Asteroid Caught Marching Across Tadpole Nebula

This infrared image from NASA's Wide-field Infrared Survey Explorer, or WISE, showcases the Tadpole Nebula, a star-forming hub in the Auriga constellation about 12,000 light-years from Earth. As WISE scanned the sky, capturing this mosaic of stitched-together frames, it happened to catch an asteroid in our solar system passing by. The asteroid, called 1719 Jens, left tracks across the image. A second asteroid was also observed cruising by.

But that's not all that WISE caught in this busy image -- two natural satellites orbiting above WISE streak through the image, appearing as faint green trails. This Tadpole region is chock full of stars as young as only a million years old -- infants in stellar terms -- and masses over 10 times that of our sun. It is called the Tadpole nebula because the masses of hot, young stars are blasting out ultraviolet radiation that has etched the gas into two tadpole-shaped pillars, called Sim 129 and Sim 130. These "tadpoles" appear as the yellow squiggles near the center of the frame. The knotted regions at their heads are likely to contain new young stars. WISE's infrared vision is helping to ferret out hidden stars such as these.

The 1719 Jens asteroid, discovered in 1950, orbits in the main asteroid belt between Mars and Jupiter. The space rock, which has a diameter of 19 kilometers (12 miles), rotates every 5.9 hours and orbits the sun every 4.3 years.

Twenty-five frames of the region, taken at all four of the wavelengths detected by WISE, were combined into this one image. The space telescope caught 1719 Jens in 11 successive frames. Infrared light of 3.4 microns is color-coded blue: 4.6-micron light is cyan; 12-micron-light is green; and 22-micron light is red.

WISE is an all-sky survey, snapping pictures of the whole sky, including everything from asteroids to stars to powerful, distant galaxies.

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Meteor Lights Up Atlanta Skies

Some stats on the meteor:

Initial speed: 23.6 km/s (52,800 mph)
Start location: 84.131 W, 33.981 N, Altitude 104.6 km (65.0 miles)
End location: 84.109 W, 33.524 N, Altitude 41.3 km (25.7 miles)

View from all sky camera located at Huntsville, Al.

View from all sky camera located at Tullahoma, Tenn.

 

View from all sky camera located at Cartersville, Ga.

The meteor was too bright for the all sky camera in Cartersville, Ga., to accurately determine the center of light, so manual analysis will be required to determine a more accurate end point.

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A Planet as Big as Its Star

This artist's concept shows the smallest star known to host a planet. The planet, called VB 10b, was discovered using astrometry, a method in which the wobble induced by a planet on its star is measured precisely on the sky.

The dim, red star, called VB 10, is a so-called M-dwarf, located 20 light-years away in the constellation Aquila. It has only one-twelfth the mass, and one-tenth the size, of our sun. The planet is a gas giant similar in size to Jupiter but with six times the mass. Though the planet is less massive than its star, the two orbs would have a similar diameter.

VB 10b orbits its star about every 9 months at a distance of 50 million kilometers (30 million miles).

Read more......

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Our Planet and Sun

What causes the sun to vary? 

We live in the extended atmosphere of a magnetic variable star that drives our solar system and sustains life on Earth. Our Sun varies in every way we can observe it. The Sun gives off light in the infrared, visible, ultraviolet, and at x-ray energies, and it gives off magnetic field, bulk plasma (the solar wind) and energetic particles moving up to nearly the speed of light, and all of these emissions vary. These variations occur on timescales from milliseconds to billions of years. Most of these variations are related to the solar magnetic field, which is caused by the moving plasma inside the rotating Sun, which make a dynamo. 

How do the Earth and Heliosphere respond?

Our planet is immersed in this seemingly invisible yet exotic and inherently dangerous environment. Above the protective cocoon of Earth’s lower atmosphere is a plasma soup composed of electrified and magnetized matter entwined with penetrating radiation and energetic particles. The Earth’s magnetic field interacts with the Sun’s outer atmosphere to create this extraordinary environment.

Our Sun’s explosive energy output forms an immense, complex magnetic fields structure. Hugely inflated by the solar wind, this colossal bubble of magnetism known as the heliosphere stretches far beyond the orbit of Pluto, from where it controls the entry of cosmic rays into the solar system. On its way through the Milky Way this extended atmosphere of the Sun affects all planetary bodies in the solar system. It is itself influenced by slowly changing interstellar conditions that in turn can affect Earth’s habitability. In fact, the Sun’s extended atmosphere drives some of the greatest changes in the near-Earth space environment affecting our magnetosphere, atmosphere, ionosphere, and potentially our climate.

What are the impacts on humanity?

Modern society depends heavily on a variety of technologies that are susceptible to the extremes of space weather — severe disturbances of the upper atmosphere and of the near-Earth space environment that are driven by the magnetic activity of the Sun. Strong electrical currents driven in the Earth’s surface during auroral events can disrupt and damage modern electric power grids and may contribute to the corrosion of oil and gas pipelines. Changes in the ionosphere during geomagnetic storms driven by magnetic activity of the Sun interfere with high-frequency radio communications and GPS navigation. During polar cap absorption events caused by solar protons, radio communications can be severely compromised for commercial airliners on transpolar crossing routes. Exposure of spacecraft to energetic particles during solar energetic particle events and radiation belt enhancements can cause temporary operational anomalies, damage critical electronics, degrade solar arrays, and blind optical systems such as imagers and star trackers used on commercial and government satellites.

Harsh conditions in the space environment also pose significant risks for the journey of exploration. Although space is a near-vacuum, the very-thinly-spread particles and fields are like an ocean that can affect the spacecraft and astronauts that travel through it. Like seafaring voyagers, space explorers must be constantly aware of the current space weather and be prepared to handle the most extreme conditions that might be encountered.

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METEOR CRATER

The Meteor Crater in the state of Arizona was the first crater to be identified as an impact crater. Between 20,000 to 50,000 years ago, a small asteroid about 80 feet in diameter impacted the Earth and formed the crater. Meteor Crater Arizona, USA The crater is the best preserved crater on Earth and measures 1.2 km in diameter. For many years, scientists had denied that there were any impact craters on Earth. The origin of this crater has been a source of controversy for many years. The discovery of fragments of the Canyon Diablo meteorite help prove that the feature was in fact an impact crater.

Meteor Crater Arizona, USA From the Smithsonian Scientific Series (1929), taken by the U.S. Army Air Service. Public domain.

Meteor Crater Arizona, USA From the Smithsonian Scientific Series (1938), public domain.

Meteor Crater Arizona, USA From the "World's Greatest Wonders" (1930), public domain.

Meteor Crater Arizona, USA Photos taken by Jim Hurley in the winter of 1978.

http://www.nasa.gov/

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Geminids Meteor Shower: 'Up All Night'

you can still enjoy the best meteor shower of the year. The 2010 Geminid meteor shower promises to be lively, with realistic viewing rates of 50-80 meteors per hour and potential peaks reaching 120 meteors per hour. Anytime between Dec. 12-16 is a valid window for Geminid-watching, but the night of Dec. 13-14 is the anticipated peak.

Geminids are pieces of debris from an object called 3200 Phaethon. Long thought to be an asteroid, Phaethon is now classified as an extinct comet. Basically it is the rocky skeleton of a comet that lost its ice after too many close encounters with the sun. Earth runs into a stream of debris from 3200 Phaethon every year in mid-December, causing meteors to fly from the constellation Gemini. When the Geminids first appeared in the late 19th century, shortly before the U.S. Civil War, the shower was weak and attracted little attention. There was no hint that it would ever become a major display.

What's going on? Jupiter's gravity has been acting on Phaethon's debris stream, causing it to shift more and more toward Earth's orbit. Each December brings a deeper plunge into the debris stream.

Meteor expert Peter Brown of the University of Western Ontario (UWO) says the trend could continue for some time to come. "Based on modeling of the debris done by Jim Jones in the UWO meteor group back in the 1980s, it is likely that Geminid activity will increase for the next few decades, perhaps getting 20% to 50% higher than current rates."

A 50% increase would boost the Geminids to 200 or more meteors per hour, year in and year out. "That would be an amazing annual display," says Cooke.

Moreover, says Brown, "the proportion of large, bright Geminids should also increase in the next few decades, according to Jones' model." So the Geminids could turn into a "fireball shower."

Brown cautions that "other models of the debris stream come to different conclusions, in some cases suggesting that Geminids will decrease in intensity in the coming decades. We understand little about the details of the formation and evolution of Phaethon's debris despite many years of efforts."

Recent trends favor a good show. Enjoy the Geminids!

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