On August 19th, 2015, the HTV-5 spacecraft was launched aboard an H-IIB rocket from the Tanegashima Space Center. It is carrying 4.5 tons of supplies, experiment hardware and spare parts for use on the International Space Station. (Read the Full Story)
Credit: JAXA/NASA
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| NASA’s New Horizons spacecraft obtained this view of Pluto at a distance of about 280,000 miles (450,000 kilometers) on July 14, 2015. Credit: NASA |
NEW YORK — The first-ever flyby of Pluto left scientists and the public wide-eyed, and the surprises will likely keep on coming.
NASA’s New Horizons spacecraft zoomed through the Pluto system on July 14, coming within 7,800 miles (12,500 kilometers) of the dwarf planet’s surface. Images captured by the probe have revealed a world with its own cryogenic geology, situated in a diverse array of moons.
At the American Museum of Natural History here, Emily Rice, an astrophysicist at the College of Staten Island, and Jackie Faherty, an astronomer with the Carnegie Institute, took an audience on a journey with New Horizons last week to highlight the science. [New Horizons’ Pluto Flyby: Complete Coverage]
The Aug. 11 presentation was in the museum’s Hayden Planetarium and used its skylike dome to immerse people in the vastness of space. The show, called “Visiting Pluto and Friends in the 21st Century,” was part of the museum’s “Astronomy Live” series.
Using new visualization technologies, Rice and Faherty offered views of Pluto and its five moons as New Horizons might have seen them and placed the dwarf planet system in relation to the sun and Earth.
Carter Emmart, who directs Astrovisualization at the museum’s Rose Center for Earth and Space, Skyped in from Singapore to show off some of the technology, and to talk about how New Horizons made its way through the Pluto system.
“I’m calling from the future,” he quipped, noting the time difference. (Singapore lies on the other side of the International Date Line.)
The 3D view showed the shadows of Pluto and gave a feel for how the spacecraft was oriented, and how the craft had to move in space to get the pictures that NASA sent around the world.
Rice said the accuracy of the flyby was quite good; the probe arrived within 90 seconds of its targeted time.
“It’s like hitting a hole in one on a golf course in Los Angeles from New York,” she said.
New Horizons also had to navigate among Pluto’s five moons — Charon, Nix, Hydra, Styx and Kerberos. Styx and Kerberos weren’t discovered until 2011 and 2012, when New Horizons was well on its way to Pluto. (The $720 million mission launched in January 2006.)
Later in the show, Rice called up an old artist’s rendering of Pluto, which had been created long before New Horizons’ historic flyby. [Flying Over Pluto: Ice Mountains and ‘Young’ Plains (Video)]
“We were so wrong,” she said. The old picture doesn’t show ice mountains, or even a surface that bears much resemblance to the one New Horizons showed.
Faherty and Rice also demonstrated how New Horizons studied Pluto’s thin atmosphere, using a picture of Pluto “eclipsing” the sun. A hazy ring marked the edge of the dwarf planet, showing that there was some gas diffusing the light. The atmosphere contains methane-based chemicals called tholins.
“The tholins probably rain out,” Faherty said, adding that they are what give Pluto its reddish-brown color.
The big highlight of the mission, though, was finding that Pluto’s surface has been reworked in the recent past — it’s smooth in places, and cratered lightly or not at all. This suggests that some sort of internal heat source remained active until relatively recently, and may still be active today, mission scientists have said.
“But we don’t know what it is,” Faherty said.
Many more pictures are coming from New Horizons; they’ll just take a long time to transmit. Mission team members have said the complete flyby data set probably won’t come down to Earth until late 2016. Emmart said the data-transmission rate is akin to that of a dial-up connection, and New Horizons is a good 3 billion miles (4.8 billion km) from Earth..
Pluto wasn’t the only object that got attention during the planetarium show; Charon did as well. Faherty noted that Charon is “Pluto’s opposite” in that it’s made mostly of water ice rather than mostly rock, methane and nitrogen. She pointed out the tantalizing features that New Horizons saw, such as a large, miles-deep canyon and the dark spot near the moon’s north pole, which has been dubbed Mordor.
The two scientists also mentioned the dwarf planet Ceres, which is currently being studied by NASA’s orbiting Dawn spacecraft. Dawn has spotted intriguing bright spots on Ceres’ surface that could be ice or salts of some sort; Dawn is moving down to a lower orbit to map the surface and get a better look.
Then there is the European Space Agency’s Rosetta mission, which began orbiting Comet 67P/Churyumov–Gerasimenko in August 2014 and dropped a lander named Philae onto the icy object’s surface three months later.
Comet 67P harbored its own surprises. “When they [Rosetta scientists] saw it, they said, ‘Oh damn, it looks like a rubber duck,’” Rice said.
Philae didn’t manage to land in quite the way the mission planners hoped; it actually bounced off the comet twice and came to rest in a place where it couldn’t get as much sunlight as it needed to run its instruments continually.
But Philae did gather data for more than two days on the comet’s surface, and the Rosetta mothership continues to study the object from orbit. Rice showed one photo taken by Philae during its November 2014 descent, at a distance of just 30 feet (9 meters) from 67P’s surface. It showed the place where scientists think the lander initially hit the surface. [Surprising Comet Discoveries by Rosetta and Philae (Infographic)]
Rosetta’s mission will end when the lander is sent into the comet in September 2016. “I would call it crashing; Jackie would call it landing,” Rice said.
Even Mercury got a place in the sun (no pun intended). NASA’s MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) mission, which ended in April of this year, gathered a wealth of new data about the small planet, which is smaller than the Jupiter moon Ganymede, the solar system’s largest satellite.
Rice brought up an emotional moment with one of the mission specialists on MESSENGER. “I asked if he was sad that the mission was over,” she said. “He said he woke up one morning and wanted to look for new images from MESSENGER, and there weren’t any.”
Its fuel tank empty, MESSENGER was deliberately crashed into the planet’s surface on April 30.
The show ended with a journey to the Oort Cloud, a huge comet repository that lies perhaps 2 light-years from the sun. None of the objects that inhabit this distant realm have been imaged yet.
After the presentation, audience members got a chance to ask questions, some about the future of New Horizons. One person asked how long New Horizons would last. Rice noted that the probe’s plutonium power source could keep it going for years yet — perhaps another decade or two. But keeping New Horizons going has less to do with science and engineering than with Earthly politics.
“It’s all dependent on the funding,” Rice said.
Another question was whether New Horizons has solar panels in case it might pass another star. “It would take about 100,000 years for it to get to another star,” Rice said. “And it’s going in the wrong direction.” So the probe wasn’t designed with solar panels.
New Horizons will fly by another object in the Kuiper Belt — the ring of icy bodies beyond Pluto — in 2019 if NASA approves and funds a proposed extended misison.
“Maybe other Kuiper Belt objects won’t be as sexy as Pluto, but who knows?” Rice said.
Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.
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| Diagram of the Lagrange points associated with the sun-Earth system. Credit: NASA / WMAP Science Team |
A Lagrange point is a location in space where the combined gravitational forces of two large bodies, such as Earth and the sun or Earth and the moon, equal the centrifugal force felt by a much smaller third body. The interaction of the forces creates a point of equilibrium where a spacecraft may be “parked” to make observations.
These points are named after Joseph-Louis Lagrange, an 18th-century mathematician who wrote about them in a 1772 paper concerning what he called the “three-body problem.” They are also called Lagrangian points and libration points.
There are five Lagrange points around major bodies such as a planet or a star. Three of them lie along the line connecting the two large bodies. In the Earth-sun system, for example, the first point, L1, lies between Earth and the sun at about 1 million miles from Earth. L1 gets an uninterrupted view of the sun, and is currently occupied by the Solar and Heliospheric Observatory (SOHO) and the Deep Space Climate Observatory.
L2 also lies a million miles from Earth, but in the opposite direction of the sun. At this point, with the Earth, moon and sun behind it, a spacecraft can get a clear view of deep space. NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) is currently at this spot measuring the cosmic background radiation left over from the Big Bang. The James Webb Space Telescope will move into this region in 2018.
The third Lagrange point, L3, lies behind the sun, opposite Earth’s orbit. For now, science has not found a use for this spot, although science fiction has.
“NASA is unlikely to find any use for the L3 point since it remains hidden behind the sun at all times,” NASA wrote on a web page about Lagrange points. “The idea of a hidden ‘Planet-X’ at the L3 point has been a popular topic in science fiction writing. The instability of Planet X’s orbit (on a time scale of 150 years) didn’t stop Hollywood from turning out classics like ‘The Man from Planet X.’”
L1, L2 and L3 are all unstable points with precarious equilibrium. If a spacecraft at L3 drifted toward or away from Earth, it would fall irreversibly toward the sun or Earth, “like a barely balanced cart atop a steep hill,” according to astronomer Neil DeGrasse Tyson. Spacecraft must make slight adjustments to maintain their orbits.
Points L4 and L5, however, are stable, “like a ball in a large bowl,” according to the European Space Agency. These points lie along Earth’s orbit at 60 degrees ahead of and behind Earth, forming the apex of two equilateral triangles that have the large masses (Earth and the sun, for example) as their vertices.
Because of the stability of these points, dust and asteroids tend to accumulate in these regions. Asteroids that surround the L4 and L5 points are called Trojans in honor of the asteroids Agamemnon, Achilles and Hector (all characters in the story of the siege of Troy) that are between Jupiter and the Sun. NASA states that there have been thousands of these types of asteroids found in our solar system, including Earth’s only known Trojan asteroid, 2010 TK7.
L4 and L5 are also possible points for a space colony due to their relative proximity to Earth, at least according to the writings of Gerard O’Neill and related thinkers. In the 1970s and 1980s, a group called the L5 Society promoted this idea among its members. In the late 1980s, it merged into a group that is now known as the National Space Society, an advocacy organization that promotes the idea of forming civilizations beyond Earth.
If a spacecraft uses a Lagrange point close to Earth, there are many benefits to the location, the Jet Propulsion Laboratory’s Amy Mainzer told Space.com.
Mainzer is principal investigator of NEOWISE, a mission that searches for near-Earth asteroids using the Wide-field Infrared Survey Explorer (WISE) spacecraft that orbits close to our planet. While WISE is doing well with its current three-year mission that concludes in 2016, Mainzer said, a spacecraft placed at a Lagrange point would be able to do more.
Far from the interfering heat and light of the sun, an asteroid-hunting spacecraft at a Lagrange point would be more sensitive to the tiny infrared signals from asteroids. It could point over a wide range of directions, except very close to the sun. And it wouldn’t need coolant to stay cool, as WISE required for the first phase of its mission between 2009 and 2011 — the location itself would allow for natural cooling. The James Webb Space Telescope will take advantage of the thermal environment at the sun-Earth L2 point to help keep cool.
L1 and L2 also “allow you to have enormous bandwidth” because over conventional Ka-band radio, the communication speeds are very high, Mainzer said. “Otherwise, the data rates just become very slow,” she said, since a spacecraft in orbit around the sun (known as heliocentric orbit) would eventually drift far from Earth.
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| An illustration depicts NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft in orbit above the moon. Credit: NASA Ames/Dana Berry |
The moon doesn’t have any gaudy casinos or buzzing diner signs, but it does have neon.
NASA’s LADEE spacecraft has made the first-ever detection of neon in the wispy lunar atmosphere, which is properly known as an “exosphere” because it’s so thin — about 100 trillion times less dense than that of Earth at sea level.
“The presence of neon in the exosphere of the moon has been a subject of speculation since the Apollo missions, but no credible detections were made,” study lead author Mehdi Benna, of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland, Baltimore County, said in a statement. “We were very pleased to not only finally confirm its presence, but to show that it is relatively abundant.” [The Moon: 10 Surprising Lunar Facts]
But the gas is not abundant enough on the moon to generate the famous neon glow, NASA officials said.
LADEE — which is short for Lunar Atmosphere and Dust Environment Explorer — studied the moon’s exosphere from orbit for seven months, from September 2013 through the end of its mission in April 2014.
The spacecraft’s Neutral Mass Spectrometer (NMS) instrument determined that the moon’s atmosphere is composed mainly of helium, argon and neon. Most of this material comes from the solar wind, a diverse stream of particles flowing from the sun at about 1 million mph (1.6 million km/h). (Other elements in the solar wind tend to stick to the lunar surface, because they’re more volatile than helium, argon and neon, NASA officials said.)
But the NMS data showed that some of the exospheric gases come from moon rocks, via the process of radioactive decay. About 20 percent of the helium probably came from the decay of uranium and thorium, and some of the argon from the decay of potassium-40 into argon-40, researchers said.
“We were also surprised to find that argon-40 creates a local bulge above an unusual part of the moon’s surface, the region containing [the dark volcanic plains] Mare Imbrium and Oceanus Procellarum,” Benna said. “One could not help [but] notice that this region happens to be the place where potassium-40 is most abundant on the surface. So there may be a connection between the atmospheric argon, the surface potassium and deep interior sources.”
LADEE’s measurements also revealed that argon abundance changed by about 25 percent over the course of the spacecraft’s mission, possibly as a result of outgassing caused by the Earth’s strong gravitational tug, researchers said.
The new results, which were published May 28 in the journal Geophysical Research Letters, should give scientists a better understanding of exospheres in general, and that of the moon in particular, researchers said.
“It’s critical to learn about the lunar exosphere before sustained human exploration substantially alters it,” Benna said.
Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.
If the fictional USS Enterprise raced the ship from “Battlestar Galactica” to the nearest star system, which would get there first?
A new graphic from Travelmath.com seeks to answer that question, which sounds like a typical opening argument over beers. The graphic shows fictional travel times across the universe for spaceships from several sci-fi franchises as well as comic-book characters such as Iron Man and Superman.
When leaving Earth on a voyage to Alpha Centauri, it turns out, Galactica would get there in just 29 minutes, traveling at an average speed of 53.4 trillion miles per hour (85.9 trillion kilometers per hour). The USS Enterprise from “Star Trek” would take more than 161 days, at a speed of “just” 6.6 billion mph (10.6 km/h). [The 10 Greatest Sci-Fi Spaceships of All Time]
To calculate the blazing-fast speeds for the various characters and spaceships portrayed, Travelmath.com consulted online fan encyclopedias from different franchises. You can actually race the sci-fi spaceships and fliers on Travelmath.com to see who wins, with each race accompanied by its own animation.
From the Milky Way to Andromeda, the graphic pits three famous ships from the Star Wars universe: the Death Star, the Millennium Falcon and the X-Wing. It turns out to be not much of a contest, with the Millennium Falcon getting there in 100 days, two times faster than the X-Wing and eight times faster than the Death Star.
Regardless, the superhero Dr. Manhattan from the comic miniseries “Watchmen” could beat all three of them, according to the graphic, because his travel is instantaneous.
The graphic also claims that Superman would beat “Firefly’s” Serenity ship in a race from Earth to Neptune (4 hours as opposed to 42 days), and Iron Man could get around the world in 3 hours — 10 times faster than a TIE fighter from “Star Wars.”
Travelmath is a service that offers information on travel distance, travel time and travel cost between Earth destinations, including flight and driving times. For real-life fliers, such as F-16 jets and passenger planes, the site uses information from aircraft manufacturers’ websites.
Follow Elizabeth Howell @howellspace, or Space.com @Spacedotcom. We’re also on Facebook and Google+. Original article on Space.com.
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| NASA photo ISS044-E-45576 showing storms over southern Mexico on Aug. 10, 2015. Credit: NASA |
Editor’s note: Updated to include a second photo of another sprite captured moments later by the same camera (added at bottom of article).
This gorgeous photo, captured from the International Space Station on the night of Aug. 10, 2015, shows an orbital view of thunderstorms over the city lights of southern Mexico as a recumbent Orion rises over Earth’s limb. But wait, there’s more: along the right edge of the picture a cluster of bright red and purple streamers can be seen rising above a blue-white flash of lightning: it’s an enormous red sprite caught on camera!
PHOTOS: Chasing Red Sprites and Blue Jets
First photographed in 1989, red sprites are very brief flashes of optical activity that are associated with powerful lightning. So-called because of their elusive nature, sprites typically appear as branching red tendrils reaching up above the region of an exceptionally strong lightning flash. These electrical discharges can extend as high as 55 miles (90 kilometers) into the atmosphere, with the brightest region usually around altitudes of 40–45 miles (65–75 km).
Sprites don’t last very long — 3–10 milliseconds at most — and so to catch one (technically here it’s a cluster of them) on camera is a real feat… or, in this case, a great surprise!
PHOTO: Mysterious Sprite Photographed by ISS Astronaut
Sprites have been photographed from the ISS before (it’s a great place from which to observe these phenomena, which are often obscured from the ground by storm clouds) but this is one of the best images of one I’ve seen yet.
ANALYSIS: Origin of Mysterious Jellyfish Lightning ‘Sprites’ Revealed
(And in case you’re wondering that’s the moon (not the sun) shining brightly in the star-filled sky, and the yellow-green light surrounding the planet isn’t aurora — it’s a different phenomena called airglow.)
Learn more about the history of sprite research at the University of Alaska Fairbanks website.
UPDATE (11:50 p.m. ET): Just a few minutes earlier the same storm had created another sprite outburst, which was amazingly also captured on camera as the ISS was moving southeast:
This article was provided by Discovery News.
From his backyard in Östersund, Sweden, professional photographer and astrophotographer Göran Strand took a look at the sun using his portable solar telescope “to see if something interesting was going on.” And sure enough, there was something VERY interesting going on. Something was towering over the solar disk — something that looked like… the Eiffel Tower?
Of course, this isn’t the famous Parisian landmark, nor is it some Photoshop trickery; the structure Strand had spotted was a solar prominence, and a beautiful one at that.
PHOTOS: Simmering Solar Views from SDO
“This big prominence got my attention right away, even in my small 50mm telescope it was a beautiful sight,” Strand told Discovery News via email. “While setting up my bigger solar telescope I thought of how the prominence looked and that it reminded me of the Eiffel Tower in Paris.”
Using a larger Lunt 80mm hydrogen alpha pressure-tuned solar telescope hooked up to a Point Grey Grasshopper 3 camera, he captured a thousand photos and stacked the best 300 shots to produce this mesmerizing solar portrait:
In the final image, the size of the Earth has been added to give a sense of scale. A rough comparison suggested that this prominence is approximately 7-Earth diameters high, reaching high into the sun’s atmosphere (the corona).
NEWS: Sun Unleashes Spectacular Solar Eruption
Prominences are large structures of magnetized plasma that can erupt from the sun’s chromosphere and arc high into the corona. As the plasma in the sun’s corona can have temperatures exceeding a million degrees Kelvin (Celsius), the plasma in prominences can be a hundred times cooler, at a similar temperature to the chromosphere.
As they are cooler than the surrounding corona, they generate visible light and can therefore be spotted fairly easily though specialized equipment such as solar telescopes and eclipse glasses. (NOTE: Never look directly at the sun as serious eye injuries and even blindness can result.)
Also, as the sun is rich in ionized hydrogen, astronomers use hydrogen alpha (or H-α) filters to produce observations of stunning detail of prominences and chromospheric features on the solar disk.
PHOTOS: The Psychedelic Anatomy of a Solar Flare
For more of Strand’s outstanding work, check out his website, Instagram, Twitter and Facebook.
Originally published on Discovery News.
This stunning image of an aurora was taken was taken in Norstead, a Viking village replica.
The Norstead Viking Village in L’anse aux Meadows, Newfoundland is the only confirmed Viking site in North America. Astrophotographer Adam Woodworth took the image on June 22 while visiting the area.
“The aurora was coming from all directions it seemed like, this was the first time I’d witnessed a strong aurora display so far north. L’anse aux Meadows is near the northern most tip of Newfoundland, certainly the farthest north I’ve ever been. An experience I’ll never forget!” Woodworth wrote in an email to Space.com. [Amazing Aurora Photos of 2015]
The image also shows Viking building replicas made out of sod and wood. Woodworth’s image is a blend of two exposures for depth of field. He used a Nikon D810A, Nikon 14-24mm f/2.8 lens. The sky view was created with a single shot set at ISO 3200, 14mm, f/2.8, with a 1-second exposure. The foreground was then taken as a single shot at ISO 1600, 14mm, f/5.6, with a 2-minute exposure.
Auroras occur when charged particles from the sun’s solar wind interact with Earth’s upper atmosphere (at altitudes above 50 miles, or 80 km), causing a glow. The particles are funneled to Earth’s polar regions by the planet’s magnetic field. The auroras over the North Pole are known as the aurora borealis, or the northern lights. The lights over the South Pole are dubbed the aurora australis, or southern lights.
To see more amazing night sky photos submitted by SPACE.com readers, visit our astrophotography archive.
Editor’s note: If you have a night sky photo you’d like to share for a possible story or image gallery, send images and comments in to Space.com at spacephotos@space.com.
Follow Space.com on Twitter @Spacedotcom. We’re also on Facebook & Google+. Original story at Space.com.
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| The image that accompanied the “Mars Spectacular” email of 2003, which sparked the recurring Mars Hoax. Credit: Origin Unknown |
Here we go again.
The infamous Mars Hoax that has circulated widely through the Internet since its first appearance in 2003, when it originated in the form of an email message titled “Mars Spectacular,” has reared its ugly head yet again.
The unknown source behind that 2003 email was likely honestly and earnestly trying to provide some interesting information to the general public in advance of a historically close approach of Mars to the Earth in late August 2003. [Quiz: Mars Myths and Misconceptions]
Unfortunately, the message ended up giving countless people the wrong impression of what was to be seen in the night sky. The confusion arose from the following passage in the “Mars Spectacular” email:
“The encounter will culminate on Aug. 27 when Mars comes to within 34,649,589 miles (55,763,108 kilometers) of Earth and will be (next to the moon) the brightest object in the night sky. It will attain a magnitude of -2.9 and will appear 25.11 arc seconds wide. At a modest 75-power magnification, Mars will look as large as the full moon to the naked eye. Mars will be easy to spot.”
Many people, it seems, glossed over the words, “At a modest 75-power magnification” — partly because the email featured a line break just after this phrase — and fixated solely on “Mars will look as large as the full moon to the naked eye” (without realizing a telescope would be needed to pull of this trick).
Of course, the message immediately went viral and was passed on to countless others who couldn’t resist forwarding it to their entire address book. Thus, the Mars Hoax was born. [7 Biggest Mysteries of Mars]
And ever since, it has been all but impossible to get the proverbial genie back in the bottle.
The “Mars Spectacular” message was meant to apply only to August 2003, although every year since, during the month of August, the message has resurfaced and has propagated through cyberspace on to many other unsuspecting individuals. It amazes me that the hoax keeps drawing people in 12 years after it first emerged.
To give you an idea of just how prevalent the Mars Hoax has become, consider this story:
Back on Aug. 27, 2007, one of nature’s great sky shows, a total eclipse of the moon, occurred across the United States. On the day before the eclipse, the people who run the “answer line” at New York City’s Hayden Planetarium expected a heavy volume of phone inquiries from the general public concerning advice on how to view the eclipse. Fifty-one calls were logged that day, but amazingly, only three concerned the upcoming eclipse; the other 48 were calls asking about how to see Mars when it was due to appear as large as the full moon!
Mars Myths & Misconceptions: Quiz
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Interestingly, most of the original email message is substantially correct (for 2003). But there were also a few inaccuracies. For instance, after 2003, the next time that Mars will come closer to Earth will be in 2287, not 60,000 years from now. (The message confusingly implies that both of those figures are accurate.) And the 2003 rendezvous marked the closest Mars had come to Earth in more than 59,000 years, not merely 5,000 years.
Furthermore, in 2003, Mars was not the brightest object in the night sky other than the moon. That honor went to Venus. In fact, even at its very brightest, Mars was a full magnitude fainterthan Venus.
And even at its brightest, Mars appeared to the naked eye as nothing more than an extremely bright, yellowish-orange star, not at all like the full moon!
So if you have already received this infamous Mars email, or if you receive it in the coming days, delete it!
In fact, why not take a few moments and forward this column to all those in your address book? Think of it as an antidote to the Mars Hoax virus.
This month, Mars is much dimmer and far less conspicuous than it was in August 2003. The Red Planet is 239 million miles (385 million km) from Earth, nearly seven times farther away than it was a dozen years ago. And at magnitude +1.7, Mars is about 70 times fainter compared to 2003, so you actually might need binoculars to pick up the planet in the twilight sky.
Currently, Mars is very slowly becoming evident in the dawn sky. It is rising 90 minutes before the sun. Search in the east-northeast sky, below the stars Castor and Pollux in Gemini.
In terms of actual size, Mars is almost twice as big as the moon — about 4,213 miles (6,780 km) in diameter, compared to 2,160 miles (3,475 km) for the moon.
But the great distance between Mars and Earth means that the Red Planet never appears anywhere near as large as the moon in Earth’s sky. The average distance of the moon from Earth is 238,000 miles (382,900 km). For Mars to appear to loom as large as the moon does from Earth, it would have to be a mere two Earth-moon distances away, or roughly 476,000 miles (766,000 km).
Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmer’s Almanac and other publications, and he is also an on-camera meteorologist for News 12 Westchester, N.Y. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.
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| On Jan. 7, 2014, the sun unleashed a major solar flare and coronal mass ejection (the bright spot at center right), but the Earth’s magnetic field channeled the worst of the solar storm away from the planet, scientists say. Credit: Möstl et al., Nature Communications |
This article was originally published on The Conversation. The publication contributed this article to Space.com’s Expert Voices: Op-Ed & Insights.
The Earth’s magnetic field – known as the “magnetosphere” – protects our atmosphere from the “solar wind.” That’s the constant stream of charged particles flowing outward from the sun. When the magnetosphere shields Earth from these solar particles, they get funneled toward the polar regions of our atmosphere.
As the particles crash into the atmosphere’s ionospheric layer, light is given off, creating beautiful multicolored displays of aurora near both the North and South Poles. These are stunning visual representations of the complex interactions in the near-Earth space environment, which we collectively term “space weather.”
The same space weather that generates these beautiful displays can cause havoc for a wide range of technologies. We’ve known for a while that space weather in high-latitude regions near the poles can cause power grid failures, sometimes causing heavy damage. The most famous instance was the March 1989 blackout in the Northeastern US and up through Quebec, Canada that left millions without power for 12 hours.
But we haven’t thought of equatorial regions as being prime targets. Our new research shows that areas closer to the equator still experience bad space weather – and its disturbing effects on power grid infrastructure.
High above the ground in the upper atmosphere are fluctuating electric currents driven by interactions in the magnetosphere and ionosphere. These atmospheric currents cause strong changes in the strength of the local magnetic field on the ground. We can’t feel the magnetic field ourselves, but researchers measure and track it at various points on the Earth’s surface.
That’s all well and good. The problem comes in when these atmospheric currents cause swift changes in the magnetic field. When the magnetic field abruptly changes, it can generate electric currents in conductors at the Earth’s surface – for instance, long pipes or wires such as oil and gas pipelines or power transmission lines. This process of electric current generation is called magnetic induction.
These electric currents are not-so-creatively called geomagnetically induced currents, or GICs for short. The high-latitude regions are most susceptible to GICs because of the intense electric currents flowing through the auroras, thanks to the way the solar wind gets diverted when it hits the Earth’s magnetosphere. However, the entire planet can be affected to varying degrees.
When they occur, GICs effectively generate extra electric current in power grid infrastructure through magnetic induction. Power grids, during large events, can end up taking on more electricity than they can handle. These induced currents have caused numerous equipment failures that have led to power outages for large populations.
Those same geomagnetically induced currents that happen in the high-latitude regions can happen around the equator of our planet too. There, they are caused not by the auroral electric current system we find near the poles, but by a weaker low-latitude counterpart called the equatorial electrojet. Like the high-latitude ionospheric current system, the equatorial electrojet’s electric current can be detected on the ground using magnetic field observations.
Recently researchers reported that GIC activity is enhanced at the equator during severe geomagnetic storms – that’s when solar eruptions called “coronal mass ejections” trigger shock waves that hit the Earth. They pointed the finger at the equatorial electrojet as a suspected cause.
In our new research article in Geophysical Research Letters, we show that countries near the magnetic equator are more vulnerable to space weather than previously thought.
Rather than focusing on severe geomagnetic storms, such as the 2003 Halloween event that caused power grid problems in Sweden (among many other things), we took a different tack. Our analysis focused on the arrival of interplanetary shocks. These are abrupt pressure increases in the solar wind – that stream of plasma constantly flowing out of the sun. When these shocks hit the Earth’s magnetosphere, the impact causes a sudden magnetic field change that can be measured all over the world.
Interplanetary shocks regularly announce the beginning of a geomagnetic storm. But many pass by relatively benignly without developing into a full-blown geomagnetic storm. We noticed that the magnetic response to these shock arrivals was sometimes significantly stronger at the magnetic equator when compared to locations only a few degrees away. Why?
An analysis of how these equatorial responses differed throughout the day revealed they were strongest around noon and weakest at night. This daily contrast corresponds to the well-known variations in the equatorial electrojet. It’s strong evidence that the equatorial electrojet is amplifying the geomagnetically induced current activity during interplanetary shock arrivals in a way that hasn’t really been recognized until now.
This result has significant implications for the many countries located beneath the equatorial electrojet that may be operating power infrastructure not initially designed to cope with space weather. These countries need to look into ways of protecting their infrastructure during geomagnetically quiet periods as well as during severe geomagnetic storms.
One of our coauthors, Dr Endawoke Yizengaw from Boston College, grew up in Ethiopia, within the equatorial electrojet’s region of influence. He recalls regular unexplained power outages during his childhood and wonders whether interplanetary shocks may have played a role. We hope to be able to answer this question in the near future.
Scientists around the world are conducting ongoing research to better understand the effects of these geomagnetically induced currents on power grids. It’s becoming increasingly clear that we need to investigate the effects of quiet periods, not just major events. What happens during these quiet times, and in regions often overlooked, can have a significant impact on our increasingly technology-dependent society.
Brett Carter is Research Scientist in Space Weather and Ionospheric Physics at Boston College and Alexa Halford is Postdoctoral Research Associate in Physics and Astronomy at Dartmouth College
This article was originally published on The Conversation. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Space.com.
Dr. Schnittman finds poetry in the notion that two invisible entities could interact to shed light on one another.
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| Artist’s concept of the Thirty Meter Telescope atop the volcanic peak of Mauna Kea in Hawaii. The construction phase of the TMT project officially kicked off in October 2014; the telescope should achieve “first light” in 2022, if all goes according to plan. Credit: Courtesy TMT International Observatory |
The group building a huge telescope on Hawaii’s tallest mountain plans to restart construction this week, ending a two-month delay caused by protestors opposed to the ambitious project.
Construction of the Thirty Meter Telescope (TMT) on Hawaii’s Mauna Kea volcano — work that was halted in April after a series of protests—will resume on Wednesday (June 24), project representatives said in a statement issued over the weekend.
“Our period of inactivity has made us a better organization in the long run,” Henry Yang, chair of the TMT International Observatory Board, said in the statement. “We are now comfortable that we can be better stewards and better neighbors during our temporary and limited use of this precious land, which will allow us to explore the heavens and broaden the boundaries of science in the interest of humanity.” [The Biggest Telescopes on Earth: How They Measure Up]
Construction of the $1.4 billion TMT began in October near the top of Mauna Kea, which rises 13,796 feet (4,205 meters) into the sky from the Big Island of Hawaii. The TMT will link up 492 small, hexagonal mirrors to form a giant light-collecting surface 98 feet (30 m) wide.
Once complete in the early 2020s, the observatory will return images 10 times sharper than those captured by NASA’s iconic Hubble Space Telescope, TMT representatives have said. Astronomers will put the telescope to a number of uses: searching for and characterizing exoplanets, for example, and investigating the nature of mysterious dark matter and dark energy. (Two other huge, ground-based scopes — the Giant Magellan Telescope and the European Extremely Large Telescope — should come online in Chile at about the same time as TMT, and do similar work.)
But not everybody is enamored with the TMT. Native Hawaiians regard the peaks of mountains throughout the island chain as sacred, and Mauna Kea may be the most sacred one of all.
So building another telescope on this dormant volanco, which already houses a number of observatories, has been controversial from the start. For instance, protestors disrupted the TMT’s groundbreaking ceremony in October, and further demonstrations in March and April resulted in a number of arrests and eventually halted construction altogether.
In his statement, Yang said TMT representatives are “mindful of those who have concerns, and yet, we hope they will permit us to proceed with this important task while reserving their right to peaceful protest.” But another showdown appears to be looming Wednesday.
“By proceeding with the project, the TMT officials neglect to acknowledge and act on the concerns of citizens of Hawai’i who have voiced their strong disapproval of the project. This action further demonstrates the lack of respect that the State of Hawai’i and project officials have for Native Hawaiians and their culture, in addition to the health and well-being of the people and the environment,” members of the group Idle No More Mauna Kea wrote in a Facebook post Sunday (June 21).
“Members of the global Mauna Kea ‘Ohana [family] are asked to lift prayers, songs and chants for our mauna [mountain] and those who will be standing physically on the mauna,” they added. “Those who are on island and plan to be on the mauna Wednesday morning are asked to bring their highest selves to protect the mauna and stand with compassion, patience, love and forgiveness in their hearts. Bring digital cameras, phones and video cameras to the mauna to document the day as it unfolds.”
Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.
Early summer is an “in-between” time in the skies. The realm of the galaxies has moved off to the west, but the summer Milky Way has not yet arrived. This is the best time of year to observe globular clusters and double stars.
The centerpiece of the early summer constellations is Boötes, the herdsman, with the bright star Arcturus at his heart. Arcturus is easy to find by following the “arc” of the Big Dipper’s handle away from the ladle: it is the only bright star in this part of the sky. Alternately, if you live in the Northern Hemisphere, simply look straight overhead around 11 p.m. your local time.
Although Boötes looks like it might be pronounced like “booties,” the diaeresis (double dot) over the second “o” gives you a clue: the two “o”s are pronounced separately: Boh-OO-tes. Its stars form a distinctive kite shape, complete with tail. [The Brightest Stars in the Night Sky]
Arcturus is the third brightest star in the night sky, after Sirius and Canopus. It is relatively close to us, only 37 light-years distant. It is an orange giant star, slightly cooler than the sun, but quite a bit larger in diameter.
Boötes contains relatively few deep sky objects, but is rich in double and variable stars. Izar (Epsilon Boötis) is one of the finest double stars in the sky. With a separation of only 2.9 arc seconds, it requires at least 3 inches aperture, steady skies, and high magnification to see its duality; its stars are gold and greenish in colour. Alkalurops (Mu Boötis) is a much wider double at 2 arc minutes separation, but it is a challenge to see that one of its stars is itself a double.
Although not within Boötes itself, most amateur astronomers use the stars of Boötes to star-hop to the Messier globular cluster Messier 3 in the dim constellation of Canes Venatici. M3 forms an almost perfect equilateral triangle with Arcturus and Rho Boötis. This is one of the finest globular clusters in the sky.
Just to the left (east) of Boötes is a small circlet of stars forming Corona Borealis, the northern crown. Look within the circle to see if you can see R Corona Borealis, a very unusual variable star. Some have called this an “inverse nova.” Most of the time, it shines steadily with a brightness of about magnitude 7, just below naked eye visibility, but easily seen in binoculars. At long and irregular intervals, instead of brightening like a nova, it dims by about 6 magnitudes. This dimming is caused by occasional expulsion of a dark obscuring cloud of dust. Currently R is entering its dark phase, but keep watching, and it should soon reappear.
Constellation Quiz: What’s Your Cosmic IQ?
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Below Corona Borealis is one of the most unusual constellations, or rather “half constellations.” Serpens represents a snake cut in half, each half held in one hand of Ophiuchus. This is the front half: Serpens Caput, or the head of the serpent. The other half, located quite a ways to the east, is Serpens Cauda, the tail of the Serpent. A triangle is supposed to represent the head of the spent, but I always see this and the two stars above as a large “X.”
The brightest star in Serpens bears the ugly name Unukalhai, which is Arabic for “the serpent’s neck.” Just above Unukalhai is Delta Serpentis, a fine pair of pale yellow stars in a telescope.
But the real prize in Serpens Caput is the globular cluster Messier 5, every bit as fine as Messier 3 to the northwest. Like all globular clusters, M5 responds well to aperture and magnification. Besides resolving the cluster into myriads of tiny stars, a large telescope will reveal chains of stars and clusters within the cluster.
This article was provided to SPACE.com by Simulation Curriculum, the leader in space science curriculum solutions and the makers of Starry Night and SkySafari. Follow Starry Night on Twitter @StarryNightEdu. Follow us @Spacedotcom, Facebookand Google+. Original article on Space.com.
