Tag: Astronomy
Geminid Meteor Shower Dec 13-14, 2017; NASA Tells You How to View
Photo Credit: Leonid 2001, Hawaii, Courtesy NASA MEO.
The Geminid meteor shower will put on a dazzling show for skywatchers when it peaks overnight on Dec. 13-14.
Credits: NASA
Maybe you’ve already seen a bright meteor streak across the December sky? The annual Geminid meteor shower has arrived. It’s a good time to bundle up, go outside and let the universe blow your mind!
“With August’s Perseids obscured by bright moonlight, the Geminids will be the best shower this year,” said Bill Cooke with NASA’s Meteoroid Environment Office. “The thin, waning crescent Moon won’t spoil the show.”
The shower will peak overnight Dec. 13-14 with rates around one per minute under good conditions, according to Cooke. Geminids can be seen on nights before and after the Dec. 14 peak, although they will appear less frequently.
“Geminid activity is broad,” said Cooke. “Good rates will be seen between 7:30 p.m. on Dec. 13 and dawn local time the morning of Dec. 14, with the most meteors visible from midnight to 4 a.m. on Dec. 14, when the radiant is highest in the sky.”
About the Geminid Shower
The Geminids are active every December, when Earth passes through a massive trail of dusty debris shed by a weird, rocky object named 3200 Phaethon. The dust and grit burn up when they run into Earth’s atmosphere in a flurry of “shooting stars.”
“Phaethon’s nature is debated,” said Cooke. “It’s either a near-Earth asteroid or an extinct comet, sometimes called a rock comet.”
As an added bonus this year, astronomers will have a chance to study Phaethon up close in mid-December, when it passes nearest to Earth since its discovery in 1983.
Meteor showers are named after the location of the radiant, usually a star or constellation close to where they appear in the night sky. The Geminid radiant is in the constellation Gemini.
The Geminids can be seen with the naked eye under clear, dark skies over most of the world, though the best view is from the Northern Hemisphere. Observers will see fewer Geminids in the Southern Hemisphere, where the radiant doesn’t climb very high over the horizon.
Observing the Geminids
Skywatching is easy. Just get away from bright lights and look up in any direction! Give your eyes time to adjust to the dark. Meteors appear all over the sky.
Not all the meteors you might see belong to the Geminid shower, however. Some might be sporadic background meteors, and some might be from weaker, active showers like the Monocerotids, Sigma Hydrids and the Comae Berenicids.
“When you see a meteor, try to trace it backwards,” said Cooke. “If you end up in the constellation Gemini there’s a good chance you’ve seen a Geminid.”
Learn More about the Geminids
Cooke and other meteor experts from NASA’s Meteoroid Environment Office will be live on Facebook to discuss the Geminids and why meteors and meteoroids are important to NASA beginning at 8 p.m. EST on Dec. 12.
And if it’s cloudy where you are, NASA will broadcast the Geminid shower live via Ustream starting at sunset Dec. 13 from the Automated Lunar and Meteor Observatory at NASA’s Marshall Space Flight Center in Huntsville, Alabama.
You can also see Geminid meteors on NASA’s All Sky Fireball network page. Follow NASA Meteor Watch on Facebook for information about meteor showers and fireballs throughout the year.
Molly Porter
Marshall Space Flight Center, Huntsville, Ala.
Merging neutron stars scatter gold & platinum into space: Images are beautiful
European Southern Observatory (ESO) Telescopes Observe First Light from Gravitational Wave Source
Merging neutron stars scatter gold and platinum into space
For the first time ever, astronomers have observed both gravitational waves and light (electromagnetic radiation) from the same event, thanks to a global collaborative effort and the quick reactions of both ESO’s facilities and others around the world.
On 17 August 2017 the NSF‘s Laser Interferometer Gravitational-Wave Observatory (LIGO) in the United States, working with the Virgo Interferometer in Italy, detected gravitational waves passing the Earth. This event, the fifth ever detected, was named GW170817. About two seconds later, two space observatories, NASA’s Fermi Gamma-ray Space Telescope and ESA’s INTErnational Gamma Ray Astrophysics Laboratory (INTEGRAL), detected a short gamma-ray burst from the same area of the sky.
ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and by Australia as a strategic partner.
Artist’s impression of merging neutron stars
This artist’s impression shows two tiny but very dense neutron stars at the point at which they merge and explode as a kilonova. Such a very rare event is expected to produce both gravitational waves and a short gamma-ray burst, both of which were observed on 17 August 2017 by LIGO–Virgo and Fermi/INTEGRAL respectively. Subsequent detailed observations with many ESO telescopes confirmed that this object, seen in the galaxy NGC 4993 about 130 million light-years from the Earth, is indeed a kilonova. Such objects are the main source of very heavy chemical elements, such as gold and platinum, in the Universe. Credit: ESO/L. Calçada/M. Kornmesser
Composite of images of NGC 4993 and kilonova from many ESO instruments
This composite shows images of the galaxy NGC 4993 from several different ESO telescopes and instruments. They all reveal a faint source of light close to the centre. This is a kilonova, the explosion resulting from the merger of two neutron stars. This merger produced both gravitational waves, detected by LIGO–Virgo, and gamma rays, detected by Fermi and INTEGRAL in space. Credit: VLT/VIMOS. VLT/MUSE, MPG/ESO 2.2-metre telescope/GROND, VISTA/VIRCAM, VST/OmegaCAM
Artist’s impression of a kilonova explosion
The merging of two neutron stars produces a violent explosion known as a kilonova. Such an event is expected to expel heavy chemical elements into space. This picture shows some of these elements, along with their atomic numbers. Credit: ESO/L. Calçada/M. Kornmesser
Artist’s impression of merging neutron stars
This artist’s impression shows two tiny but very dense neutron stars at the point at which they merge and explode as a kilonova. Such a very rare event is expected to produce both gravitational waves and a short gamma-ray burst, both of which were observed on 17 August 2017 by LIGO–Virgo and Fermi/INTEGRAL respectively. Subsequent detailed observations with many ESO telescopes confirmed that this object, seen in the galaxy NGC 4993 about 130 million light-years from the Earth, is indeed a kilonova. Such objects are the main source of very heavy chemical elements, such as gold and platinum, in the Universe. Credit: ESO/L. Calçada/M. Kornmesser
Artist’s impression of merging neutron stars
This artist’s impression shows two tiny but very dense neutron stars at the point at which they merge and explode as a kilonova. Such a very rare event is expected to produce both gravitational waves and a short gamma-ray burst, both of which were observed on 17 August 2017 by LIGO–Virgo and Fermi/INTEGRAL respectively. Subsequent detailed observations with many ESO telescopes confirmed that this object, seen in the galaxy NGC 4993 about 130 million light-years from the Earth, is indeed a kilonova. Such objects are the main source of very heavy chemical elements, such as gold and platinum, in the Universe. Credit: University of Warwick/Mark Garlick
Cataclysmic collision
Artist’s illustration of two merging neutron stars. The rippling space-time grid represents gravitational waves that travel out from the collision, while the narrow beams show the bursts of gamma rays that are shot out just seconds after the gravitational waves. Swirling clouds of material ejected from the merging stars are also depicted. The clouds glow with visible and other wavelengths of light. Credit: NSF/LIGO/Sonoma State University/A. Simonnet
Video Animation: Neutron star merger animation ending with kilonova explosion
This artist’s impression video shows how two tiny but very dense neutron stars merge and explode as a kilonova. Such a very rare event is expected to produce both gravitational waves and a short gamma-ray burst, both of which were observed on 17 August 2017 by LIGO–Virgo and Fermi/INTEGRAL respectively. Subsequent detailed observations with many ESO telescopes have confirmed that this object, seen in the galaxy NGC 4993 about 130 million light-years from the Earth, is indeed a kilonova. Such objects are the main source of very heavy chemical elements, such as gold and platinum in the Universe. Credit: ESO/L. Calçada. Music: Johan B. Monell (www.johanmonell.com)
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