Terry's Astronomy Thread.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
January 30, 2013

-Saturn is at western quadrature: 90° west of the Sun in the morning sky.

Mercury is hidden deep in the sunset.

Astro Picture of the Day:
January 30, 2013

Source:
Has a new planet been discovered? What is pictured above is a remarkable 24 hour mosaic surrounding a spot on Sounio, Greece, right here on planet Earth. Images taken at night compose the top half of the picture, with star trails lasting as long as 11 hours visible. Contrastingly, images taken during the day compose the bottom of the image, with the Sun being captured once every 15 minutes. The image center shows a Little Prince wide angle projection centered on the ground but including gravel, grass, trees, Saint John's church, clouds, crepuscular rays, and even a signature icon of the photographer - the Temple of Poseidon. Meticulous planning as well as several transition shots and expert digital processing eventually culminated in this image documenting half of the final two days of last year.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
January 31, 2013

-Jupiter's moon Io crosses Jupiter's face from 7:59 to 11:09 p.m. EST. Io's tiny black shadow follows behind across Jupiter from 10:10 p.m. to 12:21 a.m. EST. Meanwhile, Jupiter's Great Red Spot (actually pale orange-tan) crosses the planet's central meridian around 8:07 p.m. EST.
Mercury is hidden deep in the sunset.

-Saturn rises in the middle of the night this week and shines high during dawn. The Moon is positioned here for the middle of North America. The blue 10° scale is about the width of your fist at arm's length.

Astro Picture of the Day:
January 31, 2013

Source:
The delightful Dark Doodad Nebula drifts through southern skies, a tantalizing target for binoculars in the constellation Musca, The Fly. The dusty cosmic cloud is seen against rich starfields just south of the prominent Coalsack Nebula and the Southern Cross. Stretching for about 3 degrees across this scene the Dark Doodad seems punctuated at its southern tip (lower left) by globular star cluster NGC 4372. Of course NGC 4372 roams the halo of our Milky Way Galaxy, a background object some 20,000 light-years away and only by chance along our line-of-sight to the Dark Doodad. The Dark Doodad's well defined silhouette belongs to the Musca molecular cloud, but its better known alliterative moniker was first coined by astro-imager and writer Dennis di Cicco in 1986 while observing comet Halley from the Australian outback. The Dark Doodad is around 700 light-years distant and over 30 light-years long.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 1, 2013

-The sky's biggest well-known asterism (informal star pattern) is the Winter Hexagon or Winter Circle. It fills the sky toward the east and south these evenings. Start with brilliant Sirius at its bottom. Going clockwise from there, march through Procyon, then Pollux and Castor, then Menkalinen and Capella overhead, down to Aldebaran (overshone by Jupiter this season!), down to Rigel, and back to Sirius.

Astro Picture of the Day:
February 1, 2013

Source:
Beyond a fertile field of satellite communication antennas at Kennedy Space Center, an Atlas V rocket streaks into orbit in this long exposure photograph. In the thoughtfully composed image recorded on the evening of January 30, the antennas in the foreground bring to mind the rocket's payload, a Tracking and Data Relay Satellite (TDRS; sounds like TEE-dress). This TDRS-K is the first in a next-generation series adding to the constellation of NASA's communication satellites. Operating from geosynchronous orbit 22,300 miles (36,000 kilometers) above planet Earth, the network of TDRS satellites relays communications, data, and commands between spacecraft and ground stations. Formerly the TDRS network provided communications for space shuttle missions. In fact, many TDRS satellites were ferried as far as low Earth orbit on space shuttles. The TDRS network continues to support major spacecraft like the International Space Station, the Hubble Space Telescope, and the Fermi Gamma-ray Space Telescope.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 2, 2013

-our latitude makes a big difference in how the constellations appear. (Your longitude does not.) For instance, if you're as far north as 46° (roughly Portland, Minneapolis, Montreal, and central France), bright Capella passes straight through your zenith around 8 or 9 p.m. If you're as far south as 21° N (Guadalajara, Cuba, the mid-Sahara, and Kolkata), Jupiter currently crosses straight overhead in the evening.

-Wherever you are, Jupiter and Capella pass closest to your zenith exactly one hour apart. Jupiter goes first.

-Saturn and the last-quarter Moon rise together tonight around midnight or 1 a.m. By dawn (Sunday the 3rd) they're high in the south, as shown above.

News Posted Today:
February 1, 2013
The First-Ever Meteorite from Mercury?


Astro Picture of the Day:
February 2, 2013

Source:
Beyond a fertile field of satellite communication antennas at Kennedy Space Center, an Atlas V rocket streaks into orbit in this long exposure photograph. In the thoughtfully composed image recorded on the evening of January 30, the antennas in the foreground bring to mind the rocket's payload, a Tracking and Data Relay Satellite (TDRS; sounds like TEE-dress). This TDRS-K is the first in a next-generation series adding to the constellation of NASA's communication satellites. Operating from geosynchronous orbit 22,300 miles (36,000 kilometers) above planet Earth, the network of TDRS satellites relays communications, data, and commands between spacecraft and ground stations. Formerly the TDRS network provided communications for space shuttle missions. In fact, many TDRS satellites were ferried as far as low Earth orbit on space shuttles. The TDRS network continues to support major spacecraft like the International Space Station, the Hubble Space Telescope, and the Fermi Gamma-ray Space Telescope.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 3, 2013

-February is when Orion stands highest in the south in early evening. And this season, Orion is framed between the two brightest points in the sky: Jupiter high to its upper right and Sirius down to its lower left. Introduce them to someone!

Mercury (magnitude –1.1) is emerging from the glow of sunset. On February 1st it's still very deep in bright twilight, but day by day it becomes higher and easier to see. Check for it each clear evening starting about 30 minutes after sunset, just above the west-southwest horizon. Bring binoculars.

-There too is fainter Mars (magnitude +1.2). Mars is above Mercury until February 7th and 8th, when they pass less than 1° apart. After that Mercury is higher — coming into an excellent apparition of its own.

Mercury peaks in the early evening sky from February 11th to 21st, while much fainter Mars appears lower each evening. The two planets pass spectacularly close to each other on February 7th and 8th. Their disks are shown in their correct shapes and orientations, but their sizes are exaggerated hugely, roughly matching their appearance through a telescope at high magnification.

Astro Picture of the Day:
February 3, 2013

Source:
This esthetic close-up of cosmic clouds and stellar winds features LL Orionis, interacting with the Orion Nebula flow. Adrift in Orion's stellar nursery and still in its formative years, variable star LL Orionis produces a wind more energetic than the wind from our own middle-aged Sun. As the fast stellar wind runs into slow moving gas a shock front is formed, analogous to the bow wave of a boat moving through water or a plane traveling at supersonic speed. The small, arcing, graceful structure just above and left of center is LL Ori's cosmic bow shock, measuring about half a light-year across. The slower gas is flowing away from the Orion Nebula's hot central star cluster, the Trapezium, located off the upper left corner of the picture. In three dimensions, LL Ori's wrap-around shock front is shaped like a bowl that appears brightest when viewed along the "bottom" edge. The beautiful picture is part of a large mosaic view of the complex stellar nursery in Orion, filled with a myriad of fluid shapes associated with star formation.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 4, 2013

-Jupiter's biggest moon, Ganymede, fades into eclipse by Jupiter's shadow around 7:35 p.m. EST. It reappears around 9:53 p.m. EST. Both events take place just east of the planet. Europa happens to be just south of Ganymede's reappearance point, by a bit less than a Jupiter diameter. When can you detect the first trace of Ganymede coming back?
Later, Jupiter's Great Red Spot rotates across the planet's centerline at 11:25 p.m. EST.

-Mars (magnitude +1.2) is sinking deeper into the sunset. Brighter Mercury becomes your marker for finding it this week.

Astro Picture of the Day:
February 4, 2013

http://apod.nasa.gov/apod/ap130204.html

Source:
Namibia has some of the darkest nights visible from any continent. It is therefore home to some of the more spectacular skyscapes, a few of which have been captured in the above time-lapse video. Visible at the movie start are unusual quiver trees perched before a deep starfield highlighted by the central band of our Milky Way Galaxy. This bright band of stars and gas appears to pivot around the celestial south pole as our Earth rotates. The remains of camel thorn trees are then seen against a sky that includes a fuzzy patch on the far right that is the Large Magellanic Cloud, a small satellite galaxy to the Milky Way. A bright sunlight-reflecting satellite passes quickly overhead. Quiver trees appear again, now showing their unusual trunks, while the Small Magellanic Cloud becomes clearly visible in the background. Artificial lights illuminate a mist that surround camel thorn trees in Deadvlei. In the final sequence, natural Namibian stone arches are captured against the advancing shadows of the setting moon. This video incorporates over 16,000 images shot over two years, and won top honors among the 2012 Travel Photographer of the Year awards.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 5, 2013

-With the Moon gone from the evening sky, this week is a fine time to look for the zodiacal light from the Northern Hemisphere. At a clear, dark site with clean air, look west at the very end of twilight for a vague but huge, tall pyramid of pearly light. It's tilted left to align along the constellations of the zodiac — or more exactly, along the ecliptic line. So it points toward toward Jupiter. What you're seeing is sunlit interplanetary dust — comet and asteroid debris — orbiting the Sun near the plane of the solar system.

-Comet PanSTARRS update. The incoming comet that we hoped would make a fine showing in March has been weakening. It may not even reach naked-eye visibility, what with its low altitude in evening twilight. The comet is currently expected to peak at magnitude +1 or +2 in March, not 0 or brighter as formerly predicted.

Astro Picture of the Day:
February 5, 2013

Source:
What if you saw your shadow on Mars and it wasn't human? Then you might be the robotic Curiosity rover currently exploring Mars. Curiosity landed in Gale Crater last August and has been busy looking for signs of ancient running water and clues that Mars could once have harbored life. Pictured above, Curiosity has taken a wide panorama that includes its own shadow in the direction opposite the Sun. The image was taken in November from a location dubbed Point Lake, although no water presently exists there. Curiosity has already discovered several indications of dried streambeds on Mars, and is scheduled to continue its exploration by climbing nearby Mt. Sharp over the next few years.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 6, 2013

-Jupiter (magnitude –2.5, in Taurus) dominates the high south in early evening, and the southwest later. To its left is orange Aldebaran; to its right are the Pleiades. The whole group sets around 2 or 3 a.m.

-In a telescope, Jupiter is shrinking (from 43 to 42 arcseconds wide this week) as Earth pulls farther ahead of it in our faster orbit around the Sun.

Astro Picture of the Day:
February 6, 2013

Source:
The spiral arms of bright galaxy M106 sprawl through this remarkable multiframe portrait, composed of data from ground- and space-based telescopes. Also known as NGC 4258, M106 can be found toward the northern constellation Canes Venatici. The well-measured distance to M106 is 23.5 million light-years, making this cosmic scene about 80,000 light-years across. Typical in grand spiral galaxies, dark dust lanes, youthful blue star clusters, and pinkish star forming regions trace spiral arms that converge on the bright nucleus of older yellowish stars. But this detailed composite reveals hints of two anomalous arms that don't align with the more familiar tracers. Seen here in red hues, sweeping filaments of glowing hydrogen gas seem to rise from the central region of M106, evidence of energetic jets of material blasting into the galaxy's disk. The jets are likely powered by matter falling into a massive central black hole.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 7, 2013

-Challenging Mercury-Mars conjunction. Look low in the west-southwest a half hour after sunset. Faint Mars is within 3/4° upper left of brighter Mercury (seen from North America), as shown here. Quite an interesting pair in binoculars!

Astro Picture of the Day:
February 7, 2013

Source:
Currently sweeping through southern skies, Comet Lemmon (C/2012 F6) was named for its discovery last year as part of the Mount Lemmon (Arizona) Survey. Brighter than expected but still just below naked-eye visibility, Comet Lemmon sports a stunning lime green coma and faint divided tail in this telescopic image from February 4. The greenish tint comes from the coma's diatomic C2 gas fluorescing in sunlight. Captured from an observatory near Sydney, Australia, the color composite is constructed from a series of individual exposures registered on the comet. Across the 1 degree wide field of view, the star trails are a consequence of the comet's relatively rapid motion against the background of stars near the South Celestial Pole. Moving north, the comet should grower brighter, reaching a peak (3rd magnitude or so) when it is closest to the Sun in late March. By early April it should be visible from the northern hemisphere. Of course, this year Comet Lemmon may be just another pretty comet as skygazers on planet Earth also eagerly anticipate views of Comet PANSTARRS and Comet ISON.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 8, 2013

-Mercury-Mars Conjunction. Mars is less than ½° from Mercury low in the west-southwest in bright twilight, as shown at right (for North America). They'll certainly be an interesting pair through a telescope, though both will be tiny and blurred at such a low altitude.

News Posted Today:
January 30, 2013
Asteroid 2012 DA14 to Zip Past Earth



Astro Picture of the Day:
February 8, 2013

Source:
Grand spiral galaxies often seem to get all the glory, flaunting their young, bright, blue star clusters in beautiful, symmetric spiral arms. But small galaxies form stars too, like nearby NGC 6822, also known as Barnard's Galaxy. Beyond the rich starfields in the constellation Sagittarius, NGC 6822 is a mere 1.5 million light-years away, a member of our Local Group of galaxies. About 7,000 light-years across, the dwarf irregular galaxy is seen to be filled with young blue stars and mottled with the telltale pinkish hydrogen glow of star forming regions in the deep color composite image. Contributing to the science of LITTLE THINGS, this portrait of a small galaxy was made as part of the Lowell Amateur Research Initiative (LARI), welcoming collaborations with amateur astronomers. More info on LITTLE THINGS here.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 9, 2013

-Mars now appears 1.1° below brighter Mercury (for North America), low in the sunset glow.

-Venus (magnitude –3.9) is buried deep in the glow of sunrise.

Astro Picture of the Day:
February 9, 2013

Source:
One hundred years ago today the Great Meteor Procession of 1913 occurred, a sky event described by some as "magnificent" and "entrancing" and which left people feeling "spellbound" and "privileged". Because one had to be in a right location, outside, and under clear skies, only about 1,000 people noted seeing the procession. Lucky sky gazers - particularly those near Toronto, Canada - had their eyes drawn to an amazing train of bright meteors streaming across the sky, in groups, over the course of a few minutes. A current leading progenitor hypothesis is that a single large meteor once grazed the Earth's atmosphere and broke up. When the resulting pieces next encountered the Earth, they came in over south-central Canada, traveled thousands of kilometers as they crossed over the northeastern USA, and eventually fell into the central Atlantic ocean. Pictured above is a digital scan of a halftone hand-tinted image by the artist Gustav Hahn who was fortunate enough to witness the event first hand. Although nothing quite like the Great Meteor Procession of 1913 has been reported since, numerous bright fireballs - themselves pretty spectacular - have since been recorded, some even on video. Such as this one in 1992 which hit a car, shown below:

[igotrhythm]

Re: Terry's Astronomy Thread.

In a similar vein.

http://www.cracked.com/article_20237...-in-space.html

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 10, 2013

-New Moon; exact at 2:20 a.m. EST on this date (11:20 p.m. on the 19th PST).

Challenge: Catch your record young Moon? Very low in the west shortly after sunset, if the air is very clear, binoculars may show an extremely thin crescent Moon well to the lower right of Mercury and Mars (viewed from North America), as illustrated below. If you see the crescent from the Eastern time zone, you're seeing it when it's only 15 or 16 hours old — a remarkable record that you may not beat in a lifetime! Seen three hours later in twilight from the Pacific time zone, the Moon will be 18 or 19 hours old — still likely a record for your logbook. Record the time you detect the Moon to the minute, and calculate how long this is from the time of new Moon given above.

Astro Picture of the Day:
February 10, 2013

Source:
The first identified compact galaxy group, Stephan's Quintet is featured in this stunning image from the newly upgraded Hubble Space Telescope. About 300 million light-years away, only four galaxies of the group are actually locked in a cosmic dance of repeated close encounters. The odd man out is easy to spot, though. The four interacting galaxies (NGC 7319, 7318A, 7318B, and 7317) have an overall yellowish cast and tend to have distorted loops and tails, grown under the influence of disruptive gravitational tides. But the bluish galaxy at the upper left (NGC 7320) is much closer than the others. A mere 40 million light-years distant, it isn't part of the interacting group. In fact, individual stars in the foreground galaxy can be seen in the sharp Hubble image, hinting that it is much closer than the others. Stephan's Quintet lies within the boundaries of the high flying constellation Pegasus.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 11, 2013

-Mercury shines lower left of the Moon, as shown below. And bring binoculars for a last shot at faint, low Mars.

Mars (magnitude +1.2) is becoming a real challenge as it sinks lower low into the sunset. Brighter Mercury is your marker for finding it.

Astro Picture of the Day:
February 11, 2013

Source:
Massive stars, abrasive winds, mountains of dust, and energetic light sculpt one of the largest and most picturesque regions of star formation in the Local Group of Galaxies. Known as N11, the region is visible on the upper right of many images of its home galaxy, the Milky Way neighbor known as the Large Magellanic Clouds (LMC). The above image was taken for scientific purposes by the Hubble Space Telescope and reprocessed for artistry by an amateur to win the Hubble's Hidden Treasures competition. Although the section imaged above is known as NGC 1763, the entire N11 emission nebula is second in LMC size only to 30 Doradus. Studying the stars in N11 has shown that it actually houses three successive generations of star formation. Compact globules of dark dust housing emerging young stars are also visible around the image.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
February 12, 2013

-Mercury shines far below the crescent Moon as twilight fades.
The eclipsing binary star Algol should be at minimum light, magnitude 3.4 instead of its usual 2.3, for a couple hours centered on 11:23 p.m. EST.
-Algol takes several additional hours to fade and to rebrighten.

Astro Picture of the Day:
February 12, 2013

Source:
Some auroras can only be seen with a camera. They are called subvisual and are too faint to be seen with the unaided eye. In the above image, the green aurora were easily visible to the eye, but the red aurora only became apparent after a 20-second camera exposure. The reason is that the human eye only accumulates light for a fraction of a second at a time, while a camera shutter can be left open much longer. When photographing an already picturesque scene near Anchorage, Alaska, USA, last autumn, a camera caught both the visual green and subvisual red aurora reflected in a lily pad-covered lake. High above, thousands of stars were visible including the Pleiades star cluster, while the planet Jupiter posed near the horizon, just above clouds, toward the image right. Auroras are caused by energetic particles from the Sun impacting the Earth's magnetosphere, causing electrons and protons to rain down near the Earth's poles and impact the air. Both red and green aurora are typically created by excited oxygen atoms, with red emission, when visible, dominating higher up. Auroras are known to have many shapes and colors.