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MU69: New Horizons’ Next Kuiper Belt Target Is One Big Mystery

mu-mu-land — Not as advertised? 2014 MU69 could be one big Kuiper Belt mess (NASA/JHU-APL/SwRI/Steve Gribben)

“All bound for Mu Mu Land” — The KLF, ‘Justified and Ancient’ (seems appropriate)

After visiting Pluto on July 14, 2015, NASA’s epic New Horizons mission soared into the great unknown, a.k.a. the Kuiper Belt. This strange region, which extends beyond Pluto’s orbit, is known to be populated with dwarf planets, comets, asteroids and junk that was left behind after the solar system’s formation, five billion years ago.

In an effort to better understand the solar system’s boondocks, New Horizons is on a trajectory that will create a second flyby opportunity. On New Year’s Day 2019, the spacecraft will buzz a mysterious object called 2014 MU69. But although we know this Kuiper Belt Object is out there, astronomers aren’t entirely sure what it is. And that’s a bit of a problem.

For two seconds on June 3, astronomers were presented with an opportunity to better observe MU69, but instead of clearing up its mystery the occultation event has created more questions than answers.

An occultation is when an object, like a distant asteroid, drifts in front of a background star. If astronomers time it perfectly, they can observe the star at the time of occultation in a bid to image the tiny shadow that will rapidly speed across our planet. And in the case of the June 3 event, dozens of mission team members and collaborators were ready and waiting along the predicted shadow track in South Africa and Argentina. In all, 100,000 images were taken of the star during the rapid occultation.

What they saw — or, indeed, didn’t see — is a bit of a conundrum.

“These data show that MU69 might not be as dark or as large as some expected,” said Marc Buie, a New Horizons science team member and occultation team leader from Southwest Research Institute (SwRI) in Boulder, Colo., in a statement.

Observations by the Hubble Space Telescope had previously estimated that MU69 is between 12- to 25-miles wide. That might be a pretty big overestimation by all accounts. And it may not be a single object at all.

“These results are telling us something really interesting,” said Alan Stern, New Horizons Principal Investigator also of SwRI. “The fact that we accomplished the occultation observations from every planned observing site but didn’t detect the object itself likely means that either MU69 is highly reflective and smaller than some expected, or it may be a binary or even a swarm of smaller bodies left from the time when the planets in our solar system formed.”

If it’s the latter, this could pose a problem for New Horizons.

Before the mission encountered Pluto in 2015, there was concern that the dwarf planet’s neighborhood might have been filled with debris. This concern was heightened after Pluto’s moons Styx and Kerberos were revealed by Hubble in 2011, only four years before New Horizons was set to barrel through the system. If there were more sub-resolution chunks near Pluto, they would have been regarded as collision risks.

Although New Horizons survived the Pluto encounter, if MU69 is a swarm of debris and not a solid object, mission scientists will have to assess the impact risk once again when New Horizons attempts its second flyby in 2019.

More occultations are forecast for July 10 and July 17, and NASA will also be flying its airborne observatory SOFIA through the occultation path on July 10 in hopes of better resolving MU69’s true nature.

So, as New Horizons speeds toward MU69, one of the most ancient objects in our sun’s domain, mystery and potential danger awaits.

What Will It Take To Blow Up Pluto?

“25 billion of your biggest bombs please. I’ll pay credit, thanks!”

"I love the smell of venting volatiles in the morning..."

The Pluto debate frustrates me, as you may have noticed. It’s not that I have particularly strong views about whether it should be called a planet or a dwarf planet or a plutoid or pygmy planetoid, it’s that I really don’t care; I actually see Pluto’s “demotion” as exciting progress in the field of Solar System science rather than any derogatory gesture aimed at Pluto. Pluto is still Pluto; it hasn’t been knocked out of orbit, it hasn’t even been “bombed” (unlike our poor old Moon), it’s just being filed under a different category.

A King Amongst Dwarfs

In my opinion, calling Pluto a “planet” was unworkable, especially after a bigger dwarf planet was discovered in 2005 by a team of astronomers led by Dr. Mike Brown. This dwarf planet was named Eris (or 136199 Eris) and at first it seemed like we had gained a tenth planet.

The “ten planets” thing was short lived, however. In recognition that Eris probably represented the beginning of a spate of discoveries of welterweight worlds, the International Astronomical Union (IAU) took a vote in 2006 and decided to redefine what constitutes a planet. Pluto was in the firing line, became a rounding error and was dropped from the planetary club.

But it wasn’t all bad for the little guy. Pluto was designated king of all “plutoids” (trans-Neptunian dwarf planets) in 2008, meaning another three dwarf planets now orbited the Sun with this designation (Eris, Haumea, and Makemake in addition to Pluto).

In a previous Astroengine article, I made the point (and I’m going to quote myself because I can):

Just so my opinion is known, I don’t care what Pluto is called. If NASA decided to explode Pluto as part of a Kuiper belt clearing project, then yes, I might be a bit annoyed; I’d even start a blog titled “Save Pluto.” But calling Pluto a dwarf planet (or the rather cute plutino) really doesn’t bother me.

I haven’t really thought much about this statement until, today, @PlutoKiller himself (Mike Brown) tweeted, “Seriously, what just happened? The entire discussion is on placing explosives in the solar system. Pluto has not even been mentioned.” I then fired off a reply saying something about building a New Horizons 2 and packing it with plutonium to which @PlutoKiller said, Evil Santa-style: “Just in time for Xmas.”

And then the penny dropped.

Kuiper Belt Cruelness

To be honest, I’m astonished I haven’t thought of this before. Looking at Mike’s Twitter feed should have been enough inspiration, but until I wondered down the bombing Pluto => plutonium enrichment => lets fly a shedload of plutonium to Pluto path, that I asked the question: How much energy is needed to completely destroy Pluto?

Now we’re talking! Time for some Kuiper belt mayhem!

I’m not talking about simply bombing Pluto and making a big crater, I’m not even talking about fire bombing all the volatiles out of its frozen surface, I want to remove Pluto from existence. Why do I want to do this? Well, for fun, and because @PlutoKiller himself said so. And it’s Halloween, so why not?

So how much energy is required to do this?

For this gargantuan task, I cheated and looked up the method used by Matt Springer over at Built on Facts to derive how much energy was required by the Star Wars Death Star to shred Earth. In that case, 2.2 × 10³² Joules was needed to totally erase our planet (that’s a week’s-worth of solar output). That’s a lot, right?

Plutoid Killing Equation

Now, energy is energy and mass is mass, let’s give Pluto the same treatment. Using the following equation (known henceforth as the “Plutoid Killing Equation”, or simply PluKE), we can find out how much energy we need to erase Pluto:

The equation that can turn a dwarf planet into dust, as derived by Matt Springer.

This equation is the total gravitational binding energy of a sphere of mass, M and radius, R. G is the Gravitational Constant. For Pluto, a sphere, its vital statistics are:

M_Pluto = 1.305 × 10²² kg

R_Pluto = 1.153 × 10⁶ m

and

G = 6.673 × 10^-11 m³ kg^-1 s^-2

Plugging the numbers into PluKE, we can derive the total energy required to kill Pluto, literally:

E_Pluto(dead) = 5.914×10²⁷ Joules

But what does this number mean? This is the bare minimum energy required to match the gravitational binding energy of Pluto. If you want to rip the dwarf planet apart (plus pyrotechnics and speeding debris), you’ll need a lot more energy. However, nearly 6×10²⁷ Joules (that’s a 6 followed by 27 zeros) delivered into Pluto in one second should give the little world a very bad day.

Tsar Very Much

But how can we “deliver” this vast quantity of energy in one second? I suspect that any super-advanced civilization hell-bent of wiping out planets will have a better idea of this than me, but using weapons that are available to modern man might be a good place to start. Forget the uber-powerful death ray emitted by the Death Star, that’s sci-fi. It may not be sci-fact, but how about sending some nuclear bombs to the Kuiper belt?

How many bombs will we need? Ten? Ten dozen? A thousand?

The most powerful nuclear weapon tested was the Soviet 58 MT Tsar Bomba in 1961. So if we know how much energy is released by one of those beasts, we should be able to work out how many we’ll need to send to the unsuspecting Pluto.

1 MT = 1 megaton of TNT = 4.184×10¹⁵ Joules

therefore, a single Tsar Bomba has the potential to release an energy of:

58 MT = 58 × 4.184×10¹⁵ Joules = 2.427×10¹⁷ Joules

We needed 6×10²⁷ Joules to wipe out Pluto, obviously the 2.4×10¹⁷ Joules a single bomb can deliver is woefully short of our goal. So how many Tsar Bomba weapons do we need?

(6×10²⁷ Joules) / (2.4×10¹⁷ Joules) = 2.5×10¹⁰

We need to build 25,000,000,000 nuclear bombs. 25 billion. Ouch.

Obviously, looking at this estimation, it is impossible to destroy a dwarf planet as puny as Pluto using the most powerful weapon known to man. Also, it’s worth keeping in mind that this is the bare minimum of energy that needs to be applied to Pluto to match its gravitational binding energy, so to destroy it, you’ll need a lot more bombs.

There’s also the question of how to distribute the weapons. Would you put them all in one place? Distribute them all around the globe? Perhaps burrow into the centre of the body? I suppose putting all the bombs in one place might be impressive, kicking a chunk of plutoid into space.

Now I must report these findings to @PlutoKiller himself, I fear he won’t be happy with the outcome of my calculations…

Pluto Could Still Be A Planet! (Who Cares?)

pluto_alone1

All right, that title was a little harsh, but I think you get the point. It’s not that I don’t love Pluto, Pluto is a fine little planet… dwarf planet… hold on, plutoid. It holds a certain charm and mystique, plus we have the mother of all NASA missions (New Horizons) gliding its way to the outer icy reaches of the Solar System — the Kuiper Belt to be precise — to take a look at Pluto, up close, for the first time. I can’t wait for 2015 when the spacecraft starts taking snapshots, it will be awesome.

But what of the small planety-thingy’s status? Is it still a planetary outcast, destined for a life on Cosmic Skid Row? Or is Pluto about to get the mother of all reprieves and be re-classified as a planet? Does it really matter?

The reason why I ask is that the whole “demotion” thing was seen as bad news. I actually saw it as an exciting development in Solar System exploration (but hoped it wouldn’t tarnish the little rock’s popularity all the same). In actuality, Pluto is 27% less massive than the recently discovered dwarf planet Eris, so how could Pluto still be called a planet? Should Eris be classified as a planet, then? In light of new dwarf planet discoveries, Pluto became a rounding error and had to be re-classified. The International Astronomical Union drew up some planetary rules and found that Pluto didn’t have the gravitational clout to clear its own orbit and so was re-classified as a dwarf planet in 2006.

Suddenly, Pluto had “fans” that took the re-classification personally and got angry at the IAU for throwing Pluto out of the planetary club. Their reason? Only 4% of IAU members were present for the re-classification vote, they saw it as a personal slight against the “9th planet.” Even the nutty state of Illinois was FURIOUS and reinstated Pluto as a planet… (just in the state of Illinois).

We’ve heard this emotional story of planetary bullying over and over, so I won’t go over the details again. The whole Pluto story has been widely covered, many people pointing the finger at the evil IAU 4%, some have even gone as far as saying this is evidence that there is a growing rift between the public and scientists (let’s take national votes on scientific decisions! That would be fun). But what does it really matter? Really.

Is the Pluto re-classification a breech of our human rights? How about planetary rights? Is it indicative of the number of idiot scientists who voted in the 2006 IAU poll? Is this an indicator of poor scientific thinking? Could a war be sparked over this atrocity? Was it really a ‘bad’ decision?

Just so my opinion is known, I don’t care what Pluto is called. If NASA decided to explode Pluto as part of a Kuiper belt clearing project, then yes, I might be a bit annoyed; I’d even start a blog titled “Save Pluto.” But calling Pluto a dwarf planet (or the rather cute plutino) really doesn’t bother me. It’s a consequence of scientific endeavour, despite the perceived “controversy.” As the legendary astronomer Patrick Moore said, “…you can call it whatever you like!” Pluto is still Pluto.

However, it looks like Pluto might be re-classified again… big yawn.

This time, heavy hitter Alan Stern, Principal Investigator for the New Horizons mission, weighed in with his opinion on the matter. “Any definition that allows a planet in one location but not another is unworkable. Take Earth. Move it to Pluto’s orbit, and it will be instantly disqualified as a planet,” Stern said.

This implies that if Earth was moved to the Kuiper belt, as things move a lot more sluggishly out there, a planet with the gravitational pull of the Earth couldn’t clear its orbit, therefore the “must clear its own orbit” criteria is a bad location-based definition for a planet. (I would argue that there’s every possibility that Earth could clear it’s own orbit at that distance given enough time, but what would I know, I’m no planetary physicist, but everyone seems to have an opinion about Pluto, so there’s mine.)

This analogy is a bit like saying a car driven down a country lane is a car. But a car driven on a freeway is a bike.

There is the counter argument to this case; if there was something as big as Mars, or even Earth, it may have tunnelled out a path through the Kuiper belt, thereby clearing its orbit. Alas, there appears to be no solid consensus as to the nature of this littered volume of space (at least until 2015), hence all the fuss.

Now there’s some big noise that the IAU will reconvene and discuss the Pluto hoopla again, giving a vague glimmer of hope to pro-planet plutonites that the 2006 decision will be overthrown. Alas, I very much doubt that as, quite frankly, there are more pressing (and more interesting) matters to discuss such as: what the hell hit Jupiter?! We should re-classify Jupiter as ‘the inner Solar System’s gaseous protector’!

Source: New Scientist

Is Pluto Affected by the Pioneer Anomaly?

From Pluto, looking at its icy moons in the Kuiper belt (NASA)

The Pioneer Effect is a mysterious observation of a number of man-made probes that venture through and beyond the Solar System. Originally noticed in the slight drift of the Pioneer 10 and Pioneer 11 spacecraft (launched in 1972 and 1973) from their calculated trajectories, scientists have been at a loss to explain the tiny, yet constant, extra-sunward acceleration.

Some theories suggest that invisible clouds of dark matter are slowing these probes down, causing them to be influenced by the Sun’s gravity more than expected. Other suggestions include ideas that Einstein’s theory of General Relativity needs to be tweaked when considering interplanetary distances.

However, there are other, more mundane ideas. Perhaps there is a tiny fuel leak in the probes’ mechanics, or the distribution of heat through the spacecraft is causing a preferential release of infrared photons from one side, nudging them off course.

Finding an answer to the Pioneer effect probably won’t surface any time soon, but it is an enduring mystery that could have a comparatively simple explanation, within the realms of known science, but there’s also the possibility that we could also be looking at some entirely new physics.

In an attempt to single out whether the Pioneer anomaly is an artefact with the spaceships themselves, or unknown in the physics of the Universe, astronomers decided to analyse the orbits of the planets in the outer Solar System. The rationale being that if this is a large-scale influence, some observable periodic effects should be evident in the orbit of Pluto.

So far, no effect, periodic or otherwise, has been observed in the orbit of Pluto. If the effect isn’t big enough to influence Pluto, does this mean we can narrow the search down to spaceship-specific artefacts?

Not so fast.

Gary Page and John Wallin from George Mason University in Virginia and David Dixon from Jornada Observatory in New Mexico, have published a paper pointing out that the suggestion that the Pioneer effect doesn’t influence Pluto is flawed. Pluto’s orbit is far less understood than the orbits of the inner Solar System planets, as, let’s face it, Pluto is far away.

We simply don’t possess the data required to cancel out the Pioneer effect on planetary bodies in the outer-Solar System to reach the conclusion the anomaly doesn’t influence Pluto.

“Of course, this does not mean that the Pioneer effect exists. It does mean that we cannot deny the existence of the Pioneer effect on the basis of motions of the Pluto as currently known.” — Page et al., 2009

So, back to the drawing board. This is a fascinating study into a true Solar System mystery; bets are on as to the real reason why our interplanetary probes are being knocked off course…

Source: The Physics arXiv Blog

Naming Pluto: The Trailer

I can’t emphasise enough how much I love this short film. It may only be 13 minutes long, but it is as small as it is mighty, much like the dwarf planet itself.

“Naming Pluto” documents the adventure of how Pluto got its name. Inevitably with most astronomical studies, there can be some controversy surrounding the naming of celestial objects, often depending on traditional naming protocol and who made the discovery first. The naming of Pluto on the other hand appears to take on a more natural tact, starting with a conversation in 1930 involving a little girl named Venetia Phair and her grandfather, over breakfast in Oxfordshire.

Father Films have just released a trailer for their magnificent film, giving you a taster as to what to expect. I had the pleasure of watching and reviewing a copy late last year, and I was blown away by the accuracy, wonder and history that can be packed into 13 minutes (note that the DVD has extras included, extending the content to 40 minutes). I fell in love with Pluto all over again – suddenly the fact that the IAU had demoted the planet to a dwarf planet (and then to a plutoid) didn’t matter any more. Written, directed and produced by Ginita Jimenez, Naming Pluto is in the true spirit of the International Year of Astronomy, capturing the excitement surrounding a tiny member of the Solar System with excellence. I wholeheartedly recommend this short film, it needs to be in your DVD collection! Patrick Moore is also at his best, giving the proceeds his unique style. And don’t just take it from me, Astronomy Now has also given the film a highly enthusiastic review.

Check out the Naming Pluto Facebook events page for more information »

You can purchase a copy of the DVD and poster from the Father Films website.

For more, check out my reviews of Naming Pluto on the Universe Today and Astroengine.com.

Ceres: Life? Pluto: Not So Much

The dwarf planet soap opera continues…

The dwarf planet Ceres. Fuzzy (NASA/Hubble)

Could the dwarf planet Ceres maintain life? Possibly, says a scientist from a German university. According to new research, this ex-asteroid (who did a deal with the IAU to sell out Pluto, trading in its asteroid status to become a dwarf planet, at the expense of Pluto being demoted from being a planet. Obviously) may have harboured microbial life near geothermal vents in hypothetical liquid oceans (I emphasise hypothetical). Not only that, but Ceres’ chilly microbes could have been kicked into space by meteorites, spreading life throughout the Solar System. Forget Mars (you’re looking too hard), forget Europa (a moon? With life? Pah), the new giver of life could be Ceres, the dwarf planet we know next to nothing about.

Then there’s Pluto. Not much chance of life there either (although it would be fun to speculate, there is methane there after all), but the hard-done-by newly-christened dwarf planet has a rather bizarre atmosphere. Its temperature profile is upside down. Oh, and Pluto has just been reunited with its planetary status… in Illinois only (because a governor really does know more about planets than 400 members of the International Astronomical Union).
Continue reading “Ceres: Life? Pluto: Not So Much”

Naming Pluto: A Review

Naming Pluto, the story of Venetia Phair (© Father Films)

When my copy of the “Naming Pluto” DVD arrived in the post, I was very excited. However, this wasn’t the original plan.

Only a few days earlier, the short film was being aired down the road at the Los Angeles Femme Festival in Beverly Hills and the film’s writer, producer and director Ginita Jimenez had invited me along. Alas, I couldn’t be there (really frustrating as you know how much I love premiers!), so Ginita kindly posted a copy to me.

I had little idea about the history of the naming of Pluto (and I only had a general knowledge about how and when it was discovered), so I was looking forward to being educated as well as entertained.

Fortunately, I had the night to myself to watch Naming Pluto and take notes for a future review of the short film (just posted on the Universe Today). So I dimmed the lights and started the DVD. For the next 13 minutes, I didn’t write a word…
Continue reading “Naming Pluto: A Review”

Strangest Kuiper Belt Objects: The Top Five

The Kuiper belt is strange. Most of this strangeness probably comes from the fact that we are only just beginning to uncover this mysterious region of the Solar System. Unlike the Oort Cloud which (possibly) lies beyond 3 × 10¹² km away (over 20,000 AU, or a whopping 0.3 light years), we can actually observe the objects inside the Kuiper belt as, compared to the Oort Cloud, the Kuiper belt is on our interplanetary doorstep.

But that doesn’t mean it’s close. The Kuiper belt exists in a region of space 30–55 AU from the Sun; this is where Pluto lives (as Pluto itself is a “Kuiper belt object”, or KBO). As astronomical techniques become more advanced however, we are able to discover more KBOs in the zoo of icy-rocky bodies that live in this region.

Having just written about an oddball pair of “highly split” KBOs, I feel compelled to list my top five favourite KBOs. Here are my favourites, as some are really funny-lookin’ and others have some serious personal issues…
Continue reading “Strangest Kuiper Belt Objects: The Top Five”