Bezoek Husqvarna Motorcycles op de Motorbeurs in Utrecht! Je vindt ons in HAL 7. 23 tm 26 februari.
Bezoek Husqvarna Motorcycles op de Motorbeurs in Utrecht! Je vindt ons in HAL 7. 23 tm 26 februari.
NASA’s Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.
The discovery sets a new record for greatest number of habitable-zone planets found around a single star outside our solar system. All of these seven planets could have liquid water – key to life as we know it – under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.
“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen, associate administrator of the agency’s Science Mission Directorate in Washington. “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”
At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets.
This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system. Assisted by several ground-based telescopes, including the European Southern Observatory’s Very Large Telescope, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.
The new results were published Wednesday in the journal Nature, and announced at a news briefing at NASA Headquarters in Washington.
Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them, allowing their density to be estimated.
Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces. The mass of the seventh and farthest exoplanet has not yet been estimated – scientists believe it could be an icy, “snowball-like” world, but further observations are needed.
“The seven wonders of TRAPPIST-1 are the first Earth-size planets that have been found orbiting this kind of star,” said Michael Gillon, lead author of the paper and the principal investigator of the TRAPPIST exoplanet survey at the University of Liege, Belgium. “It is also the best target yet for studying the atmospheres of potentially habitable, Earth-size worlds.”
In contrast to our sun, the TRAPPIST-1 star – classified as an ultra-cool dwarf – is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun. The planets also are very close to each other. If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth’s sky.
The planets may also be tidally locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong winds blowing from the day side to the night side, and extreme temperature changes.
Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. In the fall of 2016, Spitzer observed TRAPPIST-1 nearly continuously for 500 hours. Spitzer is uniquely positioned in its orbit to observe enough crossing – transits – of the planets in front of the host star to reveal the complex architecture of the system. Engineers optimized Spitzer’s ability to observe transiting planets during Spitzer’s “warm mission,” which began after the spacecraft’s coolant ran out as planned after the first five years of operations.
“This is the most exciting result I have seen in the 14 years of Spitzer operations,” said Sean Carey, manager of NASA’s Spitzer Science Center at Caltech/IPAC in Pasadena, California. “Spitzer will follow up in the fall to further refine our understanding of these planets so that the James Webb Space Telescope can follow up. More observations of the system are sure to reveal more secrets.”
Following up on the Spitzer discovery, NASA’s Hubble Space Telescope has initiated the screening of four of the planets, including the three inside the habitable zone. These observations aim at assessing the presence of puffy, hydrogen-dominated atmospheres, typical for gaseous worlds like Neptune, around these planets.
In May 2016, the Hubble team observed the two innermost planets, and found no evidence for such puffy atmospheres. This strengthened the case that the planets closest to the star are rocky in nature.
“The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets,” said Nikole Lewis, co-leader of the Hubble study and astronomer at the Space Telescope Science Institute in Baltimore, Maryland. NASA’s planet-hunting Kepler space telescope also is studying the TRAPPIST-1 system, making measurements of the star’s minuscule changes in brightness due to transiting planets. Operating as the K2 mission, the spacecraft’s observations will allow astronomers to refine the properties of the known planets, as well as search for additional planets in the system. The K2 observations conclude in early March and will be made available on the public archive.
Spitzer, Hubble, and Kepler will help astronomers plan for follow-up studies using NASA’s upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone, and other components of a planet’s atmosphere. Webb also will analyze planets’ temperatures and surface pressures – key factors in assessing their habitability.
NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate. Science operations are conducted at the Spitzer Science Center, at Caltech, in Pasadena, California. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at Caltech/IPAC. Caltech manages JPL for NASA.
The beauty of the Monster Energy Supercross series is that just as one class settles down, another begins. The 250SX East division will fire into life in Minneapolis this weekend and, hey, it is wide open! Who do you think is going to win the opener? Let us know by voting on the poll that sits below and join in the conversation on social media.
The final active weekend of the off-season was a turbulent one for Red Bull KTM, as they lost Jeffrey Herlings in Italy and Pauls Jonass crashed in a spectacular fashion in France. The latter did not escape unscathed and suffered yet another concussion, although doctors described it as a “light” one.
Although it usually takes a rider quite some time to recover from an impact like that, the KTM Factory Racing outfit have confirmed that Jonass expects to race the first FIM Motocross World Championship round next weekend. “They confirmed the rider should take rest for four to five days and the medical examinations he has had so far are satisfactory,” the statement explained. “Jonass is also expected to be fit to ride in the opening round of MX2.”
Pauls Jonass missed the final five rounds of the 2016 FIM Motocross World Championship with a concussion and enters the new season as a favourite for the title.
Launching soon, aboard the 10th SpaceX commercial resupply mission, will be a technology module called Raven, which will bring NASA one step closer to having a relative navigation capability. When affixed outside the International Space Station, Raven will test foundational technologies that will enable autonomous rendezvous in space, meaning they will not necessitate any human involvement — even from the ground.
To envision why autonomous rendezvous is important in space missions, imagine this scenario: one spacecraft following another satellite, steadily closing the gap — with each vehicle traveling more than 16,000 miles per hour in the darkness of space. The satellite that is being serviced, the client, is a multi-ton craft that is running out of fuel. The fully robotic servicing satellite, the servicer, named Restore-L follows in pursuit, carrying life-extending propellant and tools.
The client, not designed to be serviced, does not have markings to making it easier for the servicer to find and secure it. The servicer has to do this on its own, using an advanced machine vision system, perfected using the data collected by Raven aboard the space station. Successful servicing first depends on the servicer’s ability to accurately locate and match speed with the client satellite.
To further complicate this scenario, the servicer is far from Earth, creating a communications delay for command and data exchange to and from space. The delay prevents ground operators from quickly and accurately providing commands to the servicer in order to prevent a possible collision within the last few feet of the rendezvous.
Therefore, the servicer has to perform relative navigation with its client, and it needs to do so autonomously (by itself, with no human guidance), and in real time.
“Two spacecraft autonomously rendezvousing is crucial for many future NASA missions and Raven is maturing this never-before-attempted technology,” said Ben Reed, deputy division director, for the Satellite Servicing Projects Division (SSPD) at NASA’s Goddard Space Flight Center in Greenbelt, Maryland — the office developing and managing this demonstration mission.
Raven will demonstrate the capability of a groundbreaking relative navigation system, housed within its carry-on luggage-sized frame, which will allow a spacecraft server to find, and if necessary, catch its intended target. Raven aims to lead to a fully developed, mature system available for future NASA missions.
Five days after launch, Raven will be removed from the unpressurized “trunk” of the SpaceX Dragon spacecraft by the Dextre robotic arm, and attached on a payload platform outside the space station. From this perch, Raven will begin providing information for the development of a mature real-time relative navigation system.
During its stay aboard the space station, Raven’s components will join forces to independently image and track incoming and outgoing visiting space station spacecraft. To do this, Raven’s sensors will feed data they “see” to a processor, which will run sets of instructions (also known as special pose algorithms) to gauge the relative distance between Raven and the spacecraft it is tracking. Then, based on these calculations, the processor will autonomously send commands that swivel the Raven module on its gimbal, or pointing system, to keep the sensors trained on the vehicle, while continuing to tracking it. While these maneuvers take place, NASA operators on the ground will evaluate how Raven’s technologies work together as a system, and will make adjustments to increase Raven’s tracking performance.
Over its two-year lifespan, Raven will test these critical technologies that are expected to support future NASA missions for decades to come. One upcoming application for this technology is its use in the Restore-L servicing mission which will navigate to refuel Landsat 7, a U.S. government Earth-observing satellite already in orbit. An additional application is the potential use for systems on NASA’s Journey to Mars. Raven is on track to advance and mature the sensors, machine vision algorithms, and processing necessary to implement a robust autonomous rendezvous and docking system for NASA. SSPD is developing and managing both the Raven and Restore-L demonstration missions.
We’ve brought together 14 ’17 model year motocross bikes from all the major brands – KTM, Husqvarna, Honda, Kawasaki, Yamaha and Suzuki – and put them head-to-head in the UK’s biggest 2017 motocross bike test. We’ve Ridden, Ragged and Rated all the MX1 and MX2 bikes (250Fs, 350Fs and 450Fs) and in the April issue of Dirt Bike Rider (out on March 10) we’ll have an in-depth mega test feature for you to pour over, which will include us crowning the 2017 winners! It’s the only full shootout test you’ll find in the UK for the 2017 model year! To give you a teaser we teamed up with Toofast Media to bring you a sweet video edit, so smash that play button below. Big thanks to the team that helped bring this huge project together and of course the manufactures. And a special thanks to Buttercup Farm MX for the use of the track. Thanks guys. Enjoy the edit.
ALESSAGGIO E CORSA
77 x 53,6
A pedale (optional elettrico)
Iniezione Elettronica Corpo Farfallato
Benzina senza piombo
Generatore Kokusan, elettronica Microtec
Kayaba USD 48 mm
Tm Racing Pneumatici
Anteriore: 80 / 100 x 21 [1.60″] Posteriore: 100 / 90 x 19 [1.85″]
Anteriore: Disco Wave 270 mm con pompa Nissin e pinza Brembo
Posteriore: Disco Wave 245 mm con pompa e pinza Nissin
Plastica 7,5 Litri
Doppio albero a camme in testa con bilancieri a dito e 4 Valvole in Titanio
Recovery efforts are underway at NASA’s Michoud Assembly Facility in New Orleans, which was impacted by a tornado at 11:25 a.m. CST Tuesday. All 3,500 employees at the facility have been accounted for, with five sustaining minor injuries.
“Our hearts go out to our employees and the people in New Orleans who have suffered from this serious storm,” said Keith Hefner, director of the facility. “The safety of our team is always our main concern, and we are pleased to report that we’ve identified only minor injuries.”
The facility is currently closed and will remain closed Wednesday, Feb. 8, with only emergency personnel on site to continue damage assessments. All NASA employees and tenants who are not involved in emergency operations have been evacuated. Local law enforcement helped ensure employees arrived home safely. All utilities and services to the facility are being secured and efforts are underway to restore power.
At this time, emergency personnel have identified damage to building numbers 103, 350 and additional structures. Building 103, Michoud’s main manufacturing building, has roof damage in several areas. Approximately 200 parked cars were damaged, and there was damage to roads and other areas near Michoud.
“Michoud has a comprehensive emergency plan that we activated today to ensure the safety of our people and to secure our facilities,” said Hefner. “I am proud of our dedicated team onsite who are successfully implementing that plan.”
Hardware for NASA’s heavy-lift rocket, the Space Launch System, and the Orion spacecraft is secure, and no damage from the storm has been idenfied to hardware or the barge Pegasus docked at Michoud.
A giant black hole ripped apart a star and then gorged on its remains for about a decade, according to astronomers. This is more than ten times longer than any observed episode of a star’s death by black hole.
Researchers made this discovery using data from NASA’s Chandra X-ray Observatory and Swift satellite as well as ESA’s XMM-Newton.
The trio of orbiting X-ray telescopes found evidence for a “tidal disruption event” (TDE), wherein the tidal forces due to the intense gravity from a black hole can destroy an object – such as a star – that wanders too close. During a TDE, some of the stellar debris is flung outward at high speeds, while the rest falls toward the black hole. As it travels inwards to be ingested by the black hole, the material heats up to millions of degrees and generates a distinct X-ray flare.
“We have witnessed a star’s spectacular and prolonged demise,” said Dacheng Lin from the University of New Hampshire in Durham, New Hampshire, who led the study. “Dozens of tidal disruption events have been detected since the 1990s, but none that remained bright for nearly as long as this one.”
The extraordinary long bright phase of this event spanning over ten years means that among observed TDEs this was either the most massive star ever to be completely torn apart during one of these events, or the first where a smaller star was completely torn apart.
The X-ray source containing this force-fed black hole, known by its abbreviated name of XJ1500+0154, is located in a small galaxy about 1.8 billion light years from Earth.
The source was not detected in a Chandra observation on April 2nd, 2005, but was detected in an XMM-Newton observation on July 23rd, 2005, and reached peak brightness in a Chandra observation on June 5, 2008. These observations show that the source became at least 100 times brighter in X-rays. Since then, Chandra, Swift, and XMM-Newton have observed it multiple times.
The sharp X-ray vision of Chandra data shows that XJ1500+0154 is located at the center of its host galaxy, the expected location for a supermassive black hole.
The X-ray data also indicate that radiation from material surrounding this black hole has consistently surpassed the so-called Eddington limit, defined by a balance between the outward pressure of radiation from the hot gas and the inward pull of the gravity of the black hole.
“For most of the time we’ve been looking at this object, it has been growing rapidly,” said co-author James Guillochon of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. “This tells us something unusual – like a star twice as heavy as our Sun – is being fed into the black hole.”
The conclusion that supermassive black holes can grow, from TDEs and perhaps other means, at rates above those corresponding to the Eddington limit has important implications. Such rapid growth may help explain how supermassive black holes were able to reach masses about a billion times higher than the sun when the universe was only about a billion years old.
“This event shows that black holes really can grow at extraordinarily high rates,” said co-author Stefanie Komossa of QianNan Normal University for Nationalities in Duyun City, China. “This may help understand how precocious black holes came to be.”
Based on the modeling by the researchers the black hole’s feeding supply should be significantly reduced in the next decade. This would result in XJ1500+0154 fading in X-ray brightness over the next several years.
A paper describing these results appears on February 6th issue in Nature Astronomy and is available online. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.