Look Up! Perseid Meteor Shower Peaks Aug. 11-12

Asteroid Watch logo.

Aug. 2, 2016

Make plans now to stay up late or set the alarm early next week to see a cosmic display of “shooting stars” light up the night sky. Known for it’s fast and bright meteors, the annual Perseid meteor shower is anticipated to be one of the best potential meteor viewing opportunities this year.

The Perseids show up every year in August when Earth ventures through trails of debris left behind by an ancient comet. This year, Earth may be in for a closer encounter than usual with the comet trails that result in meteor shower, setting the stage for a spectacular display.

Image above: An outburst of Perseid meteors lights up the sky in August 2009 in this time-lapse image. Stargazers expect a similar outburst during next week’s Perseid meteor shower, which will be visible overnight on Aug. 11 and 12. Image Credits: NASA/JPL.

“Forecasters are predicting a Perseid outburst this year with double normal rates on the night of Aug. 11-12,” said Bill Cooke with NASA’s Meteoroid Environments Office in Huntsville, Alabama. “Under perfect conditions, rates could soar to 200 meteors per hour.”

An outburst is a meteor shower with more meteors than usual. The last Perseid outburst occurred in 2009.

Every Perseid meteor is a tiny piece of the comet Swift-Tuttle, which orbits the sun every 133 years. Each swing through the inner solar system can leave trillions of small particles in its wake. When Earth crosses paths with Swift-Tuttle’s debris, specks of comet-stuff hit Earth’s atmosphere and disintegrate in flashes of light. These meteors are called Perseids because they seem to fly out of the constellation Perseus.

Most years, Earth might graze the edge of Swift-Tuttle’s debris stream, where there’s less activity. Occasionally, though, Jupiter’s gravity tugs the huge network of dust trails closer, and Earth plows through closer to the middle, where there’s more material.

This may be one of those years. Experts at NASA and elsewhere agree that three or more streams are on a collision course with Earth.

“Here’s something to think about. The meteors you’ll see this year are from comet flybys that occurred hundreds if not thousands of years ago,” said Cooke. “And they’ve traveled billions of miles before their kamikaze run into Earth’s atmosphere.”

How to Watch the Perseids

The best way to see the Perseids is to go outside between midnight and dawn on the morning of Aug. 12. Allow about 45 minutes for your eyes to adjust to the dark. Lie on your back and look straight up. Increased activity may also be seen on Aug. 12-13.

For stargazers experiencing cloudy or light-polluted skies, a live broadcast of the Perseid meteor shower will be available via Ustream overnight on Aug. 11-12 and Aug. 13-14, beginning at 10 p.m. EDT.: http://www.ustream.tv/channel/nasa-msfc

Meteor Moment: Viewing Tips.

More about the Perseids

Perseid meteors travel at the blistering speed of 132,000 miles per hour (59 kilometers per second). That’s 500 times faster than the fastest car in the world. At that speed, even a smidgen of dust makes a vivid streak of light when it collides with Earth’s atmosphere. Peak temperatures can reach anywhere from 3,000 to 10,000 degrees Fahrenheit as they speed across the sky.

The Perseids pose no danger to Earth. Most burn up 50 miles above our planet. But an outburst could mean trouble for spacecraft.

About the Meteoroid Environment Office

It’s Cooke’s job to help NASA understand and prepare for risks posed by meteoroids. He leads a team of meteor experts in the Meteoroid Environments Office at NASA’s Marshall Space Flight Center. They study meteoroids in space so that NASA can protect our nation’s satellites, spacecraft and even astronauts aboard the International Space Station from these bits of tiny space debris.

Related links:

Meteors & Meteorites: http://www.nasa.gov/topics/solarsystem/features/watchtheskies/index.html

Meteoroid Environments Office: https://www.nasa.gov/offices/meo/home/index.html

Image (mentioned), Video, Text, Credits: NASA/Jennifer Harbaugh.

Greetings, Orbiter.ch

Regarding Rhea

NASA - Cassini Mission to Saturn patch.

Aug. 1, 2016

Rhea, like many moons in the outer solar system, appears dazzlingly bright in full sunlight. This is the signature of the water ice that forms most of the moon's surface.

Rhea (949 miles or 1,527 kilometers across) is Saturn's second largest moon after Titan. Its ancient surface is one of the most heavily cratered of all of Saturn's moons. Subtle albedo variations across the disk of Rhea hint at past geologic activity.

This view looks toward the anti-Saturn hemisphere of Rhea. North on Rhea is up and rotated 36 degrees to the right. The image was taken with the Cassini spacecraft narrow-angle camera on June 3, 2016 using a spectral filter which preferentially admits wavelengths of ultraviolet light centered at 338 nanometers.

The view was acquired at a distance of approximately 365,000 miles (587,000 kilometers) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 9 degrees. Image scale is 2.4 miles (3.9 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org and ESA's website: http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image, Text, Credits: NASA/JPL-Caltech/Space Science Institute/Tony Greicius.

Greetings, Orbiter.ch

The LHC takes a break before heading to new heights

CERN - European Organization for Nuclear Research logo.

30 July 2016

The Large Hadron Collider (LHC). Image Credit: CERN

The Large Hadron Collider (LHC) has been on Olympic form recently. In just two months, the accelerator delivered almost five times as much data as in the whole of 2015, smashing one record after another for luminosity, i.e. the number of collisions. The counter for integrated luminosity, which indicates the cumulative number of collisions delivered to the experiments, is approaching 20 inverse femtobarns (fb^-1), not far from the 25 fb^-1 target for 2016 as a whole!  This is great news for the experiments, which have been able to add data to their analyses ahead of presenting their latest results at the ICHEP 2016 (link is external) conference, which begins in a week’s time in Chicago in the United States.

The LHC operators have been clocking up long periods of operation, during which the beams have been circulating and colliding without a single hiccup along the way. You might think that the operators just sit there twiddling their thumbs while the beams circulate, but this couldn’t be further from the truth. The LHC is operating so well thanks to their constant checks and adjustments, which improve the operation of the accelerator and its thousands of components. And sometimes they stop the collisions altogether to carry out detailed studies of the accelerator, as is the case this week. Twenty days each year are devoted to these so-called machine development periods.

Image above: In the CERN Control Centre, Jan Uythoven and his colleagues perform studies to improve the operation of the LHC. (Image: Maximilien Brice/CERN).

“Studies like those we are carrying out this week have helped to pave the way for the excellent performance at the LHC in recent months,” says Jan Uythoven, who is in charge of the current machine development period. “The tests we’re doing are essential to maintain and even improve the performance of the LHC over the coming months and years.”

One of the main goals of the tests is to increase the luminosity even further. To do this, the operators can play with the size of the beam at the collision points in the centre of the experiments. The more the proton bunches that form the beam are compressed, the better the chances of collisions. “We are testing new settings for the quadrupole magnets that focus the beam,” explains Jan Uythoven. Another area being studied is beam instability, which is one of the operators’ pet hates. Each time that beam intensity is increased or the way in which the accelerator is filled is changed, the operators have to adjust all of the machine’s parameters to avoid the beams becoming unstable. When instabilities arise, the operators have to stop the beams and dump them. Another aspect of the current tests concerns the optimisation of the process for injecting proton bunches, in order to reduce the spreading of the beam.

After six days of studies, the LHC will resume its collision marathon next Monday.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Related links:

Large Hadron Collider (LHC): http://home.cern/topics/large-hadron-collider

ICHEP 2016: https://www.ichep2016.org/

For more information about the European Organization for Nuclear Research (CERN), visit: http://home.web.cern.ch/

Image (mentioned), Text, Credits: CERN/Corinne Pralavorio.

Five Years Post-Launch, Juno Is at a Turning Point

NASA - JUNO Mission logo.

July 29, 2016

Artist's view of Juno spacecraft over Jupiter. Image Credit: NASA

Five years after departing Earth, and a month after slipping into orbit around Jupiter, NASA's Juno spacecraft is nearing a turning point. On July 31 at 12:41 p.m. PDT (3:41 p.m. EDT), Juno will reach the farthest point in its orbit of Jupiter for the first time, known as “apojove,” 5 million miles (8.1 million kilometers) from the giant planet. After that point, Jupiter's gravitational grip on Juno will cause the spacecraft to begin falling back toward the planet for another pass, this time with its scientific eyes wide open.

The spacecraft is currently executing the first of two long orbits prior to beginning its science mission. Each capture orbit is nearly two months long -- quite the wait for the mission's eager team of scientists -- but it's nothing compared to the long wait the team endured on the trek to Jupiter.

Juno launched on Aug. 5, 2011. The spacecraft took a long, looping path around the inner solar system to set up an Earth flyby, in which our planet's gravity flung the spinning probe onward toward Jupiter.

"For five years we've been focused on getting to Jupiter. Now we're there, and we're concentrating on beginning dozens of flybys of Jupiter to get the science we're after," said Scott Bolton, Juno principal investigator at Southwest Research Institute in San Antonio.

Image above: This diagram shows the Juno spacecraft's orbits, including its two long, stretched-out capture orbits. The spacecraft's position on July 31 is indicated at left. Image Credits: NASA/JPL-Caltech.

Juno arrived at Jupiter on July 4, firing its main rocket engine as planned for 35 minutes. The flawless maneuver allowed Jupiter's gravity to capture the solar powered spacecraft into the first of two 53.4-day-long orbits, referred to as capture orbits. Following the capture orbits, Juno will fire its engine once more to shorten its orbital period to 14 days and begin its science mission.

But before that happens, on Aug. 27, Juno must finish its first lap around Jupiter, with a finish line that represents the mission's closest pass over the gas giant. During the encounter, Juno will skim past Jupiter at a mere 2,600 miles (4,200 kilometers) above the cloud tops.

Juno's science instruments were turned off during orbit insertion, to simplify spacecraft operations during that critical maneuver. In contrast, all the instruments will be collecting data during the Aug. 27 pass, which serves as a trial run before the mission gets to work collecting the precious data it came for.

"We're in an excellent state of health, with the spacecraft and all the instruments fully checked out and ready for our first up-close look at Jupiter," said Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory, Pasadena, California.

With its powerful suite of science instruments, Juno will probe Jupiter's deep structure, atmospheric circulation and the high-energy physics of its magnetic environment. What Juno finds there will reveal important clues to Jupiter's formation and evolution, along with insights about how our planetary system and others are built.

JPL manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. Juno is part of NASA's New Frontiers Program, which is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama, for NASA's Science Mission Directorate. Caltech in Pasadena manages JPL for NASA.

More information on the Juno mission is available at: http://www.nasa.gov/juno

The public can follow the mission on Facebook and Twitter at:

http://www.facebook.com/NASAJuno

http://www.twitter.com/NASAJuno

Images (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Preston Dyches/DC Agle.

Greetings, Orbiter.ch

Hubble Gazes at Long-dead Star

NASA - Hubble Space Telescope patch.

July 29, 2016

This NASA/ESA Hubble Space Telescope image captures the remnants of a long-dead star. These rippling wisps of ionized gas, named DEM L316A, are located some 160,000 light-years away within one of the Milky Way’s closest galactic neighbors — the Large Magellanic Cloud (LMC).

The explosion that formed DEM L316A was an example of an especially energetic and bright variety of supernova, known as a Type Ia. Such supernova events are thought to occur when a white dwarf star steals more material than it can handle from a nearby companion, and becomes unbalanced. The result is a spectacular release of energy in the form of a bright, violent explosion, which ejects the star’s outer layers into the surrounding space at immense speeds. As this expelled gas travels through the interstellar material, it heats up and ionizes it, producing the faint glow that Hubble’s Wide Field Camera 3 has captured here.

The LMC orbits the Milky Way as a satellite galaxy and is the fourth largest in our group of galaxies, the Local Group. DEM L316A is not the only supernova remnant in the LMC; Hubble came across another one in 2010 with SNR 0509, and in 2013 it snapped SNR 0519.

For more information about the Hubble Space Telescope, visit:

http://hubblesite.org/
http://www.nasa.gov/hubble
https://www.spacetelescope.org/

Image credits: ESA (European Space Agency)/Hubble & NASA, Y. Chu/Text credits: ESA/NASA/Rob Garner.

Greetings, Orbiter.ch

Mars Gullies Likely Not Formed by Liquid Water

NASA - Mars Reconnaissance Orbiter (MRO) logo.

July 29, 2016

Animation above: Martian gullies as seen in the top image from HiRISE on NASA's Mars Reconnaissance Orbiter resemble gullies on Earth that are carved by liquid water. However, when they are observed with the addition of mineralogical information from CRISM, no evidence for alteration by water appears. Animation Credits: NASA/JPL-Caltech/UA/JHUAPL.

New findings using data from NASA's Mars Reconnaissance Orbiter show that gullies on modern Mars are likely not being formed by flowing liquid water. This new evidence will allow researchers to further narrow theories about how Martian gullies form, and reveal more details about Mars' recent geologic processes.

Scientists use the term "gully" for features on Mars that share three characteristics in their shape:  an alcove at the top, a channel, and an apron of deposited material at the bottom. Gullies are distinct from another type of feature on Martian slopes, streaks called "recurring slope lineae," or RSL, which are distinguished by seasonal darkening and fading, rather than characteristics of how the ground is shaped. Water in the form of hydrated salt has been identified at RSL sites. The new study focuses on gullies and their formation process by adding composition information to previously acquired imaging.

Researchers from the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, examined high-resolution compositional data from more than 100 gully sites throughout Mars. These data, collected by the orbiter's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), were then correlated with images from the same spacecraft's High Resolution Imaging Science Experiment (HiRISE) camera and Context Camera (CTX).

Images above: Martian gullies as seen in the top image from HiRISE on NASA's Mars Reconnaissance Orbiter resemble gullies on Earth that are carved by liquid water. However, when they are observed with the addition of mineralogical information from CRISM (bottom), no evidence for alteration by water appears. Images Credits: NASA/JPL-Caltech/UA/JHUAPL.

The findings showed no mineralogical evidence for abundant liquid water or its by-products, thus pointing to mechanisms other than the flow of water -- such as the freeze and thaw of carbon dioxide frost -- as being the major drivers of recent gully evolution.

The findings were published in Geophysical Research Letters: http://onlinelibrary.wiley.com/doi/10.1002/2016GL068956/full

Gullies are a widespread and common feature on the Martian surface, mostly occurring between 30 and 50 degrees latitude in both the northern and southern hemispheres, generally on slopes that face toward the poles. On Earth, similar gullies are formed by flowing liquid water; however, under current conditions, liquid water is transient on the surface of Mars, and may occur only as small amounts of brine even at RSL streaks. The lack of sufficient water to carve gullies has resulted in a variety of theories for the gullies' creation, including different mechanisms involving evaporation of water and carbon dioxide frost.

"The HiRISE team and others had shown there was seasonal activity in gullies -- primarily in the southern hemisphere -- over the past couple of years, and carbon dioxide frost is the main mechanism they suspected of causing it. However, other researchers favored liquid water as the main mechanism," said Jorge Núñez of APL, the lead author of the paper. "What HiRISE and other imagers were not able to determine on their own was the composition of the material in gullies, because they are optical cameras. To bring another important piece in to help solve the puzzle, we used CRISM, an imaging spectrometer, to look at what kinds of minerals were present in the gullies and see if they could shed light on the main mechanism responsible."

Núñez and his colleagues took advantage of a new CRISM data product called Map-projected Targeted Reduced Data Records. It allowed them to more easily perform their analyses and then correlate the findings with HiRISE imagery.

Artist's view of Mars Reconnaissance Orbiter (MRO). Image Credit: NASA

"On Earth and on Mars, we know that the presence of phyllosilicates -- clays -- or other hydrated minerals indicates formation in liquid water," Núñez said. "In our study, we found no evidence for clays or other hydrated minerals in most of the gullies we studied, and when we did see them, they were erosional debris from ancient rocks, exposed and transported downslope, rather than altered in more recent flowing water. These gullies are carving into the terrain and exposing clays that likely formed billions of years ago when liquid water was more stable on the Martian surface."

Other researchers have created computer models that show how sublimation of seasonal carbon dioxide frost can create gullies similar to those observed on Mars, and how their shape can mimic the types of gullies that liquid water would create. The new study adds support to those models.

APL built and operates CRISM, one of six instruments with which the Mars Reconnaissance Orbiter project has been examining Mars since 2006. NASA's Jet Propulsion Laboratory, a division of the Caltech in Pasadena, California manages the project for the NASA Science Mission Directorate in Washington. Lockheed Martin Space Systems of Denver built the orbiter and supports its operations.

Related links:

Map-projected Targeted Reduced Data Records: http://crism.jhuapl.edu/newscenter/articles/20160317.php

Mars Reconnaissance Orbiter project: http://www.nasa.gov/mro

Mars Reconnaissance Orbiter (MRO): http://www.nasa.gov/mission_pages/MRO/main/index.html

Images (mentioned), Animation (mentioned), Text, Credits; NASA/Tony Greicius/JPL/Guy Webster/Johns Hopkins University Applied Physics Laboratory/Geoff Brown.

Greetings, Orbiter.ch

New furnace a step towards future collider development

CERN - European Organization for Nuclear Research logo.

July 28, 2016

A new furnace arrived at CERN’s Large Magnet Facility last month and is currently being installed and tested.

The furnace completes the equipment required for the production of superconducting coils, which are needed for the High-Luminosity LHC (HL-LHC) upgrade and future circular colliders.

Superconducting accelerator magnets are key for reaching higher energies and luminosities in particle accelerators.

Image above: The new furnace is currently being installed and tested. (Image: Friedrich Lackner/CERN).

The HL-LHC upgrade aims for magnetic fields up to 11T for the dipole magnets while the Future Circular Collider study explores using magnets with a field of 16 Tesla, almost double the 8.3 Tesla of the superconducting magnets used in the LHC.

To reach these goals new superconducting materials are needed.

“Nb₃Sn has been chosen for the next generation of superconducting magnets. The field achieved with this material can reach up to 16T. The production of such coils is complex as we must first wind the coils and then perform the heat treatment that allows the tin and niobium to react and turn into the superconducting Nb3Sn compound.” explains Friedrich Lackner, a project engineer who supervises the coil production for HL-LHC.

Once the material has undergone this heat treatment it becomes very brittle, which is why this process is performed after the winding process — the opposite to magnets in the LHC.

The new 32-metre-long furnace, called GL010000, will allow the heat treatment of coils with a length up to 11m and can reach temperatures up to 900°C providing a sufficient margin for future challenges.

This treatment involves a two week long process during which the coils are raised to different temperature plateaus up to 665°C. A special feature of this oven is that it is able to raise the coils to such high temperatures completely uniformly throughout the entire oven, making sure one part doesn’t heat more or less than another.

The installation of the new furnace at CERN’s Large Magnet Facility (LMF) will help scientists researching and developing the new materials needed for future colliders to understand the superconductor development based on this  Nb₃Sn alloy, and will allow CERN to lead the production of superconducting coils and the development of high-field magnets.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Related links:

High-Luminosity LHC (HL-LHC): http://home.cern/topics/high-luminosity-lhc

Future Circular Collider study: http://home.cern/about/accelerators/future-circular-collider

Nb₃Sn: http://home.cern/cern-people/updates/2016/07/once-upon-time-there-was-superconducting-niobium-tin

For more information about the European Organization for Nuclear Research (CERN), visit: http://home.web.cern.ch/

Image (mentioned), Text, Credits: CERN/Harriet Jarlett, Panagiotis Charitos.

Best regards, Orbiter.ch