Is there any material natural or otherwise a free floating liquid that can exist in space?
No liquid can be completely stable in a vacuum, since all liquids have some non-zero vapour pressure, and so will evaporate at some rate. However some liquids have an exceptionally low vapour pressure, and so can be used in a vacuum.
The vapour pressure of silcone fluid DC705, which is used in diffusion pumps is 2.6e-8, and it is designed to function in a high vacuum.
If a location could be found at which it was warmed sufficiently to remain liquid (in deep space it would just freeze, whereas too close to the sun and its vapour pressure would rise) it could remain in a liquid state for some time. Not indefinitely but it could be stable for a while.
My answer is: superionic water, at high pressure and low temperature. During the superionic phase, the hydrogen and oxygen within water molecules behave bizarrely; hydrogen ions move like a liquid, inside of a solid crystal lattice of oxygen.
Derivation of answer, and references:
Any element or molecule will evaporate (essentially boil) in low enough pressure, even at extremely low temperatures; albeit slowly (by human standards).
Both extreme pressure and low temperature is necessary to prolong the lifespan (duration) of an element or molecule's liquidity.
Something contained must also be "free floating" (to comply with the terms of your question) - thus suggesting liquid hydrogen (or deuterium) seems a stretch, but it's a clue for the direction to look.
From the article: "Settling Arguments About Hydrogen With 168 Giant Lasers":
At ultracold temperatures, below -423 degrees Fahrenheit, hydrogen condenses into a liquid. It also turns into a liquid at higher temperatures when squeezed under immense pressure. The molecules remain intact, and this state of liquid hydrogen is an insulator - a poor conductor of electricity.
Under even higher pressures, the molecules break apart into individual atoms, and the electrons in the atoms are then able to flow freely and readily conduct electricity - the definition of a metal.
Liquid metallic hydrogen does not naturally occur on Earth - except possibly at the core. But at Jupiter, the solar system's largest planet, most of the hydrogen could be flowing as a liquid metal and generating the planet's powerful magnetic fields.
Preventing freezing (solidification) of the hydrogen is the key, and the use of pressure will alter the phase change diagram.
The article: "Two Pathways to Metallic Hydrogen and Deuterium" (by the Silvera Group, Department of Physics, Harvard) has some photos of liquid hydrogen:
"Images of hydrogen at different pressures and low temperature showing the progression from a transparent molecular solid to a black semiconducting solid to a brilliant shiny metal of hydrogen."
It was also realized that at a lower, but still high pressure and very high temperatures, there is a temperature driven transition to liquid atomic metallic hydrogen (LMH). This liquid-liquid phase transition is sometimes called the Plasma Phase Transition or the PPT. We have determined the phase line for LMH and liquid atomic deuterium for several values of P and T, as well as optical properties and optical conductivity. We observe isotopic differences in the phase lines.
LMH is the principle component of giant outer planets such as Jupiter and gives rise to its magnetic field via the dynamo.
BUT, there are the terms of your question (which the answerer ought not to fudge on): "Is there any material, natural or otherwise, a free floating liquid that can exist in space?"
So simply pressurizing hydrogen didn't seem to meet the requirements of "free flowing" (unless you'll accept it as one answer) - but it hinted at the direction I should look.
The clue led me to superionic water, at high pressure and low temperature.
From the Nature article: "Experimental evidence for superionic water ice using shock compression" (Nature Physicsvolume 14, pages297-302 (2018)) and also written up at LiveScience: "This Ice Is Nearly As Hot As the Sun. Scientists Have Now Made It on Earth":
It's both solid and liquid, it's 60 times denser than ordinary water ice, and it forms at temperatures almost as hot as the sun's surface.
It's superionic ice - and for the first time, scientists have made it in the lab.
This high-pressure form of water ice has long been thought to exist in the interiors of Uranus and Neptune. But until now, its existence was only theoretical.
Scientists first predicted the existence of a weird water phase that makes the substance both solid and liquid at the same time 30 years ago. It's also way denser than ordinary water ice because it forms only under extreme heat and pressure, such as those found inside giant planets. During the superionic phase, the hydrogen and oxygen within water molecules behave bizarrely; hydrogen ions move like a liquid, inside of a solid crystal lattice of oxygen.
Making the ice was complicated. First, the team compressed water into an ultrastrong cubic crystalline ice, in a different crystal form than what you see in ordinary ice cubes. To do that, the researchers used diamond anvil cells to apply 360,000 pounds per square inch (2.5 gigapascals (GPa) of pressure; that's about 25,000 times the atmospheric pressure on Earth). Next, the researchers heated and compressed the cells even further, using laser-driven shocks. Each crystal ice structure received up to six laser beams of more than 100 times that high pressure.
"Because we pre-compressed the water, there is less shock-heating than if we shock-compressed ambient liquid water," Millot said. The new method lets researchers "access much colder states at high pressure than in previous shock-compression studies."
Once the superionic ice was ready, the team moved quickly to analyze its optical and thermodynamic properties. They had only 10 to 20 nanoseconds to perform the work, before pressure waves released the compression, and the water dissolved. And the results were bizarre. They found that the ice melts at an extraordinary 8,540 degrees Fahrenheit (4,725 degrees Celsius ) at 29 million pounds per square inch (200 GPa) of pressure. That pressure is about 2 million times the atmospheric pressure on Earth
The new findings could provide a peek inside the interiors of planets such as Uranus and Neptune. Planetary scientists suggest these worlds' innards are composed of up to 65 percent water by mass, plus some ammonia and methane.
Thus, hydrogen can be liquid and "float freely" in space - but only in a lattice of oxygen, under the extreme pressures, at the core of one of our gas giants (or other similar objects in space).
Cosmic voids - vast underdense regions, forming an essential feature of the cosmic web and occupying most of the volume of the Universe - could contain as much as 20% of the 'normal' matter (i.e. the matter that makes up stars, planets, gas and dust) in the cosmos, .
Voids have typical sizes of hundreds of millions of light years and occupy about 90% of known space. Although their name suggests that voids are completely empty of galaxies, this is not actually true.
Voids: The huge spaces between galaxy clusters or between filaments (the largest-scale structures in the Universe), which contain very few, or no, galaxies.
- Big regions of empty space found amidst galaxy clusters and superclusters.
Volatiles - Chemical compounds that become gaseous at very low temperatures.
- Immense volumes of space in which few galaxies, and clusters of galaxies can be found
Volatile - Element or compound that vaporizes at low temperature. Water and carbon dioxide are examples of volatiles
Waning Crescent - The Moon's crescent phase that occurs just before new moon .
. Enormous regions of relatively empty space between galaxy superclusters.
Volatiles. Chemical compounds that are gaseous at low temperatures.
Volume. The amount of space occupied by a body or fluid.
to filaments: environmental transformations of galaxies in the SDSS L6
Teet Kuutma, Antti Tamm and Elmo Tempel
discovered was in the constellation of Bootes in 1981. It occupies 2% of the total universe.
are regions which contain something other than the considered material. Commonly the void is air, but it could also be vacuum, liquid, solid, or a different gas or gaseous mixture.
Large areas in the Universe where there are apparently few, if any, galaxies. This is in contrast to areas where large clusters of galaxies reside. See also large-scale structure
Volans See feature article .
28.3 The Distribution of Galaxies in Space
Volcanoes8.2 Earth's Crust
volume3.2 Newton's Great Synthesis .
The galaxies appear to be arranged in a network of strings, or filaments, surrounding large, relatively empty regions of space known as
measure some 100 Mpc across. For a time they were the largest objects in the universe known to astronomers.
rate are functions of the local values of density, temperature and the chemical composition only, then the structure of a star is uniquely determined by the mass and the chemical composition. (When isothermal cores occur in the interiors of stars, then multiple-valued solutions become possible.) [H76]
Observations of enormous numbers of galaxies seem to indicate that there are large regions that are more or less empty of galaxies these are called
. Other areas contain galaxy superclusters.
, our own Milky Way galaxy is about 100,000 light years from edge to edge. That's its diameter.
The arrangement of the superclusters and
looks like a bunch of soap bubbles or swiss cheese with the galaxies on the borders of the huge holes. Although the picture above is only a two-dimensional version of the three-dimensional map, you can still see the lacy, foamy structure.
- The Eridanus Supervoid (CBM Cold Spot/WMAP Cold Spot), or super
in general, are huge regions in space that are completely devoid of galaxies, and while several others are known, the Eridanus Supervoid stretches over about a billion light years, making it the biggest yet discovered.
, and filaments cause the large-scale structure of the universe to resemble foam bubbles.
The galaxies and clusters of galaxies that make up the visible universe are concentrated in a complex scaffold that surrounds a network of enormous cosmic
The magnetic lamellae are covered with a layer of aluminized mylar that also covers the
That is, the galaxies lie along the walls of the bubbles, and inside the bubbles are
Galaxies that are found in
, the nominally-empty tens-of-Mpc regions of space in the large scale structure of the universe. These essentially isolated galaxies comprise only about 7% of all galaxies. They are generally blue (star-forming, or "young") and gas-rich.
, chambers whose ceiling is the height of a relaxed Eudore's thickness. Storage chambers may be much thicker, depending on the nature of the items being kept.
There are regions with very little matter (called
) and other regions with large concentrations of galaxies (superclusters or even clusters of superclusters). Matter isn't evenly spread out but appears to be rather clumpy. This is an important characteristic of the Universe that we'll run into it later.
are estimated to comprise 25 to 35 percent of Phobos' volume) is inconsistent with an asteroidal origin. Observations of Phobos in the thermal infrared suggest a composition containing mainly phyllosilicates, which are well known from the surface of Mars.
It looks "spongy" because the patches are composed of small bright elements interlaced with dark
are caused by jets of cooler gas from the Sun's lower atmosphere, the chromosphere, which is at about 10,000 degrees Fahrenheit.
In nuclear engineering, the void coefficient is a number that can be used to estimate how much the reactivity of a nuclear reactor changes as
form in the reactor Neutron moderator or coolant.
from effecting neutronics and thermal hydraulics of the nuclear core on a global scale.
, and a higher-than-average temperature of the CMB in the direction of clusters.
Q: Do you believe?
Its walls are made of both dark and visible matter (in the form of billions of galaxies and great quantities of gases), and giant
are thought to lie between the web walls. Previously, astronomers have said they've mapped parts of the cosmic web using distant, bright quasars as a guide.
Observations indicate that clusters of galaxies are strewn in sheets and filaments surrounding large
and that as much as 90 percent of the mass in the universe may have escaped detection.
Various explanations have been given including globules of dust within the cluster, or
of diminishing stellar densities in the dark areas. Recent investigation favors an unusually low stellar density in the dark patches.
Note that while there are many
Removing the blocking filter within your DSLR camera requires disassembling the entire body, which also
New matter is constantly being created, and used to form new stars and galaxies which fill the
left as the previous generations expand away from each other.
Was there a big bang, a time when the whole Universe suddenly came into being? If so, .
These superclusters then form surfaces like the surfaces of bubbles, with virtual
in between (Margaret J. Geller, John P. Huchra and Valerie De Lapparen, 1986). In 1989, Geller and Huchra discovered this "Great Wall," a sheet of galaxies that extends for at least 500 million light-years, perhaps even more.
There are actually sheets (or walls) of galaxies surrounding vast
that are nearly deficient of galaxies. Clusters and chains of galaxies and clusters of galaxies are found across space where such walls intersect.
When a diagram is drawn of the universe it looks like a bubbly structure with huge sheet and filaments of galaxies that are surrounded by gigantic
Scientists have designed a computer model called the Millennium Simulation, to try to understand how the galaxy formed and its structure.
A simulation showing a section of the Universe at its broadest scale. A web of cosmic filaments forms a lattice of matter, enclosing vast
. Credit: Tiamat simulation, Greg Poole
The direction in which a galaxy spins depends on its mass, researchers have found.
We paid particular attention to the Milky Way's shadowy
, caused by light-blocking gas and dust between us and the billions of stars in our galaxy's disk. For the ancient Incas, these dark clouds, rather than outlines traced by bright stars, formed their constellations.
Lower density of low mass halos
Reduced number of low mass halos
Suppressed number of low mass halos within high mass halos
between structure remain empty (unlike CDM with empty halos filling the void)
late-formation of low mass halos
suppressed halo formation at high redshifts .
When the telescope is not powered up, you must be careful not to spin (rotate) the scope - in other words, change its azimuth. Doing so
the warranty if you break it. Only the altitude ("tilt") may be manually adjusted when the scope is not plugged in.
Dark nebulae, sometimes called absorption nebulae, are dust clouds free of nearby stars that rather than emitting or reflecting light absorb it and block our view of objects that lie beyond. They range from small black
only a few arcminutes across to the Great Rift which spans more than 100 degrees and is easily .
Clusters are then grouped together in superclusters which contain dozens of clusters. Superclusters are up to 30 Mpc across. Recent observations show that superclusters are arranged in sheets with huge
in between, and that matter in the universe is arranged in a filamentary structure.
SpaceBook home .
These galaxies are gathered together into great clusters and sheets, surrounding vast, empty
of space. The redshifts of external galaxies are believed (again, by general consensus) to be due to the expansion of space itself -- another result of the big bang.
Gravitation also acts to group billions of stars into galaxies and to group galaxies into clusters and superclusters, and gravitation also causes most galaxies to cluster along dense strandlike structures formed by dark matter, with enormous
Scientists calculate that there are at least 100 billion galaxies in the observable universe, each one brimming with stars. On a very large scale, they form a bubbly structure, in which vast sheets and filaments of galaxies surround gargantuan
Things are much the same at larger scales, with galaxies being separated by volumes of space filled with gas and dust. At the largest scale, where galaxy clusters and superclusters exist, you have a wispy network of large-scale structures consisting of dense filaments of matter and gigantic cosmic
to uneven distribution of matter soon after the big bang, when the volume of the universe was still small and those microwave started out as high-energy gamma rays. Their uneven distribution may be related to the observed fact that matter in today's universe seems to be clumped in distinct galaxies, with big
Once the orbit of an asteroid's moon has been established, it can be used to derive the density of the parent asteroid without knowing its mass. When that was done for Eugenia, its density turned out to be only 1.2 grams per cubic cm. That implies that Eugenia has large
Superclusters range in size from 100 million to 500 million light years and are usually embedded in large sheets and walls of galaxies surrounding large
in which very few galaxies exist. Superclusters formed in the early universe when matter clumped together under the influence of gravity.
foamed plastics Plastic materials, used primarily for insulation, in which a foaming agent is used to provide minute
to improve insulating qualities-often foamed in place within the structure. focal length The distance between the optical center of a lens, or the surface of a mirror, and its focus.
Mysteries of the Local Void: Scientists Map a Vast Emptiness Around the Milky Way
As the universe expands, the local void grows emptier.
Astronomers mapped out the Local Void — an extensive, empty region of space that borders the Milky Way — revealing new details about the structure of our cosmic neighborhood.
Although it was discovered more than 30 years ago, the Local Void's exact size and shape have remained a bit of a mystery.
The new study mapped the size and shape of the cosmic void using observations of the movement of galaxies to create a 3D map of the local universe, showing how the Local Void becomes "emptier" as the universe expands, officials with the University of Hawaii's Institute for Astronomy said in a statement.
The Local Void was discovered in 1987 by Brent Tully, an astronomer at the University of Hawaii who is also the lead author of the new study, and Richard Fisher, an astrophysicist at the National Radio Astronomy Observatory in Charlottesville, Virginia. The pair noted that while the Milky Way is surrounded by other galaxies and cosmic structures, our galaxy also sits at the edge of a large, empty region.
However, it was difficult to observe the Local Void since it is located behind the center of the Milky Way from our perspective here on Earth.
For this study, the team measured the motion of 18,000 galaxies to develop a map that shows the boundaries between where matter is present and where it is absent in order to outline the edge of the Local Void.
Measuring the empty region in our cosmic neighborhood helps weigh in on a longstanding astronomical mystery. While we know that the universe is expanding, scientists have wondered why the Milky Way, our largest neighboring galaxy Andromeda and smaller surrounding galaxies deviate from the speed of expansion by 1.3 million mph (600 kilometers per second).
Galaxies tend to move towards denser areas in the universe, pulled by the gravity of surrounding bodies in space, while moving away from the less populated regions. Therefore, the study found that at least half of this deviation is a combination of the gravitational tug by the Virgo Cluster, a nearby cluster of galaxies, and the expansion of the Local Void as it grows emptier while the universe continues to expand, according to the statement.
Depending on the temperature and pressure, the matter may transition from one state into another:
- Solids may melt into liquids
- Solids may sublimate into gases (sublimation)
- Liquids may vaporize into gases
- Liquids may freeze into solids
- Gases may condense into liquids
- Gases may deposit into solids (deposition)
Increasing pressure and decreasing temperature forces atoms and molecules closer to each other so their arrangement becomes more ordered. Gases become liquids liquids become solids. On the other hand, increasing temperature and decreasing pressure allows particles to move father apart. Solids become liquids liquids become gases. Depending on the conditions, a substance may skip a phase, so a solid may become a gas or a gas may become a solid without experiencing the liquid phase.
Probing the Cosmic Web
Astronomers are interested in the cosmic "web" of material that streams between galaxies and clusters. They ask where it's coming from, where it's headed, how warm it is, and how much there is of it.
They look mainly for hydrogen since it is the main element in space and emits light at a specific ultraviolet wavelength called Lyman-alpha. Earth's atmosphere blocks light at ultraviolet wavelengths, so Lyman-alpha is most easily observed from space. That means most instruments that observe it are above Earth's atmosphere. They're either aboard high-altitude balloons or on orbiting spacecraft. But, the light from the very distant universe that travels through the IGM has its wavelengths stretched by the expansion of the universe that is, the light arrives "red-shifted", which allows astronomers to detect the fingerprint of the Lyman-alpha signal in the light they get through the Cosmic Web Imager and other ground-based instruments.
Astronomers have focused in on light from objects that were active way back when the galaxy was only 2 billion years old. In cosmic terms, that's like looking at the universe when it was an infant. At that time, the first galaxies were ablaze with star formation. Some galaxies were just starting to form, colliding with each other to create larger and larger stellar cities. Many "blobs" out there turn out to be these just-starting-to-pull-themselves-together proto-galaxies. At least one that astronomers have studied turns out to be quite huge, three times larger than the Milky Way Galaxy (which itself is about 100,000 light-years in diameter). The Imager has also studied distant quasars, like the one shown above, to track their environments and activities. Quasars are very active "engines" in the hearts of galaxies. They're likely powered by black holes, which gobble up superheated material that's giving off strong radiation as it spirals into the black hole.
Bulk nanobubbles in the mineral and environmental areas: Updating research and applications
3.1.3 Hydrodynamic cavitation by axial flow shearing
The liquid flow (or a gas-liquid mixture) is split (divided) into several spiral rotating vortexes, moving along a special chamber and the discharge piping from the pump. This rotational movement is maintained until the kinetic energy is depleted, producing an intense shear through respective centrifugal forces, triggering nucleation and gas bubble formation by pressure fluctuation [ 107 , 109 , 110 ]
The Dissolved Air Flotation (DAF) process is a conventional method for treating waters and wastewaters in which the separation of solids from water occurs by bubbles generated by hydrodynamic cavitation, after depressurization of the air-saturated water stream through a flow constrictor [ 99–102 ]. The presence of NBs, generated jointly with microbubbles in DAF was discovered a few years ago by our group, and a bubble separation technique, based on the uprising movement of the microbubbles, abandoning the aqueous medium, was developed [ 13 , 14 , 17 , 69 ]. This allowed the analysis of aqueous dispersions containing only bulk NBs.
Azevedo et al. [ 13 ], studied (batch trials) the effects of air saturation pressure (Psat) and liquid surface tension on the NBs generation (size and concentration of NBs) by depressurization of air-saturated water through a needle valve. The most important contribution of their work was the effect observed at low saturation pressures (<3 bar), when the amount of dissolved air in water is lower, the numerical concentration of generated NBs steadily increases, particularly at low air/water interfacial tension ( Fig. 2 ). Under these conditions, a substantial decrease in the cloud of microbubbles (30–100 μm) was visually observed, and noticeably a hugely higher amount of NBs generated, of >10 9 bubbles/mL!
Fig. 2 . NBs concentration (density) as a function of saturation pressure at two aqueous surface tension values. Conditions: pH = 7 surface tension of 49 mN m −1 obtained using 100 mg L −1 α-Terpineol surface tension of 72.5 mN m −1 obtained using DI water. Measurements were performed with the NTA technique. Source: with permission of Azevedo et al. [ 13 ].
According to Henry's law, at high pressures, more air is dissolved in water and hence available to the growth of the gas nuclei formed after cavitation, maximizing the generation of MBs, instead of NBs. Then, because the concentration of generated MBs at Psat < 3 bar was notably low, their interaction with the bulk phase NBs was significantly reduced, and the NBs concentration increased.
Furthermore, the nanobubbles generation by hydrodynamic cavitation appears to depend on operating parameters similar to those studies of Takahashi et al. [ 111 ] on the minimum “energy” ΔF required for bubble formation:
where γ is the surface tension of the liquid, Psat is the air-in-liquid saturation pressure, and Po is the atmospheric pressure.
Accordingly, a certain amount of energy must be transferred to the liquid phase to form bubbles by a cavity phenomenon. Decreasing the air/liquid interfacial tension lessens the liquid/solid attrition, enhances the flow fluid velocity and increases the kinetics of bubble formation (precipitation and nucleation) at the flow constrictor.
Fig. 3 shows the effect of the water/air surface tension (modified with 100 mg.L −1 of α-terpineol) on the concentration of nanobubbles, taken data from Azevedo et al. [ 13 ] work. The lower the surface tension the higher is the concentration (1.5 × 10 9 bubbles/ml), in a linear proportion with R 2 = 0.91.
Fig. 3 . The concentration of bulk nanobubbles as a function of the water/air surface tension. The linear regression presented a correlation factor, R 2 = 0.91. The surface tension was modified by the addition of α-terpineol. Conditions: pH 7 Psat = 2.5 bar. Measurements were performed with the NTA technique. Data adapted with permission of Azevedo et al. [ 13 ].
If I were going to pull an epic heist on a diamond planet, wouldn’t hiding out in a universally massive void that is larger than galaxies (and has less going on than Kadykchan, Russia) be an excellent choice? Perhaps there we could start the first universal free trade black market. Maybe we could add a little activity to these voids and make them less… well, void. By definition, an astronomical void is a space with few to no galaxies in it. These voids, along with superclusters (a mosh pit of galaxy clusters) are thought to be the largest things in the Universe. These things are huge – and I mean these voids may reach up to 500 million light years across! Quick light travel recap: If you are two blocks from me and I turn a flashlight on and off, the light seems to reach your eyes almost instantaneously. But the light from the Sun takes roughly 8 minutes to reach Earth as it travels over 92 million miles. In some of these voids, you have to wait hundreds of millions of years for light to cross from one side to another. So in reality, for us to actually cross one or even just hide out in one is rather improbable (and don’t start thinking that traveling to one would be easy – they are pretty far away, too).
The closest void to us on Earth is the Local Void (clever, right?). This guy is 150 million light years across and sits at the edge of our local group of galaxies. It is believed that the center of the Local Void is at least 75 million light years from Earth. So far one dwarf galaxy, Eso 461-36, has been found traveling at 135 miles per second through the Local Void towards someplace more exciting. By comparison, the Milky Way and all its neighboring galaxies (the Local Cluster) are moving away from the void (due to gravity) at around 175 miles per second. Apparently this is not a popular cosmic “hang out” spot.
ESO 461-36 in the Local Void
Our next contender is the Boötes (boh-OH-teez) Void (or the Great Void, for the more dramatic), discovered in 1981 and located in the vicinity of the constellation of the same name. At 250 to 330 million light years across, the Boötes Void is one of the largest voids out there that we’ve discovered. So far 60 galaxies have been discovered in the Boötes Void and all of those are found in a tube shape running through the void. For a fun thought experiment consider the distance between us and our closest galactic neighbor, Andromeda. At about 2.5 million light years, this would only cover about 1% of the Boötes Void. If we are to use a rough estimate of about 1 galaxy every 10 million light years (4 times farther than Andromeda) there should be approximately 2,000 galaxies in the Boötes Void. It’s thought that this void might have been created by the merging of smaller voids. Expressing the vastness that is the Boötes Void, astronomer Greg Aldering said, “If the Milky Way had been in the center of the Boötes void, we wouldn’t have known there were other galaxies until the 1960s.” (For comparison, we first discovered other galaxies in the 1920s.)
The stars you see in the circle are actually in front of the void!
Credit: Richard Powell, An Atlas of the Universe
The next big nothing on our list is the Eridanus Supervoid, which is located in the direction of the constellation Eridanus, about 6 to 10 billion light years away. To be fair, this may not be a void at all. But if it is, this monstrosity is around 500 million light years across and would be one of the largest structures in the visible Universe. To give you an understanding of why we think this void is out there, we have to look at the Cosmic Radiation Background (CMB) of the Universe. Simply put, in a very young Universe everything was much closer together and much more dense. This density created a lot of heat, and as the Universe expanded it cooled. But the radiation from those early times is still visible, and that is the CMB. By looking at the CMB, scientists can find variations in temperature in the Universe, and these variances can show us where things are clustered (like galaxies) and where things are empty (voids). The clusters give off more energy than the voids and create these variances. One of the largest cold spots found is theorized to be this supervoid. There are definitely other theories about this cold spot, but that’s not what this blog is about.
The CMB cold spot
Credit: NASA/WMAP Science Team
What causes theses voids? Gravity’s very lengthy grasp likes to set everything up in nice packages in the Universe. So as life goes on in the cosmos, things start to aggregate towards each other into clusters. Like moons around a planet, planets around a star, and stars around a massive black hole (like in the Milky Way), galaxies cluster together into what we call, well, clusters. At any rate, when these clusters form, voids are left behind… and as time goes on, more and more of these clusters form, and the voids multiply and combine into more and bigger voids. Generally, with the standard model of the Universe, scientists can calculate how big these voids should be and what is inside them. But occasionally we get some surprises, as in the Eridanus Supervoid – it’s exceptionally big! But in science there are often more questions than answers.
A nice diagram to give you a sense of size (click to view larger)
Credit: Andrew Z. Colvin
Now that we’ve explored large nothings in the cosmos, maybe we can find a light at the end of our tunnel. And maybe that light could actually be a large burst of high energy gamma rays coming from my favorite thing in the Universe, a Magnetar.
If you have any questions that need to be answered or just want to comment on the awesome blog you just read, have at it and I may regard it in the next blog.
Experimental Analysis of Natural Convection Within a Thermosyphon
The heat transfer characteristics of a thermosyphon designed to passively cool cylindrical heat sources are experimentally studied. The analysis is based on recognizing the physics of the flow within different regions of the thermosyphon to develop empirical heat transfer correlations. The basic system consists of three concentric cylinders, with an outer channel between the outer two cylinders, and an inner channel between the inner two cylinders. Tests were conducted with two different process material container diameters, representing the inner cylinder, and several different power levels. The experimentally determined local and average Nu numbers for the inner channel are in good agreement with previous work for natural convection between vertical parallel plates, one uniformly heated and the other thermally insulated. The implication is that the heat transfer off of each surface is independent of the adjacent surface for sufficiently high Ra numbers. The heat transfer is independent because of limited interaction between the boundary layers at sufficiently high Ra numbers. As a result of the limited interaction, the maximum temperature within the system remained constant, or decreased slightly when the radii of the inner cylinders increased for the same amount of heat removal.
In another amazingly gorgeous image, Hubble has captured a unique planetary nebula nested inside an open star cluster. Both the cluster (NGC 2818A) and the nebula (NGC 2818) reside over 10,000 light-years away, in the southern constellation Pyxis (the Compass). This spectacular structure contains the outer layers of a sun-like star that were sent off into interstellar space during the star’s final stages of life. These glowing gaseous shrouds were shed by the star after it ran out of fuel to sustain the nuclear reactions in its core. Our own sun will undergo a similar process, but not for another 5 billion years or so. But what a beautiful way to go!
More about this image:
The image was taken in November 2008 with the Wide Field Planetary Camera 2. NGC 2818 is one of very few planetary nebulae in our galaxy located within an open cluster. The colors in the image represent a range of emissions coming from the clouds of the nebula: red represents nitrogen, green represents hydrogen, and blue represents oxygen.
Open clusters, in general, are loosely bound and they disperse over hundreds of millions of years. Stars that form planetary nebulae typically live for billions of years. Hence, it is rare that an open cluster survives long enough for one of its members to form a planetary nebula. This open cluster is particularly ancient, estimated to be nearly one billion years old.
Planetary nebulae can have extremely varied structures. NGC 2818 has a complex shape that is difficult to interpret. However, because of its location within the cluster, astronomers have access to information about the nebula, such as its age and distance, that might not otherwise be known.
Planetary nebulae fade away gradually over tens of thousands of years. The hot, remnant stellar core of NGC 2818 will eventually cool off for billions of years as a white dwarf.
Venus Possibly Had Continents, Oceans
A new look at data gathered from the Galileo spacecraft in 1990 reveals that Venus at one time may have been habitable, with evidence of past continents and oceans. In a flyby of Venus on the spacecraft’s journey to Jupiter, a near-infrared mapping instrument detected signatures which the researchers have interpreted as granite. An international team led by planetary scientist George Hashimoto, at Okayama University, Japan, found that Venus’s highland regions emitted less infrared radiation than its lowlands. One interpretation of this dichotomy, says the team’s new paper, is that the highlands are composed largely of ‘felsic’ rocks, particularly granite. Granite, which on Earth is found in continental crust, requires water for its formation.
The Galileo spacecraft was the first use of infrared to look at Venus. Scientists had believed that only radar could see through the dense clouds of sulfuric acid in Venus’s atmosphere to the surface. “Detecting the surface in the infrared is a breakthrough,” co-author Kevin Baines from JPL was quoted in an article in Nature.
The article also quoted another JPL scientist, David Crisp, who was not involved in this study as saying these new conclusions aren’t supported either by the available data or the team’s own models.
“We understand our paper doesn’t resolve everything,” responds co-author Seiji Sugita, a planetary scientist at the University of Tokyo. Sugita says the next step is to apply their models to data from the European Space Agency’s Venus Express spacecraft, which is already orbiting Venus, and the Japanese Space Agency’s Venus Climate Orbiter, scheduled for launch in 2010.
The possible presence of granite suggests that tectonic plate movement and continent formation may have occurred on Venus, as well as recycling of water and carbon between the planet’s mantle and atmosphere.
Venus is now hellishly hot and dry, with an atmosphere of 96% carbon dioxide and a surface temperature of around 460 degrees C, but some scientists think our neighboring planet may have once have been more like Earth.
Another scientist quoted in the Nature article, geophysicist Norm Sleep of Stanford University in California said Venus might have once been almost entirely underwater. “Although without further geochemical data, he adds, we don’t know whether this early ocean’s temperature was 30 degrees C or 150 degrees C,” he said.
But any ocean on Venus would have lasted only a few hundred million years. As the Sun became hotter and brighter, the planet experienced a runaway greenhouse effect. “Any life on Venus that hadn’t figured out how to colonize the cloud tops a billion years after the planet’s formation would have been in big trouble,” says Sleep.
Radio Astronomers Form Telescope the Size of Earth
Telescopes located all around the world are being used together to work in real-time as a single gigantic instrument. As part of the opening events for the International Year of Astronomy 2009 in Paris, (watch live) a nearly continuous 33-hour observation is being conducted on January 15-16. 17 telescopes in Asia, Australia, Europe, North America and South America, are taking part in the mammoth project.
Using an astronomical technique called electronic, real-time Very Long Baseline Interferometry, or e-VLBI, participating telescopes will observe the same object simultaneously. Data from each telescope will be streamed across the globe through high-speed optical networks to a purpose-built supercomputer at JIVE in the Netherlands. This machine acts as the focus of the giant distributed telescope, the largest real-time telescope ever, combining the signals collected from instruments across the world.
Link to a page that displays cumulative on-the-fly generated plots of the selected type. Approximately every 5 minutes a new image is generated, incorporating all the data collected so far they are being being built up as the experiment progresses.
“By combining information from such widely separated radio telescopes we can produce incredibly sharp images with up to one hundred times better resolution than those available from the best optical telescopes”, said Simon Garrington, Director of the UK’s MERLIN/VLBI National Facility. “It’s like being able to sit here in Manchester and read a newspaper in London”.
With e-VLBI the ability to send data electronically and combine it in real-time has the additional advantage of providing results to astronomers within hours of conducting an observation, rather than weeks later via the traditional VLBI method of recording data onto disks and shipping it to the correlator.
JIVE Director Huib Jan van Langevelde explained, “With VLBI we can zoom in on the most energetic events in the universe, and the new e-VLBI technique allows us to do this fast enough to catch such events on the time-scale that they occur and respond quickly.”
Was Galileo the First?
Italian Galileo Galilei has usually been attributed with making the first celestial observations with a telescope and then creating notations and drawings to record his observations. And that’s the focus of what’s being celebrated during this International Year of Astronomy. But a British historian is taking this opportunity to publicize the work of another astronomer, Thomas Harriot, who actually was the first person to create drawings of the what the Moon looks like through a telescope, doing so well before Galileo. Historian Allan Chapman says dated maps prove that Harriot drew Moon maps several months earlier than Galileo, in July 1609. You can hear Chapman talk about Harriot in today’s 365 Days of Astronomy Podcast.
Chapman says that according to historical documents, Harriot used a ‘Dutch trunke’ (telescope), and turned it towards the Moon on July 26, 1609, and created drawings, becoming the first astronomer to do so.
Historical documents show Galileo first observed the moons of Jupiter on January 7, 1610, and later made drawings of Earth’s moon.
Harriot’s crude drawings show a rough outline of the lunar terminator (the line marking the division between night and day on the Moon, as seen from the Earth) and includes a handful of features like the dark areas Mare Crisium, Mare Tranquilitatis and Mare Foecunditatis.
Harriot's drawing of the whole moon. Image: (c) Lord Egremont
Harriot went on to produce further maps from 1610 to 1613. Not all of these are dated, but they show an increasing level of detail. By 1613 he had created two maps of the whole Moon, with many identifiable features such as lunar craters that crucially are depicted in their correct relative positions.
Thomas Harriot. Credit: RAS
But Harriot remains relatively unknown. Unlike Galileo, he did not publish his drawings. Dr. Chapman attributes this to his comfortable position as a ‘well-maintained philosopher to a great and wealthy nobleman’ with a generous salary. Harriot had comfortable housing and a specially provided observing chamber on top of Sion House, all of which contrasted with Galileo’s financial pressures.
Dr. Chapman believes that the time has come to give Harriot the credit he deserves. “Thomas Harriot is an unsung hero of science. His drawings mark the beginning of the era of modern astronomy we now live in, where telescopes large and small give us extraordinary information about the Universe we inhabit.”
Ground-Based Telescopes Observe Atmospheres of Exoplanets
For the first time, astronomers have measured light emitted from extrasolar planets around sun-like stars using ground-based telescopes. The observations were obtained simultaneously and independently by two separate teams for two different planets. Incredibly, they were also able to determine properties of the exoplanets’ atmospheres as well. Measuring the light emitted from a planet at different wavelengths reveals the planet’s spectrum, which can be used to determine the planet’s day-side temperature. In addition, this spectrum can reveal many physical processes in the planet’s atmosphere, such as the presence of molecules like water, carbon monoxide and methane, and the redistribution of heat around the planet. “This first direct detection of light emitted by another planet, using existing telescopes on the ground, is a major milestone in the study of planets beyond our own Solar System,” said Professor Gary Davis, Director of the United Kingdom Infrared Telescope (UKIRT). “This is a very exciting scientific discovery.”
The measurements of the first planet, TrES-3b, were conducted by a team of Astronomers from the University of Leiden, using the William Herschel Telescope (WHT) on La Palma (Canary Islands, Spain) and the United Kingdom Infrared Telescope on Mauna Kea in Hawai`i. TrES-3b is in a very tight orbit around its host star, TrES-3, transiting the stellar disk once per 31 hours. For comparison, Mercury orbits the sun once every 88 days. TrES-3b is just a little larger than Jupiter, yet orbits around its parent star much closer than Mercury does, making it a “hot jupiter.”
UKIRT observations caught the planet transiting in front of the star, from which the size of the planet has been worked out extremely precisely. The WHT observations also show the moment the planet moves behind the star, and allow the strength of the planet light to be measured. Astronomers have been trying to observe this effect from the ground for many years, and this is the first success.
Ernst de Mooij, leader of the research team, said, “While a few such observations have been conducted previously from space, they involved measurements at long wavelengths, where the contrast in brightness between the planet and the star is much higher. These are not only the first ground-based observations of this kind, they are also the first to be conducted in the near-infrared, at wavelengths of 2 micron for this planet, where it emits most of its radiation.”
This image shows a comparison between the sizes of the orbits of TrES-3b and Mercury around the primary star. Note that while the orbits are to scale, the sizes of the planets and the star are not.
The researchers determined the temperature of TrES-3b to be a slightly over 2000 Kelvin. “Since we know how much energy it should receive by the type of its host star, this gives us insights into the thermal structure of the planet’s atmosphere,” added Dr. Ignas Snellen, “which is consistent with the prediction that this planet should have a so-called ‘inversion layer.’ It is absolutely amazing that we can now really probe the properties of such a distant world”.
An atmospheric inversion layer is a layer of air where the normal change of temperature with altitude reverses. Current theory says that there are two types of “hot jupiters,” one with an inversion layer, and one without. One theory is that the presence of an inversion layer would depend on the amount of light the planet receives from its star. If the inversion layer could be confirmed, for example by measurements at other wavelengths, these observations would fit in perfectly with this theory.
A second team has made a ground-based detection of a different extrasolar planet, OGLE-TR-56b,using the Southern Observatory’s Very Large Telescope. This planet is about 5,000 light-years away, located towards the center of the galaxy. The planet is quite hot its atmosphere is more than 4,400 degrees Fahrenheit (2,400 degrees Celsius). This is one of the hottest extrasolar planets detected.
The researchers say both landmark observations will open up a new window for studying exoplanets and their atmospheres using ground-based telescopes, and show great promise for using future extremely large telescopes which will have much higher sensitivity than the telescopes used today.
Source: Joint Astronomy Center
Where In The Universe Challenge #38
Are you up for another Where In The Universe Challenge? Take a look and see if you can name where in the Universe this image is from. Give yourself extra points if you can name the spacecraft responsible for the image. As usual, we’ll provide the image today, but won’t reveal the answer until tomorrow. This gives you a chance to mull over the image, and provide your answer/guess in the comment section — if you’re up to the challenge! Check back tomorrow on this same post to see how you did. Good luck!
UPDATE: (1/15) The answer has been posted below. No peeking before you make your guess!
As many of you guessed (knew), these are radar images taken by the Cassini spacecraft of Saturn’s moon Titan. The image shows dunes 330 feet (100 meters) high that run parallel to each other for hundreds of miles at Titan’s equator. One dune field runs more than 930 miles (1500 km) long.
The images look just like radar images of deserts in Africa, as seen below, showing that similar wind-driven processes might be taking place on Titan:
Top image courtesy Earth Sciences and Image Analysis Laboratory, NASA Johnson Space Center bottom image
Great job, everyone. Come back again next week for another WITU Challenge!
Fine Young Big Blue Cannibal Stars
Stars known as “blue stragglers” have stumped astronomers for years. Blue stragglers are found in open or globular clusters, and are hotter, bigger and bluer than other stars in the same vicinity. According to conventional theories, these massive stars should have died long ago because all stars in a cluster are born at the same time and should therefore be at a similar phase. Instead of being older, however, these massive rogue stars appear to be much younger than the other stars and are found in virtually every observed cluster. But now researchers have discovered these mysterious overweight stars are the result of ‘stellar cannibalism’ where plasma is gradually pulled from one star to another to form a massive, unusually hot star that appears younger than it is. The process takes place in binary stars – star systems consisting of two stars orbiting around their common center of mass. This helps to resolve a long standing mystery in stellar evolution.
Two theories for Blue Stragglers were that blue stragglers were either created through collisions with other stars or that one star in a binary system was ‘reborn’ by pulling matter off its companion.
The researchers, led by Dr. Christian Knigge from Southampton University and Professor Alison Sills from the McMaster University, looked at blue stragglers in 56 globular clusters. They found that the total number of blue stragglers in a given cluster did not correlate with predicted collision rate – dispelling the theory that blue stragglers are created through collisions with other stars.
They did, however, discover a connection between the total mass contained in the core of the globular cluster and the number of blue stragglers observed within in. Since more massive cores also contain more binary stars, they were able to infer a relationship between blue stragglers and binaries in globular clusters. They also showed that this conclusion is supported by preliminary observations that directly measured the abundance of binary stars in cluster cores. All of this points to “stellar cannibalism” as the primary mechanism for blue straggler formation.
“This is the strongest and most direct evidence to date that most blue stragglers, even those found in the cluster cores, are the offspring of two binary stars,” said Dr. Knigge. “In our future work we will want to determine whether the binary parents of blue stragglers evolve mostly in isolation, or whether dynamical encounters with other stars in the clusters are required somewhere along the line in order to explain our results.”
The research, which is part funded by the UK’s Science and Technology Facilities Council (STFC) will be published in the journal Nature on Thursday January 15.
The constellation of Serpens is unique – being the only one to be divided into two parts. Serpens Cauda represents the eastern half. Serpens was one of the 48 constellations listed by the 1st century astronomer Ptolemy and it remains one of the 88 modern constellations. The entire constellation spans 637 square degrees of sky and contains 9 main stars within its asterism and 57 Bayer Flamsteed designated stars within its confines. Serpens Caput is bordered by the constellations of Aquila, Sagittarius, Scutum and separated from its counterpart by Ophiuchus. Serpens Cauda can be seen by all observers located at latitudes between +80° and -80° and is best seen at culmination during the month of July.
In mythology, Serpens represents a huge snake held by the constellation Ophiuchus. It can either be referred to as simply “Serpens” or by its western half (Caput – the “Snake’s Head”) or its eastern half (Cauda – the “Snake’s Tail”). Ophiuchus was believed to have been the son of Apollo and a healer. According to legend, the snake is also meant to represent healing as it sheds its skin in rebirth.
Let’s begin our binocular tour of Serpens Cauda with its brightest star – Eta Serpentis – the “n” symbol on our map. Eta Serpentis is approximately 61 light years from Earth and it is an orange K-type giant star about 15 times more luminous than our Sun. Don’t forget Xi, the squiggle at the southern border, either… while it’s strictly a visual double star, this 105 light year distant group is very attractive in binoculars!
Are you ready for more? Then let’s head to M16 (RA 18 : 18.8 Dec -13 : 47). While the attendant open cluster NGC 6611 was discovered by Cheseaux in 1745-6, it was Charles Messier who cataloged the object as Messier 16. And he was the first to note the nearby nebula IC 4703, now commonly known as the Eagle. At 7000 light-years distant, this roughly 7th magnitude cluster and nebula can be spotted in binoculars, but at best it is only a hint. As part of the same giant cloud of gas and dust as neighboring M17, the Eagle is also a place of starbirth illuminated by these hot, high energy stellar youngsters which are only about five and a half million years old.
In small to mid-sized telescopes, the cluster of around 20 brighter stars comes alive with a faint nebulosity that tends to be brighter in three areas. For larger telescopes, low power is essential for Messier 16. With good conditions, it is very possible to see areas of dark obscuration and the wonderful notch where the “Pillars of Creation” are located. Immortalized by the Hubble Space Telescope, they won’t be nearly as grand or as colorful as the HST saw them, but what a thrill to know they are there!
For binoculars and all telescopes, let’s take a look a IC 4756 (RA 18 : 39.0 Dec +05 : 27). This huge, 5th magnitude open star cluster is sometimes referred to as “Graff’s Cluster”. Located about about 13,000 light years away from our solar system, you will see far more stars than you can count in this terrific field!
Comet Lulin is On the Way!
A new comet is swinging around the sun, and soon it will be more visible to stargazers, perhaps even with the naked eye. Both professional and amateur astronomers have been tracking this unusual comet, named Comet Lulin. Thanks to amateur astronomer Gregg Ruppel, who lives in the St. Louis, Missouri area for sharing images he has acquired of Comet Lulin. Gregg took the image above on January 11, 2009. The most interesting characteristic of this comet is its orbit. Lulin is actually moving in the opposite direction as the planets, so its apparent velocity will be quite fast. Estimates are it will be moving about 5 degrees a day across the sky, so when viewed with a telescope or binoculars, you may be able to see the comet’s apparent motion against the background stars. This is quite unusual! Today, January 14, the comet is at perihelion, closest to the sun. As it moves to its closest approach to Earth on February 24, Lulin is expected to brighten to naked-eye visibility in rural areas, (at best about magnitude 5 or 6) and will be observable low in the sky in an east-southeast direction before dawn.
Comet Lulin on January 8, 2009. Credit: Gregg Ruppel
The comet will pass 0.41 Astronomical Units from earth at its closest distance to Earth, about 14.5 times the distance between the Earth and the Moon. It has a parabolic trajectory, which means it may have never come this way before –this may be its first visit to the inner solar system
Lulin was jointly discovered by Asian astronomers in July of 2007. Quanzhi Ye from China first saw the comet on images obtained by Chi-Sheng Lin from Taiwan, at the Lu-lin Observatory.
The discovery of Comet Lulin (also known as C/ 2227 2007 N3) was part of the Lulin Sky Survey project to explore the various populations of small bodies in the solar system, especially objects that could be a hazard to the Earth.
It has both a tail and an anti-tail, visible in this image.
Lulin's Tails. Credit: Gregg Ruppel.
Thanks again to Gregg Ruppel for the great images of Comet Lulin. For more information about Lulin, see Gregg’s Astronomy Page, Quanzhi Ye’s page, Lu-lin Observatory, and the Visual Astronomy website.
Spaceweather.com also has a page of Lulin images. . And Aaron Slack has put together a page of links about Comet Lulin on his Caffeinated Astronomy blog. (Love the name of that blog!)
Of course, Lulin isn’t the pseudoscience theory of a 2012 comet.
The constellation of Serpens is unique – being the only one to be divided into two parts. Serpens Caput represents the western half. Serpens was one of the 48 constellations listed by the 1st century astronomer Ptolemy and it remains one of the 88 modern constellations. The entire constellation spans 637 square degrees of sky and contains 9 main stars within its asterism and 57 Bayer Flamsteed designated stars within its confines. Serpens Caput is bordered by the constellations of Hercules, Corona Borealis, Virgo, Libra, Bootes and separated from its counterpart by Ophiuchus. Serpens Caput can be seen by all observers located at latitudes between +80° and ?80° and is best seen at culmination during the month of July.
In mythology, Serpens represents a huge snake held by the constellation Ophiuchus. It can either be referred to as simply “Serpens” or by its western half (Caput – the “Snake’s Head”) or its eastern half (Cauda – the “Snake’s Tail”). Ophiuchus was believed to have been the son of Apollo and a healer. According to legend, the snake is also meant to represent healing as it sheds its skin in rebirth.
Let’s begin our binocular tour of Serpen Caput with its brightest star – Alpha Serpentis – the “a” symbol on our map. Alpha Serpentis goes by the proper name Unukalhai, meaning loosely the “heart of the serpent”. Alpha Serpentis is approximately 73.2 light years from Earth and it is a great binary star for a small telescope. The primary, Alpha Serpentis A is an orange K-type giant star about 15 times larger than our Sun and its 11th magnitude B star is about 58 arcseconds from the primary. But don’t stop there! If skies are steady, power up and keep looking for the 13th magnitude C star located 2.3 arcminutes from A.
Now, aim your telescope towards Theta – the ” symbol on our chart. Theta Serpentis is located 132 light years from our solar system and goes by the name of Alya, which means “fat tail”. Guess what? It’s also a great multiple star system! Both Theta-1 Serpentis and Theta-2 Serpentis are white A-type main sequence dwarf stars, very close in magnitude and separated by 22 arcseconds, but Theta Serpentis C is a yellow G-type star that is widely separated from this par by about 7 arc minutes.
For binoculars and all telescopes, let’s take a look a Messier 5 (RA 15 : 18.6 Dec +02 : 05). At nearly unaided eye visible, you’ll like this one! This fifth brightest globular cluster in the sky is considered one of the most ancient at 13 billion years old. Located further away from the dusty galactic center, resolution explodes as we move up in aperture. Easily seen as a round ball of unresolved stars in binoculars, small scopes begin to pick up individual stellar points at higher magnifications. Careful attention shows that M5 is not perfectly round. Its brightest 11th and 12th magnitude stars actually are randomly distributed but seem to array themselves in great arcs.
For a big telescope challenge, try NGC 6118 (RA 16 : 21.8 Dec -02 : 17). It is a very low surface brightness, 13th magnitude spiral galaxy, and although its fairly large, it’s pretty hard to see in small telescopes. This quality has given rise to the nickname the “Blinking Galaxy”, since it only seems to appear during averted vision – only to disappear if the angle isn’t right. About 80 million light-years away, NGC 6118 is a grand-design spiral seen at an angle, with a very small central bar and tightly wound spiral arms. Thank to imagining by the VLA, we know more about this galaxy than ever. In 2004 a supernova event was caught near the galaxy’s center – believed to be the collision of two binary stars!
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Why is the Solar System so Bizarre?
As alien planets around other stars are discovered, astronomers have tried to tackle and understand how our own solar system came to be.
The differences in the planets within our solar system have no easy explanation, and scientists are studying how planets are formed in hopes of better grasping the unique characteristics of our solar system.
This research could, in fact, get a boost from the hunt for alien worlds, some astronomers have said, particularly if patterns arise in their observations of extrasolar planetary systems.