Of small steps and giant leaps of collective imagination

The Wire
July 16, 2015

Is the M5 star cluster really out there? Credit: HST/ESA/NASA
Is the M5 star cluster really out there? Credit: HST/ESA/NASA

We may all harbour a gene that moves us to explore and find new realms of experience but the physical act of discovery has become far removed from the first principles of physics.

At 6.23 am on Wednesday, when a signal from the New Horizons probe near Pluto reached a giant antenna in Madrid, cheers went up around the world – with their epicentre focused on the Applied Physics Laboratory in Maryland, USA.

And the moment it received the signal, the antenna’s computer also relayed a message through the Internet that updated a webpage showing the world that New Horizons had phoned home. NASA TV was broadcasting a scene of celebration at the APL and Twitter was going berserk as usual. Subtract these instruments of communication and the memory of humankind’s rendezvous with Pluto on the morning of July 15 (IST) is delivered not by the bridge of logic but a leap of faith.

In a memorable article in Nature in 2012, the physicist Daniel Sarewitz made an argument that highlighted the strength and importance of good science communication in building scientific knowledge. Sarewitz contended that it was impossible for anyone but trained theoretical physicists to understand what the Higgs boson really was, how the Higgs mechanism that underpins it worked, or how any of them had been discovered at the Large Hadron Collider earlier that year. The reason, he said, was that a large part of high-energy physics is entirely mathematical, devoid of any physical counterparts, and explores nature in states the human condition could never physically encounter.

As a result, without the full knowledge of the mathematics involved, any lay person’s conviction in the existence of the Higgs boson would be punctured here and there with gaps in knowledge – gaps the person will be continuously ignoring in favour of the faith placed in the integrity of thousands of scientists and engineers working at the LHC, and in the comprehensibility of science writing. In other words, most people on the planet won’t know the Higgs boson exists but they’ll believe it does.

Such modularisation of knowledge – into blocks of information we know exist and other blocks we believe exist – becomes more apparent the greater the interaction with sophisticated technology. And paradoxically, the more we are insulated from it, the easier it is to enjoy its findings.

Consider the example of the Hubble space telescope, rightly called one of the greatest astronomical implements to have ever been devised by humankind.

Its impressive suite of five instruments, highly polished mirrors and advanced housing all enable it to see the universe in visible-to-ultraviolet light in exquisite detail. Its opaque engineering is inaccessible to most but this gap in public knowledge has been compensated many times over by the richness of its observations. In a sense, we no longer concern ourselves with how the telescope works because we have drunk our fill with what it has seen of the universe for us – a vast, multihued space filled with the light of a trillion stars. What Hubble has seen makes us comfortable conflating belief and knowledge.

The farther our gaze strays from home, the more we will become reliant on technology that is beyond the average person’s intellect to comprehend, on rules of physics that are increasingly removed from first principles, on science communication that is able to devise cleverer abstractions. Whether we like it or not, our experience, and memory, of exploration is becoming more belief-ridden.

Like the Hubble, then, has New Horizons entered a phase of transience, too? Not yet. Its Long-Range Reconnaissance Imager has captured spectacular images of Pluto, but none yet quite so spectacular as to mask our reliance on non-human actors to obtain them. We know the probe exists because the method of broadcasting an electromagnetic signal is somewhat easily understood, but then again most of us only believe that the probe is functioning normally. And this will increasingly be the case with the smaller scales we want to explore and the larger distances we want to travel.

Space probes have always been sophisticated bits of equipment but with the Internet – especially when NASA TV, DSN Now and  Twitter are the prioritised channels of worldwide information dissemination – there is a perpetual yet dissonant reminder of our reliance on technology, a reminder of the Voyager Moment of our times being a celebration of technological prowess rather than exploratory zeal.

Our moment was in fact a radio signal reaching Madrid, a barely romantic event. None of this is a lament but only a recognition of the growing discernibility of the gaps in our knowledge, of our isolation by chasms of entangled 1s and 0s from the greatest achievements of our times. To be sure, the ultimate benefactor is science but one that is increasingly built upon a body of evidence that is far too specialised to become something that can be treasured equally by all of us.

Probe encounters glitch 10 days ahead of historic rendezvous with Pluto

The Wire
July 6, 2015

In the last mile of its 3,464-day journey and only ten days away from a historic rendezvous with the dwarf planet Pluto, the New Horizons probe experienced an anomaly on July 4 and prompted the on-board computer to switch to ‘safe mode’. The event caused a communications blackout between New Horizons and mission control at the Applied Physics Laboratory, Maryland, for 90 minutes on Saturday. Now, the probe is transmitting telemetry signals that will help scientists fix it – hopefully in time for its encounter with Pluto and its moons.

And until it’s fixed, science missions – including the detailed pictures it’s been taking of Pluto and Charon of late – will be on pause. Not surprisingly, the incident will have the scientists and engineers operating the probenervous. As Alan Stern, the mission’s principal investigator, said in June, “There’s only one Pluto flyby planned in all of history, and it’s happening next month!”

New Horizons was launched by NASA on January 19, 2006, with the primary objective of studying Pluto’s surface and atmosphere up-close, as well as observe its moons Charon, Nix, Hydra, Styx and Kerberos. In order to reduce mission costs at the time of launch, New Horizons was not designed to land on Pluto but to fly by it at a distance of about 13,000 km. On planetary scales, that’s small and excellent enough to fetch the dwarf planet out of the blur.

That historic flyby is supposed to happen on July 14. By then, the on-board anomaly needs to be recognized and fixed or the scientists, and humankind, risk losing years of efforts and patient waiting. Nonetheless, if the issue is fixed after the probe has flown past Pluto, it will still be used to study the Plutonian neighbourhood of which we know little. This is the region of space containing the Kuiper Belt objects, a belt of asteroids like the one between the orbits of Mars and Jupiter but over 20-times wider and denser. They comprise the matter leftover after the Solar System’s planets had formed.

According to Emily Lakdawalla, a planetary scientist affiliated with the Planetary Society, the probe is on the right trajectory even on the safe mode. She also wrote that there were no pictures set to be taken by the probe on July 4, but some on July 5 and 6 that might be missed.

Safe modes are not an uncommon occurrence on the computers operating satellites and probes, and even rovers. They are in effect similar to how a computer running the Windows OS sometimes slips into safe-mode, often to eliminate a bug that threatens some critical function, by reverting to a very primitive state conducive to troubleshooting.

In March 2013, the Curiosity rover on Mars entered into safe-mode following a computer glitch. In the next two days, its controllers transmitted the necessary code for the software running the rover to fix itself, and the rover was back online again. More recently, in April 2015, the Rosetta probe that’s tracking comet 67P/C-G went into safe-mode after its computer lost contact with radio signals from Earth, thanks to dust blown from the comet interfering with the antennae.

However, what makes the troubleshooting tricky is that New Horizons is 4.8 billion km away – a distance that radio signals take 4.5 hours to travel. This means the total time taken for mission control to send a message to New Horizonsand receive a reply is nine hours, and that the problem is likely to be fixed over the course of the next few days. Until then, let’s keep out fingers crossed.

Update: At 8 am (IST) on July 6, NASA put out a statement saying the problem in the computer had been resolved and that New Horizons would be able to revert to its original science plan on July 7.

The investigation into the anomaly that caused New Horizons to enter “safe mode” on July 4 has concluded that no hardware or software fault occurred on the spacecraft. The underlying cause of the incident was a hard-to-detect timing flaw in the spacecraft command sequence that occurred during an operation to prepare for the close flyby. No similar operations are planned for the remainder of the Pluto encounter.

It added that the down-time will have had a minor effect on the probe’s science objectives in the two days.

Pluto-bound probe takes first colour images of the dwarf planet and its moon

The Wire
June 22, 2015

A GIF of Charon orbiting Pluto compiled using images taken by the New Horizons MVIC Color Imager between May 29 and June 3, 2015. Credit: NASA
Credit: NASA

It may not look like much, but this heavily pixelated GIF image is cause for celebration. It effectively cost a robotic space probe more than nine years of travel and $600 million in manufacturing and operational charges. But then again, that’s not why the image is (and must be) celebrated. That privilege goes to the fact that these are the first colour photographs of our most adored dwarf planet. Say hello to an orangeish Pluto, being orbited by a grayish Charon.

Technically, it’s wrong to say Charon orbits Pluto – the two bodies were recently observed by the probe, New Horizons, to be orbiting a point in space called the barycenter. The barycenter is always closer to the larger body, so Pluto’s orbital radius is much smaller than Charon’s (as the GIF below shows).

A GIF showing Pluto and Charon in a binary system, compiled using images taken by the New Horizons MVIC Color Imager. Credit: NASA
A GIF showing Pluto and Charon in a binary system, compiled using images taken by the New Horizons MVIC Color Imager. Credit: NASA

As New Horizons gets closer to Pluto, its images will become sharper, affording humankind its first glimpse of the dwarf planet as it actually looks – not as imaginative illustrators have depicted it over the years. Alex Parker, a planetary astronomer at the Southwest Research Institute, Texas, had computed a “histogram of hues” in April 2015 showing that most people who didn’t use the correct reddish hue when depicting Pluto went for blueish hues.

On July 14, 2015, we’ll have the sharpest images to date of Pluto and Charon as New Horizons will make the first of its planned flybys, the manoeuvres it was built for, as it will study the atmosphere and surface characteristics of the bodies (here’s why it matters). The image resolution then will be down to a few kilometers. Astronomers can’t wait. On June 16, the National Space Society put out an anthemic video about the New Horizons mission, calling Pluto and its moons “the farthest worlds to be explored by humankind”.

Studying our primal horizons at the Kuiper belt

In August this year, the New Horizons spacecraft will cross into the region of space beyond Neptune’s orbit. It won’t be the first human object to go this far: the two Voyager space probes have already done that, and then Pioneer 10 with them. What will be special about New Horizons is that it’ll be the only one with enough power to receive commands from Earth, perform observations, and relay its findings back. Unlike the Voyager and Pioneer probes, New Horizons will not be a symbolic, space-born artifact but the first fully functional scientific experiment to travel that far. To be fair, Voyager 1 at the cusp of the interstellar medium still has its ears open for out-of-the-ordinary stuff but it doesn’t have enough juice to turn its head.

From its new perch, New Horizons will be privy to the lives of a belt of bodies named for the astronomer Gerard Kuiper, who speculated on them in the 1950s. The Kuiper belt, like the asteroid belt between Mars and Jupiter, bears signatures of the formative days of the Solar System, which were quite tumultuous. Various studies of asteroids, Kuiper belt objects (KBOs) and satellite systems of the gas giants Jupiter and Saturn have shown that after the planets formed, they moved around quite a bit before settling in their current orbits. One interesting way we know this is because of some similar properties between the asteroid belt and the KBOs. Even though they’re so far apart (~4.2 billion km between them), how could they have had a shared history?

Look to Jupiter. According to one of the models of planetary formation, called the Grand Tack Model, Jupiter once came as close to the Sun as Mars is today, adulterating the asteroid belt with objects from the Kuiper belt its prodigious gravitational pull would’ve tugged along, before moving back. Then, according to the Nice Model, Jupiter pulled in more KBOs into orbit around itself – explaining why many moons of the ice- and gas-giants in that part of the Solar System look and feel like large KBOs. However, as compelling as these models seem, they’re far from being known to be absolute true. Astronomers need to make more observations.

That’s why it’s exciting that New Horizons is entering the vicinity of the Kuiper belt. Its findings would be both seminal and extremely important in understanding how the Solar System was born, why it has an anomalous constitution of planets, and how the ice giants Uranus and Neptune came to be.


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