This image of Uranus was obtained in 2005 by the Hubble Space Telescope. Rings, southern collar and a bright cloud in the northern hemisphere are visible.
All Good Things: Countdown Begins Toward Cassini's 'Grand Finale' Around Saturn By Leonidas Papadopoulos Spoiler Artist’s concept of Cassini’s final orbits between the Saturn’s innermost rings and the planet’s cloud tops. This set of orbits will consist the last leg of Cassini’s mission, called “The Grand Finale,” which will culminate with a plunge on Saturn’s atmosphere in September 2017. Image Credit: Image Credit: NASA/JPL It has become something of a hackneyed phrase, but in the case of NASA’s Cassini spacecraft it is rather fitting: an epic mission of exploration of Saturn that has single-handedly changed our view of the ringed planet, its moons, and their potential habitability, yet like all good things it must come to an end. Having nearly completed two full decades in space, Cassini has now entered its final 18 months around Saturn on what has been a tremendously successful and productive mission, full of unexpected and ground-breaking discoveries. Last week the mission’s science team officially began the one-year countdown toward the start of Cassini’s “Grand Finale,” which will culminate with an end-of-mission daring plunge on Saturn’s cloud tops on Sept. 15, 2017. Launched on October 1997, Cassini undertook a seven-year journey of 3.5 billion km which included two flybys of Venus, one of Earth, and one of Jupiter, before finally arriving and entering orbit around Saturn in July 2004, becoming humanity’s first ever robotic spacecraft to do so. Since that time, Cassini has literally made history with every covered mile of space around the ringed giant planet and its assortage of fascinating moons, while slowly uncovering many of their long-held secrets and returning hundreds of thousands of images of unparalleled beauty. While the mission’s overall science results are too many to mention, highlights include the dispatch of the European-built Huygens probe which made humanity’s historic first soft-landing on the surface of the moon Titan, the ground-breaking discovery of water ice geysers erupting from Enceladus, the discovery of seas and lakes of liquid ethane and methane on Titan, as well as the detailed study of Saturn’s atmosphere and rings, just to name a few. A diagram showing the orbits that Cassini will follow around Saturn during the Grand Finale. The green-colored orbits represent the first phase of the Grand Finale when Cassini will reach as close as 10,000 km from Saturn’s outermost visible ring. The blue-colored orbits represent the second phase when Cassini will be positioned inside Saturn’s rings during closest approach to the planet. Image Credit: NASA/JPL Having completed its initial four-year primary mission in 2008, Cassini was given the go-ahead by NASA for an extended mission called the Cassini Equinox Mission and a third and final extension in 2010 called the Cassini Solstice Mission. The names for these extended missions weren’t arbitrary. Since one Saturnian year equals 29.4 Earth years, Cassini has been able to study the planet and its moons essentially through half of its orbit around the Sun, allowing planetary scientists to have a first close-up view of how the change of seasons affects the climate and atmospheric circulation on both Saturn and its largest moon Titan. Yet, now more than a decade after it entered orbit around the ringed giant, Cassini has spent almost all of its onboard fuel which allowed it to maneuver through the Saturn system by way of hundreds of close flybys of its largest moon Titan. Cassini’s mission planners had been preparing for the inevitable end ever since the conclusion of the spacecraft’s primary mission in 2008, while evaluating several scenarios as to the exact way with wich Cassini would make its farewell. Some of the options that were considered for Cassini’s end of mission by ground teams included an escape from Saturn toward Uranus or Neptune, an escape toward a heliocentric orbit, or an aerobraking and eventual placement in a stable orbit around Titan. All of these options were evaluated against certain factors like the time needed for the completion of each scenario, the delta-v required for the orbital changes, the fuel that would be available, as well as the best overall science return for each option. In the end, the only options that satisfied all of the required criteria were either an impact on one of Saturn’s icy satellites, or an impact on the giant planet itself. In the best interests of planetary protection, Cassini’s science team eventually chose the latter, in order to prevent the biological contamination of Saturn’s moons from any terrestrial microorganisms that could have been carried from Earth onboard the spacecraft. To that end and after shifting through a list of names that were submitted by more than 2,000 members of the public, the mission’s science team chose to appropriately name the final leg of Cassini’s trek around Saturn “The Grand Finale.” The latter is comprised of two parts. The first one, which will begin this year on Nov. 30 following the spacecraft’s penultimate Titan flyby, consists of a set of 20 elongated polar orbits around the planet which will bring Cassini within 10,000 km of Saturn’s F ring (the planet’s outermost discrete ring). This will be followed by The Grand Finale’s second phase beginning on April 22, 2017, when Cassini will use its final Titan flyby in order to change its orbital orientation and execute a daring loop that will bring it just 3,800 km above Saturn’s cloud tops, thus positioning it inside the planet’s entire ring system! From this vantage point, Cassini will complete a total of 22 highly elliptical polar orbits around Saturn before finally plunging onto the gas giant’s atmosphere on Sept. 15, 2017, putting an end to its spectacular 20-year mission. An impressive view of a part of Saturn’s rings with the planet in the background, as seen by Cassini on February 2016. During the final orbits of the Grand Finale, the spacecraft’s view of the rings is poised to be much more spectacular. Image Credit: NASA/JPL-Caltech/Space Science Institute One of the reasons that this scenario was chosen for Cassini’s end of mission was that it would return the most science compared to all the other options that had been evaluated. In fact, for Cassini’s science team, The Grand Finale represents an entire new mission on its own, which hadn’t even been considered as a possibility when the spacecraft was still on the drawing board back in the 1980s. One of the mysteries that have remained unresolved to this day involve the composition of Saturn’s internal structure as well as the planet’s exact rotation rate, which has not been measured to a great precision. Cassini’s position inside the main ring system during the second phase of The Grand Finale will allow the spacecraft to make very detail measurements of Saturn’s gravity and magnetic fields which will help scientists to better answer the remaining questions regarding the planet’s interior and overall rotation. Furthermore, a different spacecraft, Juno, which is scheduled to arrive on Jupiter this summer, will be making similar measurements regarding Jupiter’s interior at the same time, which will provide planetary scientists with great insights as to the inner workings of the Solar System’s gas giant planet’s during the same point in time. “We’ll have a much better understanding of how the planet works,” says Dr. Jonathan Fortney, a professor of astronomy at the University of California, Santa Cruz, who is part of the science team that has been selected by NASA to coordinate Cassini’s Grand Finale mission. “We really don’t know what their interiors are like. What’s great is that, in the space of a year, we’ll have once-in-a-lifetime data sets for both Jupiter and Saturn.” One other important set of science results expected to come during Cassini’s Grand Finale is the exact mass determination of Saturn’s ring system. For the entire duration of its mission to date, the spacecraft has operated solely outside of Saturn’s rings which has limited its ability to determine their mass, since it had to take into account the gravitational effects of the giant planet on the ring system. By positioning itself inside the rings, Cassini will be able to differentiate between these gravitational effects and the mass of the rings themselves. In addition, Cassini will have an unprecedented close-up view at the rings’ overall structure and composition, which might help scientists shed more light on their age and determine whether they have formed late in the planet’s history or have the same age as Saturn itself. NASA has already set officially the countdown clock ticking toward the start of Cassini’s Grand Finale, as announced late last week by Ron Baalke, a planetary scientist at the Jet Propulsion Laboratory in Pasadena, Calif., with a post on his Twitter account. This countdown marks the final 18 months of life for Cassini, which for many has been the epitome and highlight of NASA’s Planetary Science Division for the last two decades. Both Cassini and Juno will end their missions around the same time, with the latter scheduled to make a final plunge onto Jupiter’s cloud tops in February 2018. After that, and save for the Europa Clipper mission which is still in the conceptual stage, no other missions toward the outer Solar System exist in the NASA pipeline for the foreseeable future. This unfortunate reality, which is a result of cuts in the space agency’s planetary science budgets in recent years, means that we can probably not expect to see another dedicated probe toward the outer planets for the next couple of decades. This doesn’t mean that there hasn’t been a lack of proposals from the planetary science community, including mission concepts for the exploration of the ice giants Uranus and Neptune, both of which have been largely neglected ever since the Voyager 2 fly bys of the 1980s. Yet, as things stand at the moment, with the coming conclusion of the Cassini mission in 2017 and Juno in early 2018, the outer Solar System will likely remain out of reach for at least the next couple of decades. A computer rendering showing the view from the perspective of the Cassini spacecraft as it dives between the rings and Saturn’s cloud tops during the Grand Finale. Video Credit: NASA/JPL
Just 40 light years from Earth, three planets might host life forms adapted to infrared worlds May 2, 2016 This artist's impression shows an imagined view from the surface one of the three planets orbiting an ultracool dwarf star just 40 light-years from Earth that were discovered using the TRAPPIST telescope at ESO's La Silla Observatory. These …more Is there life beyond our solar system? If there is, our best bet for finding it may lie in three nearby, Earth-like exoplanets. For the first time, an international team of astronomers from MIT, the University of Liège in Belgium, and elsewhere have detected three planets orbiting an ultracool dwarf star, just 40 light years from Earth. The sizes and temperatures of these worlds are comparable to those of Earth and Venus, and are the best targets found so far for the search for life outside the solar system. The results are published today in the journal Nature. The scientists discovered the planets using TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope), a 60-centimeter telescope operated by the University of Liège, based in Chile. TRAPPIST is designed to focus on 60 nearby dwarf stars—very small, cool stars that are so faint they are invisible to optical telescopes. Belgian scientists designed TRAPPIST to monitor dwarf stars at infrared wavelengths and search for planets around them. The team focused the telescope on the ultracool dwarf star, 2MASS J23062928-0502285, now known as TRAPPIST-1, a Jupiter-sized star that is one-eighth the size of our sun and significantly cooler. Over several months starting in September 2015, the scientists observed the star's infrared signal fade slightly at regular intervals, suggesting that several objects were passing in front of the star. With further observations, the team confirmed the objects were indeed planets, with similar sizes to Earth and Venus. The two innermost planets orbit the star in 1.5 and 2.4 days, though they receive only four and two times the amount of radiation, respectively, as the Earth receives from the sun. The third planet may orbit the star in anywhere from four to 73 days, and may receive even less radiation than Earth. Given their size and proximity to their ultracool star, all three planets may have regions with temperatures well below 400 kelvins, within a range that is suitable for sustaining liquid water and life. Because the system is just 40 light years from Earth, co-author Julien de Wit, a postdoc in the Department of Earth, Atmospheric, and Planetary Sciences, says scientists will soon be able to study the planets' atmospheric compositions, as well as assess their habitability and whether life actually exists within this planetary system. "These planets are so close, and their star so small, we can study their atmosphere and composition, and further down the road, which is within our generation, assess if they are actually inhabited," de Wit says. "All of these things are achievable, and within reach now. This is a jackpot for the field." A risk, paid off For the most part, today's exoplanetary missions have been focused on finding systems around bright, solar-like stars. These stars emit radiation in the visible band—most often at yellow wavelengths—and can be seen with optical telescopes. However, because these stars are so bright, their light can overpower any signal coming from a planet. Cold dwarf stars, in contrast, are faint stars that emit radiation in the infrared band. Because they are so faint, these tiny red stars would not drown out a planetary signal, giving scientists a better chance of detecting orbiting planets. However, most missions today are not optimized to observe such stars. "That means they can't detect planets around such stars," de Wit points out. "So you have to design a completely different survey using special instruments and detectors—it's a risk." Lead authors Michael Gillon and Emmanuel Jehin, of the University of Liège, took that risk and built TRAPPIST, the proof-of-concept telescope that looks at 60 small, nearby ultracool stars. "It's not looking at 100,000 stars at a time, like the Kepler Space Telescope," de Wit says. "It's a few of them that you're spending time on, one at a time. And one paid off." "Worlds shifted in wavelength" From their observations, the scientists determined that all three planets are likely tidally locked, with permanent day and night sides. The two planets closest to the star may have day sides that are too hot, and night sides too cold, to host any life forms. However, there may be a "sweet spot" on the western side of both planets—a region that still receives daylight, but with relatively cool temperatures—that may be temperate enough to sustain conditions suitable for life. The third planet, furthest from its star, may be entirely within the habitable zone. As for next steps, de Wit says the objective is clear. "Now we have to investigate if they're habitable," de Wit says. "We will investigate what kind of atmosphere they have, and then will search for biomarkers and signs of life. We have facilities all over the globe and in space that are helping us, working from UV to radio, in all different wavelengths to tell us everything we want to know about this system. So many people will get to play with this [system]." Read more at: http://phys.org/news/2016-05-years-earth-planets-host-life.html#jCp
While it may take 800,000 years to get there, HST, JWST, and Kepler are going to be taking a good hard look at these 3 planets all thanks to their dimly lit host star. We couldn't have asked for a better, more diverse combination of planets.
Thought this was interesting. This is the speech Richard Nixon would've given to the world had Armstrong and Aldrin been stranded on the moon: http://io9.gizmodo.com/5880226/read...ase-the-apollo-11-astronauts-died-on-the-moon
SpaceX @SpaceX 8m8 minutes ago Landing confirmed. Second stage continuing to carry JCSAT-14 to a Geosynchronous Transfer Orbit. Emily Lakdawalla @elakdawalla 11m11 minutes ago Holy cow, they did it again, this time at night. Well done, @spacex!!!!!!!!!
The triple landing attempt from the Falcon Heavy launch they have planned will be phenomenal. Elon Musk is my mancrush.
The image shows the beginning of the transit of Mercury before the solar disc credit - https://twitter.com/astroaffairs
Mercury's average distance from the Sun is 57,910,000 km or 0.387 AU That's ~35,983,606 miles Mercury's diameter is 4,800 km (~2,983 miles) Meanwhile, we're 149,600,000 km (~92,957,130 miles) away from the Sun Gives you a perspective of how large the Sun is
Wow, that also puts into perspective how close that Jupiter sized planet that's just 2,000,000 miles from its sun actually is. That's like 18x closer than Mercury.
It does. The image posted above is a bit misleading, though. Images taken with the use of magnification creates a sense that the distant objects captured are closer to one another than that of which they truly are. The view of the Sun from Mercury would be something between 2.5-3x larger than from what it is from here. Mercury would receive close to 6x more sunlight than what we receive.
So lately my son has been getting into watching Neil deGrasse Tyson videos on YouTube. The other night he adamantly disagreed with Tyson, then insisted he'd prove him wrong by the time he's his age. It was on the matter of space travel via Tachyon particles.
To your point, the planets recently discovered in the triple star system are a very, very unique find. It's just the 4th time a triple star system has been discovered. KELT-4Ab is the planet closest to its sun, KELT-4A, located in the star system KELT-4. 4Ab resembles our gas giant Jupiter. It's what you call a Hot Jupiter. 4Ab orbits its sun in just 3 days, and yet it remains stable and intact. The other two stars, named KELT-B and C, are much farther away, orbiting each other every 30 days (taking four thousand years to orbit KELT-A). It is suggested that 4Ab has a view of its sun a good forty times as big as how we view our sun. That leaves the two other stars closely resembling how our view of the Moon is.
Hot Jupiter from Wikipedia: They are likely to have extreme and exotic atmospheres due to their short periods, relatively long days, and tidal locking. Atmospheric dynamics models predict strong vertical stratification with intense winds and super-rotating equatorial jets driven by radiative forcing and the transfer of heat and momentum.[12][13] The day-night temperature difference at the photosphere is predicted to be substantial, approximately 500 K for a model based on HD 209458b.[13] There are times where Mercury is pleasant enough to live on, which are the fleeting seconds just after sunrise and sunset. You can see what it is like for a day on Mercury here: http://sciencenetlinks.com/interactives/messenger/dom/DayOnMercury.html
Emma, aren't they all tidally locked, though? I feel like most of the planets we discover are tidally locked, which makes the interesting possibilities for life much more limited.
It is generally considered that most, if not all hot Jupiters, are tidally locked to their respective sun. So we can assume 4Ab is tidally locked. We won't be in a tidal locking with our Sun until the Moon drifts away. And the Moon's disappearance is predicted to outlast the time it will take for the Sun to go supernova. Even Mercury isn't tidally locked with the Sun as it is in a 3:2 spin:orbit resonance. With that said, almost all moons in our solar system are tidally locked to their respective host planet. Tidal locking is an interesting phenomena to look at as it has a lot of factors that lead to tidal locking and the stark possibility of life. The close binary stars that we have recorded throughout our minute observations of the universe are generally expected to be tidally locked. One common example of this is Tau Bootis being tidally locked with its planet, Tau Bootis Ab. Through our observations, we can conclude that some of the primary factors known to cause tidal locking is the malleability of the content of the objects, their orbital distance, and the masses of both celestial bodies. As you mentioned, the closer objects are to each other, the increase in the likelihood of tidal locking taking place. Good: stars that are just smaller than our Sun (yellow dwarf) are called M-type stars or red dwarf. They are much cooler and contain less solar masses than our Sun (ranging between .75-.50 solar masses; our Sun is the definition of a solar mass=1M). Once ruled out, red dwarfs are now considered to hold a small region where tidally locked planets overlap with the the habitable zone for the each planet. Bad: most stars recorded are the commonly seen orange and red dwarfs. That leads to the necessity of habitable orbiting planets to remain close to their red or orange dwarf host. And as we know, the closer a planet is to its star, the greater the star's forces act upon the planet - which leads to tidal locking. Tidal locking then leads to a set constant day/night cycle for each side of the planet to experience - which in return leads to the night side's air to freeze and eventually wipe away its side of the planet's atmosphere. Considerations: it mostly comes down to a planet's atmosphere when we consider habitable planets and its ice line. A planet with a thin atmosphere, similar to ours, can revolve relatively close to an orange or red dwarf star while not tidal locking. It may not be the warmest of climate though. A bit thicker atmosphere and it may be ideal. Therefore, the thicker the atmosphere, the closer the planet can be to its host star without tidally locking.
Skimming http://arxiv.org/pdf/1510.00015v1.pdf If KELT-4Ab formed past the ice line (see below) at a few AU and migrated to its present location via Kozai-Lidov oscillations and tidal friction (as in, e.g., Wu & Murray 2003; Fabrycky & Tremaine 2007), this would place constraints on the orbital parameters of the system as it existed shortly after formation. In particular, for Kozai-Lidov oscillations to be strong enough to drive the planet from ∼5 AU to 0.04 AU either the initial inclination of the outer orbit relative to the planet must have been close to 90◦, or the eccentricity of the outer orbit must have been large, or both. It is considered that the binary system KELT-4Bc drove KELT-4Ab so close to its star or that it was acted upon by another unseen gas giant, similar to the possible interaction between Jupiter and Saturn that made way for Earth and shaped our solar system (read:http://news.ucsc.edu/2015/03/wandering-jupiter.html). Currently, we know next to nothing about 4Ab other than it exists. Depending on whether its atmosphere is extremely thick may dictate whether it is tidally locked or not. Most likely, 4Ab is tidally locked with its host star and has a constant set day/night cycle. Temperatures vary greatly with one side being an estimated 2880 degrees and the other being 1300. The day side probably consists of a non-existent atmosphere due to the irradiation from its host star, molten cascades while the night side is frozen over or near solid. That would lead to an inefficient circulation of heat, causing each side to remain in the same state. Whether or not the night side has an atmosphere or not will be known in the next 3 years. Ice line (frost line):
QnA from reddit: What is our solar systems orientation as we travel around the Milky Way? Are other solar systems the same? Knowing that the north star doesn't move, my guess is that we are either spinning like a frisbee with matching planes to the Milky Way, or tilted 90 degrees to the Milky Ways plane. _________________________________________________________________________ So, within the Solar System, things tend to all rotate the same way. The Moon orbits the Earth on a plane that's very close to the plane of the Earth's orbit around the Sun. The Earth rotates in the same direction too. There are exceptions, but this is what happens in general. The Solar System all rotates the same way because it all formed from a single rotating clump of gas. As this gas fragmented, the chunks would all be rotating the same way too. So you get things all going the same way, more or less. Collisionless between objects can change things up a bit. But with the Milky Way it's quite different. A group of stars will form from a cloud of gas, but this cloud is very small compared to the size of the Milky Way. On that scale, the rotation of the Milky Way doesn't matter - instead, we're small enough that random turbulent motions really matter. Overall, the gas in the Milky Way is quite hot and turbulent - it's not a nice dense smoothly rotating disc, like the early Solar System. So star-forming clouds seem to have almost completely random rotations - if they're rotating at all. Within a star-forming cloud itself, there is even more turbulence. This cloud will collapse into a number of little clumps, all with basically random orientations. Each of these clumps is small enough and dense enough to have consistent rotation within itself, so each of these clumps will form a star system that rotates consistently, but there's little or no connection between the rotation of one star system with another. So, basically, star systems seem to rotate pretty much randomly. For our own Solar System, you can actually see the angle pretty clearly at night. All the planets, the Moon, and the Sun all orbit in basically the same plane - the "ecliptic". This is the plane of our solar system. If you go out at night with a star map, you can try to spot it. All of the astrological constellations are along the ecliptic too, so if you find Gemini, Scorpio etc, that's the plane of the solar system. The plane of the Milky Way is, of course, the Milky Way. So you can look up and compare those fairly easily. The numbers: the Earth's rotation is 24° from the plane of its orbit around the Sun (the ecliptic). The ecliptic is 60° from the Milky Way plane.
http://i.imgur.com/Wg5lmX4.gifv Mercury's transit through AIA 193 Angstroms channel AIA 193 channel highlights the outer atmosphere of the Sun - its corona - and the Sun's plasma flares. The bright regions are coronal mass ejections and the dark regions are coronal holes. Wavelength: 193 angstroms (0.0000000193 m) = Extreme Ultraviolet Primary ions seen: 11 times ionized iron (Fe XII) Characteristic temperature: 1.25 million K (2.25 million F)
http://www.realclearscience.com/blog/2016/05/three_problems_with_the_big_bang.html I wish he would have gone into more detail about each problem. I guess I'll have to do my own damn research...Reading about the Horizon Problem now.
Ingress: http://mercurytransit.gsfc.nasa.gov/assets/movies/Mercury_HMI_I/In/Mercury_HMI_I_In.mp4 Spoiler: HMI HMI - The Helioseismic and Magnetic Imager (HMI) is an instrument designed to study oscillations and the magnetic field at the solar surface, or photosphere. HMI observes the full solar disk at 6173 angstroms with a resolution of 1 arcsecond. This wavelength is great for viewing visible sunspot formations. http://mercurytransit.gsfc.nasa.gov/assets/movies/Mercury_AIA12s_304/In/Mercury_AIA12s_304_In.mp4 Spoiler: AIA 304 AIA 304 - This channel is especially good at showing areas where cooler dense plumes of plasma (filaments and prominences) are located above the visible surface of the Sun. Many of these features either can't be seen or appear as dark lines in the other channels. The bright areas show places where the plasma has a high density. Track: http://mercurytransit.gsfc.nasa.gov...AIA96s_211/Track/Mercury_AIA96s_211_Track.mp4 Spoiler: AIA 211 AIA 211 - This channel (as well as AIA 335) highlights the active region of the outer atmosphere of the Sun - the corona. Active regions, solar flares, and coronal mass ejections will appear bright here. The dark areas - called coronal holes - are places where very little radiation is emitted, yet are the main source of solar wind particles. Full disk: http://mercurytransit.gsfc.nasa.gov..._171/WholeSun/Mercury_AIA96s_171_WholeSun.mp4 Spoiler: AIA 171 This channel is especially good at showing coronal loops - the arcs extending off of the Sun where plasma moves along magnetic field lines. The brightest spots seen here are locations where the magnetic field near the surface is exceptionally strong.
The 2016 Mercury transit through different Angstrom channels as seen from the Solar Dynamics Observatory can be found here: http://mercurytransit.gsfc.nasa.gov/ For more information of the various channels and the latest auto-updated solar imagery courtesy of the SDO can be found here: http://www.solarham.net/latest_imagery/index.htm
Just announced NASA's Kepler mission has verified 1,284 new planets – the single largest finding of planets to date. “This announcement more than doubles the number of confirmed planets from Kepler,” said Ellen Stofan, chief scientist at NASA Headquarters in Washington. “This gives us hope that somewhere out there, around a star much like ours, we can eventually discover another Earth.” Analysis was performed on the Kepler space telescope’s July 2015 planet candidate catalog, which identified 4,302 potential planets. For 1,284 of the candidates, the probability of being a planet is greater than 99 percent – the minimum required to earn the status of “planet.” An additional 1,327 candidates are more likely than not to be actual planets, but they do not meet the 99 percent threshold and will require additional study. The remaining 707 are more likely to be some other astrophysical phenomena. This analysis also validated 984 candidates previously verified by other techniques. .... In the newly-validated batch of planets, nearly 550 could be rocky planets like Earth, based on their size. Nine of these orbit in their sun's habitable zone, which is the distance from a star where orbiting planets can have surface temperatures that allow liquid water to pool. With the addition of these nine, 21 exoplanets now are known to be members of this exclusive group. Spoiler: Summary of the announcement Found at: ttp://www.nasa.gov/feature/ames/kepler/briefingmaterials160510 Briefing materials: 1,284 Newly Validated Kepler Planets NASA will host a news teleconference at 1 p.m. EDT Tuesday, May 10 to announce the latest discoveries made by its planet-hunting mission, the Kepler Space Telescope. The briefing participants are: Paul Hertz, Astrophysics Division director at NASA Headquarters in Washington Timothy Morton, associate research scholar at Princeton University in New Jersey Natalie Batalha, Kepler mission scientist at NASA's Ames Research Center in Moffett Field, California Charlie Sobeck, Kepler/K2 mission manager at Ames NASA Media Advisory The research paper these findings are based on as published by The Astrophysical Journal on May 10, 2016: False Positive Probabilities For All Kepler Objects Of Interest: 1284 Newly Validated Planets And 428 Likely False Positives (Morton et al, 2016). Figure 1: Kepler measures the brightness of stars. The data will look like an EKG showing the heart beat. Whenever a planet passes in front of its parent star as viewed from the spacecraft, a tiny pulse or beat is produced. From the repeated beats we can detect and verify the existence of Earth-size planets and learn about the orbit and size of the planet. Credits: NASA Ames and Dana Berry Figure 2: The histogram shows the number of planet discoveries by year for more than the past two decades of the exoplanet search. The blue bar shows previous non-Kepler planet discoveries, the light blue bar shows previous Kepler planet discoveries, the orange bar displays the 1,284 new validated planets. Credits: NASA Ames/W. Stenzel; Princeton University/T. Morton Figure 3: Kepler's candidates require verification to determine if they are actual planets and not another object, such as a small star, mimicking a planet. Credits: NASA Ames/W. Stenzel Figure 4: Since the discovery of the first planets outside our solar system more than two decades ago, researchers have resorted to a laborious, one-by-one process of verifying suspected planets. These follow-up observations are often time and resource intensive. Credits: NASA Figure 5: Kepler candidate planets (orange) are smaller and orbit fainter stars than transiting planets detected by ground-based observatories (blue). Credits: NASA Ames/W. Stenzel; Princeton University/T. Morton Figure 6: A new statistical validation technique enables researchers to quantify the probability that any given candidate signal is in fact caused by a planet, without requiring any follow-up observations. This technique uses two different kinds of simulations-- both simulations of the detailed shapes of transit signals caused by both planets and objects, such as a star, masquerading as planets (left diagram), and also simulations of how common imposters are expected to be in the Milky Way galaxy (right diagram). Combining these two different kinds of information gives scientists a reliability score between zero and one for each candidate. Candidates with reliability greater than 99 percent are call “validated planets.” Credits: NASA Ames/W. Stenzel; Princeton University/T. Morton Figure 7: The pie chart illustrates the results of a statistical analysis performed on 4,302 potential planets from the Kepler mission’s July 2015 planet candidate catalog. For 1,284 of the candidates (orange), the probability of being a planet is greater than 99 percent – the minimum required to earn the status of “planet.” An additional 1,327 candidates (dark grey) are more likely than not to be actual planets, but they do not meet the 99 percent threshold and will require additional study. The remaining 707 candidates (light grey) are more likely to be some other astrophysical phenomena. This analysis also revalidated 984 candidates (blue) that have previously been verified by other techniques. Credits: NASA Ames/W. Stenzel; Princeton University/T. Morton Figure 8: The histogram shows the number of planets by size for all known exoplanets. The blue bars on the histogram represent all previously verified exoplanets by size. The orange bars on the histogram represent Kepler's 1,284 newly validated planets announcement on May 10, 2016. Credits: NASA Ames/W. Stenzel Figure 9: Kepler was pointed at the patch of sky near the Lyra and Cygnus constellations. The yellow portion represents Kepler’s field-of-view. Credits: NASA Figure 10: Since Kepler launched in 2009, 21 planets less than twice the size of Earth have been discovered in the habitable zones of their stars. The orange spheres represent the nine newly validated planets announcement on May 10, 2016. The blue disks represent the 12 previous known planets. These planets are plotted relative to the temperature of their star and with respect to the amount of energy received from their star in their orbit in Earth units. The sizes of the exoplanets indicate the sizes relative to one another. The images of Earth, Venus and Mars are placed on this diagram for reference. The light and dark green shaded regions indicate the conservative and optimistic habitable zone. Credits: NASA Ames/N. Batalha and W. Stenzel Figure 11: The Arc of Discovery artistic concept features NASA's astrophysics missions searching for signs of life beyond Earth. Credits: NASA Ames/N. Batalha and W. Stenzel Figure 12: The Kepler mission completed observations in May 2013, and will closeout its remaining analyses in September 2017. The Kepler Spacecraft continues to make astronomical observations as the re-purposed K2 mission.
That is done while observing just a minuscule 0.25% of the sky. What's important about this discovery and announcement is that TESS - Kepler's successor - is due to launch next year and unlike Kepler and its K2 mission, it will have all of this information readily available to utilize rather than waiting nearly a decade for the information to come out like Kepler had to. Furthermore, TESS will immediately provide the JWST with primary targets to study with using its promising exoplanetary analysis ability. Side note - TESS will be launching with Falcon 9 Full Thrust - thanks Elon Musk.
One of the reasons that most of the planets they've discovered are tidally locked is because the easiest planets to find are the ones closest to the star. They orbit so often that they are much easier to confirm. Kepler uses the transit method to find stars. So, for instance, Jupiter's year is 12 years. Kepler would have to observe it for 36 years to confirm its existence around another star.
Soooooooo can't wait for these two to come on line. They are going to change what we know about space and exoplanets on a daily basis.
Not sure about the monopole issue, but the uniformity of temperature in the universe is thought to be the result of an inflationary period in the microseconds following the Big Bang. Also, doesn't the current research in Astrophysics point to space time shaped like a saddle with Omega naught < 1? And space time does exhibit curvature - that's one of the main components of General Relativity. (Perhaps the author just means on a macro level? )
update on the star with the DYSON STRUCTURE AROUND IT ALIENS ARE REAL -- Sorry, E.T. lovers, but the results of a new study make it far less likely that KIC 8462852, popularly known as Tabby's star, is the home of industrious aliens who are gradually enclosing it in a vast shell called a Dyson sphere. Public interest in the star, which sits about 1,480 light-years away in the constellation Cygnus, began last fall when Yale astronomer Tabetha ("Tabby") Boyajian and colleagues posted a paper on an astronomy preprint server reporting that "planet hunters" - a citizen science group formed to search data from the Kepler space telescope for evidence of exoplanets - had found unusual fluctuations in the light coming from the otherwise ordinary F-type star (slightly larger and hotter than the sun). The most remarkable of these fluctuations consisted of dozens of uneven, unnatural-looking dips that appeared over a 100-day period indicating that a large number of irregularly shaped objects had passed across the face of the star and temporarily blocked some of the light coming from it. Media interest went viral last October when a group of astronomers from Pennsylvania State University released a preprint that cited KIC 8462852's "bizarre light curve" as "consistent with" a swarm of alien-constructed megastructures. The attention caused scientists at the SETI Institute to train its Alien Telescope Array on the star to see if they could detect any radio signals indicating the presence of an alien civilization. In November it reported finding "no such evidence" of signals with an artificial origin. Then a study released in January by a Louisiana State University astronomer threw even more fuel on the fire of alien speculation by announcing that the brightness of Tabby's star had dimmed by 20 percent over the last century: a finding particularly difficult to explain by natural means but consistent with the idea that aliens were gradually converting the material in the star's planetary system into giant megastructures that have been absorbing increasing amounts of energy from the star for more than a century. That study has now been accepted for publication in the peer reviewed Astrophysical Journal. However, a new study - also accepted for publication in the Astrophysical Journal - has taken a detailed look at the observations on which the LSU study was based and concluded there is no credible evidence that the brightness of the star been steadily changing over this period. The Dyson Ring, left, is the simplest form of Dyson structure. Creating a Dyson bubble would be an incredible engineering challenge but it is considered to be far more feasible than surrounding a star in a rigid sphere. Credit: Wikipedia Creative Commons License When the LSU study was posted on the physics preprint server ArXiv, it caught the attention of Vanderbilt doctoral student Michael Lund because it was based on data from a unique resource: Digital Access to a Sky Century @ Harvard. DASCH consists of more than 500,000 photographic glass plates taken by Harvard astronomers between 1885 and 1993, which the university is digitizing. Lund was concerned that the apparent 100-year dimming of Tabby's star might just be the result of observations having been made by a number of different telescopes and cameras that were used during the past century. Lund convinced his advisor, Professor of Physics and Astronomy Keivan Stassun, and a frequent collaborator, Lehigh University astronomer Joshua Pepper, that the question was worth pursuing. After they began the study, the Vanderbilt/Lehigh group discovered that another team - German amateur astronomer Michael Hippke and NASA Postdoctoral Fellow Daniel Angerhausen - were conducting research along similar lines. So the two teams decided to collaborate on the analysis, which they wrote up and submitted to the Astrophysical Journal. "Whenever you are doing archival research that combines information from a number of different sources, there are bound to be data precision limits that you must take into account," said Stassun. "In this case, we looked at variations in the brightness of a number of comparable stars in the DASCH database and found that many of them experienced a similar drop in intensity in the 1960's. That indicates the drops were caused by changes in the instrumentation not by changes in the stars' brightness." Even if aliens are not involved, Tabby's star remains "the most mysterious star in the universe" as Boyajian described it in a TED talk she gave last February. The planet hunters first detected something unusual in the star's light curve in 2009. They found a 1 percent dip that lasted a week. This is comparable to the signal that would be produced by a Jupiter-sized planet passing in front of the star. But planets produce symmetric dips and the one they found was decidedly asymmetric, like something that would be produced by an irregular-shaped object like a comet. The light from the star remained steady for two years, then it suddenly took a 15 percent plunge that lasted for a week. Another two years passed without incident but in 2013 the star began flickering with a complex series of uneven, unnatural looking dips that lasted 100 days. During the deepest of these dips, the intensity of the light coming from the star dropped 20 percent. According to Boyajian it would take an object 1,000 times the area of the Earth transiting the distant star to produce such a dramatic effect. "The Kepler data contains other cases of irregular dips like these, but never in a swarm like this," said Stassun. Boyajian and her colleagues considered a number of possible explanations, including variations in the star's output, the aftermath of an Earth/Moon type planetary collision, interstellar clumps of dust passing between the star and earth, and some kind of disruption by the star's apparent dwarf companion. However, none of their scenarios could explain all of the observations. Their best explanation was a giant comet that fragmented into a cascade of thousands of smaller comets. (This hypothesis took a hit when the LSU study was announced because it could not explain a century-long dimming.) "What does this mean for the mystery? Are there no aliens after all? Probably not! Still, the dips found by Kepler are real. Something seems to be transiting in front of this star and we still have no idea what it is!" Hippke summarized. The Kepler telescope is no longer collecting data in the Cygnus region, but Hippke reports that the mystery has captured the imagination of amateur astronomers around the world so thousands of them are pointing their telescopes at Tabby's star, snapping images and sending them to the American Association of Variable Star Observers in hopes of detecting further dips that will shed new light on this celestial mystery. Read more at: http://phys.org/news/2016-05-natural-alien-mystery-star-behavior.html#jCp -- cliffs:
Tycho's supernova remnant: Chandra movie captures expanding debris from a stellar explosion May 12, 2016 Credit: X-ray: NASA/CXC/GSFC/B.Williams et al; Optical: DSS When the star that created this supernova remnant exploded in 1572, it was so bright that it was visible during the day. And though he wasn't the first or only person to observe this stellar spectacle, the Danish astronomer Tycho Brahe wrote a book about his extensive observations of the event, gaining the honor of it being named after him. In modern times, astronomers have observed the debris field from this explosion—what is now known as Tycho's supernova remnant—using data from NASA's Chandra X-ray Observatory, the NSF's Karl G. Jansky Very Large Array (VLA) and many other telescopes. Today, they know that the Tycho remnant was created by the explosion of a white dwarf star, making it part of the so-called Type Ia class of supernovas used to track the expansion of the universe. Since much of the material being flung out from the shattered star has been heated by shock waves— similar to sonic booms from supersonic planes—passing through it, the remnant glows strongly in X-ray light. Astronomers have now used Chandra observations from 2000 through 2015 to create the longest movie of the Tycho remnant's X-ray evolution over time, using five different images. This shows the expansion from the explosion is still continuing about 450 years later, as seen from Earth's vantage point roughly 10,000 light-years away. By combining the X-ray data with some 30 years of observations in radio waves with the VLA, astronomers have also produced a movie, using three different images. Astronomers have used these X-ray and radio data to learn new things about this supernova and its remnant. (3 sec video in link at bottom.) Credit: X-ray: NASA/CXC/GSFC/B.Williams et al; Optical: DSS The researchers measured the speed of the blast wave at many different locations around the remnant. The large size of the remnant enables this motion to be measured with relatively high precision. Although the remnant is approximately circular, there are clear differences in the speed of the blast wave in different regions. The speed in the right and lower right directions is about twice as large as that in the left and the upper left directions. This difference was also seen in earlier observations. This range in speed of the blast wave's outward motion is caused by differences in the density of gas surrounding the supernova remnant. This causes an offset in position of the explosion site from the geometric center, determined by locating the center of the circular remnant. The astronomers found that the size of the offset is about 10% of the remnant's current radius, towards the upper left of the geometric center. The team also found that the maximum speed of the blast wave is about 12 million miles per hour. Offsets such as this between the explosion center and the geometric center could exist in other supernova remnants. Understanding the location of the explosion center for Type Ia supernovas is important because it narrows the search region for a surviving companion star. Any surviving companion star would help identify the trigger mechanism for the supernova, showing that the white dwarf pulled material from the companion star until it reached a critical mass and exploded. The lack of a companion star would favor the other main trigger mechanism, where two white dwarfs merge causing the critical mass to be exceeded, leaving no star behind. The significant offset from the center of the explosion to the remnant's geometric center is a relatively recent phenomenon. For the first few hundred years of the remnant, the explosion's shock was so powerful that the density of gas it was running into did not affect its motion. The density discrepancy from the left side to the right has increased as the shock moved outwards, causing the offset in position between the explosion center and the geometric center to grow with time. So, if future X-ray astronomers, say 1,000 years from now, do the same observation, they should find a much larger offset. Read more at: http://phys.org/news/2016-05-tycho-supernova-remnant-chandra-movie.html#jCp
Congress is Working Hard to Ground NASA’s Mars Mission http://fortune.com/2016/05/15/congress-nasas-mars-mission/
Went to Johnson Space Center last Friday. Such a good time and came back with a little Endeavour toy for Little 2.5 y/o Morbette! She was very happy and has been running around yelling "ROCKET SHIP" for the past few days.
Congress wants to know if NASA can really get to Mars By Alessandra Potenza on May 18, 2016 06:54 pm Members of the House Committee on Science, Space, and Technology repeatedly questioned the feasibility of NASA's strategy to get to the Red Planet by the 2030s at aspecial hearing today. Representatives cited financial concerns and some even suggested that NASA's efforts should be redirected towards cleaning up space debris and protecting Earth from possible asteroid impacts. The chief concern was cost, since the entire mission could require over a trillion dollars. Much of the money will be spent to develop new technologies — like a system to protect astronauts from space radiation — that are needed to ensure deep-space travel is even possible. Rep. Dana Rohrabacher (R-CA) and others said that the money might be better spent for other space projects, like cleaning up the space debris surrounding Earth, and creating a system to protect our planet in case of a potential asteroid impact. "There are a lot of things we could be doing in space," Rohrabacher said. "I hope that we make sure that we don’t waste dollars on things that we don’t accomplish anything with." 2014 National Research Council report, which was mandated by Congress and concluded that NASA's current strategy won't accomplish sending humans to Mars. Bridenstine questioned whether NASA's strategy improved at all. "We need to make sure that Congress is aware and understands what the objective here is and ultimately the direction we’re going to go," Bridenstine said, "because I don’t want to get another report in 10 years that says, under no circumstances will we ever get to Mars and between now and 10 years from now we will have made all these investments believing one thing and being told later something else." The hearing was meant to discuss NASA's efforts to build a habitat for astronauts on their way to Mars. It comes five months after Congress granted NASA $19.3 billion in its latestspending bill. A report attached to the bill also ordered the space agency to spend at least $55 million to develop a deep-space habitat module and to have a prototype completed by 2018. NASA plans to transport astronauts to Mars with a rocket called the Space Launch System (SLS) and a crew capsule called Orion. The space agency is currently building both; a test flight for the whole system is scheduled for 2018. But if NASA is serious about deep-space exploration, the agency has to develop a craft that can give astronauts enough space to live relatively comfortably during the months-long journey to the Red Planet. NASA announced last month that it was seeking proposals for the development of habitat prototypes from private companies, as well as US universities and nonprofits. The winning concepts will be announced in August. In March 2015, NASAhad already awarded up to $1 million to seven companies — including Boeing, Lockheed Martin, Bigelow Aerospace, and Orbital ATK — to study and develop habitats. witnesses said that NASA was in need of a much clearer plan to reach the Red Planet. Just like in that hearing, some witnesses today criticized the NASA's Asteroid Redirect Mission (ARM) and questioned its function in the larger mission of sending humans to Mars. ARM will send a robotic spacecraft to capture a small piece of an asteroid and bring it into lunar orbit, where humans on the SLS can visit it. Many planetary experts have claimed ARM won't advance scientific knowledge that much. But NASA says ARM's main goal is to test new solar electric propulsion technology that the agency says will be necessary to reach the Red Planet. At the hearing, Cursan repeated that position. "That’s the experience we will need to send cargo into Mars and eventually our crew into Mars as well," Cursan said, adding that it "could be interpreted as an essential part of going to Mars."