Tag Archives: kuiper belt

Focusing on Arrokoth promises to reveal the Kuiper Belt’s secrets

Out beyond the orbit of Neptune and the solar system’s seven other major planets lies a ring of icy bodies known as the Kuiper Belt. The disc that is 20 times as wide and an estimated 200 times as dense as the asteroid belt houses a wide array of objects, including its most famous inhabitant — the dwarf planet Pluto. But, it holds more than objects of ice and rock. The Kuiper Belt may hold the secrets of how the planets of the solar system formed, and the raw materials that created the worlds around us and our own planet. 

“The Kuiper Belt is a repository of the solar system’s most primordial material and the long-sought nursery from which most short-period comets originate,” explains David C. Jewitt, an astronomer based at the University of California, Los Angeles, who is renowned for his study of the solar system and its smaller bodies. “The scientific impact of the Kuiper Belt has been huge, in many ways reshaping our ideas about the formation and evolution of the Solar System.”

Researchers now stand on the verge of unlocking these secrets with the investigation of the Kuiper Belt contact binary Arrokoth (previously known as ‘Ultima Thule’). On January 2019, the object — named for the Native American word for ‘sky’ — became the most distant object ever visited by a man-made spacecraft.

“Most of what we know about the belt was determined using ground-based telescopes. As a result, Kuiper Belt studies have been limited to objects larger than about 100 km because the smaller ones are too faint to easily detect,” says Jewitt. “Now, 5 years after its flyby of the 2000-km-diameter Kuiper Belt object Pluto, NASA’s New Horizons spacecraft has provided the first close-up look at a small, cold classical Kuiper Belt object.”

The data collected by the New Horizons probe has allowed three separate teams of researchers to conduct the most in-depth investigation of a Kuiper Belt object ever undertaken. In the process, they discovered that our current knowledge of how these objects form is very likely incorrect. From all the evidence the three teams collected, it seems as Kuiper Belts form as a result of a far more delicate, low-velocity process than previously believed. As most astrophysicists believe that these objects — planetesimals — acted as the seeds from which the planets grew, this new model changes our idea of how the solar system formed.

How Kuiper Belt Bodies Get in shape

The majority of the clues as to Arrokoth’s low-velocity formation originate from its unusual binary lobed shape. The larger lobe is joined to the smaller lobe by an extremely narrow ‘neck.’ What is especially interesting about this shape — reminiscent of a bowling pin or a snowman — is that the lobes are perfectly aligned. 

Scientists have used all available New Horizons images of Arrokoth, taken from many angles, to determine its 3D shape, as shown in this animation. The shape provides additional insight into Arrokoth’s origins. The flattened shapes of each of Arrokoth’s lobes, as well as the remarkably close alignment of their poles and equators, point to an orderly, gentle merger of two objects formed from the same collapsing cloud of particles. Arrokoth has the physical features of a body that came together slowly, with ‘locally-sourced’ materials from a small part of the solar nebula. An object like Arrokoth wouldn’t have formed, or look the way it does, in a more chaotic accretion environment. (NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko)

John Spencer, Institute Scientist in the Department of Space Studies, Southwest Research Institute in Boulder, Colorado, led a team of researchers that reconstructed Arrokoth’s 3-dimensional shape from a series of high resolution black and white images. Spencer’s paper concludes that Arrokoth’s lobes are much flatter than was previously believed but despite this, both lobes are denser than expected.

William McKinnon, Professor of Earth and Planetary Sciences at the Califonia Institute of Technology, and his team ran simulations of different formation methods to see which conditions led to the shape recreated and Spencer and his colleagues.

Velocity simulations of the formation of Arrokoth show that the unique shape of the bi-lobed comtact binary could only be acheived by a low-velocity gathering of small particles. (W.B McKinnon, et al)
Velocity simulations of the formation of Arrokoth show that the unique shape of the bi-lobed contact binary could only be achieved by a low-velocity gathering of small particles. (W.B McKinnon, et al)

McKinnon and his team discovered that the shape of Arrokoth could only be achieved as a result of a low-velocity formation–around 3 m/s. This presents a problem to current theories of how planetesimals form.

The suggested method of planetesimal formation suggests high-velocity particles smashing together in a process called hierarchical accretion. The simulations that McKinnon produced suggest that such high-velocity collisions would not have created a larger body, but rather, would have blown it apart. The geometrical alignment of the larger and smaller lobes indicates to the team that they were once co-orbiting bodies which gradually lost angular momentum and spiralled together, resulting in a merger.

“Arrokoth’s delicate structure is difficult to reconcile with alternative models in which Arrokoth Kuiper Belt objects are fragments of larger objects shattered by energetic collisions,” Jewitt says. This supports a method of planetesimal formation called ‘cloud collapse.’

Jewitt, Science, (2020)

“A variety of evidence from Arrokoth points to gravitational collapse as the formation mechanism.  The evidence from the shape is probably most compelling,” William Grundy of Lowell Observatory says. “Gravitational collapse is a rapid but gentle process, that only draws material from a small region. Not the much more time consuming and violent process of hierarchical accretion – merging dust grains to make bigger ones, and so on up through pebbles, cobbles, boulders, incrementally larger and larger,
with more and more violent collisions as the things crashing into each other.”

Grundy, whose team analysed the thermal emissions from Arrokoth’s ‘winter’ side, goes on to explain that the speed at which cloud collapse occurs and the fact that all the material that feeds it is local to it means that all the Kuiper planetesimals should be fairly uniform.

Cold Classicals: Untouched and unpolluted

Arrokoth is part of a Kuiper Belt population referred to as ‘cold classicals,’ this particular family of bodies is important to astrophysicists researching the origins of the solar systems. This is because, at their distance from the Sun within the Kuiper Belt, they have remained virtually untouched by both other objects and by the violent radiation of the Sun.

As many of these objects, Arrokoth in particular, date back 4 billion years to the very origin of the solar system, they hold an uncontaminated record of the materials from which the solar system emerged and of the processes at play in its birth.

Arrokoth's relative smoothness can be seen from comparisons to comets found in other areas of the solar system (J. R. Spencer et al., Science10.1126/science.aay3999 (2020).
Arrokoth’s relative smoothness can be seen from comparisons to comets found in other areas of the solar system (J. R. Spencer et al., Science10.1126/science.aay3999 (2020).

Arrokoth has a relatively smooth surface in comparison with other comets, moons and planets within the solar system. It does show the signs of a few impacts, with one very noticeable 7km wide impact crater located of the smaller lobe. This few craters dotted across Arrokoth’s surface do seem to point to a few small high-velocity impacts. The characteristics of Arrokoth’s cratering allowed the team in infer its age of around 4 billion years. This places its birth right around the time the planets had begun to form in the solar system.

“The smooth, relatively un-cratered surface shows that Arrokoth is relatively pristine, so evidence of its formation hasn’t been destroyed by subsequent collisions,” Spencer explains. “The number of craters nevertheless indicates that the surface is very old, likely dating back to the time of accretion.

“The almost perfect alignment of the two lobes, and the lack of obvious damage where they meet, indicate gentle coalescence of two objects that formed in orbit around each other, something most easily accomplished by local cloud collapse.”

Heatseekers

As mentioned above, Will Grundy and his team were tasked with the analysis of thermal emissions in the radio band emitted by the side of Arrokoth facing away from the Sun.

W. M. Grundy et al., Science
10.1126/science.aay3705 (2020).

“We looked at the thermal emission at radio wavelengths from
Arrokoth’s winter night side.  Arrokoth is very cold, but it does still emit thermal radiation,” Grundy says. “The signal we saw was brighter, corresponding to a warmer temperature than expected for the winter surface temperature.  Our hypothesis is that we are seeing emission from below the surface, at depths where the warmth from last summer still lingers.”

Grundy’s team also looked at the colour imaging of Arrokoth with the aim of determining what it is composed of. “We looked at the variation of colour across the surface, finding it to be quite subtle,” he says. “There are variations in overall brightness, but the colour doesn’t change much from place to place, leading us to suspect that the brightness variations are more about regional differences in surface texture than compositional differences.”

The team determined that Arrokoth’s dark red colouration is likely to be a result of the presence of ‘messy’ molecular jumbles of organic materials that occur when radiation drives the construction of increasingly complex molecules–known as tholins.

“One open question is where Arrokoth’s tholins came from,” Grundy says. “Were they already present in the molecular cloud from which the Solar System formed?  Did they form in the protoplanetary nebula before Arrokoth accreted? Or did they form after Arrokoth accreted, through radiation from the Sun itself?”

The researcher says that all three are possible, but he considers the uniformity of Arrokoth’s colouration to favour the first two possibilities over the third. The team also searched Arrokoth for more recognisable organic molecules, spotting methanol–albeit frozen solid–but, not finding any trace of water. Something which came as a surprise to Grundy. “It was surprising not to see a clear signature of water ice since that’s such a common material in the outer solar system. Typically, comets have
around 1% methanol, relative to their water ice.”

The team believe that this disparity arises from the fact that Arrokoth accreted in a very distinct chemical environment at the extreme edge of the nebula which collapsed to create the solar system.

“If it was cold enough there for carbon monoxide (CO) and methane (CH4) to freeze as ice onto dust grains, that would enable chemical mechanisms that create methanol and potentially destroy water, too. But those mechanisms could only work where these gases are frozen solid,” Grundy says.  “Arrokoth appears to be sampling a region of the nebula where such conditions held. 

“We have not seen comets so rich in methanol, which probably means we have not seen comets that formed in this outermost part of the nebula.  Most of them probably originally formed closer to the Sun (or else at a different time in nebular history when the chemical conditions were somewhat different).”

Looking to future Kuiper Belt investigations

Investigating Kuiper Belt objects is no walk in the park, with difficulties arising from both the disc’s distance from the Sun and from the fact that Kuiper Belt objects tend to be very small. Grundy explains that as sunlight falls off by the square of its distance, object s as far away as the Kuiper Belt require the most powerful telescopes to do much of anything.

“Sending a spacecraft for a close-up look is great to do, but it took New Horizons 13 years to reach Arrokoth,” Grundy says. “It’ll probably be some time yet before another such object gets visited up-close by a spacecraft.”

Investigations of the Kuiper Belt aren't easy, the next flyby might be decades away ( Kuiper Belt Illustration – laurinemoreau.com)
Investigations of the Kuiper Belt aren’t easy, the next flyby might be decades away ( Kuiper Belt Illustration – laurinemoreau.com)

“For flybys, the journey times are very long–we flew for 13 years to get there–navigation is difficult because we don’t know the orbits of objects out there very well, we’d only been tracking Arrokoth for 4 years,” Spencer explains. “The round-trip light time is long, which makes controlling the spacecraft more challenging, and light levels are very low, so taking well-exposed, unblurred, images is difficult.”

Spencer adds that from Earth, objects like Arrokoth are mostly very faint, meaning only a small fraction of them have been discovered and learning about their detailed properties is difficult even with large telescopes. These difficulties mean that one of the things left to discover is just how common bi-lobed contact binaries like Arrokoth are in the Kuiper Belt. “Some evidence from lightcurves suggests up to 25% of cold classical could be contact binaries,” he says. ” We know that many of them are binaries composed of two objects orbiting each other, however.”

Fortunately, telescope technology promises to make leaps and bounds over the coming decades, with the launch of the space-based James Webb Space Telescope (JWST) in 2021 and the completion of the Atacama Desert based Extremely Large Telescope (ELT) in 2026.

“Both will help,” says Grundy.  “Larger telescopes are needed to collect more light and feed it to more sensitive instruments.  JWST and the new generation of extremely large telescopes set to come online over the coming years will enable new investigations of these objects.”

In terms of future spacecraft visits, Grundy believes that researchers and engineers should be thinking small, literally: “If technical advances were to enable highly miniaturized spacecraft to be flown to the Kuiper belt more quickly, that could enable a lot of things.  The big obstacles to doing that with today’sCubeSats are power, longevity, and communications, but the rapid advance of technology makes me hopeful that it will be possible to do a whole lot more with tiny little spacecraft within a few decades. 

“It’s funny how progress calls for ever bigger telescopes and ever smaller
spacecraft.”

 Future advances in telescope technology promised more detailed examinations of Kuiper Belt objects like Arrokoth. (NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/National Optical Astronomy Observatory)
Future advances in telescope technology promised more detailed examinations of Kuiper Belt objects like Arrokoth. (NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/National Optical Astronomy Observatory)

Of course one of the most lasting changes that result from this landmark triad of studies on Arrokoth published in Science is the move away from hierarchical formation models and the adoption of a gravitational or cloud collapse model to explain the creation of planetesimals. This shift will resolve one of the long-standing issues with the hierarchical model, the fact that they work quite well to grow things from dust size to pebble size, but once pebble size is reached, the particles quickly spiral-in toward the Sun. 

“I think it will shift the focus to the circumstances that trigger the collapse.  It’s a very fast way of making a planetesimal–decades instead of hundreds of millennia–but the circumstances have to be right for instabilities to concentrate solids enough for them to collapse,” Grundy explains. “It will be interesting to map out where and when planetesimals should form, what their size distributions should be, and where the solids that they are formed from should have originated.”


Original research:

W. M. Grundy et al., Science
10.1126/science.aay3705 (2020).

W. B. McKinnon et al.,
Science 10.1126/science.aay6620

J. R. Spencer et al., Science
10.1126/science.aay3999 (2020).

D. C. Jewitt et al., Science
10.1126/science.aba6889 (2020).

Arrokoth--or as it was previously known Ultima Thule--may reveal secrets about the formation of the solar system (NASA, JOHNS HOPKINS UNIVERSITY APPLIED PHYSICS LABORATORY, SOUTHWEST RESEARCH INSTITUTE, ROMAN TKACHENKO)

Arrokoth, the ‘Space Snowman’, sheds new light on how the solar system formed

Arrokoth--or as it was previously known Ultima Thule--may reveal secrets about the formation of the solar system (NASA, JOHNS HOPKINS UNIVERSITY APPLIED PHYSICS LABORATORY, SOUTHWEST RESEARCH INSTITUTE, ROMAN TKACHENKO)
Arrokoth–or as it was previously known Ultima Thule–may reveal secrets about the formation of the solar system (NASA, JOHNS HOPKINS UNIVERSITY APPLIED PHYSICS LABORATORY, SOUTHWEST RESEARCH INSTITUTE, ROMAN TKACHENKO)

Located beyond the orbit of Neptune and within the Kuiper Belt — a massive circumstellar disc of small remnants left over from the formation of the solar system — Arrokoth (previously known as ‘Ultima Thule’) represents the most distant and primitive object ever to visited by a man-made space probe. 

Revealed in a small amount of data collected during a January 2019 flyby conducted by the New Horizons probe, the double-lobed contact binary— or Kuiper Belt object 2014 MU69 to give it its formal name — is the subject of three new papers due to be published in the journal Science. The key findings of these studies were revealed at a press briefing held in Seattle, Washington, on 13th February 2020.

The research provides us with a stunningly detailed picture of the compact binary’s composition and origins and suggests a rethink of how planetary building blocks–planetesimals form.

“Data from Arrokoth has given us clues about the formation of planets and our cosmic origins,” says Marc Buie, of the Southwest Research Institute, who was part of the New Horizons team that first discovered the object. “We believe this ancient body, composed of two distinct lobes that merged into one entity, may harbour answers that contribute to our understanding of the origin of life on Earth.”

New Horizons Path of Exploration (NASA)

The authors believe that their results could help rule out a hierarchical formation model of planetesimal formation, in which objects from different areas of the nebula of gas and dust violently collide to create larger bodies.

The shape of Arrokoth, with its two distinctive lobes, seems to favour a much more delicate formation process, that of local cloud collapse. This would involve regions of the nebula collapsing with smaller particles gradually accumulating together.

If planetesimals form differently then previously modelled, the fact that they are the building blocks of the planets means that we may also have to revise our ideas of how the planets themselves form.

As the planetesimal is composed of pure and unchanged material, its detailed study could answer long-standing questions about the elements which were present during the solar system’s planet-formation phase.

“The mission of the New Horizon probe was to explore the solar system’s ‘third zone’,” Alan Stern, the principal investigator of the New Horizons mission says describing the Kuiper Belt where icy planetesimals and dwarf planets lurk. “It is the best-preserved region of the solar system, important for understanding its origins.”

Each of the three separate papers focuses on different aspects of Arrokoth’s formation and composition, offering new insights into planetesimals and the conditions and composition of the early solar system. 

Three papers, three lines of evidence pointing to a new paradigm of planetesimal formation

William McKinnon and his team investigated how Arrokoth got its unique binary shape discovering that its two ‘lobes’ were once separate independent bodies. 

McKinnon and his team believe that the two separate objects which comprise Arrokoth formed in the same vicinity joined together in a surprisingly gentle process. As hierarchical accretion, is anything but gentle McKinnon and his team think that Arrokoth formed as a result of a local collapse of the nebula. 

“They’re just touching, it’s almost as if they’re kissing,” McKinnon, Professor of Earth and Planetary Sciences at the California Institute of Technology about the two lobes of Arrokoth. “There’s no evidence that the merger of these two lobes was violent. There’s no sign of catastrophic disruption.

“The merger speed must have been very low.”

The two dominant methods of planetesimal formation. Observations of Arrokoth may have ruled out high-velocity model. (McKinnon)

Whilst McKinnon and his team focused on the formation of Arrokoth’s distinctive shape, researchers led by John Spencer were studying that shape in painstaking detail. 

Spencer and his colleagues reveal that Arrokoth’s binary lobes are flattened in shape with a greater volume than originally believed. They are also almost perfectly aligned. “This tells us these are not objects that just blundered together,” Spencer “They have orbited each other for a long time, gently drifting together.”

The team have also been able to ascertain details about the surface of the contact binary, describing in their paper a smooth face with only slight cratering. This means that Arrokoth stands out from previously visited bodies within the solar system, having been struck by very few other objects. The greater consequence is that Arrokoth’s composition is unpolluted and thus may represent our best chance of studying the building blocks of the solar system.

Other comets that form closer to the Sun evolve very quickly as a result of the intense environments they find themselves in. In comparison, planetesimals that form far away from the Sun remain relatively unchanged, in Arrokoth’s case, for 4 billion years.

Will Grundy and the research team he worked with were charged with investigating the composition, colour, and temperature of Arrokoth’s surface. They found that the planetesimal’s distinctive and uniform red hue is a result of the presence of unidentified complex organic molecules — molecules formed from carbon, nitrogen, oxygen amongst other elements–present with methanol ice.

Grundy’s paper puts forward several suggestions as to how this frozen methanol could have formed on the Kuiper Belt object, including formation by irradiation of mixed water and methane ice by cosmic rays. The team was unable to detect the presence of water on Arrokoth, but they believe it could yet be present, currently ‘masked’ or hidden from view. 

The uniformity of the compact binary’s surface colour and composition provide the third line of evidence in support of the theory that it formed as a result of local nebula collapse. 

Stern does not downplay the significance of this evidence supporting a new paradigm of planetesimal formation–local cloud collapse. Comparing it to the discovery of the Cosmic Background Radiation which finally settled competition between different models of the origin of the universe he says: “This is a wonderful scientific present. It is truly a watershed moment.”

Stern concludes that every one of the attributes of Arrokoth observed point towards the cloud collapse model. As for the future, he says that the New Horizons mission has inspired other researchers to revisit another occupant of the Kuiper Belt– the dwarf planet Pluto.

Stern also points out that even though the New Horizons probe has “plenty of gas left in the tank,” the ideal mission would study Pluto for a period of a few years before moving off and investigating other bodies in the Kuiper Belt.

“We’re pretty excited, but it’s going to take a lot of work.”

How Japanese astronomers discovered the most distant object in the Kuiper Belt with a $3,000 telescope

You might think that astronomy is restricted only to extremely powerful equipment and large teams — but it turns out that’s not always the case. Sometimes, little projects can have great achievements, too.

In this case, astronomers from the National Astronomical Observatory in Tokyo have discovered an object with a radius of only 1.3 kilometers, which lies a whopping 5 billion kilometers from Earth, in the so-called Kuiper Belt, near the outer edge of the solar system. To make it even better, the project’s price tag wasn’t astronomic, it was extremely cheap.

“We got top-notch results thanks largely to our ideas. Even little guys can beat giants,” said a team member.

Artistic depiction of the newly discovered object in the Kuiper Belt. Image credits: Ko Arimatsu.

The Kuiper Belt is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune. Pluto lies in the Kuiper Belt. The belt is also home to some of the oldest rocks in the solar system, and astronomers have long theorized that there are many small, kilometer-sized objects there, but no one’s ever found one. Until now, that is.

Researchers used a technique called “occultation,” which is fairly common in astronomy (with various setups). The method entails observing a large number of stars and noting every time an object passes in front of them, dimming their light in the process. The Japanese team placed two small (28 cm) telescopes on the roof of the Miyako open-air school on the Okinawa Prefecture, Japan, and monitored approximately 2.000 stars for a total of 60 hours. They managed to deduct the existence of a small object

The astronomers used 11-inch Celestron telescopes, which are worth about $3,000 each, as well as specialized cameras and astrographs.  The whole project cost just a bit over $30,000.

“Our team had less than 0.3 percent of the budget of large international projects,” he added. “We didn’t even have enough money to build a second dome to protect our second telescope,” said Arimasu. The team also has even more ambitious goals.

“Now that we know our system works, we will investigate the Edgeworth-Kuiper Belt in more detail. We also have our sights set on the still undiscovered Oort Cloud out beyond that.”

Arimatsu also says that in addition to confirming a longstanding theory and filling an important knowledge gap, this also paves the way for more studies by teams with smaller budgets.

“The new (observation) method can broaden research projects by making them easier to join for amateurs and others.”

The study has been published in Nature Astronomy.

 

Pluto Flyby.

New Horizons wakes up for its most remote target yet — Ultima Thule

NASA’s New Horizons awakens from its slumber in time for the farthest planetary encounter in history — a flyby of Ultima Thule.

Pluto Flyby.

3D rendered artist’s impression of New Horizons flying by Pluto.
Image credits Kevin Gill.

The historic encounter is scheduled to take place on New Year’s Day in 2019. Since it wouldn’t do to sleep during such an important meeting, NASA woke the craft from its 165-day-long hibernation on June 4. This was the second period of inactivity for the craft, both of which were meant to conserve energy.  The craft will remain active through to late 2020 to beam back all the data from its contact with Ultima and the wider Kuiper Belt.

Not in Kansas anymore

The Kuiper Belt isn’t exactly a stone’s throw away — except maybe if that stone is a meteorite. It’s similar to the asteroid belt between Mars and Jupiter, only much more massive, and much farther away. The Kuiper Belt lies between 4.5 to 7.5 billion kilometers (2.8 to 4.6 billion miles) away from the Sun, roughly 20 to 50 times astronomical units (AUs), the distance between the Earth and our star.

New Horizons has already traveled an impressive stretch of this distance. It went past Pluto and is currently cruising through the belt properly, some 3.7 billion miles (6 billion kilometers) from Earth.

On June 4th, NASA ended the craft’s energy-saving hibernation mode, which was initiated last December. Ground control — situated at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland — received confirmation that onboard systems have resumed normal activity on June 5 2:12 a.m. local time, via NASA’s Deep Space Network. So far, everything seems in order and all systems are coming online without a hitch, the ream reports.

They will spend the next three days collecting navigation data from New Horizons and transmitting commands to prepare it for its Ultima flyby. It takes a lot of time to send a message that far into space, nearly 6 hours each way. The data traffic will include memory updates, subsystem and science-instrument diagnostics, as well as retrieval of information stored in New Horizon’s memory banks.

The whole process is estimated to take about two months, the team adds. On August 13th, the team will take the probe out of its stabilizing spin state. In mid- to late-August, they plan to instruct it to make distant observations of Ultima in order to refine its course towards the object. Its small size (about 20 to 23 miles in diameter) and the lack of light will make Ultima Thule hard to spot, but the team is anxious to try — this would be the first time any human has seen the object.

“Our team is already deep into planning and simulations of our upcoming flyby of Ultima Thule and excited that New Horizons is now back in an active state to ready the bird for flyby operations, which will begin in late August,” said mission Principal Investigator Alan Stern.

New Horizons is roughly 262 million kilometers (162 million miles) from Ultima — a bit under two AUs — and is speeding towards its mysterious target at a speed of 1,223,420 kilometers (760,200 miles) per day. Which is a lot.

“Exiled” asteroid shouldn’t be where it is

In the dark, frozen wasteland that lies just beyond Neptune, few things really stand out — and now, astronomers have found one of them: a carbon-rich asteroid, the first asteroid of its kind to be discovered at the outskirts of our solar system.

Artistic depiction of the exiled asteroid 2004 EW95, the first carbon-rich asteroid confirmed to exist in the Kuiper Belt and a relic of the primordial solar system. Image credits: ESO/M. Kornmesser.

It really shouldn’t be there, and as it so often happens in such studies, researchers first thought it was a mistake. Astronomers would have expected this kind of space rock in the asteroid belt between Mars and Jupiter but instead, it was drifting along just beyond Neptune.

The asteroid, which was named 2004 EW95, might be the first of a new class of space objects lurking the frigid area we call the Kuiper belt — the circumstellar disc in the outer Solar System, extending outward from the orbit of Neptune.

So how did the asteroid, which likely originated in the inner parts of our solar system, migrate so much?

It probably has a lot to do with our solar systems’ gas giants, which, in their infancies, caused quite a ruckus in the solar systems. During their early days, the gas giants probably orbited much closer to the Sun than they do today. But they started their outwards migration not long after the solar system was formed, and as they did so, they created all sorts of chaos.

Among this chaos, chunks of ice and rock such as 2004 EW95 were hurled away, which explains how it could have gotten there — and it also supports previous theoretical models of early planetary evolution. But even more interestingly, this means that the asteroid (and others of its kind) could provide insight as to how the solar system looked in its earlier days.

A lone rock far away from home

It’s not the first time objects that originated in the inner solar system were found so far away, but none were confirmed to the level of quality of 2004 EW95. It all started when Tom Seccull, a doctoral student at Queen’s University Belfast in Northern Ireland, used the European Southern Observatory’s Very Large Telescope to look at the light signatures of icy objects in the Kuiper Belt. When they found a 90-mile-long object, located 2.5 billion miles from Earth, something just wasn’t right — the object wasn’t exhibiting the same properties as its neighbors. Further analysis revealed that the object did not share the same icy past as other rocks drifting nearby. Instead, it appeared to have formed in a hotter environment, closer to the Sun.

“When we first looked at this, we thought it was wrong,” said Mr. Seccull, the lead author of the paper published in The Astrophysical Journal Letters. “The rock had been altered by the presence of liquid water.”

The team also determined the asteroid’s chemistry, using a technique called spectrometry. Since Kuiper Belt Object 2004 EW95 has a strong spectrum, its light can be broken down into different wavelengths, enabling researchers to determine what the asteroid is made of. However, identifying the chemical composition of such a distant object is extremely difficult.

The dramatic distance and the asteroid’s relatively small size make it an extremely difficult target to track, and the fact that it features carbon molecules, which makes it appear darker in color, doesn’t make it any easier.

“It’s like observing a giant mountain of coal against the pitch-black canvas of the night sky,” said Thomas Puzia, an astronomer at the Pontificia Universidad Católica de Chile and co-author of the research paper.

Still, the team was able to overcome these difficulties, finding that the asteroid contains carbon, iron oxides, and phyllosilicates (sheet-like silicate minerals). This is the first object ever found in the Kuiper belt containing these elements, all of which indicate that the asteroid formed in the inner parts of the Solar System.

With all this information, the research team concluded that 2004 EW95 probably formed between Mars and Jupiter, and was dragged along as the gas giants moved to their current orbits, thus offering important information about the dynamics of the early solar system.

We should also probably be thankful for this migration of the gas giants. Astronomers have found strong evidence that in many cases, these planets don’t move outwards, and stay in very close orbit to the Sun, creating what is called Hot Jupiters. Hot Jupiters are believed to deter the formation of rocky planets such as the Earth.

Whatsmore, as they migrate, they can destroy everything in their path, including the proto-Earth. So we should be grateful that they moved in just the right way to allow our planet to be formed, and ultimately, enable a species of primates we call humans emerge and evolve on this blue dot we claim as home.

The study “2004 EW95: A Phyllosilicate-bearing Carbonaceous Asteroid in the Kuiper Belt” by T. Seccull et al., which appeared in The Astrophysical Journal Letters.

NASA’s New Horizons probe snaps farthest image from Earth

As the interplanetary New Horizons probe woke up from its hibernating slumber, it turned its telescopic camera toward a field of stars and took a picture — making history.

For a brief period of time, this New Horizons Long Range Reconnaissance Imager (LORRI) frame of the “Wishing Well” star cluster, was the farthest image ever made by a spacecraft, breaking a 27-year record set by Voyager 1. About two hours later, New Horizons later broke the record again. Image credits: NASA/JHUAPL/SwRI.

Launched in 2006, the New Horizons mission stayed true to its name. It performed an unprecedented flyby study of the Pluto system in 2015, offering a dramatic view of the dwarf planet and its satellites. Now, the shuttle is currently on its way to study one or more other Kuiper belt objects.

Most of the time, New Horizons is sleeping — hibernating, to save energy. But every once in a while, it wakes up, and it snaps a few photos which it then beams back to Earth. With its latest wake-up, it broke the record for the farthest image humanity has ever taken away from Earth. Two hours later, it broke it again.

“New Horizons has long been a mission of firsts — first to explore Pluto, first to explore the Kuiper Belt, fastest spacecraft ever launched,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado. “And now, we’ve been able to make images farther from Earth than any spacecraft in history.”

New Horizons has observed several Kuiper Belt objects (KBOs) and dwarf planets at unique phase angles, as well as so-called Centaurs — former KBOs in unstable orbits that cross the orbits of the giant planets on the edge of our solar system. These December 2017 false-color images of KBOs 2012 HZ84 (left) and 2012 HE85 are, for now, the farthest objects from Earth ever captured by a spacecraft. They’re also the closest-ever images of Kuiper Belt objects. Image credits: NASA/JHUAPL/SwRI

When you’re traveling through 700,000 miles (1.1 million kilometers) of space each day, nothing stands still. New Horizons is one of only five shuttles which has managed to reach the escape velocity required to exit the solar system. It’s not just taking awesome photos on its path, but also carrying measurements of the plasma, dust and neutral-gas environment along the way, enabling astronomers to better understand the outskirts of our solar system. Now, it’s heading towards the Kuiper Belt, the circumstellar disk surrounding our solar system.

The Kuiper Belt is similar to the asteroid belt but is far larger: 20 times as wide and 20 to 200 times as massive. Specifically, New Horizons is targeting 2014 MU69, a mysterious object (or pair of two objects) which Alan Stern, mission principal investigator from the Southwest Research Institute (SwRI), has called “provocative” and a “scientific bonanza.”

New Horizons is reportedly healthy and everything is functioning as planned. The next awakening is scheduled for June 4. When that happens, it will break the record again.

You can follow New Horizons’ epic adventure here.

Pluto and Charon. Image: NASA

Pluto – now in color, courtesy of New Horizon

These two dim dots are none other than Pluto, the dwarf plant, and Charon, its largest moon. Though it might not look like much, this is the first ever colored photograph of the two cosmic bodies ever taken. We have NASA’s New Horizons spacecraft to thank for this, which used its Ralph color imager to make the shot from 71 million miles away.

Pluto and Charon. Image: NASA

Pluto and Charon. Image: NASA

Even though this is very exciting, soon enough we’ll be treated to some very impressive photos as the probe gets closer and closer to Pluto, eventually making a flyby on July 17. In the meantime, NASA will release some more photos from the epic journey, as we’ve become used to (thank you, NASA!). Of course, New Horizon won’t stop there. After Pluto, it will delve into the Kuiper Belt –  a region of space filled with trillions of icy bodies, remnants of the early solar system – and beyond.

“It sounds like science fiction but it is not,” said Alan Stern, the mission’s principal investigator, Agence France-Presse reported.

“Three months from today, NASA’s New Horizons spacecraft will make the first exploration of the Pluto system, the Kuiper Belt and the farthest shore of exploration ever reached by humankind,” Stern said.

The 1,000 pound spacecraft was launched nine years ago from Earth and has since made its way through most of the inner solar system, at a pace of about a million miles a day. This makes it the fastest spacecraft ever launched, powered by a plutonium nuclear reactor.

Charon, Pluto’s largest moon, is about the size of Texas. Some papers were published suggesting that the moon might have a thin atmosphere or even a frozen ocean, so it will be very exciting to see what it holds on its surface once New Horizon creeps near.

“There’s no doubt, Charon is a rising star in terms of scientific interest, and we can’t wait to reveal it in detail in July,” said Leslie Young, deputy project scientist, NASA reported.

This montage of New Horizons images shows Jupiter and its volcanic moon Io, and were taken during the spacecraft's Jupiter flyby in early 2007. Image: NASA

This montage of New Horizons images shows Jupiter and its volcanic moon Io, and were taken during the spacecraft’s Jupiter flyby in early 2007. Image: NASA

Previously, New Horizon took some of the most outstanding photos of planets like Neptune or Jupiter, and moons like Io or Europa. The scientific and artistic contribution of the probe is thus invaluable.

“This is pure exploration. We’re going to turn points of light into a planet and a system of moons before your eyes!” Stern said, according to a NASA report.

“Nothing like this has been done in a quarter century and nothing like this is planned by any space agency ever again,” he said.