Tuesday, July 8, 2014

Eureka! Kola Fireball Meteorites Found in Russia

Eureka! Kola Fireball Meteorites Found in Russia:



Amateur astronomer and physics teacher Asko Aikkila managed to catch the Kola fireball on videotape in Kuusamo, Finland on April 19, 2014. The picture has been processed to enhance the details. Credit: Asko Aikkila / Finnish Fireball Network

Amateur astronomer and physics teacher Asko Aikkila caught this image of the Kola fireball on videotape in Kuusamo, Finland on April 19, 2014. The picture has been processed to enhance the details. Credit: Asko Aikkila / Finnish Fireball Network
A spectacular fireball that crackled across the sky near the Russia-Finnish border on April 19th this year left more than a bright flash. A team of meteor researchers from Finland, Russia and the Czech Republic scoured the predicted impact zone and recently discovered extraterrestrial booty.

A 120 gram fragment of the Annama meteorite. Streamlines of molten material heated during atmospheric entry can be seen on the crust. Credit: Jakub Haloda

A 120 gram fragment (left) of the Annama meteorite found on May 29, 2014. Streamlines of molten material heated during atmospheric entry can be seen on the crust. At right, a 48g fragment found on the following day. Credit: Jakub Haloda (left) and Grigory Yakovlev
There’s a lot of excitement about the fall because it’s the first time a meteorite was found based on coordinated all-sky camera network observations by the Ursa Finnish Fireball Network.  Esko Lyytinen of the network with help from Jarmo Moilanen and Steinar Midtskogen reconstructed the meteoroid’s trajectory and dark flight (when it’s no longer luminous but yet to strike the ground) using simulations based on photos, videos and eyewitness reports.

Kola fireball meteors ended up near the Russian-Norwegian border. The fireball trajectory Esko Lyytinen of Ursa modeling of Heaven, watch videos on the findings and Murmansk.

Kola fireball meteors fell near the Russian-Norwegian border. The
fireball trajectory was modeled  byEsko Lyytinen of the Ursa Finnish Fireball Network. Credit: Kuva Mikko Suominen / Celestia with info boxes translated by the author
The initial mass of meteoroid is estimated at about 1,100 pounds (500 kg). Much of that broke apart in the atmosphere and fell harmlessly as smaller stones. An international team of scientists mounted a 5-day expedition in late May after snow melt and before green up to uncover potential space rocks in the strewnfield, the name given to the oval-shaped zone where surviving fragments pepper the ground.

Russian amateur astronomer Nikolai Kruglikov discovered the first fragment of Annama meteorite on May 29, 2014 in the middle of a dirt road. Credit: Tomas Kohout

Russian amateur astronomer Nikolai Kruglikov discovered the first meteorite fragment in the middle of a dirt road. Credit: Tomas Kohout
On May 29, 2014, first 120 gram (4.2 ounce) meteorite fragment was found by Nikolai Kruglikov of Russia’s Ural Federal University on a forest road within the predicted impact area. The crew had been searching 1o hours a day when Kruglikov stopped the car to check out a suspect rock:

 “Suddenly he started dancing and yelling. At first I could hardly believe it was a true discovery, but then I checked the composition of the rock using my instrument”, said Tomas Kohout, University of Helsinki physicist who participated in the hunt. The fusion-crusted stone displayed classic flow features from melting rock during high-speed atmospheric entry.

The very next day a second 48 gram crusted meteorite popped up. More are undoubtedly out there but the heavy brush numerous lakes make the finding challenging.

The crew is calling the new arrival the ‘Annama meteorite’ as it fell near the Annama River in Russia about 62 miles west of Murmansk.  The Czech Geological Survey examined the space rocks and determined them to be ordinary chondrites representing the outer crust of an asteroid that got busted to bits in a long-ago collision. More than 95% of stony meteorites fall into this category including the 2013 fireball of Chelyabinsk, Russia.



Dashcam video of the brilliant fireball that dropped the ‘Annama meteorites’

“The Kola fireball is a rarity – it is one of only 22 cases where it was possible to determine its pre-impact solar system orbit before the impact with Earth’s atmosphere,” says Maria Gritsevich of the Finnish Geodetic Institute. “Knowing where the meteorite originates will help us better understand the formation and evolution of the solar system.” Congratulations Ursa!

Tagged as:
Fireball,
Kola,
meteorite,
Murmansk,
strewfield
Posted by Nelio Inacio at 8:44 AM 0 comments

Incredible View: Camping Under the Milky Way

Incredible View: Camping Under the Milky Way:



A 10 panel panorama of the Milkyway, as seen from the top of the Amphitheatre mountain range in the Drakensberg Mountains, South Africa. Credit and copyright: Tanja Sund.

A 10 panel panorama of the Milkyway, as seen from the top of the Amphitheatre mountain range in the Drakensberg Mountains, South Africa. Credit and copyright: Tanja Sund.
During the summer months, many of us hit the trails and do a little camping. But how often do you get a view like this?

Wow! Click on the image above to see larger versions on Flickr.

Astrophotographer Tanja Sund and a companion pitched their tent in the Drakensberg Mountains of South Africa, a 200-kilometer-long mountainous range in the province of KwaZulu-Natal, with the tent sitting just 10 meters from a 1 kilometer-high vertical drop. “This is the home of the Tugela Waterfall, second highest waterfall in the world,” Tanja wrote on Flickr.



“The hike up to the top of the Amphitheatre took about 3 hours from the Sentinel car park, using the chain ladders to reach the summit,” Tanja said. “This is the only day hiking trail which leads to the top of the Drakensberg escarpment. We overnighted next to the Tugela falls to catch the Milkyway, which rises to the east over the local settlements.”

The image was taken on June 29, 2014.

According to the website about Drakensberg, the Zulu people named it ‘Ukhahlamba’ and the Dutch Voortrekkers ‘The Dragon Mountain.’ The Drakensberg Mountains are known for the hiking trails, areas for rock or ice-climbing, abseiling, white water rafting or helicopter rides to view the “awe-inspiring basalt cliffs, snowcapped in winter, that tower over riverine bush, lush yellowwood forests and cascading waterfalls.” At the top of Sani Pass is the highest pub in Africa, at 3,000 meters above sea level. Something for everyone!

Here’s the specs:

Canon 5D Mark III

24-70mm LII f/2.8

Shot at 24mm, F/3.2

20sec single exposures

10x image panorama

Processed in LightRoom & Photoshop.



Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Tagged as:
Astrophotos,
Camping,
Drakensberg Mountains,
milky way,
South Africa
Posted by Nelio Inacio at 8:43 AM 0 comments

How Big is Rosetta’s Comet?

How Big is Rosetta’s Comet?:



Diagram of Comet 67P/C-G compared to terrestrial landmarks (ESA)

Diagram of Comet 67P/C-G compared to terrestrial landmarks (ESA)
Pretty darn big, I’d say.

The illustration above shows the relative scale of the comet that ESA’s Rosetta and Philae spacecraft will explore “up-close and personal” later this year. And while it’s one thing to say that the nucleus of Comet 67P/Churyumov-Gerasimenko is about three by five kilometers in diameter, it’s quite another to see it in context with more familiar objects. Think about it — a comet as tall as Mt Fuji!

Artist's impression (not to scale) of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko. Credit: ESA–C. Carreau/ATG medialab.

Artist’s impression (not to scale) of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko. Credit: ESA–C. Carreau/ATG medialab.
At the time of this writing Rosetta is 35 days out on approach to Comet 67P/C-G, at a distance of about 51,000 km (31,700 miles) and closing. Three “big burn” maneuvers have already been performed between May 7 and June 4 to adjust the spacecraft’s course toward the incoming comet, and after a smaller one on June 18 and July 2 there are a total of five more to go. See details of Rosetta’s burn maneuvers here.

As incredibly sensitive as they are, Rosetta’s instruments — which were able to detect the water vapor coming from Comet 67P/C-G from a distance of over 360,000 km — have even sniffed the hydrazine exhaust from its own thruster burns.

Luckily the remaining burns are relatively small compared to the first three, with the final being very brief, so any data contamination by Rosetta’s own exhaust shouldn’t become an issue once the spacecraft has established orbit in August.

Read more: Rosetta’s Comet Already Sweating the Small Stuff

Launched in March 2004, ESA’s Rosetta mission will be the first to orbit and land a probe on a comet, observing its composition and behavior as it makes its close approach to the Sun in 2015. Click here to see where Rosetta is right now.

Source: ESA’s Rosetta blog

Tagged as:
67P/Churyumov-Gerasimenko,
burn,
comet,
esa,
rosetta,
Solar System,
spaceflight
Posted by Nelio Inacio at 8:43 AM 0 comments

NASA’s Carbon Observatory Blasts off on Workhorse Delta II to Measure Carbon Dioxide Greenhouse Gas and Watch Earth Breathe

NASA’s Carbon Observatory Blasts off on Workhorse Delta II to Measure Carbon Dioxide Greenhouse Gas and Watch Earth Breathe:



The Orbiting Carbon Observatory-2, NASA's first mission dedicated to studying carbon dioxide in Earth's atmosphere, lifts off from Vandenberg Air Force Base, California, at 2:56 a.m. Pacific Time, July 2, 2014. The two-year mission will help scientists unravel key mysteries about carbon dioxide. Credit: NASA/Bill Ingalls

The Orbiting Carbon Observatory-2, NASA’s first mission dedicated to studying carbon dioxide in Earth’s atmosphere, lifts off from Vandenberg Air Force Base, California, at 2:56 a.m. Pacific Time, July 2, 2014 on a Delta II rocket. The two-year mission will help scientists unravel key mysteries about carbon dioxide. Credit: NASA/Bill Ingalls
Following a nearly three-year long hiatus, the workhorse Delta II rocket successfully launched NASA’s first spacecraft dedicated to watching Earth breathe by studying Earth’s atmospheric carbon dioxide (CO2) – the leading human-produced greenhouse gas and the principal human-produced driver of climate change.

The Orbiting Carbon Observatory-2 (OCO-2) raced to orbit earlier this morning, during a spectacular nighttime blastoff at 2:56 a.m. PDT (5:56 a.m. EDT), Tuesday, July 2, 2014, from Vandenberg Air Force Base, California, atop a United Launch Alliance Delta II rocket.

The flawless launch marked the ‘return to flight’ of the venerable Delta II and was broadcast live on NASA TV.

Blastoff of NASA’s Orbiting Carbon Observatory-2 dedicated to studying carbon dioxide in Earth's atmosphere, from Vandenberg Air Force Base, California, at 2:56 a.m. Pacific Time, July 2, 2014. Credit: Robert Fisher/America/Space

Blastoff of NASA’s Orbiting Carbon Observatory-2 dedicated to studying carbon dioxide in Earth’s atmosphere, from Vandenberg Air Force Base, California, at 2:56 a.m. Pacific Time, July 2, 2014. Credit: Robert Fisher/America/Space
A camera mounted on the Delta II’s second stage captured a breathtaking live view of the OCO-2 spacecraft during separation from the upper stage, which propelled it into an initial 429-mile (690-kilometer) orbit.

The life giving solar arrays were unfurled soon thereafter and NASA reports that the observatory is in excellent health.

“Climate change is the challenge of our generation,” said NASA Administrator Charles Bolden in a statement.

“With OCO-2 and our existing fleet of satellites, NASA is uniquely qualified to take on the challenge of documenting and understanding these changes, predicting the ramifications, and sharing information about these changes for the benefit of society.”

NASA's Orbiting Carbon Observatory-2, or OCO-2, inside the payload fairing in the mobile service tower at Space Launch Complex 2 on Vandenberg Air Force Base in California. The fairing will protect OCO-2 during launch aboard a United Launch Alliance Delta II rocket, scheduled for 5:56 a.m. EDT on July 1. OCO-2 is NASA’s first mission dedicated to studying atmospheric carbon dioxide, the leading human-produced greenhouse gas driving changes in Earth’s climate. Credit: NASA/30th Space Wing USAF

NASA’s Orbiting Carbon Observatory-2, or OCO-2, inside the payload fairing in the mobile service tower at Space Launch Complex 2 on Vandenberg Air Force Base in California. The fairing will protect OCO-2 during launch aboard a United Launch Alliance Delta II rocket, which occurred at 5:56 a.m. EDT on July 2. OCO-2 is NASA’s first mission dedicated to studying atmospheric carbon dioxide, the leading human-produced greenhouse gas driving changes in Earth’s climate. Credit: NASA/30th Space Wing USAF
Over the next three weeks the OCO-2 probe will undergo a thorough checkout and calibration process. It will also be maneuvered into a 438-mile (705-kilometer) altitude, near-polar orbit where it will become the lead science probe at the head of the international Afternoon Constellation, or “A-Train,” of Earth-observing satellites.

“The A-Train, the first multi-satellite, formation flying “super observatory” to record the health of Earth’s atmosphere and surface environment, collects an unprecedented quantity of nearly simultaneous climate and weather measurements,” says NASA.

The 999 pound (454 kilogram) observatory is the size of a phone booth.

OCO-2 is equipped with a single science instrument consisting of three high-resolution, near-infrared spec¬trometers fed by a common telescope. It will collect global measurements of atmospheric CO2 to provide scientists with a better idea of how CO2 impacts climate change and is responsible for Earth’s warming.

OCO-2 poster. Credit: ULA/NASA

OCO-2 poster. Credit: ULA/NASA
During a minimum two-year mission the $467.7 million OCO-2 will take near global measurements to locate the sources and storage places, or ‘sinks’, for atmospheric carbon dioxide, which is a critical component of the planet’s carbon cycle.

OCO-2 was built by Orbital Sciences as a replacement for the original OCO which was destroyed during the failed launch of a Taurus XL rocket from Vandenberg back in February 2009 when the payload fairing failed to open properly and the spacecraft plunged into the ocean.

The OCO-2 mission will provide a global picture of the human and natural sources of carbon dioxide, as well as their “sinks,” the natural ocean and land processes by which carbon dioxide is pulled out of Earth’s atmosphere and stored, according to NASA.

“This challenging mission is both timely and important,” said Michael Freilich, director of the Earth Science Division of NASA’s Science Mission Directorate in Washington.

“OCO-2 will produce exquisitely precise measurements of atmospheric carbon dioxide concentrations near Earth’s surface, laying the foundation for informed policy decisions on how to adapt to and reduce future climate change.”

It will record around 100,000 precise individual CO2 measurements around the worlds entire sunlit hemisphere every day and help determine its source and fate in an effort to understand how human activities impact climate change and how we can mitigate its effects.

At the dawn of the Industrial Revolution, there were about 280 parts per million (ppm) of carbon dioxide in Earth’s atmosphere. As of today the CO2 level has risen to about 400 parts per million.

“Scientists currently don’t know exactly where and how Earth’s oceans and plants have absorbed more than half the carbon dioxide that human activities have emitted into our atmosphere since the beginning of the industrial era,” said David Crisp, OCO-2 science team leader at NASA’s Jet Propulsion Laboratory in Pasadena, California, in a statement.

“Because of this, we cannot predict precisely how these processes will operate in the future as climate changes. For society to better manage carbon dioxide levels in our atmosphere, we need to be able to measure the natural source and sink processes.”

OCO-2 is the second of NASA’s five new Earth science missions planned to launch in 2014 and is designed to operate for at least two years during its primary mission. It follows the successful blastoff of the joint NASA/JAXA Global Precipitation Measurement (GPM) Core Observatory satellite on Feb 27.

Stay tuned here for Ken’s continuing OCO-2, GPM, Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, MAVEN, MOM, Mars and more Earth & Planetary science and human spaceflight news.



Dr. Ken Kremer is a speaker, scientist, freelance science journalist (Princeton, NJ) and photographer whose articles, space exploration images and Mars mosaics have appeared in magazines, books, websites and calanders including Astronomy Picture of the Day, NBC, BBC, SPACE.com, Spaceflight Now and the covers of Aviation Week & Space Technology, Spaceflight and the Explorers Club magazines. Ken has presented at numerous educational institutions, civic & religious organizations, museums and astronomy clubs. Ken has reported first hand from the Kennedy Space Center, Cape Canaveral and NASA Wallops on over 40 launches including 8 shuttle launches. He lectures on both Human and Robotic spaceflight - www.kenkremer.com. Follow Ken on Facebook and Twitter
Tagged as:
carbon dioxide,
Climate Change,
Delta II rocket,
greenhouse gases,
NASA,
oco,
oco-2,
orbiting carbon observatory,
ULA,
United Launch Alliance,
Vandenberg Air Force Base
Posted by Nelio Inacio at 8:42 AM 0 comments

Ancient Asteroid Impacts Left Serpentine Traces On Vesta: Study

Ancient Asteroid Impacts Left Serpentine Traces On Vesta: Study:



Mosaic synthesizes some of the best views the spacecraft had of the giant asteroid Vesta. Dawn studied Vesta. The towering mountain at the south pole - more than twice the height of Mount Everest - is visible at the bottom of the image. The set of three craters known as the "snowman" can be seen at the top left. Credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA

Mosaic synthesizes some of the best views the spacecraft had of the giant asteroid Vesta. Dawn studied Vesta. The towering mountain at the south pole – more than twice the height of Mount Everest – is visible at the bottom of the image. The set of three craters known as the “snowman” can be seen at the top left. Credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA
While “dark materials” may leave some of us thinking about a certain Philip Pullman book series, on the asteroid Vesta its presence belies something equally exotic: old smaller asteroid impacts on its surface.

The dark stuff on the lighter surface has puzzled researchers since it was discovered in 2011 (and has been brought up in other studies), but a new team says it has found that serpentine is among the components.  Because that mineral can’t survive temperatures that are more than 400 degrees Celsius (752 degrees Fahrenheit), this means that scenarios such as volcanic eruptions can’t have caused it. This leaves only smaller asteroids, the team says.

“These meteorites are regarded as fragments of carbon-rich asteroids. The impacts must have been comparatively slow, because an asteroid crashing at high speeds would have produced temperatures too high to sustain serpentine,” the Max Planck Institute for Solar System Research stated.

Image of the crater Numisia on Vesta, where researchers found the spectral signature of serpentine. Picture taken by NASA's Dawn spacecraft. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Image of the crater Numisia on Vesta, where researchers found the spectral signature of serpentine. Picture taken by NASA’s Dawn spacecraft. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
“In a previous study, scientists from the MPS had calculated how dark material would be distributed on Vesta as a result of a low-speed oblique impact. Their results are consistent with the distribution of dark material on the edge of one of the two large impact basins in the southern hemisphere.”

The results came from analyzing images the NASA Dawn spacecraft took of Vesta between July 2011 and September 2012. The researchers recalibrated the data and also backed up their results by examining serpentine in laboratory conditions.

The research was published in the journal Icarus and you can also read a summary of the research here, from a presentation at the 2014 Lunar and Planetary Science Conference.

Source: Max Planck Institute for Solar System Research

Tagged as:
dawn,
serpentine,
vesta
Posted by Nelio Inacio at 8:42 AM 0 comments

Astronauts Keep an Eye on Tropical Storm Arthur from the Space Station

Astronauts Keep an Eye on Tropical Storm Arthur from the Space Station:



Astronauts on the International Space Station took this image of Tropical Storm Arthur on July 2, 2014. Credit: Reid Wiseman/NASA.

Astronauts on the International Space Station took this image of Tropical Storm Arthur on July 2, 2014. Credit: Reid Wiseman/NASA.
The first storm of the Atlantic hurricane season is easily visible from space. International Space Station astronaut Reid Wiseman tweeted this picture of the storm, saying, “Just flew over Tropical Storm Arthur – hoping it heads to sea. Looks mean.”

Forecasters said the storm is slowly strengthening off Florida’s east coast, but will move up the coast just in time for the July 4th holiday in the US. While Tropical Storm Arthur is likely to stay offshore while it cruises by Florida, it might become a hurricane by Thursday. The National Hurricane Center reported at 2 pm EDT Wednesday that a tropical storm warning is in effect for all of coastal North Carolina with a hurricane watch the for the portion of the state that extends into the Atlantic Ocean. As of the time of the report, Tropical Storm Arthur was about 160 km (100 miles) east of Daytona Beach, Florida and 378 km (235 miles) south of Charleston, South Carolina.



A graphic showing Tropical Storm Force Wind Speed Probabilities for Tropical Storm Arthur, from July 2 through July 7. Credit: National Hurricane Center/NOAA.

A graphic showing Tropical Storm Force Wind Speed Probabilities for Tropical Storm Arthur, from July 2 through July 7. Credit: National Hurricane Center/NOAA.
For current information about this storm, see the National Hurricane Center’s website.

Tagged as:
hurricanes,
International Space Station (ISS),
reid wiseman,
Tropical Storm Arthur,
Tropical Storms
Posted by Nelio Inacio at 8:41 AM 0 comments

Watch Live as Astronomers Look for Object ‘G2′ in Observing Run Webcast from the Keck Observatory

Watch Live as Astronomers Look for Object ‘G2′ in Observing Run Webcast from the Keck Observatory:





Wondering about the latest news on the intriguing object called ‘G2′ that is making its closest approach to the supermassive black hole at the center of our galaxy? You might be able to get the latest update on this object in real time during a rare live-streamed observing run from the W. M. Keck Observatory in Hawaii. Watch live above.

The two 10-meter Keck Observatory telescopes on the summit of Mauna Kea will be steered by astronomer Andrea Ghez and her team of observers from the UCLA Galactic Center Group for two nights to study our galaxy’s supermassive black hole, with an attempt to focus in on the enigmatic G2 to see if it is still intact. They’ll also be setting up a test for Einstein’s General Relativity and gathering more data on what they describe as The Paradox of Youth: young objects paradoxically developing around the black hole.

Here’s the time for the livestream in various timezones:



July 3, 2014 @ 9 pm – 10 pm Hawaii

July 4, 2014 @ Midnight – 1 am Pacific

July 4, 2014 @ 3 am – 4 am Eastern

This simulation shows the possible behavior of a gas cloud that has been observed approaching the black hole at the center of the Milky Way. Graphic by ESO/MPE/Marc Schartmann.

This simulation shows the possible behavior of a gas cloud that has been observed approaching the black hole at the center of the Milky Way. Graphic by ESO/MPE/Marc Schartmann.
The most previous observations by the Keck Observatory in Hawaii, according to an Astronomer’s Telegram from May 2, 2014 show that the gas cloud called ‘G2′ was surprisingly still intact, even during its closest approach to the supermassive black hole. This means G2 is not just a gas cloud, but likely has a star inside.

“We conclude that G2, which is currently experiencing its closest approach, is still intact, in contrast to predictions for a simple gas cloud hypothesis and therefore most likely hosts a central star,” said the May 2 Telegram. “Keck LGSAO observations of G2 will continue in the coming months to monitor how this unusual object evolves as it emerges from periapse passage.”

For additional info, see our two previous articles about G2:

Gas Cloud or Star? Mystery Object Heading Towards our Galaxy’s Supermassive Black Hole is Doomed

Object “G2? Still Intact at Closest Approach to Galactic Center, Astronomers Report

Tagged as:
G2,
Keck Observatory,
Live broadcasts,
milky way,
supermassive black hole
Posted by Nelio Inacio at 8:41 AM 0 comments

A Spectacular Set of Conjuctions on Tap for the Moon, Mars and Saturn this Weekend

A Spectacular Set of Conjuctions on Tap for the Moon, Mars and Saturn this Weekend:



Saturn passing behind the lunar limb on May 15th.

Saturn passing behind the lunar limb on May 15th. Credit: Silveryway.
Got clear skies this July 4th weekend? The Moon passes some interesting cosmic environs in the coming days, offering up some photogenic pairings worldwide and a spectacular trio of occultations for those well placed observers who find themselves along the footprint of these events.

Stellarium

The path of the Moon on July 5th, 6th and 7th. Credit: Stellarium
First, let’s look at our closest natural neighbor in space. The Moon reaches first quarter phase on Saturday, July 5th at 11:59 Universal Time (UT)/7:59 AM EDT. First Quarter is a great time to observe the Moon, as the craters along the jagged terminator where the Sun is just starting to rise stand out in stark profile. Watch for the Lunar Straight Wall and the alphabet soup of elusive features known as the Lunar X or Purbach Cross and Lunar V on evenings right around First Quarter phase.

Starry Night

Mars off of the limb of the Moon as seen from North America on the evening of July 5th. Credit: Starry Night.
Our first conjunction stop on this weekend’s lunar journey is the planet Mars. Although the Moon occults — that is, passes in front of a given planet from our Earthly perspective — exactly 16 naked eye planets in 2014 (24 if you add in Uranus events and 1 Ceres and 4 Vesta on September 28th), the Moon will only occult Mars once in 2014, on the night of July 5th/6th. Northern South America and southern Central America will have a front row seat, while the rest of North America will see a close pass less than one degree from the lunar limb. This will still present a fine photographic opportunity, as it’ll be possible to snag Mars and the limb of the Moon in the same field of view. The Moon will be 56% illuminated during the conjunction, and Mars will present an 88% illuminated disk 9.2” across shining at magnitude +0.3.

Occult 4.0

The occultation path for Mars. Graphics created using Occult 4.0.
Both will be 96 degrees east of the Sun during geocentric (Earth-centered) conjunction, which occurs around 1:00 UT on July 6th or 9:00 PM EDT on the evening of the 5th. For those positioned to catch the occultation, it’ll take about a minute for “Mars set” to occur on the lunar limb. The last occultation of Mars occurred on May 9th, 2013 and the next won’t happen ‘til March 21st, 2015.

Virginis

The footprint of Lambda Virginis…
Next up, the Moon occults the +4.5th magnitude star Lambda Virginis on July 7th centered on 8:26 UT. This event is well placed for observers in Hawaii on the evening of July 6th. Located 187 light years distant, the light that you’re seeing departed the far-flung star on 1827, only to be interrupted by the pesky limb of our Moon a second prior to arrival on Earth. This star is also of note as it’s a spectroscopic binary, and while you won’t be able to resolve the pair at a tiny separation of just 0.0002” apart, you just might be able to see the pair “wink out” in a step wise fashion that betrays its binary nature. The Moon misses the brightest star in Virgo (Spica) this month, as it’s wrapped up a series of occultations of the star in early 2014 and won’t resume until 2024. Aldebaran, Antares and Regulus also lie along the Moon’s path on occasion, and the next cycle of bright star occultations resume with Aldebaran in January 2015. You can check out a list of fainter naked eye stars occulted by the Moon this year here courtesy of the International Occultation Timing Association.

Saturn

… and the occultation footprint  for Saturn.
And finally, the Moon visits Saturn, now residing just over the border in the astronomical constellation of Libra. This occultation occurs just 49 hours after the Mars event at 2:00 UT on July 8th (10:00 PM EDT on the evening of July 7th) and favors observers in the southernmost tip of South America. As with Mars, North America will see a close miss, although it will also be possible to squeeze Saturn in the same field of view as the Moon at low power, though it’ll sit about a degree of off its limb. We’re in a cycle of occultations of Saturn this year, with 11 occurring in 2014 and the next on August 4th. The reason for this is that Saturn moves much more slowly across the sky than Mars from our perspective, making for a relatively sluggish moving target for the Moon. Saturn shines at +0.6 magnitude as the 75% illuminated Moon passes by and subtends 42” with rings and will take about five minutes to pass fully behind the Moon.

These events will make for some great pics and animation sequences for sure… can you spot Saturn or Mars near the lunar limb with binoculars or a telescope before sunset? Or catch ‘em in the frame during a local fireworks show? Let us know, if enough pics surface on Universe Today’s Flickr page, we may do a post weekend roundup!  

Tagged as:
astronomy july,
lambda virginis,
Mars occultation,
saturn occultation
Posted by Nelio Inacio at 8:40 AM 0 comments

Chandra Image May Rival July 4th Fireworks

Chandra Image May Rival July 4th Fireworks:



A new composite of NGC 4258 features X-rays from Chandra (blue), radio waves from the VLA (purple), optical data from Hubble (yellow and blue), and infrared with Spitzer (red). Image Credit: Chandra

A new composite of NGC 4258 features X-rays from Chandra (blue), radio waves from the VLA (purple), optical data from Hubble (yellow and blue), and infrared with Spitzer (red).
While Fourth of July festivities tonight may bring brilliant colors blazing across the night sky, only 23 million light-years away is another immense cosmic display, complete with a supermassive black hole, shock waves, and vast reservoirs of gas.

The night sky never ceases to amaze. And NGC 4258, also known as Messier 106, is a sight to be seen. A new image from NASA’s Chandra X-ray Observatory is shedding light on one of the galaxy’s most startling features: instead of two spiral arms, typical for any massive spiral galaxy, it appears to have four (imaged above in blue and purple).

Although the second pair of arms can be seen in visible light images as ghostly wisps of gas, they are prominent in images outside the visible spectrum, such as those using X-ray or radio waves. Unlike normal arms, they are made up of hot gas rather than stars, and their origin has remained a mystery.

Astronomers now think the arms — so-called anomalous for their atypical features — are indirectly caused by the supermassive black hole at NGC 4258’s heart.

Images from multiple telescopes help paint a complete picture. Radio data taken with the Very Large Array show that the supermassive black hole is producing powerful jets. As these jets travel through the galactic matter, they disrupt the surrounding gas and generate shock waves. These shock waves, seen by NASA’s Spitzer Space Telescope, heat the anomalous arms — composed of reservoirs of gas as massive as about 10 million Suns — to thousands of degrees.

Finally, the recent Chandra X-ray image also reveals huge bubbles of hot gas above and below the plane of the galaxy. These bubbles indicate that although much of the gas was originally in the disk of the galaxy, it was heated to such high temperatures that it was ejected into the outer regions by the jets from the supermassive black hole.

The results provide drastic implications for the fate of the galaxy. Most of the gas in the disk of the galaxy has been ejected, causing stars to form at a rate ten times slower than the Milky Way. Further, astronomers estimate that all of the remaining gas will be ejected within the next 300 million years.

Although NGC 4258 is currently a sight to be seen in any small telescope, like the best fireworks display followed by smoke, its death is inescapable.

The results were published in The Astrophysical Journal Letters and are available online.

Tagged as:
Chandra X-ray Observatory,
Messier 106,
NGC 2458
Posted by Nelio Inacio at 8:40 AM 0 comments

A Brief History Of Gliese 581d and 581g, The Planets That May Not Be

A Brief History Of Gliese 581d and 581g, The Planets That May Not Be:



Goldilocks Zone

Artists impression of Gliese 581g. Credit: Lynette Cook/NSF
Two potentially habitable planets in the Gliese 581 system are just false signals arising out of starstuff, a new study said. Gliese 581d and 581g are (study authors said) instead indications of the star’s activity and rotation. It’s the latest twist in a long tale about the system as astronomers struggle to understand how many planets could be orbiting the star.

“Our improved detection of the real planets in this system gives us confidence that we are now beginning to sufficiently eliminate Doppler signals from stellar activity to discover new, habitable exoplanets, even when they are hidden beneath stellar noise,” stated Paul Robertson, a postdoctoral fellow at Penn State University, in a press release.

“While it is unfortunate to find that two such promising planets do not exist, we feel that the results of this study will ultimately lead to more Earth-like planets.”

Planets were first announced around the system in 2007 (by a research team led by Geneva’s Stephane Udry) including Gliese 581d. The system has been under heavy scrutiny since a team led by Steven Vogt of the University of Santa Cruz announced Gliese 581g in September 2010. Both 581d and 581g were considered to be in the “habitable” region around the dwarf star they orbited, meaning the spot that’s not too far or close to the star for liquid water to exist.

Potentially habitable exoplanets and exoplanet candidates as of July 3, 2014. Gliese 581d and 581g are crossed off in the catalog. Click for larger version. Credit: PHL @ UPR Arecibo

Potentially habitable exoplanets and exoplanet candidates as of July 3, 2014. Gliese 581d and 581g are crossed off in the catalog. Click for larger version. Credit: PHL @ UPR Arecibo
About two weeks after the discovery, another team led by Geneva University’s Francesco Pepe said it could not find indications of Gliese 581g in data from HARPS (High Accuracy Radial Velocity Planet Searcher), a telescope instrument frequently used at the European Southern Observatory to confirm exoplanets. It also cast doubt on the existence of Gliese 581f, announced by a team led by Geneva’s Michel Mayor in 2009. Other researchers examined the system, too, with mixed results.

Two years later, Vogt led another research team saying that analysis of an “extended dataset” from HARPS did show Gliese 581g. But in a press release at the time from the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo, its director (Abel Mendez) said the discovery would continue to be controversial. At the time he added the planet to the list of potentially habitable exoplanets the laboratory maintains. As of yesterday, both 581d and 581g are crossed off.

The uncertainty arises from the delicacy of looking for signals of small planets around much larger stars. Astronomers typically find planets through watching them pass across the face of a star, or measuring the tug that they exert on their parent star during their orbit. It is the nature of the tug on Gliese 581 that is so interesting astronomers.

Orbital Period

The orbits of planets in the Gliese 581 system are compared to those of our own solar system. The Gliese 581 star has about 30 percent the mass of our Sun, and the outermost planet is closer to its star than the Earth is to the Sun. The 4th planet, G, is a planet that could sustain life. Credit: Zina Deretsky, National Science Foundation
“These ‘Doppler shifts’ can result from subtle changes in the star’s velocity caused by the gravitational tugs of orbiting planets,” wrote Penn State in the press release yesterday.  “But Doppler shifts of a star’s ‘absorption lines’ also can result from magnetic events like sunspots originating within the star itself — giving false clues of a planet that does not actually exist.”

The researchers now say that only three planets exist around this star. It’s impossible to fully represent the debate in a single short news article, so we encourage you to look at some of the original literature. Here is a list of papers related to Gliese 581g and another for Gliese 581d. The new paper is available online in Science.

Also, here are some past Universe Today stories about the system:

Tagged as:
gliese 581d,
Gliese 581g
Posted by Nelio Inacio at 8:39 AM 0 comments

Cannibal Galaxy Could Show How These Huge Structures Grow

Cannibal Galaxy Could Show How These Huge Structures Grow:



Image of the Umbrella Galaxy, combining data from the 0.5-meter BlackBird Remote Observatory Telescope and Suprime-Cam on the 8-meter Subaru Telescope. Credit: R. Jay Gabany

Image of the Umbrella Galaxy, combining data from the 0.5-meter BlackBird Remote Observatory Telescope and Suprime-Cam on the 8-meter Subaru Telescope. Credit: R. Jay Gabany
There’s a hungry galaxy on the loose about 62 million light-years away from us. Astronomers just revealed that the Umbrella Galaxy (NGC 4651) is busy gobbling up another galaxy, similar to how our own Milky Way Galaxy is eating the smaller Sagittarius.

“This is important because our whole concept about what galaxies are and how they grow has not been fully verified,” stated co-author Aaron Romanowsky, an astronomer at both San José State University and University of California Observatories.

“We think they are constantly consuming smaller galaxies as part of a cosmic food chain, all pulled together by a mysterious form of invisible ‘dark matter’. When a galaxy is torn apart, we sometimes get a glimpse of the hidden vista because the stripping process lights it up. That’s what occurred here.”

This type of merger and acquisition is something you often seen moving about the universe, but it’s hard to capture these images in three dimensions, scientists said. It required looking at the motions of the stream you see here to see how the smaller galaxy is being torn apart.

“Through new techniques we have been able to measure the movements of the stars in the very distant, very faint, stellar stream in the Umbrella,” stated Caroline Foster of the Australian Astronomical Observatory, who led the study. “This allows us to reconstruct the history of the system, which we couldn’t before.”

The research was published in the Monthly Notices of the Royal Astronomical Society, and is available in preprint version on Arxiv.

Sources: Keck Observatory and Australian Astronomical Observatory

Tagged as:
ngc 4651,
umbrella galaxy
Posted by Nelio Inacio at 8:39 AM 0 comments

A Protostar’s Age Gleaned Only From Sound Waves

A Protostar’s Age Gleaned Only From Sound Waves:



A composite image detailing the pre-life story of a star like the Sun, spanning about 10 million years from conception to birth. | © Pieter Degroote (KU Leuven) / background image © ESO

A composite image detailing the pre-life story of a star like the Sun, spanning about 10 million years from conception to birth. Image Credit: Pieter Degroote (KU Leuven) / ESO
Precisely dating a star can have important consequences for understanding stellar evolution and any circling exoplanets. But it’s one of the toughest plights in astronomy with only a few existing techniques.

One method is to find a star with radioactive elements like uranium and thorium, whose half-lives are known and can be used to date the star with certainty. But only about 5 percent of stars are thought to have such a chemical signature.

Another method is to look for a relationship between a star’s age and its ‘metals,’ the astronomer’s slang term for all elements heavier than helium. Throughout cosmic history, the cycle of star birth and death has steadily produced and dispersed more heavy elements leading to new generations of stars that are more heavily seeded with metals than the generation before. But the uncertainties here are huge.

The latest research is providing a new technique, showing that protostars can easily be dated by measuring the acoustic vibrations — sound waves — they emit.

Stars are born deep inside giant molecular clouds of gas. Turbulence within these clouds gives rise to pockets of gas and dust with enough mass to collapse under their own gravitational contraction. As each cloud — protostar — continues to collapse, the core gets hotter, until the temperature is sufficient enough to begin nuclear fusion, and a full-blown star is born.

Our Sun likely required about 50 million years to mature from the beginning of collapse.

Theoretical physicists have long posited that protostars vibrate differently than stars. Now, Konstanze Zwintz from KU Leuven’s Institute for Astronomy, and colleagues have tested this prediction.

The team studied the vibrations of 34 protostars in NGC 2264, all of which are less than 10 million years old. They used the Canadian MOST satellite, the European CoRoT satellite, and ground-based facilities such as the European Southern Observatory in Chile.

“Our data show that the youngest stars vibrate slower while the stars nearer to adulthood vibrate faster,” said Zwintz in a press release. “A star’s mass has a major impact on its development: stars with a smaller mass evolve slower. Heavy stars grow faster and age more quickly.”

Each stars’ vibrations are indirectly seen by their subtle changes in brightness. Bubbles of hot, bright gas rise to the star’s surface and then cool, dim, and sink in a convective loop. This overturn causes small changes in the star’s brightness, revealing hidden information about the sound waves deep within.

You can actually hear this process when the stellar light curves are converted into sound waves. Below is a video of such singing stars, produced by Nature last year.



“We now have a model that more precisely measures the age of young stars,” said Zwintz. “And we are now also able to subdivide young stars according to their various life phases.”

The results were published in Science.

Tagged as:
asteroseismology,
Stellar Age,
stellar evolution
Posted by Nelio Inacio at 8:38 AM 0 comments

Spectacular Southern Lights, Shooting Stars, Sahara Snapshots and more from ESA’s Alexander Gerst aboard ISS

Spectacular Southern Lights, Shooting Stars, Sahara Snapshots and more from ESA’s Alexander Gerst aboard ISS:



“Saw a beautiful Southern Light last night. I so wish you could see this with your own eyes!” Image taken from the International Space Station (ISS) on 5 July 2014. Credit: ESA/Alexander Gerst

“Saw a beautiful Southern Light last night. I so wish you could see this with your own eyes!” Image taken from the International Space Station (ISS) on 5 July 2014. Credit: ESA/Alexander Gerst
Spectacular snapshots of the Southern Lights, Shooting Stars, the Sahara Desert and much more are streaming back from space to Earth courtesy of Alexander Gerst, ESA’s German astronaut currently serving aboard the International Space Station (ISS).

See a gallery of Alex’s stunning space-based views collected herein – starting with the auroral fireworks seen from space. It coincides with the Earth-based fireworks of America’s 4th of July Independence Day weekend celebrations and spectacular Noctilucent Clouds (NLCs) wafting over the Northern Hemisphere. NLC gallery here.

“Saw a beautiful Southern Light last night. I so wish you could see this with your own eyes!” Alex tweeted in English.

Gerst is posting his imagery on social media including Twitter, Facebook, Google+ and ESA’s astronaut blog bilingually in English and German.

Another new snapshot of Earth’s “beautiful Southern Lights” taken from the ISS on 5 July 2014. Credit: ESA/Alexander Gerst

Another new snapshot of Earth’s “beautiful Southern Lights” taken from the ISS on 5 July 2014. Credit: ESA/Alexander Gerst
“Habe gestern ein wunderschönes Südlicht gesehen. Ich wünschte ihr könntet das mit eigenen Augen sehen!” Alex tweeted in German.

Check out Alexander’s Gerst stunning 1st timelapse video from the ISS



Video Caption: ESA astronaut Alexander Gerst’s first timelapse from the International Space Station features the first shooting star that he saw from above. Made by stitching together over 250 images this short clip shows the beauty of our world and the space around it. Published on July 5, 2014. Credit: ESA/Alexander Gerst

Here’s several of Alexander Gerst’s daylight views of the Sahara Desert and more.

“Even from space, the Sahara looks dry! Sogar vom Weltraum aus, sieht die Sahara trocken aus!” Taken from the ISS on 6 July 2014. Credit: ESA/Alexander Gerst

“Even from space, the Sahara looks dry! Sogar vom Weltraum aus, sieht die Sahara trocken aus!” Taken from the ISS on 6 July 2014. Credit: ESA/Alexander Gerst


Dr. Ken Kremer is a speaker, scientist, freelance science journalist (Princeton, NJ) and photographer whose articles, space exploration images and Mars mosaics have appeared in magazines, books, websites and calanders including Astronomy Picture of the Day, NBC, BBC, SPACE.com, Spaceflight Now and the covers of Aviation Week & Space Technology, Spaceflight and the Explorers Club magazines. Ken has presented at numerous educational institutions, civic & religious organizations, museums and astronomy clubs. Ken has reported first hand from the Kennedy Space Center, Cape Canaveral and NASA Wallops on over 40 launches including 8 shuttle launches. He lectures on both Human and Robotic spaceflight - www.kenkremer.com. Follow Ken on Facebook and Twitter
Tagged as:
alexander gerst,
esa,
International Space Station (ISS),
ISS,
NASA,
Russian Space program,
Soyuz
Posted by Nelio Inacio at 8:38 AM 0 comments

New Horizons Enters ‘Pluto-Space!’ To Celebrate, Here Are Pictures Of The Dwarf Planet

New Horizons Enters ‘Pluto-Space!’ To Celebrate, Here Are Pictures Of The Dwarf Planet:



New Horizons

New Horizons spacecraft. Image Credit: NASA
After almost nine years on the road, New Horizons is in what NASA calls “Pluto-space”! Earlier today (July 7), the spacecraft Twitter account announced New Horizons is now 29.8 Earth-sun distances (astronomical units) away from the Sun, putting it within the boundaries of Pluto’s eccentric orbit — exciting, since Pluto is the primary science target.

“Didn’t get the word? We’re farther out than Pluto’s minimum distance to the Sun. We’re in ‘Pluto-space’ now!” tweeted the New Horizons account. We’ve included some of the best Pluto pictures below, to date, to celebrate.

And while many are focused on the Pluto encounter itself, NASA is already planning for what to do next for the spacecraft. In mid-June, we  reported that the Hubble Space Telescope was doing a test search for icy Kuiper Belt objects that New Horizons could possibly fly to next.

That test search was successful enough, with two objects found, that Hubble is now doing a full-blown investigation, according to an announcement last week. Hubble will begin that work in July and conclude observations in August. New Horizons is expected to fly by Pluto and its moons in July 2015.

Pluto's surface as viewed from the Hubble Space Telescope in several pictures taken in 2002 and 2003. Though the telescope is a powerful tool, the dwarf planet is so small that it is difficult to resolve its surface. Astronomers noted a bright spot (180 degrees) with an unusual abundance of carbon monoxide frost. Credit: NASA

Pluto’s surface as viewed from the Hubble Space Telescope in several pictures taken in 2002 and 2003. Though the telescope is a powerful tool, the dwarf planet is so small that it is difficult to resolve its surface. Astronomers noted a bright spot (180 degrees) with an unusual abundance of carbon monoxide frost. Credit: NASA
Pluto and its moons, most of which were discovered while New Horizons was in development and en route. Charon was found in 1978, Nix and Hydra in 2005, Kerberos in 2011 and Styz in 2012. The New Horizons mission launched in 2007. Picture taken by the Hubble Space Telescope. Credit: NASA

Pluto and its moons, most of which were discovered while New Horizons was in development and en route. Charon was found in 1978, Nix and Hydra in 2005, Kerberos in 2011 and Styz in 2012. The New Horizons mission launched in 2006. Picture taken by the Hubble Space Telescope. Credit: NASA
Pluto and moons Charon, Hydra and Nix (left) compared to the dwarf planet Eris and its moon Dysmonia (right). This picture was taken before Kerberos and Styx were discovered in 2011 and 2012, respectively. Credit: International Astronomical Union

Pluto and moons Charon, Hydra and Nix (left) compared to the dwarf planet Eris and its moon Dysmonia (right). This picture was taken before Kerberos and Styx were discovered in 2011 and 2012, respectively. Credit: International Astronomical Union
Pluto appears as a faint white dot (see arrow) in this image taken by New Horizons in September 2006, nine months after launch. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Pluto appears as a faint white dot (see arrow) in this image taken by New Horizons in September 2006, nine months after launch. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Pluto and Charon are visible in this 2013 image from New Horizons' LOng Range Reconnaissance Imager (LORRI). It was the first image from the spacecraft showing Charon separated from Pluto. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Pluto and Charon are visible in this 2013 image from New Horizons’ LOng Range Reconnaissance Imager (LORRI). It was the first image from the spacecraft showing Charon separated from Pluto. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Tagged as:
New Horizons
Posted by Nelio Inacio at 8:37 AM 0 comments

Sketches of Saturn: Ringed Planet Dances In Raw Cassini Images

Sketches of Saturn: Ringed Planet Dances In Raw Cassini Images:



A hexagonal storm on Saturn rages in this image taken July 2, 2014. Credit: NASA/JPL/Space Science Institute

A hexagonal storm on Saturn rages in this Cassini image taken July 2, 2014. Credit: NASA/JPL/Space Science Institute
We space people are very lucky to get glimpses of Saturn (and other planets!) regularly through the raw images feature on a few spacecraft websites. This allows anyone to get a hold of the pictures as they come back from afar, allowing you to view them or alter them to try and see what they’re all about.

In an era where we are so used to high-definition pictures, examining these blurry, black-and-white shots feels novel. It makes the spacecraft seem like it is action somehow: catching a glimpse of a ringed planet as it swings by, for example.

Enclosed here are some of the latest gifts from the Cassini spacecraft, which is celebrating 10 years in Saturn’s system.

Part of Saturn's rings are visible in this July 2, 2014 image from the cassini spacecraft. Credit: NASA/JPL/Space Science Institute

Part of Saturn’s rings are visible in this July 2, 2014 image from the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute
Gazing at Saturn's rings. Picture taken by the Cassini spacecraft June 30, 2014. Credit: NASA/JPL/Space Science Institute

Gazing at Saturn’s rings. Picture taken by the Cassini spacecraft June 30, 2014. Credit: NASA/JPL/Space Science Institute
A dark shadow falls across Saturn and its rings in this raw image taken by the Cassini spacecraft July 2, 2014. Credit: NASA/JPL/Space Science Institute

A dark shadow falls across Saturn and its rings in this raw image taken by the Cassini spacecraft July 2, 2014. Credit: NASA/JPL/Space Science Institute
Eerie shadows play across Saturn in this Cassini image taken in June 2014. Credit: NASA/JPL/Space Science Institute

Eerie shadows play across Saturn in this Cassini image taken in June 2014. Credit: NASA/JPL/Space Science Institute
Posted by Nelio Inacio at 8:36 AM 0 comments

Voyager 1 Hears Sun Echoes Far Away, In Interstellar Space

Voyager 1 Hears Sun Echoes Far Away, In Interstellar Space:



Artist's concept of Voyager 1 in interstellar space. Credit: NASA/JPL-Caltech

Artist’s concept of Voyager 1 in interstellar space. Credit: NASA/JPL-Caltech
Wow! Even from interstellar space, the plucky Voyager 1 can still listen in to activities from our Sun. Whenever the Sun has a large amount of activity, the waves of energy it sends out bashes into the charged gas particles or plasma surrounding the NASA spacecraft, which has been sailing away from Earth since 1977.

There have been three events so far from our Sun (which is in solar maximum), with each one confirming scientists’ findings that interstellar space is where the spacecraft is, NASA said.

“Normally, interstellar space is like a quiet lake,” stated Voyager project scientist Ed Stone of the California Institute of Technology. “But when our sun has a burst, it sends a shock wave outward that reaches Voyager about a year later. The wave causes the plasma surrounding the spacecraft to sing.”

“The tsunami wave rings the plasma like a bell,” added Stone. “While the plasma wave instrument lets us measure the frequency of this ringing, the cosmic ray instrument reveals what struck the bell — the shock wave from the Sun.”

The discovery of this wave front confirms the previous assertion that Voyager 1 is indeed in interstellar space, NASA added. Winds from the sun push against the plasma at the edge of interstellar space, making it denser (40 times denser than what was measured before Voyager reached the milestone in 2012, in fact.)

NASA’s announcement in 2013 that Voyager 1 is in interstellar space was accompanied by intense discussion about whether it is in or out of the Solar System (it still hasn’t reached the shell of the Oort Cloud that hosts comets, a milestone that won’t be possible for 300 years). Prior to the announcement, several scientific papers had also weighed in on Voyager 1′s status, with some saying it was interstellar space and some not.

Source: NASA

Tagged as:
interstellar space,
plasma
Posted by Nelio Inacio at 8:36 AM 0 comments

Cyclone Spying: 3-D Hurricane View Of Arthur Reveals Rain Towers

Cyclone Spying: 3-D Hurricane View Of Arthur Reveals Rain Towers:



While Hurricane Arthur was still a hurricane, the new Global Precipitation Measurement (GPM) Core Observatory flew over the storm last week and captured its structure in 3-D. This was a good test of the new satellite, which is supposed to help NASA track these Atlantic storms to better precision than before.



Posted by Nelio Inacio at 8:34 AM 0 comments
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