Saturday, January 31, 2009

Unknown planet in an uncertain universe

OK its confession time in regard to what we know about the known universe. We don't know where all the bits are. Lurking in the solar system's dark recesses, is an undiscovered world - Planet X, a frozen body perhaps as large as Mars or our own dear Earth.

The discovery of new planets in the solar system would be one of the most significant addition to the solar system since the discovery of Pluto in 1930. Eeven now, pluto is still fueling a planet v non-planet debate. When the International Astronomical Union voted to downgrade Pluto to dwarf planet status in 2006, they established three criteria for a bone fide 'planet' in our solar system:
  • it must orbit the sun;
  • its gravity must suffice to mould it into a near-spherical shape; and
  • it must be massive enough to have ploughed its orbit clear of other bits and bobs.
Unfirtunately Pluto failed to make the cut. It falls down on this third point. It is just one of many objects that are contained within the Kuiper belt (KBOs). These are icy bits of debris that pepper space from Neptune's orbit at 30 astronomical units out to around 50 AU. (1AU = the distance between Earth and our sun)

Any new object would have to be well clear of the Kuiper belt to qualify as a planet. Yet intriguingly, it is studies of the belt that have suggested planet X's existence. Some KBOs travel in extremely elongated orbits around the sun. Others have steep orbits almost at right angles to the orbits of all the major planets. It was surmised that these could be signs of perturbation from a massive distant object, says a solar system scientist at the University of Hawaii.

That is by no means a general consensus. An early, slow outward migration of the giant planets could also explain some of these strange KBO orbits - although it has difficulty explaining all of the belt's observed properties and anomolies.

Over the past 20 years, huge swaths of the sky have been searched for slowly moving bodies, and well over 1000 KBOs found. But these wide-area surveys can spot only large, bright objects; longer-exposure surveys that can find smaller, dimmer objects cover only small areas of the sky. A Mars-sized object at a distance of 100 AU or more, would be so faint that it could easily have escaped detection.

That could soon change. In December 2008, the first prototype of the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) was brought into service at the Haleakala observatory on Maui, Hawaii. Soon, four telescopes - equipped with the world's largest digital cameras, at 1.4 billion pixels apiece - will search the skies for anything that blinks or moves. Its main purpose is to look out for potentially hazardous asteroids on a collision course with the Earth but other space objects and spurious inhabitants of the outer solar system should not escape its all-seeing eyes.

The discovery of a further planet would be thrilling. One of the possible explanation for its presence there would be that large bodies coalesced very early in the solar system's history, only to be ejected by the gravity of the giant planets later on. That would firm up ideas about how the solar system has developed and greater insight into its more distant recesses.

To read the full story follow this link; Planet-X

Friday, January 23, 2009

How big is your Universe.?

It is 13.7 billion years since the big bang, so light now reaching us cannot have started its journey longer ago than that. Yet the most distant object we could conceivably see today lies further away than 13.7 billion light years. That's because throughout the life of the universe, space has been expanding. Taking this into account, cosmologists calculate that the edge of our observable universe is now approximately 45 billion light years away.

Beyond that, who knows? The inflation theory of cosmology predicts that the universe grew from a bubble. Just how big that bubble has now become depends on how long inflation lasted. If it continued for a very long time - in this context "very long" is still only a fraction of a second - then the edge of our universe might lie far beyond the 45-billion-light-year limit of our vision. That could also rule out the possibility of observing the influence of other universes on our own. As physicist Matthew Kleban of New York University puts it: "It's totally possible that we live in a multiverse and we'll never know because there's been so much inflation."

More to this story at

Dirty old nuclear Rorsat leaking in orbit

Spinning around the Earth for more than two decades, an old Soviet satellite, with a dirty nuclear reactor, is leaking in orbit.

Launched by the former Soviet Union in February 1987, Cosmos 1818 was the first of two vehicles designed to evaluate an advanced nuclear power supply in low Earth orbit.

Apart from being a debris hazard, ground-watching surveillance has picked up dozens of small particles spewing into space from the 21-year-old satellite. What is this debris cloud? It's still an unexplained and worrying debris generation event.

Information on the event, first spotted in July 2008, has been highlighted in the January issue of the Orbital Debris Quarterly News - produced by the NASA Orbital Debris Program Office at the space agency's Johnson Space Center in Houston, Texas.

Interesting history
The newsletter notes that Cosmos 1818 and its sister spacecraft, Cosmos 1867 both carried into orbit a thermionic nuclear power supply. That nuclear power gear was more advanced than earlier thermoelectric nuclear devices that energized the well-known Radar Ocean Reconnaissance Satellites (RORSATs) during the 1970s and 1980s.

The most infamous RORSAT was Cosmos 954. It made an out-of-control nose dive in 1978, raining dangerous radioactive debris over Canada. Traces of this radiation now cover the whole planet.

Unlike their RORSAT cousins that operated in very low orbits, Cosmos 1818 and Cosmos 1867 were directly inserted into much higher orbits, thereby eliminating any threat of premature reentry, the Orbital Debris Quarterly News notes.

Russian space authorities have said in the past that the nuclear reactors onboard Cosmos 1818 and Cosmos 1867 functioned for roughly five and 11 months, respectively. For the next two decades, the two inactive spacecraft orbited the Earth with their dirty cargo but without significant incident.

Special observations
But on or about July 4, 2008, the dormant Cosmos 1818 satellite seemed to be breaking up, possibly following a collision with other orbiting debris. The U.S. Space Surveillance Network spotted debris of various sizes being shed from the spacecraft.

Closer observation of a few of the debris pieces revealed characteristics generally indicative of metallic spheres – perhaps bubbles of sodium potassium reactor coolant, according to the space debris newsletter.

Another idea being put forward is that a coolant tube on Cosmos 1818 became thermally stressed and breached after coasting between sunlight and dark temperatures over the two decades.

Alternatively, the hyper-velocity impact of a small particle might have generated sufficient heat to melt some of the NaK, which then would have formed spheres with metallic properties," the newsletter explained.

Trail of droplets
This is not the first case of former Soviet satellites casting off a trail of droplets in Earth orbit – dendrites of a dangerous kind to other spacecraft.

Back in March of 2004 I reported on the case of the leaking RORSATs – and whether or not the drips of NaK were, a hazard or still radioactive.

Meanwhile, according to the space debris newsletter, more analysis of the Cosmos 1818 debris is underway in hopes of pinning down the nature of the debris and the possible cause of their origin. "To date, no similar debris generation by Cosmos 1867 has been observed," the newsletter advised.

Collision space
"I can only guess for now what may be going on with RORSATs," said Don Kessler, a former NASA expert on orbital debris and now an orbital debris and meteoroid consultant in Asheville, North Carolina.

These RORSATs were placed at an altitude above 500 miles (800 kilometers), he added, in the hope that their orbit would not decay until after their radioactivity had decayed hundreds of years from now. However, this also placed the RORSATs in a region of space that has the highest collision probability with other debris.

"Most of the small debris in this region is NaK droplets, released from the RORSATs prior to 1990. Consequently, as a result of collisions with other debris, RORSATs are not likely to remain intact before they re-enter," Kessler told The most frequent type of collision would be with the older NaK droplets, impacting with very high velocities, he said.

"These smaller impacts would penetrate the RORSAT radiators, and release some of the remaining NaK. Impacts with larger debris would cause the entire RORSAT satellite to fragment," Kessler advised.

As for the wandering droplets of reactor coolant being radioactive, Kessler said. "I have never resolved the issue of whether these droplets are radioactive or not....they were certainly exposed to the RORSAT radiation. A specialist in radioactive material would best answer the question, how long NaK would remain radioactive."

Sunday, January 11, 2009

Space for Phobos Grunt!

The crater on Phobos
Russia is pushing forward on a robotic mission to Mars dubbed Phobos-Grunt - now seemingly on a countdown clock that ticks away for an October launch. If the project is on track and off the ground by that time, Phobos-Grunt would arrive at the red planet in August of next year.

The project also includes deployment of a Chinese sub-satellite -Yinghuo-1 meaning "Firefly-1" - that will gauge the Martian past in terms of how surface water on the red planet did a disappearing act. Of course the lack of atmosphere to contain the liquid and any other, even in gaseous form, is the most probable.

Phobos-Grunt is intended also to cast an orbital eye on Mars too, but then plop down on Phobos - one of that planet's two moons, scrape up on-the-spot samples and then transport those extraterrestrial tidbits to Earth in July 2012. As it swoops by Earth, the spacecraft is to release a capsule containing all the samples gathered on Phobos, to land on Earth.

The most interesting and possibly sinister item is another payload on this heady mission. Russia is also dispatching on this flight the "world's hardiest" or "toughest" organisms found here on Earth, sealed up in a bio-container for the Earth-to-Mars/Mars to Earth three year trek. The bio-module will provide 30 small tubes for individual microbe samples.

That's LIFE
The Planetary Society is at the root of this "hardy boys go to Mars" saga - dubbed LIFE, short for Living Interplanetary Flight Experiment.

LIFE is intended to help better understand the nature of life, its robustness, and its ability - or not - to move between planets. The journey will be a test of one facet of the "transpermia" hypothesis. That is, the possibility that life can voyage from planet to planet inside rocks blasted off one planetary surface by impact, to land on another planetary surface.

What sets off alarms is the blatant depositing of organisms on Mars. This is in direct contrast to the efforts and money involved in preventing hitchhiking microbes from Earth making it to the red planet in the first place.

Forward contamination.
Under The Outer Space Treaty of 1967, planetary protection policies are in place to prevent cross contamination between planets - avoiding both forward contamination on outbound spacecraft, and back contamination of Earth upon return. For this mission, it's the possibility of forward contamination that raises concerns.

International protocols
Lou Friedman, the Executive Director of The Planetary Society, made an effort to allay concerns about forward contamination.

"......the most important thing I can say to 'allay concerns' is and the Russians with whom we are working, are committed to observing the international protocols and agreements concerning planetary protection,"

"The main point is the product of probabilities of this experiment even entering Mars, let alone breaking up and then dispersing organisms in a way that they could survive on Mars is incredibly small. It is in the order of magnitude less than the minimum allowed in the international science protocols," Friedman advised.

As broached in The Planetary Society's Frequently Asked Questions about the mission: Is it likely that this experiment could contaminate Mars with life, thus confusing future searches for life on Mars?

"The short answer is that it is very unlikely, but we are doing a thorough analysis of the issue. We will fully comply with the COSPAR (Committee on Space Research of the International Council for Science) planetary protection guidelines aimed at preventing the contamination of Mars by introducing terrestrial life onto the surface of Mars."

Preliminary passenger list
On the other hand, there are some other aspects of this that still ring an alarm bell in some quarters. For example:
  • Since it's a Russian launch vehicle, and not going to the surface of Mars per se, the concerns about planetary protection are less stringent. However, if an out-of-control spacecraft impacts on the planet, that would be bad. How would NASA respond if it were a U.S. launch vehicle with the same experiment?
  • Okay, let's hope they are successful. Even so, if the experimental organisms make it back alive, it says that organisms are hardy (already known) and if they die, there's no way to interpret the data in a useful way.
  • The Phobos-Grunt mission intends to meet orbital lifetime requirements, so by COSPAR policy there is no official limit on the number of organisms the spacecraft may carry. However, I've been advised that neither the COSPAR nor NASA planetary protection officials think that sending organisms so close to Mars is a good idea, given the trouble the U.S. normally goes through to ensure that Mars spacecraft are very clean.
  • A critical question involves the specific organisms that will be transported. Both The Planetary Society and the Russian National Academy have been advised to send only "pure cultures of organisms" that could not possibly survive on Mars, selected so that they would pose a minimal contamination hazard. By the way, most organisms relevant to human exploration, such as well-studied human commensal microbes and food organisms, meet this criterion.
  • A preliminary passenger list on the LIFE experiment included a section of tundra taken from the Russian far north. Of all locations on Earth that could possibly contain organisms capable of adapting to Martian conditions, this is one of the most likely. However, The Planetary Society website indicates that the final passenger list is not yet in place. But the description still states that "a natural soil colony of microbes" will be included. This is very vague. What's up here, and what's really slated to be up and going?
  • At the end of the day, will the Russians comply with the spirit or letter of the COSPAR Planetary Protection Policy when analyzing the potential for harm? And in not doing this, would they undercut COSPAR policy?
Native tundra samples
Catharine Conley, the acting Planetary Protection Officer at NASA Headquarters said about this mission.

"The Phobos-Grunt mission intends to meet orbital lifetime requirements, so by COSPAR policy there is no official limit on the number of organisms the spacecraft may carry," Conley advised. Sending pure cultures of organisms that could not possibly survive on Mars, she added, would pose a minimal contamination hazard, and this includes most organisms relevant to human exploration.

"However, I am uncomfortable with sending native tundra samples so close to Mars, because this is a location on Earth that could possibly contain organisms capable of adapting to Martian conditions," and to do so "seems ill-advised," Conley said

John Rummel, Director of the Institute for Coastal Science & Policy at East Carolina University in Greenville, North Carolina was asked for his thoughts. He's also COSPAR Planetary Protection Panel Chair.

"The Planetary Society, as a public space advocacy group, is looking for a publicly noticeable way to demonstrate that live organisms can make the journey from Earth to Mars and return. Scientifically, however, I think that the hypothesis has already been sufficiently supported by previous work on Earth and in near-Earth space," Rummel said

"As the COSPAR Planetary Protection Panel Chair, I would judge that the threat of contaminating Mars is negligible - but I would emphasize that the Russian Academy of Sciences is the organization that should be making that determination for a Russian-launched payload, judging both the potential for contaminating Mars and the safety of returning samples of Phobos to Earth."

So space fans: Is the Phobos-Grunt mission something to groan about?

On 23 July 2008, the High Resolution Stereo Camera on board the ESA’s Mars Express took the highest-resolution full-disc image yet of the surface of the moon Phobos. Credit: ESA/DLR/FU Berlin (G. Neukum)

Full-scale mockup of Russia's Phobos-Grunt. Mission objectives are to collect samples of soil on Phobos, a satellite of Mars, and to bring the samples back to Earth to carry out comprehensive scientific research of the Martian system. Credit: CNES

The LIFE experiment to be carried onboard Russia's Phobos-Grunt mission. Credit: The Planetary Society

This diagram identifies critical systems for Russia's Phobos-Grunt sapcecraft, which is planned to return soil samples from the Martian moon Phobos. Credit: Babakin Science and Research Space Center

Saturday, January 10, 2009

Spinning in Space

Milky way 'larger than imagined'
A recent disclosure indicates that the Milky Way is considerably larger (contains more heavenly bodies), bulkier (more mass) and spinning faster (its all relative) than astronomers thought.

For decades, astronomers and stargazers thought that the Milky Way, was a weakling runt compared to the larger Andromeda, but not anymore.

Scientists mapped the Milky Way in a more detailed, three-dimensional way and found that it is 15% greater breadth. More important, it is significantly more dense, with 50% additional mass, which is similar to the weight but includes a size factor.

The new findings were presented at the American Astronomical Society's convention in Long Beach, California. Mark Reid of the Harvard-Smithsonian Centre for Astrophysics in Cambridge, Massachusetts, said it was the cosmic equivalent of him suddenly increasing his bulk from his 5ft 5in, 10 stone frame, to 6ft 3in and 15 stone.

"Previously we thought Andromeda was dominant over the Milky Way, and that we were the little sibling of Andromeda," Mr Reid said. "But now it's more like we're sibling twins."

The fact that the Milky Way and Andromeda are of similar mass means that they share a similar attraction to each other, not necessarily good news. A more massive and attractive Milky Way means that it could be heading for a more violent collision with the neighbouring Andromeda galaxy, sooner than predicted. This event is still likely to be billions of years from now.

Mr Reid and his colleagues used a large system of 10 radio telescope antennas to measure the brightest newborn stars in the galaxy at different times in Earth's orbit around the sun. They made a map of those stars, not just in the locations where they were first seen, but in the third dimension of time - something Mr Reid said has not been done before.

Using this approach, Mr Reid was able to determine the speed at which the spiral-shaped Milky Way is spinning around its centre. That speed - about 568,000mph - is faster than the 492,000mph that scientists had been using for decades.

So now you know why you were feeling a bit dizzy after the New Year Celebrations