In July of 2015, the New Horizons mission made history by being the first spacecraft to rendezvous with Pluto. In the course of conducting its flyby, the probe gathered volumes of data about Pluto’s surface, composition, atmosphere and system of moons. It also provided breathtaking images of Pluto’s “heart”, its frozen plains, mountain chains, and it’s mysterious “bladed terrain”.
Since that time, New Horizons has carried on to the Kuiper Belt for the sake of conducting more historic encounters. In preparation for these, the probe also established new records when it used its Long Range Reconnaissance Imager (LORRI) to take a series of long-distance pictures. These images, which have since been released to the public, have set the new record for the most distant images ever taken.
At present, the New Horizons probe is at a distance of 6.12 billion km (3.79 billion mi) from Earth. This means that images taken at this point are at a distance of 40.9 Astronomical Units (AUs), or the equivalent of about 41 times the distance between Earth and the Sun. This it slightly farther than the “Pale Blue Dot” image of Earth, which was snapped by the Voyager 1 mission when it was at a distance of 6.06 billion km (3.75 billion mi; 40.5 AU) from Earth.
This historic picture was taken on February 14th, 1990 (Valentine’s Day) at the behest of famed astronomer Carl Sagan. At the time, Sagan was a member of the Voyager imaging team, and he recommended that Voyager 1 take the opportunity to look back at Earth one more time before making its way to the very edge of the Solar System. For more than 27 years, this long-distance record remained unchallenged.
However, in December of 2017, the New Horizons team began conducting a routine calibration test of the LORRI instrument. This consisted of snapping pictures of the “Wishing Well” cluster (aka. the “Football Cluster” or NGC 3532), an open galactic star cluster that is located about 1321 light years from Earth in the direction of the southern constellation of Carina.
This image (shown above) was rather significant, given that this star cluster was the first target ever observed by the Hubble Space Telescope (on May 20th, 1990). While this image broke the long-distance record established by Voyager 1, the probe then turned its LORRI instrument towards objects in its flight path. As part of the probes mission to rendezvous with a KBO, the team was searching for forward-scattering rings or dust.
As a result, just two hours after it had taken the record-breaking image of the “Wishing Well” star cluster, the probe snapped pictures of the Kuiper Belt Objects (KBOs) known as 2012 HZ84 and 2012 HE85 (seen below, left and right). These images once again broke the record for being the most distant images taken from Earth (again), but also set a new record for the closest-ever images ever taken of KBOs.
“New Horizons has long been a mission of firsts — first to explore Pluto, first to explore the Kuiper Belt, fastest spacecraft ever launched. And now, we’ve been able to make images farther from Earth than any spacecraft in history.”
As one of only five spacecraft to travel beyond the Outer Planets, New Horizons has set a number of other distance records as well. These include the most-distant course-correction maneuver, which took place on Dec. 9th, 2017, and guided the spacecraft towards its planned flyby with the KBO 2014 MU69. This event, which will happen on Jan. 1st, 2019, will be the farthest planetary encounter in history.
In the course of its extended mission in the Kuiper Belt, the New Horizons team seeks to observe at least two-dozen other KBOs, dwarf planets and “Centaurs” – i.e. former KBOs that have unstable orbits that cause them to cross the orbit of the gas giants. At present, the New Horizons spacecraft is in hibernation and will be brought back online on June 4th, – when it will begin a series of checks to make sure it is ready for its planned encounter with MU69.
The spacecraft is also conducting nearly continuous measurements of the Kuiper Belt itself to learn more about its plasma, dust and neutral-gas environment. These efforts could reveal much about the formation and evolution of the Solar System, and are setting records that are not likely to be broken for many more decades!
Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at the intermediate spiral galaxy known as Messier 66.
In the 18th century, while searching the night sky for comets, French astronomer Charles Messier kept noting the presence of fixed, diffuse objects he initially mistook for comets. In time, he would come to compile a list of approximately 100 of these objects, hoping to prevent other astronomers from making the same mistake. This list – known as the Messier Catalog – would go on to become one of the most influential catalogs of Deep Sky Objects.
One of these objects is the intermediate elliptical galaxy known as Messier 66 (NGC 3627). Located about 36 million light-years from Earth in the direction of the Leo constellation, this galaxy measures 95,000 light-years in diameter. It is also the brightest and largest member of the Leo Triplet of galaxies and is well-known for its bright star clusters, dust lanes, and associated supernovae.
Description:
Enjoying life some 35 million light years from the Milky Way, the group known as the “Leo Trio” is home to bright galaxy Messier 66 – the easternmost of the two M objects. In the telescope or binoculars, you’ll find this barred spiral galaxy far more visible and much easier to see details within its knotted arms and bulging core.
Because of interaction with its neighboring galaxies, M66 shows signs of a extremely high central mass concentration as well as a resolved noncorotating clump of H I material apparently removed from one of the spiral arms. Even one of its spiral arms got it noted in Halton Arp’s collection of Peculiar Galaxies! So exactly what did it collide with?As Xiaolei Zhang (et al) indicated in a 1993 study:
“The combined CO and H I data provide new information, both on the history of the past encounter of NGC 3627 with its companion galaxy NGC 3628 and on the subsequent dynamical evolution of NGC 3627 as a result of this tidal interaction. In particular, the morphological and kinematic information indicates that the gravitational torque experienced by NGC 3627 during the close encounter triggered a sequence of dynamical processes, including the formation of prominent spiral structures, the central concentration of both the stellar and gas mass, the formation of two widely separated and outwardly located inner Lindblad resonances, and the formation of a gaseous bar inside the inner resonance. These processes in coordination allow the continuous and efficient radial mass accretion across the entire galactic disk. The observational result in the current work provides a detailed picture of a nearby interacting galaxy which is very likely in the process of evolving into a nuclear active galaxy. It also suggests one of the possible mechanisms for the formation of successive instabilities in postinteraction galaxies, which could very efficiently channel the interstellar medium into the center of the galaxy to fuel nuclear starburst and Seyfert activities.”
Ah, yes! Star forming regions… And what better way to look deeper than through the eyes of the Spitzer Space Telescope? As R. Kennicutt (University of Arizona) and the SINGS Team observed:
“M66’s blue core and bar-like structure illustrates a concentration of older stars. While the bar seems devoid of star formation, the bar ends are bright red and actively forming stars. A barred spiral offers an exquisite laboratory for star formation because it contains many different environments with varying levels of star-formation activity, e.g., nucleus, rings, bar, the bar ends and spiral arms. The SINGS image is a four-channel false-color composite, where blue indicates emission at 3.6 microns, green corresponds to 4.5 microns, and red to 5.8 and 8.0 microns. The contribution from starlight (measured at 3.6 microns) in this picture has been subtracted from the 5.8 and 8 micron images to enhance the visibility of the dust features.”
Messier 66 has also been deeply studied for evidence of forming super star clusters, too. As David Meier indicated:
“Super star clusters are thought to be precursors of globular clusters and are some of the most extreme star formation regions in the universe. They tend to occur in actively starbursting galaxies or near the cores of less active galaxies. Radio super star clusters cannot be seen in optical light because of extreme extinction, but they shine brightly in infrared and radio observations. We can be certain that there are many massive O stars in these regions because massive stars are required to provide the UV radiation that ionizes the gas and creates a thermally bright HII regions. Not many natal SSCs are currently known, so detection is an important science goal in its own right. In particular, very few SSCs are known in galactic disks. We need more detections to be able to make statistical statements about SSCs and fill in the mass range of forming star clusters. With more detections, we will be able to investigate the effects of other environments (e.g. bars, bubbles, and galactic interaction) on SSCs, which could potentially be followed up in the far future with the Square Kilometer Array to discover their effects on individual forming massive stars.”
But there’s still more. Try magnetic properties in M66’s spiral patterns. As M. Soida (et al) indicated in their 2001 study:
“By observing the interacting galaxy NGC 3627 in radio polarization we try to answer the question; to which degree does the magnetic field follow the galactic gas flow. We obtained total power and polarized intensity maps at 8.46 GHz and 4.85 GHz using the VLA in its compact D-configuration. In order to overcome the zero-spacing problems, the interferometric data were combined with single-dish measurements obtained with the Effelsberg 100-m radio telescope. The observed magnetic field structure in NGC 3627 suggests that two field components are superposed. One component smoothly fills the interarm space and shows up also in the outermost disk regions, the other component follows a symmetric S-shaped structure. In the western disk the latter component is well aligned with an optical dust lane, following a bend which is possibly caused by external interactions. However, in the SE disk the magnetic field crosses a heavy dust lane segment, apparently being insensitive to strong density-wave effects. We suggest that the magnetic field is decoupled from the gas by high turbulent diffusion, in agreement with the large Hi line width in this region. We discuss in detail the possible influence of compression effects and non-axisymmetric gas flows on the general magnetic field asymmetries in NGC 3627. On the basis of the Faraday rotation distribution we also suggest the existence of a large ionized halo around this galaxy.”
History of Observation:
Both M65 and M66 were discovered on the same night – March 1, 1780 – by Charles Messier, who described M66 as, “Nebula discovered in Leo; its light is very faint and it is very close to the preceding: They both appear in the same field in the refractor. The comet of 1773 and 1774 has passed between these two nebulae on November 1 to 2, 1773. M. Messier didn’t see them at that time, no doubt, because of the light of the comet.”
Both galaxies would be observed and cataloged by the Herschel family and further expounded upon by Admiral Smyth:
“A large elongated nebula, with a bright nucleus, on the Lion’s haunch, trending np [north preceding, NW] and sf [south following, SE]; this beautiful specimen of perspective lies just 3deg south-east of Theta Leonis. It is preceded at about 73s by another of a similar shape, which is Messier’s No. 65, and both are in the field at the same time, under a moderate power, together with several stars. They were pointed out by Mechain to Messier in 1780, and they appeared faint and hazy to him. The above is their appearance in my instrument.
“These inconceivably vast creations are followed, exactly on the same parallel, ar Delta AR=174s, by another elliptical nebula of even a more stupendous character as to apparent dimensions. It was discovered by H. [John Herschel], in sweeping, and is No. 875 in his Catalogue of 1830 [actually, probably an erroneous position for re-observed M66]. The two preceding of these singular objects were examined by Sir William Herschel, and his son [JH] also; and the latter says, “The general form of elongated nebulae is elliptic, and their condensation towards the centre is almost invariably such as would arise from the superposition of luminous elliptic strata, increasing in density towards the centre. In many cases the increase of density is obviously attended with a diminution of ellipticity, or a nearer approach to the globular form in the central than in the exterior strata.” He then supposes the general constitution of those nebulae to be that of oblate spheroidal masses of every degree of flatness from the sphere to the disk, and of every variety in respect of the law of their density, and ellipticity towards the centre. This must appear startling and paradoxical to those who imagine that the forms of these systems are maintained by forces identical with those which determine the form of a fluid mass in rotation; because, if the nebulae be only clusters of discrete stars, as in the greater number of cases there is every reason to believe them to be, no pressure can propagate through them. Consequently, since no general rotation of such a system as one mass can be supposed, Sir John suggests a scheme which he shows is not, under certain conditions, inconsistent with the law of gravitation. “It must rather be conceived,” he tells us, ” as a quiescent form, comprising within its limits an indefinite magnitude of individual constituents, which, for aught we can tell, may be moving one among the other, each animated by its own inherent projectile force, and deflected into an orbit more or less complicated, by the influence of that law of internal gravitation which may result from the compounded attractions of all its parts.”
Locating Messier 66:
Even though you might think by its apparent visual magnitude that M66 wouldn’t be visible in small binoculars, you’d be wrong. Surprisingly enough, thanks to its large size and high surface brightness, this particular galaxy is very easy to spot directly between Iota and Theta Leonis. In even 5X30 binoculars under good conditions you’ll easy see both it and M65 as two distinct gray ovals.
A small telescope will begin to bring out structure in both of these bright and wonderful galaxies, but to get a hint at the “Trio” you’ll need at least 6″ in aperture and a good dark night. If you don’t spot them right away in binoculars, don’t be disappointed – this means you probably don’t have good sky conditions and try again on a more transparent night. The pair is well suited to modestly moonlit nights with larger telescopes.
May you equally be attracted to this galactic pair!
And here are the quick facts on M66 to help you get started:
Object Name: Messier 66 Alternative Designations: M66, NGC 3627, (a member of the) Leo Trio, Leo Triplet Object Type: Type Sb Spiral Galaxy Constellation: Leo Right Ascension: 11 : 20.2 (h:m) Declination: +12 : 59 (deg:m) Distance: 35000 (kly) Visual Brightness: 8.9 (mag) Apparent Dimension: 8×2.5 (arc min)
On October 19th, 2017, the Panoramic Survey Telescope and Rapid Response System-1 (Pan-STARRS-1) in Hawaii announced the first-ever detection of an interstellar asteroid, named 1I/2017 U1 (aka. ‘Oumuamua). Originally thought to be a comet, this interstellar visitor quickly became the focus of follow-up studies that sought to determine its origin, structure, composition, and rule out the possibility that it was an alien spacecraft!
While ‘Oumuamua is the first known example of an interstellar asteroid reaching our Solar System, scientists have long suspected that such visitors are a regular occurrence. Aiming to determine just how common, a team of researchers from Harvard University conducted a study to measure the capture rate of interstellar asteroids and comets, and what role they may play in the spread of life throughout the Universe.
For the sake of their study, Lingam and Loeb constructed a three-body gravitational model, where the physics of three bodies are used to compute their respective trajectories and interactions with one another. In Lingam and Loeb’s model, Jupiter and the Sun served as the two massive bodies while a far less massive interstellar object served as the third. As Dr. Loeb explained to Universe Today via email:
“The combined gravity of the Sun and Jupiter acts as a ‘fishing net’. We suggest a new approach to searching for life, which is to examine the interstellar objects captured by this fishing net instead of the traditional approach of looking through telescope or traveling with spacecrafts to distant environments to do the same.”
Using this model, the pair then began calculating the rate at which objects comparable in size to ‘Oumuamua would be captured by the Solar System, and how often such objects would collide with the Earth over the course of its entire history. They also considered the Alpha Centauri system as a separate case for the sake of comparison. In this binary system, Alpha Centauri A and B serve as the two massive bodies and an interstellar asteroid as the third.
As Dr. Lingam indicated:
“The frequency of these objects is determined from the number density of such objects, which has been recently updated based on the discovery of ‘Oumuamua. The size distribution of these objects is unknown (and serves as a free parameter in our model), but for the sake of obtaining quantitative results, we assumed that it was similar to that of comets within our Solar System.”
In the end, they determined that a few thousands captured objects might be found within the Solar system at any time – the largest of which would be tens of km in radius. For the Alpha Centauri system, the results were even more interesting. Based on the likely rate of capture, and the maximum size of a captured object, they determined that even Earth-sized objects could have been captured in the course of the system’s history.
In other words, Alpha Centauri may have picked up some rogue planets over time, which would have had drastic impact on the evolution of the system. In this vein, the authors also explored how objects like ‘Oumuamua could have played a role in the distribution of life throughout the Universe via rocky bodies. This is a variation on the theory of lithopanspermia, where microbial life is shared between planets thanks to asteroids, comets and meteors.
In this scenario, interstellar asteroids, which originate in distant star systems, would be the be carriers of microbial life from one system to another. If such asteroids collided with Earth in the past, they could be responsible for seeding our planet and leading to the emergence of life as we know it. As Lingam explained:
“These interstellar objects could either crash directly into a planet and thus seed it with life, or be captured into the planetary system and undergo further collisions within that system to yield interplanetary panspermia (the second scenario is more likely when the captured object is large, for e.g. a fraction of the Earth’s radius).”
In addition, Lingam and Loeb offered suggestions on how future visitors to our Solar System could be studied. As Lingam summarized, the key would be to look for specific kinds of spectra from objects in our Solar Systems:
“It may be possible to look for interstellar objects (captured/unbound) in our Solar system by looking at their trajectories in detail. Alternatively, since many objects within the Solar system have similar ratios of oxygen isotopes, finding objects with very different isotopic ratios could indicate their interstellar origin. The isotope ratios can be determined through high-resolution spectroscopy if and when interstellar comets approach close to the Sun.”
“The simplest way to single out the objects who originated outside the Solar System, is to examine the abundance ratio of oxygen isotopes in the water vapor that makes their cometary tails,” added Loeb. “This can be done through high resolution spectroscopy. After identifying a trapped interstellar object, we could launch a probe that will search on its surface for signatures of primitive life or artifacts of a technological civilization.”
It would be no exaggeration to say that the discovery of ‘Oumuamua has set off something of a revolution in astronomy. In addition to validating something astronomers have long suspected, it has also provided new opportunities for research and the testing of scientific theories (such as lithopanspermia).
In the future, with any luck, robotic missions will be dispatched to these bodies to conduct direct studies and maybe even sample return missions. What these reveal about our Universe, and maybe even the spread of life throughout, is sure to be very illuminating!
The two halves of the James Webb Space Telescope are now in the same location and ready to take the next step on JWST’s journey. On February 2nd, Webb’s Optical Telescope and Integrated Science instrument module (OTIS) arrived at Northrop Grumman Aerospace Systems in Redondo Beach, California. The integrated spacecraft, consisting of the spacecraft bus and sunshield, were already there, waiting for OTIS so they could join together and become a complete spacecraft.
“The team will begin the final stages of integration of the world’s largest space telescope.” – Scott Willoughby, Northrop Grumman’s Program Manage for the JWST.
“It’s exciting to have both halves of the Webb observatory – OTIS and the integrated spacecraft element – here at our campus,” said Scott Willoughby, vice president and program manager for Webb at Northrop Grumman. “The team will begin the final stages of integration of the world’s largest space telescope.”
OTIS arrived from the Johnson Space Center in Houston, where it had successfully completed its cryogenic testing. To prepare for that journey, OTIS was placed inside a custom shipping container designed to protect the delicate and expensive Webb Telescope from any damage. That specially designed container is called the Space Telescope Transporter for Air, Road and Sea (STTARS).
STTARS is a massive container, measuring 4.6 meters (15 feet) wide, 5.2 meters (17 feet) tall, and 33.5 meters feet (110) long, and weighing approximately 75,000 kilograms (almost 165,000 pounds). It’s much larger than the James Webb itself, but even then, the primary mirror wings and the secondary mirror tripod must be folded into flight configuration in order to fit.
The next step for the JWST is to join the spacecraft itself with OTIS. Once that happens, JWST will be complete and fully integrated. Then there’ll be more tests called observatory-level testing. After that, another journey inside STTARS to Kouru, French Guiana, where the JWST will be launched in 2019.
“This is a major milestone.” – Eric Smith, director of the James Webb Space Telescope Program at NASA.
“This is a major milestone,” said Eric Smith, director of the James Webb Space Telescope Program at NASA. “The Webb observatory, which is the work of thousands of scientists and engineers across the globe, will be carefully tested to ensure it is ready to launch and enable scientists to seek the first luminous objects in the universe and search for signs of habitable planets.”
You can’t fault people, either NASA personnel or the rest of us, for getting excited about each development in the James Webb Space Telescope story. Every time the thing twitches or moves, our excitement re-spawns. It seems like everything that happens with the JWST is now a milestone in its long, uncertain journey. It’s easy to see why.
The Space Telescope That Almost Wasn’t
The James Webb ran into a lot of problems during its development. As can be expected for a ground-breaking, technology-pushing project like the Webb, it’s expensive. In 2011, when the project was well underway, it was revealed that the Webb would cost $8.8 billion, much more than the initial budget of $1.6 billion. The House of Representatives cancelled the project, then restored it, though funding was capped at $8 billion.
That was the main hurdle facing the development of the JWST, but there were others, including timeline delays. The most recent timeline change moved the launch date from 2017 to Spring 2019. As of now, the James Webb is on schedule, and on target to meet its revised budget.
The First “Super Telescope”
The JWST is the first of the “Super Telescopes” to be in operation. Once it’s in place at LaGrange Point 2 (L2), about 1.5 million km (930,000 miles) from Earth, it will begin observing, primarily in infrared. It will surpass both the Hubble Telescope and the Spitzer Telescope, and will “look back in time” to some of oldest stars and galaxies in the universe. It will also examine exoplanets and contribute to the search for life.
After multiple delays, SpaceX recently announced that the inaugural flight of their Falcon Heavy rocket would take place this Tuesday, February 6th, 2018. This rocket, which is the heaviest launch vehicle in the SpaceX fleet (and the most powerful operational rocket in the world right now), is not only central to the company’s vision of reusable rockets, but also to Musk’s long-term vision of sending humans to Mars.
As a result, people all over the world have been tuning in to watch the coverage of the event, and eagerly waiting to see the rocket take off before its launch window closes at 04:00 pm (PST) this afternoon. In keeping with Musk’s habit of sending interesting payloads into space, the rocket will be carrying his cherry-red Tesla Roadster, with the goal of depositing it into a stable orbit around Mars.
According to previous statements made by Musk, the plan calls for the Falcon Heavy to launch the Roadster on a Hohmann Transfer trajectory, an orbital maneuver where a satellite or spacecraft is transferred from one circular orbit to another. After being placed in an elliptical orbit between Earth and Mars, the Roadster would be picked up by Mars’ gravity and remain in orbit around it for (according to Musk) up to a billion years!
To add to the peculiarity of the mission payload, Musk has also been clear that he wants the car to be playing “Space Oddity” – the famous song written and performed by the late and great David Bowie – as its launched into space. This classic song recently got a shot in the arm thanks to Canadian astronaut Chris Hadfield, who performed a rendition of the song while still serving as the commander of Expedition 35 aboard the International Space Station.
But unlike Hadfield’s more positive rendition of the song (which you can watch above), in which the astronaut (Major Tom) does NOT die, Musk’s Roadster will be belting out this tune in its original form. One can only assume that he’s not a particularly superstitious man, or just has a very quirky sense of humor. Considering that a previous payload consisted of a wheel of cheese, I think we know the answer!
Musk confirmed that the launch would take place at 0:130 pm EST (10:30 am PST) in a tweet he posted yesterday, where he stated:
All systems remain green for launch at 1:30pm EST tomorrow
This was followed by an additional tweet posted at 07:59 am PST, which indicated that the launch was still on. However, Musk announced that there would be a minor delay at 09:02 am PST, which was apparently weather-related:
“About 2.5 hours to T-0 for Falcon Heavy. Watch sim for highlight reel of what we hope happens. Car actually takes 6 months to cover 200M+ miles to Mars”
“Upper atmosphere winds currently 20% above max allowable load. Holding for an hour to allow winds to diminish. #FalconHeavy“
In addition, changes were seen in the countdown clocks run by the US Air Force’s Eastern Range operations. This pushed the launch from its original time of 01:30 pm to 03:19 pm EST (12:19 am PST), and then led to the count being placed on hold. By 10:52 am PST this morning, the launch clock resumed and Musk indicated that the takeoff would commence at 3:45 pm EST (12:45 PST).
This was followed by the SpaceX ground crew commencing procedures to fuel the rocket at about 11:22 am PST.
Launch auto-sequence initiated (aka the holy mouse-click) for 3:45 liftoff #FalconHeavy
Naturally, there has been plenty of speculation about the possible outcome of the mission. Max Fagin, an aerospace engineer from Colorado and a space camp alumni, is one such person. In a video he uploaded to his Youtube channel yesterday (Feb. 5th, 2018), he clarified what the proposed launch entails and offered his thoughts on what will likely happen to the Roadster once its sent into space.
Addressing Musk’s stated goal of a Hohmann Transfer that would put the roadster into Mars’ orbit, he indicated that Musk must have been oversimplifying because there’s no reason to launch a spacecraft on such a trajectory right now. This is due to the fact that this maneuver only makes sense when Earth and Mars are at the closest points in their orbits to each other – aka. when Mars is at opposition.
This is not the case at present, and won’t be again until April-May of this year. At that point, Earth and Mars will be the closest they have been to each other since the year 2000, and will not be in such a perfect opposition again until 2033. As a result, says Fagin, a “true Hohmann Transfer launched from Earth to Mars right now would take the Roadster no closer than 90 million km from Mars – 0.6 times the distance from Earth to the Sun.”
Having said all that, here is what Fagin thinks is actually going to happen:
“Given how light the Roadster is, and given how powerful the Falcon Heavy is, I suspect Falcon heavy is going to impart a little extra delta-v to the Roadster, beyond what would be required for a minimum-energy Hohmann Transfer. This would allow the Roadster to get as close to Mars as SpaceX wanted sometime in October of 2018.”
According to Fagin’s analysis, the Roadster would still not be able to remain in the same orbit of Mars for a billion years, which was Musk’s stated goal. But it would achieve a more stable orbit than a basic Hohmann Transfer would accomplish. In that scenario, the orbit would be perturbed by close encounters with Earth, and the Roadster might eventually come back to Earth.
In other words, the plan may be more complicated than originally stated, but could be largely successful all the same. Come what may, there is no shortage of people who want to see this rocket successfully take off! After all, it’s not only SpaceX’s future that is riding on the outcome of this launch, but perhaps even the future of space exploration itself. Cheaper costs and restored launch capability, that’s what it’s all about!
Barring any further delays, which will push the launch back until tomorrow, the launch will be taking place in T-minus 20 minutes (as of the penning of this article)! In the meantime, be sure to check out SpaceX’s live coverage of the event, which begins today (Tuesday, Feb. 6th) at 12:45 pm (GMT-8):
When it comes to studying some of the most distant and oldest galaxies in the Universe, a number of challenges present themselves. In addition to being billions of light years away, these galaxies are often too faint to see clearly. Luckily, astronomers have come to rely on a technique known as Gravitational Lensing, where the gravitational force of a large object (like a galactic cluster) is used to enhance the light of these fainter galaxies.
Using this technique, an international team of astronomers recently discovered a distant and quiet galaxy that would have otherwise gone unnoticed. Led by researchers from the University of Hawaii at Manoa, the team used the Hubble Space Telescope to conduct the most extreme case of gravitational lensing to date, which allowed them to observe the faint galaxy known as eMACSJ1341-QG-1.
For the sake of their study, the team relied on the massive galaxy cluster known as eMACSJ1341.9-2441 to magnify the light coming from eMACSJ1341-QG-1, a distant and fainter galaxy. In astronomical terms, this galaxy is an example of a “quiescent galaxy”, which are basically older galaxies that have largely depleted their supplies of dust and gas and therefore do not form new stars.
The team began by taking images of the faint galaxy with the Hubble and then conducting follow-up spectroscopic observations using the ESO/X-Shooter spectrograph – which is part of the Very Large Telescope (VLT) at the Paranal Observatory in Chile. Based on their estimates, the team determined that they were able to amplify the background galaxy by a factor of 30 for the primary image, and a factor of six for the two remaining images.
This makes eMACSJ1341-QG-1 the most strongly amplified quiescent galaxy discovered to date, and by a rather large margin! As Johan Richard – an assistant astronomer at the University of Lyon who performed the lensing calculations, and a co-author on the study – indicated in a University of Hawaii News release:
“The very high magnification of this image provides us with a rare opportunity to investigate the stellar populations of this distant object and, ultimately, to reconstruct its undistorted shape and properties.”
Although other extreme magnifications have been conducted before, this discovery has set a new record for the magnification of a rare quiescent background galaxy. These older galaxies are not only very difficult to detect because of their lower luminosity; the study of them can reveal some very interesting things about the formation and evolution of galaxies in our Universe.
As Ebeling, an astronomer with the UH’s Institute of Astronomy and the lead author on the study, explained:
“We specialize in finding extremely massive clusters that act as natural telescopes and have already discovered many exciting cases of gravitational lensing. This discovery stands out, though, as the huge magnification provided by eMACSJ1341 allows us to study in detail a very rare type of galaxy.”
Quiescent galaxies are common in the local Universe, representing the end-point of galactic evolution. As such, this record-breaking find could provide some unique opportunities for studying these older galaxies and determining why star-formation ended in them. As Mikkel Stockmann, a team member from the University of Copenhagen and an expert in galaxy evolution, explained:
“[A]s we look at more distant galaxies, we are also looking back in time, so we are seeing objects that are younger and should not yet have used up their gas supply. Understanding why this galaxy has already stopped forming stars may give us critical clues about the processes that govern how galaxies evolve.”
In a similar vein, recent studies have been conducted that suggest that the presence of a Supermassive Black Hole (SMBH) could be what is responsible for galaxies becoming quiescent. As the powerful jets these black holes create begin to drain the core of galaxies of their dust and gas, potential stars find themselves starved of the material they would need to undergo gravitational collapse.
In the meantime, follow-up observations of eMACSJ1341-QG1 are being conducted using telescopes at the Paranal Observatory in Chile and the Maunakea Observatories in Hawaii. What these observations reveal is sure to tell us much about what will become of our own Milky Way Galaxy someday, when the last of the dust and gas is depleted and all its stars become red giants and long-lived red dwarfs.
The first confirmed discovery of a planet beyond our Solar System (aka. an Extrasolar Planet) was a groundbreaking event. And while the initial discoveries were made using only ground-based observatories, and were therefore few and far between, the study of exoplanets has grown considerably with the deployment of space-based telescopes like the Kepler space telescope.
As of February 1st, 2018, 3,728 planets have been confirmed in 2,794 systems, with 622 systems having more than one planet. But now, thanks to a new study by a team of astrophysicists from the University of Oklahoma, the first planets beyond our galaxy have been discovered! Using a technique predicting by Einstein’s Theory of General Relativity, this team found evidence of planets in a galaxy roughly 3.8 billion light years away.
For the sake of their study, the pair used the Gravitational Microlensing technique, which relies on the gravitational force of distant objects to bend and focus light coming from a star. As a planet passes in front of the star relative to the observer (i.e. makes a transit), the light dips measurably, which can then be used to determine the presence of a planet.
In this respect, Gravitational Microlensing is a scaled-down version of Gravitational Lensing, where an intervening object (like a galaxy cluster) is used to focus light coming from a galaxy or other large object located beyond it. It also incorporates a key element of the highly-effective Transit Method, where stars are monitored for dips in brightness to indicate the presence of an exoplanet.
In addition to this method, which is the only one capable of detecting extra-solar planets at truly great distances (on the order of billions of light years), the team also used data from NASA’s Chandra X-ray Observatory to study a distant quasar known as RX J1131–1231. Specifically, the team relied on the microlensing properties of the supermassive black hole (SMBH) located at the center of RX J1131–1231.
They also relied on the OU Supercomputing Center for Education and Research to calculate the microlensing models they employed. From this, they observed line energy shifts that could only be explained by the presence of of about 2000 unbound planets between the quasar’s stars – which ranged from being as massive as the Moon to Jupiter – per main-sequence star.
As Xinyu Dai explained in a recent University of Oklahoma press release:
“We are very excited about this discovery. This is the first time anyone has discovered planets outside our galaxy. These small planets are the best candidate for the signature we observed in this study using the microlensing technique. We analyzed the high frequency of the signature by modeling the data to determine the mass.”
While 53 planets have been discovered within the Milky Way galaxy using the Microlensing technique, this is the first time that planets have been observed in other galaxies. Much like the first confirmed discovery of an extra-solar planet, scientists were not even certain planets existed in other galaxies prior to this study. This discovery has therefore brought the study of planets beyond our Solar System to a whole new level!
And as Eduardo Guerras indicated, the discovery was possible thanks to improvements made in both modelling and instrumentation in recent years:
“This is an example of how powerful the techniques of analysis of extragalactic microlensing can be. This galaxy is located 3.8 billion light years away, and there is not the slightest chance of observing these planets directly, not even with the best telescope one can imagine in a science fiction scenario. However, we are able to study them, unveil their presence and even have an idea of their masses. This is very cool science.”
At this juncture, the odds are good that some of these discoveries will be in neighboring galaxies. Perhaps then we can begin to determine just how common planets are in our Universe. At present, it is estimated that could be as many as 100 billion planets in the Milky Way Galaxy alone! But with an estimated 1 to 2 trillion galaxies in the Universe… well, you do the math!
According to modern theories of geological evolution, the last major ice age (known as the Pliocene-Quaternary glaciation) began about 2.58 million years ago during the late Pliocene Epoch. Since then, the world has experienced several glacial and interglacial periods, and has been in an inter-glacial period (where the ice sheets have been retreating) ever since the last glacial period ended about 10,000 years ago.
According to new research, this trend experienced a bit of a hiccup during the late Paleolithic era. It was at this time – roughly 12,800 years ago, according to a new study from the University of Kansas – that a comet struck our planet and triggered massive wildfires. This impact also triggered a short glacial period that temporarily reversed the previous period of warming, which had a drastic affect on wildlife and human development.
The study in question, “Extraordinary Biomass-Burning Episode and Impact Winter Triggered by the Younger Dryas Cosmic Impact ~12,800 Years Ago”, was so large that it was divided into two parts. Part I. Ice Cores and Glaciers; and Part II. Lake, Marine, and Terrestrial Sediments, were both recently published by The Journal of Geography, part of the the University of Chicago Press’ series of scientific publications.
For the sake of their study, the team combined data from ice core, forest, pollen and other geochemical and isotopic markers obtained from more than 170 different sites across the world. Based on this data, the team concluded that roughly 12,800 years ago, a global disaster was triggered when a stream of fragments from a comet measuring about 100 km (62 mi) in diameter exploded in Earth’s atmosphere and rained down on the surface.
As KU Emeritus Professor of Physics & Astronomy Adrian Melott explained in a KU press release:
“The hypothesis is that a large comet fragmented and the chunks impacted the Earth, causing this disaster. A number of different chemical signatures — carbon dioxide, nitrate, ammonia and others — all seem to indicate that an astonishing 10 percent of the Earth’s land surface, or about 10 million square kilometers, was consumed by fires.”
According to their research, these massive wildfires also caused a massive feedback in Earth’s climate. As fires rushed across much of the planet’s landscape, the smoke and dust clogged the sky and blocked out sunlight. This triggered rapid cooling in the atmosphere, causing plants to die, food sources to dwindle, and ocean levels to drop. Last, but not least, the ice sheets which had been previously retreating began to advance again.
This quasi-ice age, according to the study, lasted about another thousand years. When the climate began to warm again, life began to recover, but was faced with a number of drastic changes. For example, fewer large animals survived, which affected the hunter-gather culture of humans all across North America. This was reflected in the different types of spear points that have been dated to this period.
What’s more, pollen samples obtained from this period indicate that pine forests were likely burned off and were replaced by poplar forests, a species that colonizes cleared areas. The authors also suggest that this impact could have been responsible for the so-called Younger Dryas cool episode. This period occurred roughly 12,000 years ago, where gradual climatic warming was temporarily reversed.
Intrinsic to this period was an increase of biomass burning and the extinctions of larger species during the late Pleistocene period (ca. 2,588,000 to 11,700 years ago). These sudden changes are believed to be what led to severe shifts in human populations, causing a decline during the 1000-year cold period, and leading to the adoption of agriculture and animal husbandry once the climate began to warm again.
In short, this new theory could help explain a number of changes that made humanity what it is today. As Mellot indicated:
“Computations suggest that the impact would have depleted the ozone layer, causing increases in skin cancer and other negative health effects. The impact hypothesis is still a hypothesis, but this study provides a massive amount of evidence, which we argue can only be all explained by a major cosmic impact.”
These studies not only provide insight into the timeline of Earth’s geological evolution, they also sheds light on the history of the Solar System. According to this study, the remnants of the meteor which struck Earth still persist within our Solar System today. Last, but not least, the climate shifts that these impacts created had a profound effect on the evolution of life here on Earth.
During the 1960s, scientists discovered a massive radio source (known as Sagittarius A*) at the center of the Milky Way, which was later revealed to be a Supermassive Black Holes (SMBH). Since then, they have learned that these SMBHs reside at the center of most massive galaxies. The presence of these black holes is also what allows the centers of these galaxies to have a higher than normal luminosity – aka. Active Galactic Nuclei (AGNs).
In the past few years, astronomers have also observed fast molecular outflows emanating from AGNs which left them puzzled. For one, it was a mystery how any particles could survive the heat and energy of a black hole’s outflow. But according to a new study produced by researchers from Northwestern University, these molecules were actually born within the winds themselves. This theory may help explain how stars form in extreme environments.
For the sake of their study, Richings developed the first-ever computer code capable of modeling the detailed chemical processes in interstellar gas which are accelerated by a growing SMBH’s radiation. Meanwhile, Claude-André Faucher-Giguère contributed his expertise, having spent his career studying the formation and evolution of galaxies. As Richings explained in a Northwestern press release:
“When a black hole wind sweeps up gas from its host galaxy, the gas is heated to high temperatures, which destroy any existing molecules. By modeling the molecular chemistry in computer simulations of black hole winds, we found that this swept-up gas can subsequently cool and form new molecules.”
The existence of energetic outflows form SMBHs was first confirmed in 2015, when researchers used the ESA’s Herschel Space Observatory and data from the Japanese/US Suzaku satellite to observe the AGN of a galaxy known as IRAS F11119+3257. Such outflows, they determined, are responsible for draining galaxies of their interstellar gas, which has an arresting effect on the formation of new stars and can lead to “red and dead” elliptical galaxies.
This was followed-up in 2017 with observations that indicated that rapidly moving new stars formed in these outflows, something that astronomers previously thought to be impossible because of the extreme conditions present within them. By theorizing that these particles are actually the product of black hole winds, Richings and Faucher-Giguère have managed to address questions raised by these previous observations.
Essentially, their theory helps explain predictions made in the past, which appeared contradictory at first glance. On the one hand, it upholds the prediction that black hole winds destroy molecules they collide with. However, it also predicts that new molecules are formed within these winds – including hydrogen, carbon monoxide and water – which can give birth to new stars. As Faucher-Giguère explained:
“This is the first time that the molecule formation process has been simulated in full detail, and in our view, it is a very compelling explanation for the observation that molecules are ubiquitous in supermassive black hole winds, which has been one of the major outstanding problems in the field.”
Richings and Faucher-Giguère look forward to the day when their theory can be confirmed by next-generation missions. They predict that new molecules formed by black hole outflows would be brighter in the infrared wavelength than pre-existing molecules. So when the James Webb Space Telescope takes to space in the Spring of 2019, it will be able to map these outflows in detail using its advance IR instruments.
One of the most exciting things about the current era of astronomy is the way new discoveries are shedding light on decades-old mysteries. But when these discoveries lead to theories that offer symmetry to what were once thought to be incongruous pieces of evidence, that’s when things get especially exciting. Basically, it lets us know that we are moving closer to a greater understanding of our Universe!
According to modern cosmological models, the Universe began in a cataclysm event known as the Big Bang. This took place roughly 13.8 billion years ago, and was followed by a period of expansion and cooling. During that time, the first hydrogen atoms formed as protons and electrons combined and the fundamental forces of physics were born. Then, about 100 million years after the Big Bang, that the first stars and galaxies began to form.
The formation of the first stars was also what allowed for the creation of heavier elements, and therefore the formation of planets and all life as we know it. However, until now, how and when this process took place has been largely theoretical since astronomers did not know where the oldest stars in our galaxy were to be found. But thanks to a new study by a team of Spanish astronomers, we may have just found the oldest star in the Milky Way!
This star is located roughly 7,500 light years from the Sun, and was found in the halo of the Milky Way along the line of sight to the Lynx constellation. Known as J0815+4729, this star is still in its main sequence and has a low mass, (around 0.7 Solar Masses), though the research team estimates that it has a surface temperature that is about 400 degrees hotter – 6,215 K (5942 °C; 10,727 °F) compared to 5778 K (5505 °C; 9940 °F).
For the sake of their study, the team was looking for a star that showed signs of being metal-poor, which would indicate that it has been in its main sequence for a very long time. The team first selected J0815+4729 from the Sloan Digital Sky Survey-III Baryon Oscillation Spectroscopic Survey (SDSS-III/BOSS) and then conducted follow-up spectroscopic investigations to determine its composition (and hence its age).
Consistent with what modern theory predicts, the star was found in the Galactic halo – the extended component of our galaxy that reaches beyond the galactic disk (the visible portion). It is in this region that the oldest and most metal-poor stars are believed to be found in galaxies, hence why the team was confident that a star dating back to the early Universe would be found here.
As Jonay González Hernández – a professor from the University of La Laguna, a member of the IAC and a co-author on the paper – explained in an IAC press release:
“Theory predicts that these stars could use material from the first supernovae, whose progenitors were the first massive stars in the galaxy, around 300 million years after the Big Bang. In spite of its age, and its distance away from us, we can still observe it.”
Spectra obtained by both the ISIS and OSIRIS instruments confirmed that the star was poor in metals, indicating that J0815+4729 has only one-millionth of the calcium and iron that the Sun contains. In addition, the team also noticed that the star has a higher carbon content than our Sun, accounting for almost 15% percent of its solar abundance (i.e. the relative abundance of its elements).
In short, J0815+4729 may be the most iron-poor and carbon-rich star currently known to astronomers. Moreover, finding it was rather difficult since the star is both weak in luminosity and was buried within a massive amount of SDSS/BOSS archival data. As Carlos Allende Prieto, another IAC researcher and a co-author on the paper, indicated:
“This star was tucked away in the database of the BOSS project, among a million stellar spectra which we have analysed, requiring a considerable observational and computational effort. It requires high-resolution spectroscopy on large telescopes to detect the chemical elements in the star, which can help us to understand the first supernovae and their progenitors.”
In the near future, the team predicts that next-generation spectrographs could allow for further research that would reveal more about the star’s chemical abundances. Such instruments include the HORS high-resolution spectrograph, which is presently in a trial phase on the Gran Telescopio Canarias (GTC).
“Detecting lithium gives us crucial information related to Big Bang nucleosynthesis,” said Rafael Rebolo, the director of the IAC and a coauthor of the paper. “We are working on a spectrograph of high-resolution and wide spectral range in order to measure the detailed chemical composition of stars with unique properties such as J0815+4719.”
These future studies are sure to be a boon for astronomers and cosmologists. In addition to being a chance to study stars that formed when the Universe was still in its infancy, they could provide new insight into the early stages of the universe, the formation of the first stars, and the properties of the first supernovae. In other words, they would put us a step closer to know how the Universe as we know it formed and evolved.