Two Asteroids To Swing Past Earth Today

Experts at a NASA lab announce that two asteroids will pass close to our planet today, September 8. The two space rocks are in unrelated orbits, the team says, and pose no danger to Earth.

Each of the celestial bodies is a few meters in diameter, and wouldn't have caused any major damage if they were to strike anyway. What's interesting is that they will both move past the planet the same day, even if they come from very different orbits.

The attached graphic reveals the paths that the two asteroids will take as they swing past Earth. When they are nearest, they should become visible to amateur astronomers with moderate-sized telescopes.

Objects of this class, 10-meter-sized near-Earth asteroids, have a very small chance of hitting the planet overall, but a high chance of passing within lunar distance.

In fact, this happens once per day on average. Such a boulder slams into the atmosphere and burns up about once every 10 years.

Astronomers estimate that the undiscovered population of NEO orbiting the solar system in our vicinity could number as much as 50 million members.

The two new objects were discovered on Sunday, September 5, by the Tucson, Arizona-based Catalina Sky Survey, experts at the NASA Jet Propulsion Laboratory (JPL) announce.

“Near-Earth asteroid 2010 RX30 is estimated to be 32 to 65 feet (10 to 20 meters) in size and will pass within 0.6 lunar distances of Earth (about 154,000 miles, or 248,000 kilometers) at 2:51 am PDT (5:51 a.m. EDT) Wednesday,” the team explains.

“The second object, 2010 RF12, estimated to be 20 to 46 feet (6 to 14 meters) in size, will pass within 0.2 lunar distances (about 49,088 miles or 79,000 kilometers) a few hours later at 2:12 pm PDT (5:12 pm EDT),” they add.

Keeping an eye on NEO is extremely important, given the large number of unknown space rocks that lurk in outer space. On top of that, our solar system features two asteroid belts.

Dangerous objects may exist in both of them, and more telescopes should be built to try and detect, identify and analyze them.

NASA's Spitzer and WISE have already been conducting such research for some time, but the sheer volume of work to be done is massive.

Santa Fe Was Impacted by Huge Asteroid

Between 1.2 billion and 330 million years ago, the area near Santa Fe, New Mexico, was the site of a major asteroid impact. The conclusion belongs to a new study, which looked at an exposed mountain wall. The feature exposes a number of rock layers that look all the same to the eye of profane individuals, but which provide geologists with a wealth of data about Earth's distant past. It is estimated that the original impact crater was no less than between 6 and 13 kilometers in diameter, Space reports.

The reason why the timing of the impact cannot be determined with more accuracy is an anomaly known as the “Great Unconformity.” This means that the rock layers corresponding to the period stretching between 1.2-1.6 billion years and 330 million years ago are missing. This may have happened for a variety of reasons, but the leading theory is that a sea existed at this location a long time ago. This and other natural factors such as water receding, erosion, winds and so on, destroyed the rocks, which only began depositing ago when seas moved back on, 330 million years ago.

It was then that the first sediments were laid down again. This is why 1.2 billion year old layers of rock now lie directly underneath much newer ones. “We need an army of scientists and graduate students studying this site, over many, many years. It could take several lifetimes to do all the necessary work,” says University of New Mexico Institute of Meteoritics expert Horton Newsom. He conducted the work with colleagues Shawn Wright and Wolf Elston. He says that the team was amazed to learn that the rock layers are exposed directly.

This means that the team no longer needs digs in order to analyze the past events, just a lot of patience. “Such impact crater cross-sections are extremely rare in the world,” the expert says. He adds that the crater has long since been eroded entirely, but argues that additional studies of the site would help experts gain additional insights into how the impact affected the rocks underneath. The group will continue working in Santa Fe, with hopes that the actual size of the impact crater, as well as its age, will be accurately established.

GOES-15 Snaps First Infrared Images

NOAA's newest Geostationary Operational Environmental Satellite (GOES-15) took its first Imager full-disk infrared image of the Earth on April 26

Experts at NASA and the US National Oceanic and Atmospheric Administration (NOAA) announce that their newest orbital satellite has finally opened its infrared “eyes” a couple of days ago. The group says that the Geostationary Operational Environmental Satellite (GOES-15) took the first images of our planet in these wavelengths from its vantage point, some 22,236 miles above the surface, on April 26.

The infrared equipment on GOES-15 is of tremendous practical importance, especially to meteorologists and weather forecasters. Observing the planet in these wavelengths enables these experts to gain more data on temperatures on the ground, in the sea and in the air, as well as to derive various other data. For example, they can calculate wind, temperature and moisture profiles for the atmosphere, and can observe how smoke plumes – such as those from volcanic eruptions – migrate across the surface of the planet. The IR instruments can also be used to monitor wildfires, experts add.

“This (image) marks the final stage of the critical events for the spacecraft and indicates that the visible and infrared spacecraft imaging instruments are performing as expected. We’re looking forward to more imagery as we finish up post-launch testing,” explains the NASA GOES deputy project manager, Andre Dress. The expert is based at the space agency's Goddard Space Flight Center (GSFC), in Greenbelt, Maryland. The new picture was snapped using the multi-channel GOES Imager instrument, Space Fellowship reports.

Another instrument that can produce advanced-quality infrared data is the GOES Sounder. Using datasets this payload collects, mathematicians can apply analysis technique to determine surface and cloud-top temperatures, as well as ozone distribution, temperature and moisture profile across the planet's atmosphere. The first infrared information came from GOES less than three weeks after the satellite relayed its first visible-light images of Earth, on April 6. The space craft was launched on March 4 this year, from the Cape Canaveral Air Force Station (CCAFS) Space Launch Complex 37, in Florida.

NOAA and NASA began verifications of GOES-15's systems on March 24. The procedures will last for about 150 days, after which time NASA will hand over operational control of the spacecraft to NOAA.

In pictures: Satellite eye on Earth - March 2010

Sandstorms in China, dark days in Dakota and hydrogen sulphide eruption along the coast of Namibia - this month's stunning shots from space

Read the whole article on The Guardian - Science

GOES-15 Opens Its 'Eyes' and Sees First Image of Earth

NOAA's newest Geostationary Operational Environmental Satellite - GOES-15 - took its first full-disk visible image of the Earth on April 6 at 17:33 UTC (1:33 p.m. EDT). Credit: NASA/NOAA/SSEC

From approximately 22,236 miles in space, NASA and the National Oceanic and Atmospheric Administration's (NOAA) newest Geostationary Operational Environmental Satellite - GOES-15 - took its first full-disk visible image of the Earth on April 6 starting at 17:33 UTC (1:33 p.m. EDT).

The black and white full-disk image showed North and South America. Draped across the U.S. was a stationary front, indicated by a drape of clouds from New England westward to Kansas, where a low pressure area is located. West of the low is an approaching cold front which lay over the Rocky Mountains, bringing snow to parts of Wyoming, Idaho and Montana. Mostly clear skies are seen over Washington, D.C. and the Chesapeake Bay, the southeastern U.S., Gulf of Mexico, California and Mexico.

GOES-15, launched on March 4, 2010, from Cape Canaveral, Fla., joins three other NOAA operational GOES spacecraft that help the agency's forecasters track life-threatening weather and solar activity that can impact the satellite-based electronics and communications industry. After five more months of tests, GOES-15 will be placed in orbital storage mode, ready for activation if any of NOAA's operational GOES spacecraft experiences trouble.

GOES-15 is the third and final spacecraft to be launched in the GOES N-P Series of geostationary environmental weather satellites. With two operational satellites, they provide weather observations that cover over 50 percent of the Earth's surface.

NASA's GOES Project is located at NASA's Goddard Space Flight Center, Greenbelt, Md. On March 24 the NASA and NOAA team began post launch verification testing, which will last for approximately 150 days. Once all the systems are checked out, the satellite will be turned over to NOAA for operational control and will be stored in-orbit, ready for activation should one of the operational GOES satellites degrade or exhaust their fuel.

New Evidence of Ice Age Comet Found in Ice Cores

A new study cites spikes of ammonium in Greenland ice cores as evidence for a giant comet impact at the end of the last ice age, and suggests that the collision may have caused a brief, final cold snap before the climate warmed up for good.

In the April Geology, researchers describe finding chemical similarities in the cores between a layer corresponding to 1908, when a 50,000-metric-ton extraterrestrial object exploded over Tunguska, Siberia, and a deeper stratum dating to 12,900 years ago. They argue that the similarity is evidence that an object weighing as much as 50 billion metric tons triggered the Younger Dryas, a millennium-long cold spell that began just as the ice age was loosing its grip (SN: 6/2/07, p. 339).

Precipitation that fell on Greenland during the winter after Tunguska contains a strong, sharp spike in ammonium ions that can’t be explained by other sources such as wildfires sparked by the fiery explosion, says study coauthor Adrian Melott, a physicist of the University of Kansas in Lawrence.

The presence of ammonium suggests that the Tunguska object was most likely a comet, rather than asteroids or meteoroids, Melott says. Any object slung into the Earth’s atmosphere from space typically moves fast enough to heat the surrounding air to about 100,000° Celsius, says Melott, so hot the nitrogen in the air splits and links up with oxygen to form nitrates. And indeed, nitrates are found in snow around the Tunguska blast. But ammonium, found along with the nitrates, contains hydrogen that most likely came from an incoming object rich in water — like an icy comet.

More than a century after the impact, scientists are still debating what kind of object blew up over Tunguska in 1908. They also disagree about whether an impact or some other climate event caused the Younger Dryas at the end of the ice age. But the presence of ammonium in Greenland ice cores at both times is accepted.

“There’s a remarkable peak of ammonium ions in ice cores from Greenland at the beginning of the Younger Dryas,” comments Paul Mayewski, a glaciologist at the University of Maine in Orono who was not involved in the new study. The new findings are “a compelling argument that a major extraterrestrial impact occurred then,” he notes.

Whenever a comet strikes Earth’s atmosphere, it leaves behind a fingerprint of ammonium, the researchers propose. Immense heat and pressure in the shock wave spark the creation of ammonia, or NH3, from nitrogen in the air and hydrogen in the comet. Some of the ammonium, or NH4+, ions generated during subsequent reactions fall back to Earth in snow and are preserved in ice cores, where they linger as signs of the cataclysmic event.

Although an impact big enough to trigger the Younger Dryas would have generated around a million times more atmospheric ammonia than the Tunguska blast did, the concentrations of ammonium ions in the Greenland ice of that age aren’t high enough.

But the relative dearth of ammonium in the ice might simply be a result of how the ice cores were sampled, Melott and his colleagues contend. Samples taken from those ice cores are spaced, on average, about 3.5 years apart, and ammonia could have been cleansed from the atmosphere so quickly that most of the sharp spike might fall between samples.

Source:- http://www.wired.com/wiredscience/2010/03/new-new-evidence-of-ice-age-comet-found-in-ice-cores/#more-20062

DigitalGlobe Surpasses One Billion Square Kilometers of Earth Imagery

DigitalGlobe (NYSE:DGI), a leading global provider of commercial high-resolution world-imagery products and services for defense and intelligence, civil government, and commercial customers, today announced that its industry-leading content library now contains more than one billion square kilometers of earth imagery, 33 percent of which is less than one year old.

"The unrivaled quality and quantity contained in DigitalGlobe's ImageLibrary is what allows us to deliver the imagery our customers need when they need it," said Jill Smith, CEO of DigitalGlobe. "The power of our industry-leading constellation enables us to persistently break new ground for the industry and we strive to offer our customers the largest collection of accurate, current satellite imagery available."

DigitalGlobe's WorldView-1, QuickBird and recently launched WorldView-2 satellites combine to form the industry's largest satellite constellation. These three satellites, together with DigitalGlobe's aerial network, enable the company to offer the highest collection capacity of high-resolution earth imagery to customers around the world, adding roughly 1.5 million square kilometers of imagery every day or three times the Earth's landmass annually. The result is DigitalGlobe's highly complete ImageLibrary, containing imagery used to inform critical decisions across a range of industries.
To see samples of DigitalGlobe's diverse imagery, go to http://www.flickr.com/photos/digitalglobe-imagery/.

To learn more about DigitalGlobe and its ImageLibrary, please visit www.digitalglobe.com.

About DigitalGlobe

DigitalGlobe (http://www.digitalglobe.com) is a leading global provider of commercial high-resolution earth imagery products and services. Sourced from our own advanced satellite constellation, our imagery solutions support a wide variety of uses within defense and intelligence, civil agencies, mapping and analysis, environmental monitoring, oil and gas exploration, infrastructure management, internet portals and navigation technology. With our collection sources and comprehensive ImageLibrary (containing more than one billion square kilometers of earth imagery and imagery products) we offer a range of on- and off-line products and services designed to enable customers to easily access and integrate our imagery into their business operations and applications. For more information, please visit www.digitalglobe.com.

Are Venus and Earth in a long-distance relationship?

The heart of Venus may belong to Earth. Our planet could be tugging on the core of Venus, exerting control over its spin.

Whenever Venus and Earth arrive at the closest point in their orbits, Venus always presents the same face to us. This could mean that Earth's gravity is tugging subtly on Venus, affecting its rotation rate. That idea, raised decades ago, was disregarded when it turned out that Venus is spinning too fast to be in such a gravitational "resonance".

But Earth could still be pulling on Venus by controlling its core, according to calculations by Gérard Caudal of the University of Versailles-Saint Quentin, France.

Caudal made large assumptions about Venus's interior, which we know little about. For his hypothesis to be correct, the planet would, like Earth, need a solid core surrounded by a liquid layer. This could allow the solid core to rotate slower than the rest of the planet. The core would also have to be asymmetric or heterogeneous, so that Earth can exert a variable tug as Venus spins. "For the resonance to be possible, there should be something that the gravity of the Earth could grasp," Caudal says.

This latter requirement could be problematic for the hypothesis, says Jean-Luc Margot of the University of California, Los Angeles. "In order to maintain a resonance, the inner core must be out of round by a significant amount," he notes.

Yet persistent imperfections in planetary cores tend to smooth out because the core is hot and under great pressure, according to David Stevenson of the California Institute of Technology in Pasadena. Still, the resonance theory is worth revisiting, he adds.

Watching for changes in Venus's spin over time using radar observations may reveal more about what's going on inside the planet, says Margot.

Journal reference: Journal of Geophysical Research

Source:- http://www.newscientist.com/article/dn18660-are-venus-and-earth-in-a-longdistance-relationship.html

Earth Rise By KAGUYA on two occasions

KAGUYA taking "Earth-rise" by HDTV (Nov. 7, 2007) [HD]

KAGUYA (SELENE) taking "Earth-rise" by HDTV on Nov. 7, 2007. Aspect ratio 16:9 and HD quality in English narration. (C)JAXA/NHK

KAGUYA taking "Full Earth-rise" by HDTV (Apr. 5, 2008) [HD]

KAGUYA (SELENE) taking "Full Earth-rise" by HDTV on Apr. 5, 2008. Aspect ratio 16:9 and HD quality in English narration. (C)JAXA/NHK