate the temperature of spacecraft. Both technologies have never been tested in space and both appear to have functioned rather well.

In the nanotechnology experiment,Â the Nano Chemsensor Unit (NCSU) uses very thin nano-tube material (10,000 times thinner than a human hair) to detect poisonous gases in a space-borne environment, primarily protecting astronauts. In fact, this new detector is only the size of a pencil eraser, but has many times the sensitivity of a household smoke detector. The NCSU performed excellently, detecting the target contaminants repeatedly. It is hoped that tiny detectors such as this will be installed in future NASA missions to detect fuel leaks or contamination by common air pollutants such as nitrogen dioxide. Exposure to the vacuum of space, radiation and vibrations at launch do not seem to significantly affect the prototype sensor. Terrestrial applications of the system include atmospheric monitoring and even explosive residueÂ detection during homeland security exercises.

The second technology to be successfully tested is a thin film that changes its characteristics depending on the amount of electric current that is passed across it. This revolutionary material could be used to “wrap” spaceships so their temperature can be regulated. The film can radiate waste heat away from the body of the spacecraft, or can insulate it, holding the heat inside. The science behind this material is known as electrochromics, and before this mission it had never been tested in space. The material is very lightweight, efficient and uses very little energy, a superb addition to any spaceflight mission. Terrestrial applications of this material include using an electrochromic film to coat buildings, making them energy efficient during the winter, but keeping homes cool during summer. This should reduce the amount of energy required to heat and cool buildings, cutting down on cost and the production of greenhouse gases.

Another exciting use of this film could be to use it to surround future robots exploring the solar system, optimizing the temperature for best performance. Also, this technology would be vital to the energy conservation on future manned Moon and Mars bases.

Whatever the application, these preliminary experiments are proving to be highly successful and may revolutionize some aspects of space- and terrestrial-based technology.

“MidSTAR is the seventh piece of hardware that the small satellite program has flown. It’s by far the most sophisticated and most ambitious. It’s proven to be the most productive and all four experiments operating in space are producing excellent data.” – Billy Smith, Director of the Small Satellite Program.

Source: Science Daily

February 25, 2008April 26, 2016 by Ian O'Neill

Record Breaking “Dark Matter Web” Structures Observed Spanning 270 Million Light Years Across

It is well documented that dark matter makes up the majority of the mass in our universe. The big problem comes when trying to prove dark matter really is out there. It is dark, and therefore cannot be seen. Dark matter may come in many shapes and sizes (from the massive black hole, to the tiny neutrino), but regardless of size, no light is emitted and therefore it cannot be observed directly. Astronomers have many tricks up their sleeves and are now able to indirectly observe massive black holes (by observing the gravitational, or lensing, effect on light passing by). Now, large-scale structures have been observed by analyzing how light from distant galaxies changes as it passes through the cosmic web of dark matter hundreds of millions of light years across…

Dark matter is believed to hold over 80% of the Universe’s total mass, leaving the remaining 20% for “normal” matter we know, understand and observe. Although we can observe billions of stars throughout space, this is only the tip of the iceberg for the total cosmic mass.

Using the influence of gravity on space-time as a tool, astronomers have observed halos of distant stars and galaxies, as their light is bent around invisible, but massive objects (such as black holes) between us and the distant light sources. Gravitational lensing has most famously been observed in the Hubble Space Telescope (HST) images where arcs of light from young and distant galaxies are warped around older galaxies in the foreground. This technique now has a use when indirectly observing the large-scale structure of dark matter intertwining its way between galaxies and clusters.

Astronomers from the University of British Columbia (UBC) in Canada have observed the largest structures ever seen of a web of dark matter stretching 270 million light years across, or 2000 times the size of the Milky Way. If we could see the web in the night sky, it would be eight times the area of the Moons disk.

This impressive observation was made possible by using dark matter gravity to signal its presence. Like the HST gravitational lensing, a similar method is employed. Called “weak gravitational lensing”, the method takes a portion of the sky and plots the distortion of the observed light from each distant galaxy. The results are then mapped to build a picture of the dark matter structure between us and the galaxies.

The team uses the Canada-France-Hawaii-Telescope (CFHT) for the observations and their technique has been developed over the last few years. The CFHT is a non-profit project that runs a 3.6 meter telescope on top of Mauna Kia in Hawaii.

Understanding the structure of dark matter as it stretches across the cosmos is essential for us to understand how the Universe was formed, how dark matter influences stars and galaxies, and will help us determine how the Universe will develop in the future.

“This new knowledge is crucial for us to understand the history and evolution of the cosmos […] Such a tool will also enable us to glimpse a little more of the nature of dark matter.” – Ludovic Van Waerbeke, Assistant Professor, Department of Physics and Astronomy, UBC

Source: UBC Press Release

February 24, 2008April 26, 2016 by Ian O'Neill

Space Debris May be Catastrophic to Future Missions (and Google Earth is Watching…)

Kessler Syndrome could be a frightening situation for space travel. No, it’s not a health risk to the human body in zero-G and it’s not a psychological disorder for astronauts spending too much time from home. Kessler Syndrome is the point at which space travel becomes impossible without hitting into a piece of space junk, jeopardizing missions and risking lives. In extreme predictions, space debris from our constant littering of low Earth orbit, collisions between bits of rubbish may become more and more frequent, causing a catastrophic cascade of debris multiplying exponentially, falling through the atmosphere and making space impassable.

In the meanwhile, space mission controllers must be acutely aware that there could be an odd bolt or piece of old satellite flying toward their spaceship at velocities faster than the fastest rifle shot. Spare a thought for the space debris trackers as they try to keep a record of the 9,000+ pieces of junk currently orbiting our planet… but wait a minute, Google Earth can give us a ringside seat!

Strict international civil aviation-style laws may need to be imposed on the worlds space agencies if future generations of the human race are going to make it in space. This stark warning comes from Tommaso Sgobba, Director of the International Association for the Advancement of Space Safety, who will be presenting his case to the United Nations in April. Sgobba’s main argument comes from the danger associated with the escalating accumulation of space debris in Earth orbit, should these high speed bits of junk hit a spaceship, satellite or an astronaut, death and disaster may ensue. It may get worse than this, possibly paralysing the Earth from having access to space at all.

“Failure to act now to regulate space to protect property and human life would be pure folly.” – Tommaso Sgobba.

Other scientists agree with Sgobba, recommending that future missions in to space abide by some strict codes of practice (possibly more strict than those imposed on international civil aviation) to drastically cut the rate of orbital littering by the 20 countries currently able to send stuff into space.

Even the most tightly controlled missions, such as the International Space Station, are expected to shed bits and pieces over the course of their lifetimes. Space junk comes in all shapes and sizes and can be anything from a small screw to entire dead satellites. Recorded examples of space junk include an old glove lost by Ed White during the first ever US space walk in 1965 (during the Gemini-4 mission), a camera that Michael Collins let slip in space in 1966 (during the Gemini-8 mission) and a pair of pliers that International Space Station astronaut Scott Parazynski dropped during an EVA last year.

Some space debris near misses include:

Space Shuttle dodge: Space Shuttle Atlantis had to avoid collision with a piece of a Russian satellite by carrying out a seven second burn of its engines in 1991.
Aircraft scare: Bits of an Russian ex-spy satellite fell through the atmosphere coming very close to a Latin American Airbus, carrying 270 passengers in 2006.
Personal injury: fortunately there is only one documented account of someone being hit by a piece of debris on the ground. In 1997 a woman from Oklahoma was hit on the shoulder by a piece of a fuel tank from a Delta II rocket. She was unhurt and lived to tell the tail.

It is hoped that tighter controls on the rockets, satellites and spacecraft will slow the rate of junk increase, but the problem is already pretty worrying for long-term missions in orbit around the Earth. The two critical regions filling with debris are in low Earth and geosynchronous orbits, a few hundred and 22,300 miles high respectively. Low Earth orbit will cause problems for spacecraft to actually leave the atmosphere and geosynchronous orbit may hinder future communication satellite insertions.

To safeguard our access into space, and avoid an increase in debris-related incidents, action will need to be taken.

Google Earth-watch

During the research on this article, I came across some work being funded by Ministry of Culture of the Republic of Slovenia, Municipality of Ljubljana, where researchers are making debris location data available to the public via a plugin for the Google Earth application. According to the groups blog, the data is taken from a U.S. government-owned space observatory so known space debris (or as the blog calls it “pollution”, which it really is) can be tracked.

On experimenting with the new space debris folder, it really did strike home as to what a problem space junk is becoming. For starters, there is an impossibly thick near-Earth layer and a distinct ring representing the geosynchronous debris. Plus, each item can be selected and information on the individual bits of debris can be found out… see the screenshots to find out what I mean…

Get the space junk plugin for Google Earth (read Google Earth documentation to learn how to use this plugin).

News Source: Guardian.co.uk

February 22, 2008April 26, 2016 by Ian O'Neill

Could Primordial Black Holes Deflect Asteriods on a Collision Course with Earth?

An artists impression of an asteroid belt. Credit: NASA

Primordial black holes (PBHs) are getting mischievous again. These artefacts from the Big Bang could be responsible for hiding inside planets or stars, they may even punch a neat, radioactive hole through the Earth. Now, they might start playing interplanetary billiards with asteroids in our solar system.

Knocking around lumps of rock may not sound very threatening when compared with the small black holes’ other accolades, but what if a large asteroid was knocked off course and sent in our direction? This could be one of the most catastrophic events yet to come from a PBH passing through our cosmic neighborhood…

As a race, we are constantly worried about the threat of asteroids hitting Earth. What if another large asteroid – like the one that possibly killed the dinosaurs around 65 million BC or the one that blew up over Tunguska in 1908 – were to come hurtling through space and smash into the Earth? The damage caused by such an impact could devastate whole nations, or plunge the world as we know it to the brink of extinction.

But help is at hand. From the combined efforts by groups such as NASAs Near Earth Object Program and international initiatives, governments and institutions are beginning to take this threat seriously. Tracking threatening Near Earth Asteroids is a science in itself, and for now at least, we can relax. There are no massive lumps of rock coming our way (that we know of). The last scare was a comparatively small asteroid called “2008 CT1” which came within 135,000 km of the Earth (about a third of the distance to the Moon) on February 5th, but there are no others forecast for some time.

So, we now have NEO monitoring down to a fine art – we are able to track and calculate the trajectory of observed asteroids throughout the solar system to a very high degree of accuracy. But what would happen if an asteroid should suddenly change direction? This shouldn’t happen right? Think again.

A researcher from the Astro Space Center of the P. N. Lebedev Physics Institute in Moscow has published works focusing on the possibility of asteroids veering off course. And the cause? Primordial black holes. There seems to be many publications out there at the moment musing what would happen should these black holes exist. If they do exist (and there is a high theoretical possibility that they do), there’s likely to be lots of them. So Alexander Shatskiy has gotten to the task of working out the probability of a PBH passing through the solar systems asteroid belts, possibly kicking an asteroid or two across Earths orbit.

Shatskiy finds that PBHs of certain masses are able to significantly change an asteroids orbit. There are estimates of just how big these PBHs can be, the lower limit is set by black hole radiation parameters (as theorized by Stephen Hawking), having little gravitational effect, and the upper limit is estimated to be as massive as the Earth (with an event horizon radius of an inch or so – golf ball size!). Naturally, the gravitational influence by the latter will be massive, greatly affecting any piece of rock as it passes by.

Should PBHs exist, the probability of finding one passing though the solar system will actually be quite high. But what is the probability of the PBH gravitationally scattering asteroids as it passes? If one assumes a PBH with a mass corresponding to the upper mass estimate (i.e. the mass of the Earth), the effect of local space would be huge. As can be seen from an asteroid map (pictured), there is a lot of rocky debris out there! So something with the mass of the Earth barrelling through and scattering an asteroid belt could have severe consequences for planets nearby.

Although this research seems pretty far-fetched, one of the calculations estimate the average periodicity of a large gravitationally disturbed asteroids falling to Earth should occur every 190 million years. According to geological studies, this estimate is approximately the same.

Shatskiy concludes that should small black holes cause deflection of asteroid orbits, perhaps our method of tracking asteroids may be outdated:

“If the hypothesis analyzed in this paper is correct, modern methods aimed at averting the asteroid danger appear to be inefficient. This is related to the fact that their main idea is revealing big meteors and asteroids with dangerous orbits and, then, monitoring these bodies. However, if the main danger consists in abrupt changes of asteroidal orbits (because of scattering on a PBH), revealing potentially dangerous bodies is hardly possible.”

Oh dear, we might be doomed after all…

Source: arXiv

February 22, 2008December 26, 2015 by Ian O'Neill

The Mysteries Behind the Dynamic Global Weather of Venus

As if the cloudy planet couldn’t get any more mysterious, Venus and its global weather patterns are baffling European Space Agency (ESA) scientists. The ESA Venus Express mission is continuing to unearth the details of what lies in and under its thick atmosphere, but Venus’s dynamic global weather patterns are very quick to consume the whole planet, like nothing we experience on Earth…

The ESA Venus Express missions Venus Monitoring Camera (VMC) is a long-term data gathering experiment to monitor the long-term progression of weather systems on the planet. On numerous occasions, the VMC has observed massive clouds of bright, hazy sulphuric acid particles form from equator to pole in a matter of days, only for it to disappear just as quickly. This suggests that fast dynamical, chemical and microphysical processes are at work on the planet in scales never before realized.

“This bright haze layer is made of sulphuric acid […] the process is a bit similar to what happens with urban smog over cities.” – Dmitri Titov, VMC Co-Investigator and Venus Express Science Coordinator, Max Planck Institute for Solar System Research, Germany.

With over 600 orbits completed, the VMC is observing the effects that solar radiation has on the dynamics of Venus’s atmosphere. It is well known that Venus’s atmosphere is carbon dioxide-rich and also contains water molecules and gaseous sulphur dioxide. Should this mix be exposed to UV radiation, the molecules will break up, forming a mix of highly reactive chemicals. As these chemicals bond, droplets of sulphuric acid form, creating planetary-scale clouds of bright haze. However, the planets atmosphere is too thick for much of the solar radiation to penetrate. For the gases to be exposed to UV radiation, some powerful atmospheric process must force them aloft, above much of the dense atmosphere, allowing them to react.

Although the bright haze of Venus’s atmosphere has been identified, many dark patches have also been observed. So far, there is no explanation for these patches of atmospheric chemicals absorbing solar UV, but the presence of the orbiting Venus Express is hoped to shine light on the dark and bright atmospheric features and how the atmosphere is mysteriously driving them.

Source: ESA