Curious Bends – where Indians come from, Irrawady dolphins, human spaceflight and more

1. A genetic history: Where do Indians come from?

“In 2005, K. Thangaraj and his colleagues at CCMB published their findings about the origin of Andaman islanders in the journal Science. The Onge turned out to have surprisingly unmixed origins. They had likely lived isolated in the islands since the arrival here of the first group of humans out of Africa. There were mutations in their mtDNA that were found nowhere else in the world. These mutations must have originated here and not spread. The Onge were an untouched link to the earliest humans who settled the planet.” (24 min read)

2. Oil spill in the Sunderbans threatens the endangered Irrawady dolphins

““Dolphins are at the top of the food chain so they will be affected sooner or later by eating the fish from these waters,” said Rubaiyat Mansur, Bangladesh head of the Wildlife Conservation Society. Mansur also worries about the more direct impact on the animals. “The oil slick collects at the confluences and meanders of the river and those are the places that the dolphins like to hang around in and look for prey,” he said. “Coming up in an oil slick, opening a blow hole and breathing in and breathing out won’t be a good idea because the air right above the oil slick will be quite toxic.”” (4 min read)

3. ISRO will launch its crew module on its first test flight on December 18

“While a capsule in orbit around Earth will re-enter with a velocity of over 28,000 km per hour, next week’s test will see the GSLV Mark III leave the crew module at a height of about 125 km with a velocity of around 19,000 km per hour. The crew module carries sensors that will make measurements of over 200 parameters during the flight, including the temperature, pressure and stress experienced at various points in the structure. “This flight will give us tremendous confidence in our design and provide important inputs for proceeding with development of the manned capsule,” observed S. Unnikrishnan Nair, project director for the Human Spaceflight Programme.” (4 min read)

4. Why are the women dying in India’s sterilisation camps?

“These dangerous conditions are not uncommon in sterilisation camps throughout India, claim women’s health activists. They say that such camps, favoured by the Indian government as a way to perform tubectomies on many women in one go, often exceed the prescribed limit for surgeries in a day, do not adequately sterilise the equipment used on patients, and do not provide counselling before operations or care afterwards. “This was waiting to happen,” Abhijit Das, a public health researcher at Delhi’s Centre for Health and Social Justice, told The BMJ.” (7 min read)

5. India is a breeding ground for the world’s super-bugs

“In the developing world, unregulated use of these drugs coupled with poor sanitation and health care are fueling the rise of resistant bacteria. In India, these factors have created the perfect breeding ground for so-called super bugs. Last year, more than 58,000 babies died from antibiotic-resistant infections.” (2 min read)

Chart of the week

“Japan is the third-largest economy after America and China. It is so wealthy that its regions boast the same economic heft as large countries. The entire economy of Brazil fits into the Kanto region that includes Tokyo, for example. Yet despite this wealth, Japan’s economic growth has been largely stagnant over a period known as the two “lost decades”. America’s GDP grew threefold during that time while China’s soared. After a short stint as prime minister in 2006-07, Shinzo Abe returned in 2012 calling for a bold, three-part plan of stimulus spending, monetary easing and structural reforms—the so-called “three arrows” of Abenomics.” The Economist has more.

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The GSLV Mk-III is no jugaad

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December 18, 2014

(Note: This piece was written in the future-tense and published before ISRO’s successful test flight this morning.)

Come Thursday, the Indian Space Research Organisation will launch its GSLV Mk-III rocket from its launch pad in Sriharikota. In the run-up, most media attention has been on a conical module the rocket will carry on board. But of greater interest is the rocket itself, which holds the key to making ISRO a serious contender in the international satellite-launch sector.

The module is part of the Crew-Module Atmospheric Reentry Experiment, which will see it being released at an altitude of 126 kilometres, upon which it will re-enter earth’s atmosphere and crash into the Bay of Bengal, some 200 kilometres west of the Andaman Islands.

Scientists at ISRO will monitor CARE during its journey and gather important data about its surface and interiors. If the module’s performance matches their predictions, India will be that much closer to using it as a crew capsule for a manned mission into space planned in the early 2020s.

Cashing in on the growth

Forgotten in the media buzz around the module is the rocket itself.

The Mk-III, a next-generation variant of ISRO’s fleet of geosynchronous satellite launch vehicles, boasts of India’s highest payload capacity yet: 10,000 kilograms to low-earth orbit and 4,000 kilograms to the highly elliptical geostationary-transfer orbit.

If the launch is successful – and if future test flights establish reliability – ISRO’s commercial space programme will be in a position to cash in on the rapidly growing global satellite-launching industry as well as give domestic engineers the leeway to design more sophisticated satellites.

This was an important consideration during the Mars Orbiter Mission. The orbiter itself, currently revolving around the Red Planet, weighs only 15 kilograms because the Polar Satellite Launch Vehicle’s payload limit to earth orbit is 1,350 kilograms. This includes all the other instruments on board to ensure a smooth journey. A heavier orbiter could have included more than the five instruments it did.

Dependence on others

In this regard, the GSLV Mk-III will be important because it will determine where India’s native space research programme is headed and how it plans to leverage the increased payload mass option.

It will also reduce India’s dependence on foreign launch vehicles to get heavier satellites into orbit, although self-reliance comes with problems of its own. The common choice in lieu of a reliable GSLV has been the French Arianespace programme, which currently serves almost 65% of the Asia-Pacific market. The Mk-III bears many structural similarities to the Ariane 6 variant. Also, both rockets have a liquid main-stage, a cryogenic upper-stage and two solid-fuel boosters.

The Ariane 6 can lift 6,500 kilograms to the geostationary-transfer orbit, and each launch costs India about $95 million. Assuming the cost-per-launch of the Mk-III is comparable to the Mk-II’s, the number approximately comes down to $40 million (this is likely to be slightly higher). Compare this to the global average price-per-launch of vehicles capable of reaching the geostationary-transfer orbit: $145.57 million, as of 2013.

Skyrocketing profits

From 1999 to 2014, ISRO launched 40 foreign satellites, all with PSLV rockets, and earned EUR 50.47 million and $17.17 million (or Rs 505.74 crore) from 19 countries. Antrix, the commercial arm of ISRO in charge of handling the contracts with foreign space agencies, has reported profits ranging from Rs 19 crore to Rs 169 crore between 2002 and 2009.

This is a pittance compared to what Arianespace made in 2013 alone: EUR 680.1 million. A reliable launch vehicle to the geostationary-transfer orbit can change this for the better and position ISRO as a serious contender in the space-launch sector, assuming it is accompanied by a more efficient Antrix and an ISRO that is willing to work with foreign counterparts, both private and governmental.

It must also consider expanding its launch capabilities to the geostationary-transfer orbit and prepare to keep up with the 5-15% growth rate recorded in the last five years in the satellites industry. Now is an opportune time, too, to get on the wagon: the agency’s flags are flying high on the success of the Mars Orbiter Mission.

Facing other challenges

ISRO has to be ready to confront the likes of SpaceX, a space transport services company which already has the Falcon 9 rocket that can launch 13,150 kilograms to low-earth orbit and 4,850 kilograms to the geostationary-transfer orbit at starting costs of $57 million per launch.

On another front, ISRO will have to move the public dialogue away from its fixation on big science missions and toward less grandiose but equally significant ones. These will help establish the space agency’s mettle in reliably executing higher-altitude launches, enhancing India’s capabilities in the space-launch and space-research sectors. These will also, in turn, serve to make high-cost missions more meaningful than simple proofs of concepts.

For example, ISRO Chairman K Radhakrishnan has announced that a project report compiled by the agency envisages a Rs 12,400-crore manned space mission by 2021. In the next seven years, thus, ISRO aims to master concepts of re-entry technology, human spaceflight and radiation protection. This will happen not just through repeated test flights and launches of crew modules but also using satellites, space-borne observatories and data analysis.

For all these reasons, the GSLV Mk-III marks an important step by ISRO, one that will expose it to greater competition from European and American launchers, increase its self-reliance in a way that it will have to justify its increasing launch capabilities with well-integrated projects, and help the agency establish a legacy over and beyond the jugaad that took it to Mars.

The Mars Orbiter Mission was launched around the same time as NASA’s MAVEN mission to Mars, and with comparable instrumental specifications. While MOM cost ISRO $74 million, MAVEN cost NASA $672 million. In fact, ISRO’s orbiter was by far the least expensive Mars satellite ever built.

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A voyager on an unknown sea

Early 2012. The Voyager 1 space-probe is millions of kilometres beyond the orbit of the dwarf planet Pluto. In fact, it’s in a region of space filled with scattered rocks and constantly perturbed by charged particles streaming in from outer space. Has it left the Solar System, then? Nobody is sure.

Late 2012. Scientists still aren’t sure if Voyager 1 has crossed over into the interstellar medium. The ISM is the region of the universe between stars, where the probe would definitely have been outside the Solar System. The probe’s batteries had been low for a while. An important instrument on-board that could’ve ‘sniffed’ at the charged particles and known where the probe was is dead. Only something like luck could save the day.

June 2013. Three papers published in Science discuss changes in the magnetic fields around the probe. Some measurements indicate Voyager 1 is in the ISM. Others say it’s just entered a new region of space, a ‘transition zone’ between the Solar System’s outermost fringes and the first tastes of the universe beyond.

August 2013. Luck finally struck. A storm on the surface of the Sun had ejected a massive burst of its own charged particles, way back in March 2012. They coursed in waves throughout the Solar System. When the waves met the charged particles Voyager 1 was swimming in, there was a resonating, a twang in the electromagnetic field. Some other instruments could pick that up well. It was confirmation that Voyager 1 was out and away.

September 2013. The announcement was made to much celebration.

But in December 2014, there was a surprise.

Tsunamis

When the charged particles from the Sun, called a coronal mass ejection, meet the sea of charged particles in the ISM, it’s like a big wave hitting a placid shore. There is a tsunami, a disturbance spreading outward like ripples in water. Scientists don’t know how potent these tsunamis can be, but they assumed not too much because of the distances involved as well as the timescales.

They were wrong. On December 15, NASA reported that Voyager 1 was still recording the effects of a tsunami that had been unleashed 10 months ago, in February. As Don Gurnett, professor of physics at the University of Iowa, noted, “Most people would have thought the interstellar medium would have been smooth and quiet. But these shock waves seem to be more common than we thought.”

Just like a small ball floating on the surface of a pond bobs up and down when ripples pass under it, Voyager 1’s instruments pick up a bobbing of the electromagnetic field around it. These oscillations can be translated to and relayed as a sound with rising and falling pitches. Listen to it here.

One of the telltale signs that Voyager 1 is in interstellar space is that the sea of particles – or plasma – it’s cruising through gets thicker, as if more viscous. Based on observations, the plasma density has been increasing the farther out Voyager 1 goes. “Is that because the interstellar medium is denser as Voyager moves away from the heliosphere, or is it from the shock wave itself? We don’t know yet,” said Ed Stone, project scientist for the Voyager mission at Caltech.

If you’ve listened to the audio file, you’ll see how eerie it feels. The Sun’s coronal mass ejection behaves like a lighthouse in this sense. As its light – in the form of the charged particles – sweeps through space, the little boat called Voyager 1 finds its way in a rough and uncharted sea, one bob at a time. Here’s to the Sun keeping it going.

 

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A new LHC: 10 things to look out for

Through an extraordinary routine, the most powerful machine built by humankind is slowly but surely gearing up for its relaunch in March 2015. The Large Hadron Collider (LHC), straddling the national borders of France and Switzerland, will reawaken after two years of upgrades and fixes to smash protons at nearly twice the energy it did during its first run that ended in March 2012. Here are 10 things to look out for: five upgrades and five possible exciting discoveries.

Technical advancements

  1. Higher collision energy – In its previous run, each beam of protons destined for collision with other beams was accelerated to 3.5-4 TeV. By May 2015, each beam will be accelerated to 6.5-7 TeV. By doubling the collision energy, scientists hope to be able to observe higher-energy phenomena, such as heavier, more elusive particles.
  2. Higher collision frequency – Each beam has bunches of protons that are collided with other oncoming bunches at a fixed frequency. During the previous run, this frequency was once every 50 nanoseconds. In the new run, this will be doubled to once every 25 nanoseconds. With more collisions happening per unit time, rarer phenomena will happen more frequently and become easier to spot.
  3. Higher instantaneous luminosity – This is the detectability of particles per second. It will be increased by 10 times, to 1 × 1034 per cm2 per second. By 2022, engineers will aim to increase it to 7.73 × 1034 per cm2 per second.
  4. New pixel sensors – An extra layer of pixel sensors, to handle the higher luminosity regime, will be added around the beam pipe within the ATLAS and CMS detectors. While the CMS was built with higher luminosities in mind, ATLAS wasn’t, and its pixel sensors are expected to wear out within a year. As an intermediate solution, a temporary layer of sensors will be added to last until 2018.
  5. New neutron shields – Because of the doubled collision energy and frequency, instruments could be damaged by high-energy neutrons flying out of the beam pipe. To prevent this, advanced neutron shields will be screwed on around the pipe.

Research advancements

  1. Dark matter – The LHC is adept at finding particles both fundamental and composite previously unseen before. One area of physics desperately looking for a particle of its own is dark matter. It’s only natural for both quests to converge at the collider. A leader candidate particle for dark matter is the WIMP: weakly-interacting massive particle. If the LHC finds it, or finds something like it, it could be the next big thing after the Higgs boson, perhaps bigger.
  2. Dark energy – The universe is expanding at an accelerating pace. There is a uniform field of energy pervading it throughout that is causing this expansion, called the dark energy field. The source of dark energy’s potential is the vacuum of space, where extremely short-lived particles continuously pop in and out of existence. But to drive the expansion of the entire universe, the vacuum’s potential should be 10120 times what observations show it to be. At the LHC, the study of fundamental particles could drive better understanding of what the vacuum actually holds and where dark energy’s potential comes from.
  3. Supersymmetry – The Standard Model of particle physics defines humankind’s understanding of the behavior of all known fundamental particles. However, some of their properties are puzzling. For example, some natural forces are too strong for no known reason; some particles are too light. For this, physicists have a theory of particulate interactions called supersymmetry, SUSY for short. And SUSY predicts the existence of some particles that don’t exist in the Model yet, called supersymmetric partners. These are heavy particles that could show themselves in the LHC’s new higher-energy regime. Like with the dark matter WIMPs, finding a SUSY particle could by a Nobel Prize-winner.
  4. Higgs boson – One particle that’s too light in the Standard Model is the Higgs boson. As a result, physicists think it might not be the only Higgs boson out there. Perhaps there are others with the same properties but weigh lesser or more.
  5. Antimatter reactions – Among the class of particles called mesons, one – designated B0 – holds the clue to answering a question that has astrophysicists stymied for decades: Why does the universe have more matter than antimatter if, when it first came into existence, there were equal amounts of both? An older result from the LHC shows the B0 meson decays into more matter particles than antimatter ones. Probing further about why this is so will be another prominent quest of the LHC’s.

Bonus: Extra dimensions – Many alternate theories of fundamental particles require the existence of extra dimensions. The way to look for them is to create extremely high energies and then look for particles that might pop into one of the three dimensions we occupy from another that we don’t.

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Why I like astronomy

A friend and I have entered into an arrangement to decide who between us is the better writer (I think he’s the better one, and he thinks I am). We each have picked a topic and then proceeded to write 800-1,500-word piece on both topics – mine and his.

Once done, we’ll send our pieces out to people we know outside of our mutual friends circles to rate each piece on a scale of 1 to 10. At the end of this exercise, we hope to be able to know who comes out on top. The first topic I’ll be writing on is ‘Why I like astronomy’.


Once Dawn arrives at Ceres, it will spiral in (from blue to red) toward the asteroid's surface and map it.

NASA Dawn’s path around the dwarf planet Ceres. Dawn spirals in (from blue to red) toward the asteroid’s surface and then maps it. Photo: NASA/JPL

It’s hard to imagine that one of the first things that fascinated the first intelligent humans, Homo sapiens, wasn’t the sky above. That it wasn’t the moon’s silver gaze and the multitude of pearly stars floating in a gentle sea of perfect black. That they didn’t look up in unfettered wonder at this celestial dance that played out in infinite patterns. That the moon’s coming and going and the stars’ weaving dance with unceasing regularity didn’t strike them with awe, loneliness, apprehension, fear and ultimately hope.

For a time, it’s hard to imagine that they awakened to witness anything else more unfathomable. Over the many millennia since, more passions have been kindled by astronomy than anything else – if only because looking into the universe helped us situate ourselves as equal humans in others’ eyes, and found our aspirations on the threshold of the universe’s inviting vastness and so understand who we are and where we come from.

Astronomy is the proto-pursuit, the first among all adventures. Almost all the ancient civilizations – Indian, American, Mesopotamian, Chineseh, Greek, Roman and Babylonian – built observatories to look deeper into the sky. Eclipses were logged for their mystifying effects on sunlight; lunar cycles followed for their effects on the ebb and flow of rivers; manuals conceived to use the stars for mariners to find their way on the high seas; and the Sun’s clockwork journeys through the sky used to lodge Earth at the centre of the universe.

What we got as a result were our first sense of spirituality, agriculture, trade and a purpose. It was clear even then that the lights in the sky had a lot to offer: it’s not for nothing that the earliest computer built (150-80 BC) was the enigmatic Antikythera mechanism, to predict the paths of the Sun, moon and the planets. Understanding them was, in many ways, a significant endeavour because all those civilizations understood that the sky was a resource they all shared and bonded over.

As humans fashioned better tools, so did we become wiser about what the objects in the sky were telling us. And with more wisdom came also more knowledge that we were unique not because we rested at the centre of the universe but because we were able to witness it. The inculcation of this inward gaze is no more exemplified than by the ardour of some of the Renaissance’s intellectual giants: Nicolaus Copernicus, Francis Bacon, Galileo Galilei and Johannes Kepler.

Kepler’s work was burned publicly while Galileo was imprisoned because their beliefs defied the conceit that the Church held close to its heart, that humankind was unique. These men – alongside starry-eyed painters, sculptors, writers, poets and travellers – are even today considered some of the greatest ever to have lived because they chose to learn from the humility, at a time of prevalent hubris, that astronomy availed them.

From the 17th century to now, these ‘greater ontologies’ have been dimmed in the world’s eyes not least because the sophistication of our tools has got ahead of us – thanks ironically to the collaborations their precursors made possible. Together with the universe’s boundless offerings, not everyone is considered to be an astronomer because being an astronomer has come to presuppose not just a curiosity for what lies beyond Earth’s point-like sphere of influence but also knowledge of the instruments and the formulae required to understand what it is that we’re really observing.

The conflict between particles and waves, between quantum field theory and the general theory of relativity, between the loony reality we’re uncovering at the smallest scales and the imperturbable motion of stars and galaxies floating on the guiding rails of each other’s gravities – these conflicts are what are shaping humankind’s greatest ambitions today, and our investigations of them are constantly usurped by the natural wonders of the universe. It may be endearing to note that offshoots of scientific advancements in astronomy have led to wonders that we take for granted: from the capacitive touchscreens on our smartphones to vacuum tubes that were the progenitors of much of the electronics industry to metallic alloys used in medical diagnostic equipment.

On the other hand, this historiography – the progression from the straightforwardness of the early years to the devious sophistication that floods scientific research today – is what makes me sad when the people with the authority to make great things possible are contrarily able to view astronomy as a pursuit indifferent to the human condition. It’s as if we have let our wonderment become victimised by the tragic memories of our own mismanagement.

Like the first Homo sapien, we need only look up at the sky again to entrance ourselves all over again. At the columns of yellow, green and pink that envelope Nordic horizons when the Sun discharges a burst of charged particles. At the Milky Way adorning the Atacama’s skies, itself crowned by the majestic Pleiades cluster. At Venus, Mars and Jupiter twinkling in the night to remind ourselves that other worlds don’t inhabit just our fantasies. At the unnamed colors that look back at us from the hearts of gas clouds and nebulae that bespeak the universe’s slow jaunt through time so we can yearn for beauty that is timeless.

At the bright flash of a supernova’s light disappearing into a black hole so we can reimagine our own mortality. At the deceptively complex laws of physics that swirl currents in little pools of rainwater with just the same finesse as in the spinning hearts of massive galaxies. At the awkward meeting of fundamental particles as they script the most wonderful wonders of the universe. At the sheer, incomprehensible differences in magnitude between the starstuff that makes us and the stars themselves, between the vice that haunts us and the patient virtue that awaits us.

 

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Why you should care about what the New Horizons probe will be up to

Artist's concept of the New Horizons spacecraft during its planned encounter with Pluto and its moon, Charon.

Artist’s concept of the New Horizons spacecraft during its planned encounter with Pluto and its moon, Charon. Image: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

How many space-probes do we know that have been asleep for years on end before waking up in time for their scientific missions? Rosetta was the most recent, and still fresh in the public imagination. Some time before that was Voyager 1. These probes’ journeys provide interesting perspective for the times we live in, set to receive knowledge garnered from unexplored worlds billions of kilometers and many light-hours away1. These two probes will soon be joined by New Horizons, which on December 6 will beep back into life as it approaches the Solar System’s most controversial (dwarf) planet: Pluto.

NASA launched New Horizons in January 2006. In all this time, it has been cruising through the interplanetary realm, flying by Jupiter in 2007 and using the gas giant’s prodigious gravity to give itself a boost. By the time it encounters Pluto, it will be 4.6 billion kilometers from Earth. Even at its velocity of more than 10 km/s[2], it has taken 9.5 years to get where it is: about 250 days away.

To ensure it has enough juice to perform observations and dodge space-dust, mission engineers placed New Horizons in hibernation mode, not letting it perform any intense operations that could’ve induced wear and tear or battery consumption, It only sent a weekly signal home saying if everything was okay on-board. On December 6, this will change. New Horizons will be stoked back to life at 3 pm EST (4.30 am IST the next day). Ninety minutes later, the probe will send a signal to Earth reporting that it’s awake (but because it’s so far away, the signal will take more than four hours to reach mission control). Then, scientists and engineers will take six weeks to prepare the probe for its encounter with Pluto, which is expected to start January 15, 2015.

Fortune favors the prepared

New Horizons’ uniqueness lies with the fact that, together with all the probes that have traveled as far as it has or beyond, its primary scientific mission is the farthest to date. This means that, unlike Voyager 1 & 2 and Pioneer 10 & 11, New Horizons will be more active than passive, if only by virtue of having more juice leftover. It will be able to prioritize what to investigate instead of having to rely on good fortune.

For example, in September 2013, scientists at NASA announced that they had received signals in August 2012 that indicated Voyager 1 could have finally crossed the outer bounds of the Solar System and drifted into the interstellar medium. Apparently, however, there had been some confusion about the probe’s exact environment around February 2012 itself. Scientists were unsure from which direction certain charged particles were coming in, which would’ve indicated if Voyager 1 had entered the interstellar medium.

The only instrument on-board that could’ve quickly resolved the issue was a plasma sensor that could take but intermittent readings because of low battery. As a result, the scientists had to rely on good fortune, which came in the form of a massive burst of charged particles from the Sun in March. The particles set off a pattern of disturbances in the electromagnetic field around the probe that provided sufficient data to settle the matter: Voyager 1 was out and away.

The Kuiper Belt objects

In fact, New Horizons is already in an area of many unknowns. When it crossed the orbit of Neptune in August 2014, it entered the territory of a belt of rocks called the Kuiper Belt. The Kuiper Belt Objects (KBOs) have as much to say about the history of the Solar System as the Sun at its center has to say about its future. KBOs comprise rocky bodies and dust that didn’t clump together in the system’s younger days to form planets. They’re the system’s residues, and they have been pulled inward or pushed outward according to whichever planets’ paths they crossed.

This ‘path-crossing’ is evident in intriguing ways. For one, the distance between the asteroid belt between the orbits of Mars and Jupiter and the Kuiper Belt is some 4.2 billion km. However, many of the bodies in the two belts have very similar physical and chemical characteristics, betraying a shared history. For another, Neptune’s moon Triton is the only moon with a retrograde orbit in the Solar System: it orbits Neptune in the direction opposite to its planet rotation. As a result, it is thought to have been captured by Neptune from among the KBOs.

These observations have encouraged a hypothetical model of the Solar System’s early years, when Jupiter didn’t form where it is right now – between the orbits of the asteroids and Saturn – but somewhere else. Then, it is thought to have moved outward, gathering up the KBOs, then inward dragging them along, depositing some of them in the asteroid belt, then moving back outward again, before ‘collecting’ some of them around itself, Saturn, Uranus and Neptune as some of their moons.

The confusion Jupiter might've caused during its journey through a younger Solar System.

The confusion Jupiter might’ve caused during its journey through a younger Solar System. Image: http://www.astro.washington.edu/courses/astro557/GrandTack2.pdf

However, it’s not known for sure if this is what happened even if it helps explain strange similarities between bodies now in different parts of the Solar System. New Horizons could investigate the KBOs (Pluto’s declassification as not-a-planet was because astronomers think it’s just a large KBO) for signatures of these plausible inter-planetary migrations.

Whether or not it finds anything significant will also have important implications for why the Solar System has no planets that are heavier than Earth but lighter than Uranus. This feature has found to be increasingly anomalous because the NASA Kepler mission, as of December 2011, had discovered 680 of such so-called ‘super-Earths’, out of 2,326 planetary candidates. The chemical composition of KBOs could hold the clue because of the way the largest planets of their kind in the Solar System are composed. Both Uranus and Neptune are composed mainly of ice and rock; the largest planets are both gas giants; and the largest rocky planet is Earth. Of these, Uranus and Neptune could’ve been much heavier but aren’t for unknown reasons.

Dwarf Lord of the rings

Another curiosity that New Horizons can and will investigate is if Pluto has rings. Despite it just being a giant lump of rock about 2,300 km across, Pluto has five known moons (Charon, Nix, Hydra, Kerberos and Styx) of its own. Astronomers are curious if it also boasts a ring system, populated with smaller KBOs and dust particles kicked up as a result of collisions between themselves. This will be a tricky investigation because the dust particles could be moving around at almost 50,000 km/hr. If any of them hit New Horizons, the impact could be like a bullet and damage critical systems on-board.

According to Simon Porter, one of the New Horizons mission scientists, his colleagues will try to avoid a worst-case scenario like this by turning the probe’s 2.1-meter-wide dish antenna to face toward incoming projectiles and act like a shield. (At the same time, this dish antenna is a vital part of New Horizons because it enables effective communication from as much as 7.5 billion km away.)

Ultimately, if and when New Horizons manages to get within 27,000 km of Pluto, it will start mapping the dwarf planet’s surface, looking for signs of craters and tectonic activity, and study its atmosphere in detail. It’s known that the Pluto’s surface has frozen methane and carbon monoxide, frozen because the surface temperature is -230 degrees Celsius. Further investigation of these features will help scientists determine if Pluto is a KBO or a small planet, and the features will themselves throw light on how KBOs could’ve interacted among themselves when the Solar System was forming, and how that could’ve influenced how, where and when planets formed.

Away and beyond

New Horizons will accumulate enough data in the process that it will take until late 2016 to completely transmit it to Earth. In the meantime, the probe will continue onward in its journey to studying KBOs. Already, using the Hubble space telescope, astronomers have selected three prospective Kuiper Belt denizens for New Horizons to study, designated PT1, PT2 and PT3. They’re located about 44 AU from the Sun, which means the probe will be able to reach them by 20203. Each measures about 30-55 km across. After the Pluto mission, New Horizons’ maneuverability will decrease, and the probe will rely on good ol’ fortune to study the three candidates.

Pluto is now about 40 AU (5.98 billion km) from the Sun. The Solar System, however, extends to a distance of at least 121 AU (18.1 billion km), based on where Voyager 1 encountered the interstellar medium. This is a region of space called the heliopause, where the stream of charged particles being constantly emitted by the Sun encounters streams of particles from other stars. Here, the Solar System ends. Between the KBOs and the heliopause is a vast region of space populated by scattered rocks.

An artist's conception of where the Voyager and Pioneer probes are relative to the heliopause.

An artist’s conception of where the Voyager and Pioneer probes are relative to the heliopause. Image: http://voyager.jpl.nasa.gov/mission/interstellar.html

The farther outward the probe goes, the further it will be able to investigate the history of the Solar System. It’s not coincidental that the as yet unanswered questions about the Solar System concern its past and the least explored regions of the Solar System are its outer fringes – fringes that span a radial distance of 41-times the distance between the Sun and Pluto (as it is now). In this not-so-empty space, the Sun’s influence is weak and steadily tapering off, vulnerable to particulate encroachments from neighboring stars.

It is hard to imagine that the Solar System could’ve formed without any external influences. The Sun was formed after a part of a larger gas cloud collapsed under its own gravitational strength, and the remaining gas, dust and debris went on to form the planets, asteroids, KBOs and even some comets. Beyond Pluto, until the heliopause and into the interstellar medium – as New Horizons sails into these regions, it will join a veteran fleet of probes looking for any clue they can find that will tell us how we came to be, and if we’re special at all.

Footnotes

1Fitting that they happen now because the 2010s is when the NASA Deep Space Network turns 50. (“From rovers on the surface of Mars to Voyager 1 near the edge of the solar system, spacecraft regularly call home to Earth. For five decades, the Deep Space Network has been at the other end of the line.” Wow!)

2But ideas travel faster. When New Horizons was launched, Pluto was still a planet.

3By this time, the James Webb Space Telescope is expected to be launched. Planned as a successor to the Hubble and Spitzer space telescopes, the JWST will be specialized to observe in the long-wavelength visible to mid-infrared parts of the spectrum, giving it more resolution than the Hubble had to study the KBOs.

Featured image credit: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
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Sauron’s singularity: Sucking in light but lighting up the universe

This composite image shows the central region of the spiral galaxy NGC 4151, dubbed the 'Eye of Sauron' by astronomers for its similarity to the eye of the malevolent character in 'The Lord of the Rings'.

This composite image shows the central region of the spiral galaxy NGC 4151, dubbed the ‘Eye of Sauron’ by astronomers for its similarity to the eye of the malevolent character in ‘The Lord of the Rings’. Image: X-ray: NASA/CXC/CfA/J.Wang et al.; Optical: Isaac Newton Group of Telescopes, La Palma/Jacobus Kapteyn Telescope, Radio: NSF/NRAO/VLA

When heavier stars run out of hydrogen to fuse into helium, the fusion reactions that keep the stars from imploding due to their own gravity become more difficult (as they infeasibly fuse helium into heavier elements) and eventually stop happening. At this stage, they blow away their outermost layer of gases and collapse into neutron stars (If the parent star is heavy enough, the neutron star collapses into a black hole).

The neutron star is an extremely dense, rapidly rotating body composed mostly of neutrons and ridden with powerful magnetic fields. These magnetic fields accelerate particles on and around some neutron stars and eject them in beams from the poles. Because the star is spinning, these beams periodically point toward and away from Earth, making them look like flashing points of light in the night sky.

For this reason, such neutron stars are called pulsars, and pulsars are used as ‘cosmic candlesticks’, relatively fixed points of light that astronomers use to gauge distances in the universe. Pulsars can remain stable for 10-100 million years, making them reliable on par with atomic clocks when it comes to keeping time as well.

The keys to their relevance for human observations are the stability and distinctness of the beams. Astronomers would use any other natural object like pulsars if only they emitted radiation that was long-lasting and distinguishable from the other light in the universe. Now, they might have a new kind of candidates starting with the ‘Eye of Sauron’.

That’s the common name of the galaxy NGC 4151, located about 40 million light-years from Earth. A group of Danish astrophysicists have measured the distance between the supermassive black hole at the heart of this galaxy and Earth by studying how it is heating up gas clouds and a ring of dust that surround it.

The clouds are heated as they’re compressed by the black hole’s intense gravitational pull. In the process, they emit ultraviolet radiation. The UV radiation then heats up a ring of dust orbiting the black hole at a large distance, and in turn the ring emits infrared radiation. Effectively, thanks to the thermal cascade, there are two concentric ‘zones’ of radiation around the singularity.

Astronomers from the Niels Bohr Institute at the University of Copenhagen used the twin Keck Telescopes in Hawaii and this effect to their advantage when trying to measure how far the black hole is from Earth. Darach Watson, an associate professor at the institute, explained,

Using telescopes on Earth, we [measured] the time delay between the ultraviolet light from the black hole and the subsequent infrared radiation emitted from the dust cloud.

Keeping in mind the speed of light, Watson’s team calculated the delay to be 30 light-days, corresponding to a distance of about 777 million km between the cloud of irradiated gas and the ring of dust.

If this weren’t cool enough, the astronomers then used a technique from 19th century (a.k.a. high school) optics to measure the distance between the black hole itself and Earth.

The most powerful astronomical telescopes are not built to observe electromagnetic radiation at all wavelengths because their resolution depends on the wavelength of the radiation they’re observing. Specifically, a telescope with a fixed lens diameter will have lower angular resolution (which is good) when observing radiation of lower wavelengths. So each of the 10-meter-wide Keck Telescopes will have an angular resolution of 8.75 arc-seconds when observing infrared emissions but 1.6 arc-seconds when observing UV light – an increase in resolution by 5.4-times.

But what makes Keck much better is a technique called interferometry. The two telescopes are separated by 85 meters, which makes their collective effective lens diameter 85 meters. The resultant interference pattern due to the difference in the time at which light reaches each of the lenses is then corrected for by computers, giving rise to an image of the object as if it were observed by an 85-meter-wide telescope.

Related: What is Very Long Baseline Interferometry?

Using interferometry, Watson and his colleagues were able to measure the diameter of the entire dust ring. As a result, they had two fixed distances in the night sky: the distance between the ring and the cloud of gas, and the width of the ring. The only thing left to find out the black hole’s distance from Earth was simple trigonometry, and a simple trigonometric calculation later, the astronomers had their answer: 62 million light-years.

Clouds of gas and rings of dust are common around supermassive black holes, which often reside at the center of large galaxies (the one at the Milky Way’s center is called Sagittarius A*). This means the ‘Eye of Sauron’ needn’t be an uncommon occurrence and could instead join pulsars in holding up candles in space’s dark for astronomers.

And coolness wasn’t the only outcome of the Niels Bohr Institute group’s experiment. Their work heralds a long-sought element of precision missing until now in measuring the masses of black holes. As Watson explained, again,

The calculations of the mass of the supermassive black holes at the heart of galaxies depends on two main factors: the rotational speed of the stars in the galaxy and how far it is from the black hole to the stars. The rotational speed can be observed and the distance from the black hole out to the rotating disc of stars can now be calculated precisely using the new method.

Watson & co. were able to find that the ‘Eye of Sauron’ was 40% heavier than expected.

So, not just coolness…

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… but also awesomeness.

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