Sometimes I complain about the earthly weather, but mostly I like to post about astronomy and space events. Hope you enjoy the articles.
By: Susie77, 10:06 PM GMT on September 28, 2013
From Space Weather
OHIO FIREBALL: Last night, a meteor exploded in the skies above the US midwest. Witnesses report shadows cast upon the ground, unusual sounds, and a swirling contrail marking the aftermath of the blast. A NASA all-sky camera in Hiram, Ohio, recorded the fireball at 11:33 pm EDT:
"This was a very bright event," reports Bill Cooke of NASA's Meteoroid Environment Office. "Flares saturated our meteor cameras, and made determination of the end point (the terminus of the fireball's flight through the atmosphere) virtually impossible. Judging from the brightness, we are dealing with a meter class object."
Data from multiple cameras shows that the meteoroid hit Earth's atmosphere traveling 51 km/s (114,000 mph) and passed almost directly over Columbus, Ohio. Cooke has prepared a preliminary map of the ground track. According to the American Meteor Society, the fireball was visible from at least 14 US states.
By: Susie77, 6:29 PM GMT on September 12, 2013
[This gives me goosebumps]
NASA Spacecraft Embarks on Historic Journey Into Interstellar Space
Sept 12, 2013
Artist's concept depicts NASA's Voyager 1 spacecraft entering interstellar space
The Space Between: This artist's concept shows the Voyager 1 spacecraft entering the space between stars. Interstellar space is dominated by plasma, ionized gas (illustrated here as brownish haze), that was thrown off by giant stars millions of years ago.
After decades of exploration, Voyager 1 reaches a historic milestone for mankind--interstellar space. Learn how the team discovered the craft had reached the space between the stars.
PASADENA, Calif. -- NASA's Voyager 1 spacecraft officially is the first human-made object to venture into interstellar space. The 36-year-old probe is about 12 billion miles (19 billion kilometers) from our sun.
New and unexpected data indicate Voyager 1 has been traveling for about one year through plasma, or ionized gas, present in the space between stars. Voyager is in a transitional region immediately outside the solar bubble, where some effects from our sun are still evident. A report on the analysis of this new data, an effort led by Don Gurnett and the plasma wave science team at the University of Iowa, Iowa City, is published in Thursday's edition of the journal Science.
"Now that we have new, key data, we believe this is mankind's historic leap into interstellar space," said Ed Stone, Voyager project scientist based at the California Institute of Technology, Pasadena. "The Voyager team needed time to analyze those observations and make sense of them. But we can now answer the question we've all been asking -- 'Are we there yet?' Yes, we are."
Voyager 1 first detected the increased pressure of interstellar space on the heliosphere, the bubble of charged particles surrounding the sun that reaches far beyond the outer planets, in 2004. Scientists then ramped up their search for evidence of the spacecraft's interstellar arrival, knowing the data analysis and interpretation could take months or years.
Voyager 1 does not have a working plasma sensor, so scientists needed a different way to measure the spacecraft's plasma environment to make a definitive determination of its location. A coronal mass ejection, or a massive burst of solar wind and magnetic fields, that erupted from the sun in March 2012 provided scientists the data they needed. When this unexpected gift from the sun eventually arrived at Voyager 1's location 13 months later, in April 2013, the plasma around the spacecraft began to vibrate like a violin string. On April 9, Voyager 1's plasma wave instrument detected the movement. The pitch of the oscillations helped scientists determine the density of the plasma. The particular oscillations meant the spacecraft was bathed in plasma more than 40 times denser than what they had encountered in the outer layer of the heliosphere. Density of this sort is to be expected in interstellar space.
The plasma wave science team reviewed its data and found an earlier, fainter set of oscillations in October and November 2012. Through extrapolation of measured plasma densities from both events, the team determined Voyager 1 first entered interstellar space in August 2012.
"We literally jumped out of our seats when we saw these oscillations in our data -- they showed us the spacecraft was in an entirely new region, comparable to what was expected in interstellar space, and totally different than in the solar bubble," Gurnett said. "Clearly we had passed through the heliopause, which is the long-hypothesized boundary between the solar plasma and the interstellar plasma."
The new plasma data suggested a timeframe consistent with abrupt, durable changes in the density of energetic particles that were first detected on Aug. 25, 2012. The Voyager team generally accepts this date as the date of interstellar arrival. The charged particle and plasma changes were what would have been expected during a crossing of the heliopause.
"The team’s hard work to build durable spacecraft and carefully manage the Voyager spacecraft's limited resources paid off in another first for NASA and humanity," said Suzanne Dodd, Voyager project manager, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We expect the fields and particles science instruments on Voyager will continue to send back data through at least 2020. We can't wait to see what the Voyager instruments show us next about deep space."
Voyager 1 and its twin, Voyager 2, were launched 16 days apart in 1977. Both spacecraft flew by Jupiter and Saturn. Voyager 2 also flew by Uranus and Neptune. Voyager 2, launched before Voyager 1, is the longest continuously operated spacecraft. It is about 9.5 billion miles (15 billion kilometers) away from our sun.
Voyager mission controllers still talk to or receive data from Voyager 1 and Voyager 2 every day, though the emitted signals are currently very dim, at about 23 watts -- the power of a refrigerator light bulb. By the time the signals get to Earth, they are a fraction of a billion-billionth of a watt. Data from Voyager 1's instruments are transmitted to Earth typically at 160 bits per second, and captured by 34- and 70-meter NASA Deep Space Network stations. Traveling at the speed of light, a signal from Voyager 1 takes about 17 hours to travel to Earth. After the data are transmitted to JPL and processed by the science teams, Voyager data are made publicly available.
“Voyager has boldly gone where no probe has gone before, marking one of the most significant technological achievements in the annals of the history of science, and adding a new chapter in human scientific dreams and endeavors,” said John Grunsfeld, NASA’s associate administrator for science in Washington. “Perhaps some future deep space explorers will catch up with Voyager, our first interstellar envoy, and reflect on how this intrepid spacecraft helped enable their journey.”
Scientists do not know when Voyager 1 will reach the undisturbed part of interstellar space where there is no influence from our sun. They also are not certain when Voyager 2 is expected to cross into interstellar space, but they believe it is not very far behind.
JPL built and operates the twin Voyager spacecraft. The Voyagers Interstellar Mission is a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of NASA's Science Mission Directorate in Washington. NASA's Deep Space Network, managed by JPL, is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions.
The cost of the Voyager 1 and Voyager 2 missions -- including launch, mission operations and the spacecraft’s nuclear batteries, which were provided by the Department of Energy -- is about $988 million through September.
For a sound file of the oscillations detected by Voyager in interstellar space, animations and other information, visit: http://www.nasa.gov/voyager .
For an image of the radio signal from Voyager 1 on Feb. 21 by the National Radio Astronomy Observatory's Very Long Baseline Array, which links telescopes from Hawaii to St. Croix, visit:
Jia-Rui C. Cook/D.C. Agle 818-354-0850/818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
Dwayne Brown 202-358-1726
By: Susie77, 3:09 PM GMT on September 11, 2013
New Comet Lovejoy
By Deborah Byrd
Move over Comet ISON. A new Comet Lovejoy has arrived
Australian amateur astronomer Terry Lovejoy has discovered a new comet. The new Comet Lovejoy will occupy the same part of the sky as Comet ISON by November 2013.
Many are anticipating the brightening of Comet ISON, which is now in Earth’s predawn sky, not far from the bright planets Jupiter and Mars, but too faint to see without telescopes and/or photographic equipment. Read more about Comet ISON here. In the meantime, on September 9, 2013, noted comet discoverer Terry Lovejoy of Australia announced another new comet, bringing his total number of comet discoveries to four. The newest Comet Lovejoy will be in the same part of the sky as Comet ISON beginning in November. What a cool photo opportunity!
The new comet has been formally labeled as C/2013 R1 Lovejoy. Terry Lovejoy apparently used a relatively small 8-inch (20 cm) Schmidt-Cassegrain reflecting telescope to photograph the new comet for two nights, as this faint object was located on the sky’s dome in front of the border between our constellations Orion and Monoceros.
Read Terry Lovejoy’s own discovery story here.
Now that the comet has been confirmed by other astronomers, amateur astronomers will be getting excited! Watch this space.
Both Comet ISON and Comet Lovejoy are faint now. Both will get brighter. Unlike ISON, no one is expecting Comet Lovejoy to become visible to the eye alone. It might not be all that easy to spot through a telescope. So why the excitement? For sure, some will photograph the two comets together on the sky’s dome.
By the way, there will actually be three comets visible in the sky together in early November. Comet Encke will be joining the crowd around then. Read more the “comet convoy” at Cumbrian Sky.
Bottom line: Australian amateur astronomer Terry Lovejoy has discovered a new comet, his fourth. The new Comet Lovejoy will be in the same part of the sky as Comet ISON beginning around the start of November 2013. For those with the right equipment, it’ll be a great photo opportunity.