| | 9 new stories for 2016/05/03
Three New Earth-sized Planets Found Just 40 Light-Years Away 
Three more potentially Earthlike worlds have been discovered in our galactic backyard, announced online today by the European Southern Observatory. Researchers using the 60-cm TRAPPIST telescope at ESO's La Silla observatory in Chile have identified three Earth-sized exoplanets orbiting a star just 40 light-years away. The star, originally classified as 2MASS J23062928-0502285 but now known more conveniently as TRAPPIST-1, is a dim "ultracool" brown dwarf only .05% as bright as our Sun . Located in the constellation Aquarius, it's now the 37th-farthest star known to host orbiting exoplanets. The exoplanets were discovered via the transit method ( TRAPPIST stands for Transiting Planets and Planetes imals Small Telescope) through which the light from a star is observed to dim slightly by planets passing in front of it from our point of view. This is the same method that NASA's Kepler spacecraft has used to find over 1,000 confirmed exoplanets. As a brown dwarf " failed star" TRAPPIST-1 is a very small and dim and isn't easily visible from Earth, but it's its very dimness that has allowed its planets to be discovered with existing technology. Their subtle silhouettes may have been lost in the glare of larger, brighter stars. Follow-up measurements of the three exoplanets indicated that they are all approximately Earth-sized and have temperatures ranging from Earthlike to Venuslike (which is, admittedly, a fairly large range.) They orbit their host star very closely with periods measured in Earth days, not years. "With such short orbital periods, the planets are between 20 and 100 times closer to their star than the Earth to the Sun," said Michael Gillon, lead author of the research paper. "The structure of this planetary system is much more similar in scale to the system of Jupiter's moons than to that of the Solar System." Read more: Mini Solar System Around a Brown Dwarf Although these three new exoplanets are Earth-sized they do not yet classify as "potentially habitable," at least by the standards of the Planetary Habitability Laboratory (PHL) operated by the University of Puerto Rico at Arecibo. The planets fall outside PHL's required habitable zone; two are too close to the host star and one is too far away. In addition there are certain factors that planets orbiting brown dwarfs would have to contend with in order to be friendly to life, not the least of which is overheating from tidal flexing as a result of being so close to their host star. This does not guarantee that the exoplanets are completely uninhabitable, though; it's entirely possible that there are regions on or within them where life could exist, not unlike Mars or some of the moons in our own Solar System. The exoplanets are all likely tidally locked in their orbits, so even though the closest two are too hot on their star-facing side and too cold on the other, there may be regions along the east or west terminators that maintain a climate conducive to life. "Now we have to investigate if they're habitable," said co-author Julien de Wit at MIT in Cambridge, Mass. "We will investigate what kind of atmosphere they have, and then will search for biomarkers and signs of life." Discovering three planets orbiting such a small yet extremely common type of star hints that there are likely many, many more such worlds in our galaxy and the Universe as a whole. "So far, the existence of such 'red worlds' orbiting ultra-cool dwarf stars was purely theoretical, but now we have not just one lonely planet around such a faint red star but a complete system of three planets," said study co-author Emmanuel Jehin. The team's research was presented in a paper entitled "Temperate Earth-sized planets transiting a nearby ultracool dwarf star" and will be published in Nature. Source: ESO, PHL, and MITThe post Three New Earth-sized Planets Found Just 40 Light-Years Away appeared first on Universe Today.
Scientists Assemble Fresh Global Map of Pluto Comprising Sharpest Flyby Images 
The science team leading NASA's New Horizons mission that unveiled the true nature of Pluto's long hidden looks during the history making maiden close encounter last July, have published a fresh global map that offers the sharpest and most spectacular glimpse yet of the mysterious, icy world. The newly updated global Pluto map is comprised of all the highest resolution images transmitted back to Earth thus far and provides the best perspective to date. Click on the lead image above to enjoy Pluto revealed at its finest thus far. Click on this link to view the highest resolution version. Prior to the our first ever flyby of the Pluto planetary system barely 8 months ago, the planet was nothing more than a fuzzy blob with very little in the way of identifiable surface features - even in the most powerful telescopic views lovingly obtained from the Hubble Space Telescope (HST). Dead center in the new map is the mesmerizing heart shaped region informally known as Tombaugh Regio, unveiled in all its glory and dominating the diminutive world. The panchromatic (black-and-white) global map of Pluto published by the team includes the latest images received as of less than one week ago on April 25. The images were captured by New Horizons' high resolution Long Range Reconnaissance Imager (LORRI). The science team is working on assembling an updated color map. During its closest approach at approximately 7:49 a.m. EDT (11:49 UTC) on July 14, 2015, the New Horizons spacecraft swoop to within about 12,500 kilometers (nearly 7,750 miles) of Pluto's surface and about 17,900 miles (28,800 kilometers) from Charon, the largest moon. The map includes all resolved images of Pluto's surface acquired in the final week of the approach period ahead of the flyby starting on July 7, and continuing through to the day of closest approach on July 14, 2015 - and transmitted back so far. The pixel resolutions are easily seen to vary widely across the map as you scan the global map from left to right - depending on which Plutonian hemisphere was closest to the spacecraft during the period of close flyby. They range from the highest resolution of 770 feet (235 meters), at center, to 18 miles (30 kilometers) at the far left and right edges. The Charon-facing hemisphere (left and right edges of the map) had a pixel resolution of 18 miles (30 kilometers). "This non-encounter hemisphere was seen from much greater range and is, therefore, in far less detail," noted the team. However the hemisphere facing New Horizons during the spacecraft's closest approach on July 14, 2015 (map center) had a far higher pixel resolution reaching to 770 feet (235 meters). Coincidentally and fortuitously the spectacularly diverse terrain of Tombaugh Regio and the Sputnik Planum area of the hearts left ventricle with ice flows and volcanoes, mountains and river channels was in the region facing the camera and sports the highest resolution imagery. See below a newly released shaded relief map of Sputnik Planum. "Sputnik Planum – shows that the vast expanse of the icy surface is on average 2 miles (3 kilometers) lower than the surrounding terrain. Angular blocks of water ice along the western edge of Sputnik Planum can be seen "floating" in the bright deposits of softer, denser solid nitrogen," according to the team. Even more stunning images and groundbreaking data will continue streaming back from New Horizons until early fall, across over 3 billion miles of interplanetary space. Thus the global map of Pluto will be periodically updated. Its taking over a year to receive the full complement of some 50 gigabits of data due to the limited bandwidth available from the transmitter on the piano-shaped probe as it hurtled past Pluto, its largest moon Charon and four smaller moons. Pluto is the last planet in our solar system to be visited in the initial reconnaissance of planets by spacecraft from Earth since the dawn of the Space Age. New Horizons remains on target to fly by a second Kuiper Belt Object (KBO) on Jan. 1, 2019 - tentatively named PT1, for Potential Target 1. It is much smaller than Pluto and was recently selected based on images taken by NASA's Hubble Space Telescope. Stay tuned here for Ken's continuing Earth and planetary science and human spaceflight news. Ken Kremer The post Scientists Assemble Fresh Global Map of Pluto Comprising Sharpest Flyby Images appeared first on Universe Today.
Fuel Control Valve Faulted for Atlas Launch Anomaly, Flights Resume Soon 
A critical fuel control valve has been faulted for the Atlas V launch anomaly that forced a premature shutdown of the rockets first stage engines during its most recent launch of a Cygnus cargo freighter to the International Space Station (ISS) last month - that nevertheless was successful in delivering the payload to its intended orbit. Having identified the root cause of the engine shortfall, workers for Atlas rocket builder United Launch Alliance (ULA), have now stacked the booster slated for the next planned liftoff in the processing facility at their Cape Canaveral launch pad, the company announced in a statement Friday. The Atlas rockets Centaur upper stage fired longer than normal after the first stage anomaly, saving the day by making up for the significant lack of thrust and "delivering Cygnus to a precise orbit, well within the required accuracy," ULA said. ULA says it hopes to resume launches of the 20 story tall rocket as soon as this summer, starting with the MUOS-5 communications satellite payload for the U.S. Navy. Following a painstaking investigation to fully evaluate all the data, the ULA engineering team "determined an anomaly with the RD-180 Mixture Ratio Control Valve (MRCV) assembly caused a reduction in fuel flow during the boost phase of the flight," the company confirmed in a statement. The Atlas V first stages are powered by the Russian-made RD AMROSS RD-180 engines. The dual nozzle powerplants have been completely reliable in 62 Atlas launches to date. The RD-180s are fueled by a mixture of RP-1 kerosene and liquid oxygen stored in the first stage. The Centaur RL10C-1 second stage powerplant had to make up for a thrust and velocity deficiency resulting from a 6 second shorter than planned firing of the first stage RD-180 engines. "The Centaur [upper stage] burned for longer than planned," Lyn Chassagne, ULA spokesperson, told Universe Today. Indeed Centaur fired for a minute longer than planned to inject Cygnus into its proper orbit. "The first stage cut-off occurred approximately 6 seconds early, however the Centaur was able to burn an additional approximately 60 seconds longer and achieve mission success, delivering Cygnus to its required orbit," said ULA. MUOS-5 was originally supposed to blastoff on May 5. But the liftoff was put on hold soon after the Atlas V launch anomaly experienced during the March 22, 2016 launch of the Orbital ATK Cygnus OA-6 supply ship to the ISS for NASA. Since then, ULA mounted a thorough investigation to determine the root cause and identify fixes to correct the problem with RD-180 Mixture Ratio Control Valve (MRCV) assembly, while postponing all Atlas V launches. ULA has inspected, analyzed and tested their entire stockpile of RD-180 engines. Last Friday, the Atlas V first stage for the MUOS-5 launch was erected inside ULA's Vertical Integration Facility (VIF) at Space Launch Complex-41 on Cape Canaveral Air Force Station, Florida. The five solid motors have been attached and the Centaur is next. In this configuration, known as Launch Vehicle on Stand (LVOS) operation, technicians can further inspect and confirm that the RD-180 engines are ready to support a launch. The two stage Atlas V for MUOS-5 will launch in its most powerful 551 configuration with five solid rocket boosters attached to the first stage, a single engine Aerojet Rocketdyne RL10C-1 Centaur upper stage and a 5-meter-diameter payload fairing. The RD-180s were supposed to fire for 255.5 seconds, or just over 4 minutes. But instead they shut down prematurely resulting in decreased velocity that had to be supplemented by the Centaur RL10C-1 to get to the intended orbit needed to reach the orbiting outpost. The liquid oxygen/liquid hydrogen fueled Aerojet Rocketdyne RL10C-1 engine was planned to fire for 818 seconds or about 13.6 minutes. The single engine produces 22,900 lbf of thrust. The Atlas V first and second stages are preprogrammed to swiftly react to a wide range of anomalous situations to account for the unexpected. The rocket and launch teams conduct countless simulations to react to off nominal situations. "The Atlas V's robust system design, software and vehicle margins enabled the successful outcome for this mission," Chassagne said. "As with all launches, we will continue to focus on mission success and work to meet our customer's needs." ULA currently sports a year's long manifest of future Atlas V launches in the pipeline. It includes a wide range of payloads for NASA, US and foreign governments, and military and commercial customers - all of who are depending on ULA maintaining its string of 106 straight launches with a 100% record of success since the company formed in 2006. The Orbital ATK Cygnus CRS-6 space freighter was loaded with 3513 kg (7700 pounds) of science experiments and hardware, crew supplies, spare parts, gear and station hardware for the orbital laboratory in support of over 250 research experiments being conducted on board by the Expedition 47 and 48 crews. Cygnus successfully arrived and berthed at the ISS on March 26 as planned. An exact date for the MUOS-5 launch has yet to be confirmed on the Eastern Range with the US Air Force. ULA is in the process of coordinating launch dates with customers for their remaining Atlas V launches in 2016. The 15,000 pound MUOS payload is a next-generation narrowband tactical satellite communications system designed to significantly improve ground communications for U.S. forces on the move. ULA says they expect minimal impact and foresee completing all launches planned for 2016, including the top priority OSIRIS-REx asteroid mission for NASA which has a specific launch window requirement. Stay tuned here for Ken's continuing Earth and planetary science and human spaceflight news. Ken Kremer The post Fuel Control Valve Faulted for Atlas Launch Anomaly, Flights Resume Soon appeared first on Universe Today.
Fermi Links Neutrino Blast To Known Extragalactic Blazar 
A unique observatory buried deep in the clear ice of the South Pole region, an orbiting observatory that monitors gamma rays, a powerful outburst from a black hole 10 billion light years away, and a super-energetic neutrino named Big Bird. These are the cast of characters that populate a paper published in Nature Physics, on Monday April 18th. The observatory that resides deep in the cold dark of the Antarctic ice has one job: to detect neutrinos. Neutrinos are strange, standoffish particles, sometimes called 'ghost particles' because they're so difficult to detect. They're like the noble gases of the particle world. Though neutrinos vastly outnumber all other atoms in our Universe, they rarely interact with other particles, and they have no electrical charge. This allows them to pass through normal matter almost unimpeded. To even detect them, you need a dark, undisturbed place, isolated from cosmic rays and background radiation. This explains why they built an observatory in solid ice. This observatory, called the IceCube Neutrino Observatory, is the ideal place to detect neutrinos. On the rare occasion when a neutrino does interact with the ice surrounding the observatory, a charged particle is created. This particle can be either an electron, muon, or tau. If these charged particles are of sufficiently high energy, then the strings of detectors that make up IceCube can detect it. Once this data is analyzed, the source of the neutrinos can be known. The next actor in this scenario is NASA's Fermi Gamma-Ray Space Telescope. Fermi was launched in 2008, with a specific job in mind. Its job is to look at some of the exceptional phenomena in our Universe that generate extraordinarily large amounts of energy, like super-massive black holes, exploding stars, jets of hot gas moving at relativistic speeds, and merging neutron stars. These things generate enormous amounts of gamma-ray energy, the part of the electromagnetic spectrum that Fermi looks at exclusively. Next comes PKS B1424-418, a distant galaxy with a black hole at its center. About 10 billion years ago, this black hole produced a powerful outburst of energy, called a blazar because it's pointed at Earth. The light from this outburst started arriving at Earth in 2012. For a year, the blazar in PKS B1424-418 shone 15-30 times brighter in the gamma spectrum than it did before the burst. Detecting neutrinos is a rare occurrence. So far, IceCube has detected about a hundred of them. For some reason, the most energetic of these neutrinos are named after characters on the popular children's show called Sesame Street. In December 2012, IceCube detected an exceptionally energetic neutrino, and named it Big Bird. Big Bird had an energy level greater than 2 quadrillion electron volts. That's an enormous amount of energy shoved into a particle that is thought to have less than one millionth the mass of an electron. Big Bird was clearly a big deal, and scientists wanted to know its source. IceCube was able to narrow the source down, but not pinpoint it. Its source was determined to be a 32 degree wide patch of the southern sky. Though helpful, that patch is still the size of 64 full Moons. Still, it was intriguing, because in that patch of sky was PKS B1424-418, the source of the blazar energy detected by Fermi. However, there are also other blazars in that section of the sky. The scientists looking for Big Bird's source needed more data. They got it from TANAMI, an observing program that used the combined power of several networked terrestrial telescopes to create a virtual telescope 9,650 km(6,000 miles) across. TANAMI is a long-term program monitoring 100 active galaxies that are located in the southern sky. Since TANAMI is watching other active galaxies, and the energetic jets coming from them, it was able to exclude them as the source for Big Bird. The team behind this new paper, including lead author Matthias Kadler of the University of Wuerzberg in Germany, think they've found the source for Big Bird. They say, with only a 5 percent chance of being wrong, that PKS B1424-418 is indeed Big Bird's source. As they say in their paper, "The outburst of PKS B1424–418 provides an energy output high enough to explain the observed petaelectronvolt event (Big Bird), suggestive of a direct physical association." So what does this mean? It means that we can pinpoint the source of a neutrino. And that's good for science. Neutrinos are notoriously difficult to detect, and they're not that well understood. The new detection method, involving the Fermi Telescope in conjunction with the TANAMI array, will not only be able to locate the source of super-energetic neutrinos, but now the detection of a neutrino by IceCube will generate a real-time alert when the source of the neutrino can be narrowed down to an area about the size of the full Moon. This promises to open a whole new window on neutrinos, the plentiful yet elusive 'ghost particles' that populate the Universe. The post Fermi Links Neutrino Blast To Known Extragalactic Blazar appeared first on Universe Today.
The Constellation Aries 
Welcome back to constellation Friday! Today, in honor of our dear friend and contributor, Tammy Plotner, we examine the Aries constellation. Enjoy! In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of the then-known 48 constellations. His treatise, known as the Almagest, would serve as the authoritative source of astronomy for over a thousand years to come. Since the development of modern telescopes and astronomy, this list has come to be expanded to include the 88 constellation that are recognized by the International Astronomical Union (IAU) today. Of these constellations, Aries - named in honor of the Ram from classical Greek mythology - is featured rather prominently. This faint constellation has deep roots, and is believed to date all the way back to the astrological systems of the ancient Babylonians. Positioned on the ecliptic plane, it is bordered by constellations of Perseus, Triangulum, Pisces, Cetus and Taurus, and is also the traditional home of the vernal equinox. Name and Meaning: In classical mythology, Aries is the Ram - perhaps the golden one who saved Helle and Phrixos from a king Cretheus for false accusations. Aries the Ram is the also the first astrological sign in the Zodiac - associated with the god Ares and masculinity. Under the tropical zodiac, the Sun is in Aries roughly from March 21st to April 19th, by definition beginning at vernal equinox. The vernal equinox has moved in the constellation Pisces, but sometimes it is still called the first point of Aries. Notable Features: Aries has three prominent stars forming an asterism - Alpha, Beta and Gamma Arietis, all of which have been traditionally used for navigation. Alpha Arietis, called Hamal, is an orange giant with an apparent magnitude of 2.0, making it the brightest star in the constellation. Located 66 light-years from Earth, this star's traditional name comes from the Arabic word for "lamb", or "head of the ram" ( ras al-hamal). Beta Arietis (Sheratan) is a blue-white star star with an apparent magnitude of 2.64 that is located 59 light-years from Earth. Its traditional name comes from the Arabic word " sharatayn", which means "the two signs", referring to both Beta and Gamma Areitis in their position as heralds of the vernal equinox. This star is also a spectroscopic binary, meaning that its companion is only known through analysis of the spectra. Gamma Arietis (Mesarthim) is binary star with two white-hued components that are located 164 light-years from Earth. Its traditional name is the subject of scholarly debate, with some claiming it may be derived from a corruption of " al-sharatan" (Arabic for "pair"), a word for "fat ram", from the Sanskrit "first star of Aries", or the Hebrew for "ministerial servants". Aries is also home to several faint Deep Sky Objects. These include NGC 772, an unbarred spiral galaxy located 130 million light-years from Earth which is visible to the southeast of Beta Arietis. It has a small companion galaxy, NGC 770, that is about 113,000 light-years away from the larger galaxy. Another spiral galaxy in Aries is NGC 673, a weakly barred spiral galaxy that is 235 million light-years distant from Earth. For those who have a larger telescope, there are several faint galaxies that can be spotted. NGC 697 is a good example, a 13th magnitude spiral galaxy located within Aries that is part of a galaxy group. NGC 972 is also part of a galaxy group and is equally faint, at magnitude 12. NGC 1156 is a dwarf irregular galaxy that is considered to a Magellanic-type, with a larger than average core and a a H II nucleus containing zones of counter-rotating gas (which is thought to be the result of tidal interactions with another gas-rich galaxy some time in the past). Aries is also home to several meteor showers. The May Arietids are a daylight meteor shower which begins between May 4th and June 6th with maximum activity happening on May 16th. The Epsilon Arietids are also a daylight occurrence, which are active between April 25th to May 27th with peak activity on May 9th. The very best daytime Arietids occur from May 22nd to July 2nd with a maximum on June 8th, when the meteoroid stream produces one meteor every minute. Historically speaking, the Delta Arietid meteor shower was first noted in 1959 by analyzing photographic meteor orbits, and activity occurs between December 8th and December 13th. The Autumn Arietid meteor shower begins on or about September 7th and runs through October 27th. Maximum activity occurs about October 8th, and the fall rate is about 3 to 5 (average) meteors per hour. History of Observation: Though representations of Aries as The Ram comes to us from classical antiquity, it is believed that this constellation has existed since the days of ancient Babylon. In the description of the Babylonian zodiac contained in the MUL.APIN (the compendium on Babylonian astrology) Aries was the final station along the ecliptic, and was known as MULLÚ.?UN.GÁ, which translates to "The Agrarian Worker" or "The Hired Man." The shift in identification from the constellation as the Agrarian Worker to the Ram likely occurred in later Babylonian tradition because of its growing association with Dumuzi the Shepherd. By the time the MUL.APIN was created (1000 BCE) , modern Aries was identified with both Dumuzi's ram and a hired laborer. In ancient Egyptian astronomy, Aries was associated with the god Amon-Ra, who was depicted as a man with a ram's head and represented fertility and creativity. Because it was the location of the vernal equinox, it was called the "Indicator of the Reborn Sun". Aries acquired the title of "Lord of the Head" in Egypt, referring to its symbolic and mythological importance. In traditional Chinese astronomy, stars from Aries were used in several constellations. Alpha, Beta, and Gamma Arietis formed a constellation called Lou, variously translated as "bond", "lasso", and "sickle", which was associated with the ritual sacrifice of cattle. This constellation has also been associated with harvest-time as it could represent a woman carrying a basket of food on her head. Other stars were part of the constellations Wei - the namesake of the 17th lunar mansion, representing granaries - and Tianyin, thought to represent the Emperor's hunting partner. Similarly, in Hindu astronomy, Beta and Gamma Arietis were known as the Aswins, and were associated with the first lunar mansion. Because the Hindu new year began with the vernal equinox, the Rig Veda contains over 50 new-year's related hymns to the twins, making them some of the most prominent characters in the work. Aries itself was known as " Aja" and " Mesha". In Hebrew astronomy Aries was named " Teli", which signified either Simeon or Gad, and generally symbolizes the "Lamb of the World". The neighboring Syrians and Turks named the constellation "Amru" and "Kuzi", respectively. In indigenous Peruvian astronomy, a constellation with most of the same stars was called the "Market Moon" and the "Kneeling Terrace", as a reminder of when to hold the annual harvest festival, Ayri Huay. In his Almagest, Ptolemy listed Aries as one of the 48 constellations. This tradition was maintained by Medieval Muslim astronomers such as al-Sufi, who modeled the constellation as a ram based on the precedent of Ptolemy. During the Scientific Revolution, John Flamsteed also followed Ptolemy's description in his Atlas Coelestis - a star atlas that was published posthumously in 1729 . In 1922, the International Astronomical Union adopted it as one of the 88 constellation and defined its recommended three-letter abbreviation as "Ari". Finding Aries: Only its Alpha and Beta stars - Hamal and Sheratan - are easy to recognize. They represent the head of the Ram. Teegarden's star, a recent discovery in the constellation of Aries, is one of Sun's closest neighbors (around 12 light years away). It appears to be a red dwarf, a class of low temperature and low luminosity stars. This would explain why it was not discovered earlier, since it has an apparent magnitude of only 15.4. For the unaided eye and observing with binoculars, check out Alpha Arietis - aka. Hamal. It has one of the most accurately-measured angular diameters - 0.00680" (the width of a penny seen from 60 km away) - and is some 55 times brighter and five times more massive than our Sun. Now have a look at Beta Arietis - aka. Sheratan. Beta shines at magnitude 2.7 and is located 60 light years from Earth. Back at the turn of the 20th century it was discovered to be a spectroscopic binary, with a period of 106 days. According to Jim Kaler's fine research,"Sheratan stands out as a result of the extremely high eccentricity of the orbit (0.88), the companion trapped in a record-holding elongated path." Moreover, the star is an observational treasure. The two stars are so close together that they cannot be separated directly through the telescope, and all we ever actually see is one star. Detection via the spectrum also requires that the stars to be close and moving quickly. However, sophisticated observation of Sheratan with an interferometer, a device that makes use of the interfering properties of light to resolve ultra-fine detail, allow (as for the brighter component of Mizar) the pair to be resolved. The masses of the stars (through gravitational theory) can then be measured with high accuracy. Averaging 0.64 Astronomical Units apart (89 percent Venus' distance from the Sun), a star with the mass of the Sun (1.02 solar) orbits a double-solar-mass (2.00) star every 107 days. Since luminosity is very sensitive to mass, 95 percent of the light of the system is produced by the heavier star. The huge eccentricity adds the spice. As they wheel around each other, the smaller one (undoubtedly a class G star like the Sun) approaches as close as 0.08 AU (only 20 percent Mercury's distance from the Sun), and then half an orbit later loops around at 1.2 AU, 16 times farther away and 20 percent farther than Earth from the Sun. No close planets could survive the gravitational onslaught. Such stars, in which the doubling is "visible" by two techniques (only about 40 are known, and Sheratan is one of the brighter ones), allows accurate assessment of the theoretical relation between stellar mass and luminosity, and provides powerful evidence that the theory is correct. The higher mass star will die first. In a couple billion years, the lower mass G star will be the king of the pair, while the current luminary will be a shrunken dim white dwarf. For those using small telescopes, a good place to stargaze is around Gamma Arietis - aka. Mesarthim. This wide, double star with blue/white members of 4.6 magnitude is an easy one to spot. For this reason, Mesarthim was one of the very first double stars to be discovered by Robert Hooke while looking for a comet in 1664. Another easily spotted star is the binary star is Lambda, it is also a very wide double with a 5th magnitude primary and 5th magnitude secondary. For something a little harder, try 5th magnitude Pi. The 8.8 magnitude companion is on 3 arc seconds away and will really test the resolving power of your optics and the stability of your skies. Use your highest power. If you don't have luck, try 30 Arietis. The magnitude 7 primary star is a lovely golden yellow and the secondary is about magnitude 8 and is a distinct blue separated by about 40 arc seconds. For a nice outreach project, try observing 53 Arietis - the "Runaway star". Along with AE Aurigae and Mu Columbae 53 Arietis appears to be cruising right along from the region of the Great Orion Nebula! Thank you for reading; and as always, enjoy your stargazing! We have written many interesting articles about the constellation here at Universe Today. Here is What Are The Constellations?, What Is The Zodiac?, and Zodiac Signs And Their Dates. Be sure to check out The Messier Catalog while you're at it! For more information, check out the IAUs list of Constellations, and the Students for the Exploration and Development of Space page on Aries and Constellation Families. The post The Constellation Aries appeared first on Universe Today.
The New Vostochny Cosmodrome Brings Launches Back To Russian Soil 
Russia's new Vostochny Cosmodrome launched its first rocket on Wednesday, April 27th, carrying three new satellites into orbit. After an initial 24-hour launch delay due to a computer-initiated abort, a Soyuz-2.1a lifted off from its pad at 10:01 am EDT. Every successful space launch is important in its own way, but this one even more so because of the importance of this new cosmodrome to Russia. The breakup of the Soviet Union in 1991 threw that country into chaos. The formal dissolution of the USSR on December 26th, 1991, created a lot of financial and political turmoil. The Soviet space program was a victim of that chaos, and with the USSR's main cosmodrome now located on foreign territory, at Baikonur, Kazakhstan, things were uncertain. Roscosmos, the Russian space agency, has been renting the Baikonur cosmodrome for $115 million annually. But this dependence on a foreign launch site has been a thorn in the side of Russia for decades. Russia is a fiercely independent and proud nation, so it surprised no one when construction of a new spaceport was announced. In 2010, Vladimir Putin emphasized the importance of the new facility, saying "The creation of a new space center ... is one of modern Russia's biggest and most ambitious projects." The new facility, called the Vostochny Cosmodrome, will eventually be home to multiple launch pads, though only one is functional for now. It's located at 51 degrees north, whereas the Baikonur site is located at 46 degrees North. Though further north, it will still be able to launch almost the same payloads as Baikonur. Russia has other spaceports on its own territory. The Svobodny Cosmodrome is also located in Russia's far east, and at the same 51 degrees north as Vostochny. But Svobodny was originally an ICBM launch site, and couldn't handle the launching of crewed missions. All crewed missions had to be launched from Baikonur. Russia has another cosmodrome, the Plesetsk Cosmodrome, where satellites can be launched into geostationary orbit. The site for the new Vostochny Cosmodrome (Vostochny means 'eastern' in Russian) was chosen for a few reasons. The site is serviced by both highway and rail, and is remote enough that launch paths won't interfere with any built up areas. It's also located several hundred kilometres from the Pacific Ocean, to avoid complications that proximity to an ocean can cause, yet close enough that spent stages can be jettisoned and will fall harmlessly into the ocean. Vostochny is about the same size as the Kennedy Space Centre in Cape Canaveral. Vostochny covers 551.5 square kilometers, while the Kennedy facility covers 583 square kilometers. The new cosmodrome will eventually house over 400 separate facilities, including engineering and transport infrastructure. The Vostochny Cosmodrome project has suffered some setbacks. Parts of the assembly complex for the Soyuz 2 rocket were built too small, which delayed the planned initial launch set for December 2015. There've been accusations of corruption, and even a worker's strike in the Spring of 2015 over unpaid wages. These and other problems led Valdimir Putin to release a statement saying he was taking personal control of the project. Since then, Putin has kept a close eye on the Vostochny project. In response to the recent 24 hour launch delay of the cosmodrome's inaugural launch, Putin criticized Roscosmos for the delay, and for all of the glitches and failures in the Russian space program recently. But, ever the politician, Putin also tempered his remarks, saying "Despite all its failings, Russia remains the world leader in the number of space launches." "But the fact that we're encountering a large number of failures is bad. There must be a timely and professional reaction," he added. As for Vostochny itself, it will allow Russia to conduct much more of its space launches on its own soil. By 2020, Vostochny will conduct 45% of Russia's space launches. Baikonur will still be used, but much more sparingly. It currently is responsible for 65% of Russian launches, but that will drop to 11%. The Plesetsk Cosmodrome will account for the other 44%. As for the inaugural launch, it went flawlessly after its initial 24 hour technical delay. The three satellites it carried into orbit will fulfill several different functions. Together, they will study the Earth's upper atmosphere, observe gamma-ray bursts, and test new electronics modules for use in space. They will also carry high-resolution cameras for remote sensing and scientific work, test communication systems with ground stations, and will develop control algorithms for use with nano-satellites. The post The New Vostochny Cosmodrome Brings Launches Back To Russian Soil appeared first on Universe Today.
Weekly Space Hangout – Apr. 29, 2016: Dr. Michael Richmond Host: Fraser Cain (@fcain) Special Guest:
Dr. Michael Richmond is a Physics and Astronomy professor at Rochester Institute of Technology, Rochester, NY, and is the director of the RIT Observatory. Dr. Richmond’s research interest is Supernovae and Variable Stars. Guests:
Paul M. Sutter (pmsutter.com / @PaulMattSutter)
Morgan Rehnberg (MorganRehnberg.com / @MorganRehnberg) Their stories this week:
A new life for Dawn? SpaceX to send Dragon to Mars Makemake has a moon! Titan’s seas are methane, not ethane Nearby recent supernova We’ve had an abundance of news stories for the past few months, and not enough time to get to them all. So we’ve started a new system. Instead of adding all of the stories to the spreadsheet each week, we are now using a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover! We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page. You can also join in the discussion between episodes over at our Weekly Space Hangout Crew group in G+! The post Weekly Space Hangout – Apr. 29, 2016: Dr. Michael Richmond appeared first on Universe Today.
How Do We Terraform Mercury? 
Welcome back to another installment in the "Definitive Guide to Terraforming" series! We complete our tour of the Solar System with the planet Mercury. Someday, humans could make a home on this hostile planet, leading to the first Hermians! The planet Mercury is an intensely hot place. As the nearest planet to our Sun, surface temperatures can get up to a scorching 700 K (427° C). Ah, but there's a flip-side to that coin. Due to it having no atmosphere to speak of, Mercury only experiences intensely hot conditions on the side that is directly facing the Sun. On the nighttime side, temperatures drop to well below freezing, as low as 100 K (-173° C). Due to its low orbital period and slow rate of rotation, the nighttime side remains in the dark for an extended period of time. What's more, in the northern polar region, which is permanently shaded, conditions are cold enough that water is able to exist there in ice form. Because of this, and a few reasons besides, there are many who believe that humanity could colonize and even terraform parts of Mercury someday. The Planet Mercury: With a mean radius of 2440 km and a mass of 3.3022×1023 kg, Mercury is the smallest planet in our Solar System – equivalent in size to 0.38 Earths. And while it is smaller than the largest natural satellites in our system – such as Ganymede and Titan – it is more massive. In fact, Mercury's density (at 5.427 g/cm 3) is the second highest in the Solar System, only slightly less than Earth's (5.515 g/cm 3). Mercury also has the most eccentric orbit of any planet in the Solar System. With an eccentricity of 0.205, its distance from the Sun ranges from 46 to 70 million km (29-43 million mi), and takes 87.969 Earth days to complete an orbit. But with an average orbital speed of 47.362 km/s, Mercury also takes 58.646 days to complete a single rotation. This means that it takes 176 Earth days for the sun to rise and set on Mercury, which is twice as long as a single Hermian year. As one of the four terrestrial planets of the Solar System, Mercury is composed of approximately 70% metallic and 30% silicate material. Based on its density and size, a number of inferences can be made about its internal structure. For example, geologists estimate that Mercury's core occupies about 42% of its volume, compared to Earth's 17%. The interior is believed to be composed of a molten iron which is surrounded by a 500 – 700 km mantle of silicate material. At the outermost layer is Mercury's crust, which is believed to be 100 – 300 km thick. The surface is also marked by numerous narrow ridges that extend up to hundreds of kilometers in length. It is believed that these were formed as Mercury's core and mantle cooled and contracted at a time when the crust had already solidified. Mercury's core has a higher iron content than that of any other major planet in the Solar System, and several theories have been proposed to explain this. The most widely accepted theory is that Mercury was once a larger planet which was struck by a planetesimal that stripped away much of the original crust and mantle, leaving behind the core as a major component. Another theory is that Mercury formed from the solar nebula before the Sun's energy output had stabilized, and was twice its present mass. However, most of this mass was vaporized as the protosun contracted and exposed it to extreme temperatures. A third hypothesis is that the solar nebula caused drag on the particles from which Mercury was accreting, which meant that lighter particles were lost and not gathered to form Mercury. At a glance, Mercury looks similar to the Earth's moon. It has a dry landscape pockmarked by asteroid impact craters and ancient lava flows. Combined with extensive plains, these indicate that the planet has been geologically inactive for billions of years. However, unlike the Moon and Mars, which have significant stretches of similar geology, Mercury's surface appears much more jumbled. The vast majority of Mercury's surface is hostile to life, where temperatures gravitate between extremely hot and cold – i.e. 700 K (427 °C; 800 °F) 100 K (-173 °C; -280 °F). This is due to its proximity to the Sun, the almost total lack of an atmosphere, and its very slow rotation. However, at the poles, temperatures are consistently low -93 °C (-135 °F) due to it being permanently shadowed. In 2012, NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging ( MESSENGER) probe detected signs of water ice and organic molecules in Mercury's northern polar region. For over twenty years, scientists had suspected that in this area, Mercury's craters could contain ice that was most likely deposited by comets in the past. Radar signals appeared to confirm as much, but it took the MESSENGER mission to confirm it. Scientists believe that Mercury's southern pole may also have ice. All told, it is estimated that Mercury could hold between 100 billion to 1 trillion tons of water ice at both poles, and the ice could be up to 20 meters deep in places. In the north pole, this water is particularly concentrated in craters like the Tryggvadottir, Tolkien, Kandinsky, and Prokofiev craters - which measure between 31 to 112 km in diameter. https://youtu.be/PwSne3G9J2o In addition, the MESSENGER mission also noted the presence of "hollows" on Mercury's surface which appeared to reach underground. Similar to hollows observed on the Moon and Mars, these features could be indicative of lava tubes that were formed during Mercury's volcanically-active past. In both of these cases, stable lava tubes are seen as a possible location for colonies that would be shielded from radiation, space, and other hazards. Possible Methods: While terraforming an entire planet like Mercury is not exactly practical, its subsurface geology, cratered surface, and orbital characteristics make colonizing and terraforming some parts of it attractive. For example, in the northern polar region, where permanently-shadowed craters house water ice and organic molecules, domed structures could be set up that would allow any atmosphere created within to be contained. This is a variation on the " Shell Worlds" concept, which in turn is part of the larger concepts known as paraterraforming - where a world is enclosed (in whole or in part) in an artificial shell in order to transform its environment. Using this process, the northern craters could be enclosed within a dome, orbital mirrors could focus sunlight within the domes, and the water ice could be evaporated. Through the process of photolysis, the water vapor could be converted into oxygen gas and hydrogen, the latter of which could either be harvested as fuel, or vented into space. Ammonia could also be introduced, most likely mined from the outer Solar System, and converted into nitrogen gas through the introduction of specific strains of bacteria - Nitrosomonas, Pseudomonas and Clostridium species – that would convert the ammonia into nitrites (NO²-) and then nitrogen gas. Lava tubes on Mercury could similarly be colonized, with settlements built within stable ones. These areas would be naturally shielded to cosmic and solar radiation, extremes in temperature, and could be pressurized to create breathable atmospheres. In addition, at this depth, Mercury experiences far less in the way of temperature variations and would be warm enough to be habitable. Potential Benefits: Mercury's relative proximity to Earth makes it a good location for terraforming and colonization. On average, Mercury is 77 million km (48 million miles) from Earth. To put that distance in perspective, it took the Mariner 10 probe (which took a much more direct route than MESSENGER) took a little under five months to reach Mercury from Earth. Colonies established on Mercury would also be in a good position to provide extensive minerals and solar power to other planets. As the second-densest planet in the Solar System, Mercury has an abundance of iron, nickel and silicate minerals that would be of use locally and elsewhere. Also, its proximity to the Sun means that solar operations, possibly in the form of space-based solar arrays, could harness abundant energy. This energy could then be beamed to other worlds for local use. Solar wind also adds hydrogen and helium to the planet's exosphere, while radioactive decay within its crust is an additional source of helium. These could also be mined to create hydrogen fuel and helium-3, both of which could be used to power fusion reactors both on and off-planet. As a result, colonies on Mercury, thanks to the abundance of water ice, minerals and other elements, would likely be largely self-sufficient as well. Unlike other potential sites that would require the importation of vast amounts of resources, Mercury's first wave of colonists (aka. Hermians) could begin to see to much of their own needs shortly after setting down. Potential Challenges: As always, the prospect of terraforming Mercury presents several challenges, an addressing one requires that others be addressed simultaneously. Fortunately, compared to many other planets (or moons) in the Solar System, they are fewer in number. In short, the challenges come down to issues of distance, technology, resources and infrastructure, and natural hazards. To address the first, travel to and from Mercury would still take a significant amount of time using existing technology. While closer than many other potential sites, several trips would need to be made by crewed spacecraft, construction ships and support craft, which would take time and cost quite a lot using existing technology. In addition, hauling resources from the outer Solar System would take on the order on decades using the conventional engines and spacecraft. Which brings us to item two: technology. In order for ships to travel to and from the outer Solar System to procure ammonia and other volatiles in large quantities (and in a reasonable amount of time), they would need to be equipped with advanced propulsion systems to make the journey. This could take the form of Nuclear-Thermal Propulsion (NTP), Fusion-drive systems, or some other advanced concept. But thus far, no such drive systems exist, with some being decades or more away from feasibility. As for the next item, resources and infrastructure, colonizing and paraterraforming Mercury would require plenty of both. To start, it would take an immense amount of minerals and other materials to construct domes large enough to encase any of Mercury's polar craters. Building orbital mirrors would be similarly be taxing. And while these minerals could be harvested locally, the process would be very expensive. Similarly, the technology behind space-based solar power is not even close to where it would need to be harvest energy from the Sun and beam it directly to Earth (or other locations across the Solar System). Here too, the technology needs to come a long way; and even after we have that worked out, creating such a network between Mercury and other planets would be very expensive. At the same time, it would require a level of infrastructure that also does not yet exist. Aside from a large fleet of spacecraft to ferry colonists, settling Mercury would also require a significant amount of construction vessels and automated robots. We would also need a series of stations between Earth and Mercury to provide for refueling and resupply. And last, any construction and settlement efforts would have to deal with the dangers of exposure to extreme heat and Solar radiation. While a colony in the northern polar region and within Mercury's lava tubes would be shielded, labor crews and construction ships would have to risk working in extremely hazardous conditions in order to build them. Conclusion: In the end, and compared to other terraforming ventures, the colonization and paraterrforming of Mercury does seems rather doable. While it would require a huge commitment in terms of resources, the creation of technology and infrastructure that does not yet exist, and some serious hazard pay for the work crews who would assemble the Hermian settlements, the advantages could be enough to justify such an undertaking. A colonized Mercury would mean abundant minerals and energy for the rest of the Solar System. Having these resources at our fingertips would be intrinsic to creating a post-scarcity economy, and could speed the development of colonies and terraforming efforts elsewhere. We have written many interesting articles about Mercury and terraforming here at Universe Today. Here's The Planet Mercury, The Definitive Guide to Terraforming, How Do We Terraforming Mars?, How Do We Terraform Venus?, How Do We Terraform the Moon?, How Do We Terraform Jupiter's Moons?, and How Do We Terraform Saturn's Moons? We've also got articles that explore the more radical side of terraforming, like Could We Terraform Jupiter?, Could We Terraform The Sun?, and Could We Terraform A Black Hole? Astronomy Cast also has a good episode on the subject, Episode 49: Mercury And if you like the videos, come check out our Patreon page and find out how you can get these videos early while helping us bring you more great content! The post How Do We Terraform Mercury? appeared first on Universe Today.
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