Terry's Astronomy Thread.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-"Cassiopeia" usually means "Cold!". Late fall and winter are when this landmark constellation is high overhead (seen from mid-northern latitudes), but even on hot June evenings it's lurking low. After dark, look for it down near the north horizon. It's a wide, upright W. The farther north you are the higher it'll appear. But even as far south as San Diego and Atlanta it's completely above the horizon.

-Mercury, Venus, and Jupiter are still visible in the afterglow of sunset, forming a straight line pointing downward just above the west-northwest horizon as shown at the top of this page. Venus is the brightest. Jupiter, the bottom one, becomes harder to see each day and is gone by the end of the week. Mercury on top is having its best evening appearance of 2013.

Astro Picture of the Day:
June 3, 2013

Source:
Could life ever have existed on Mars? To help find out, humanity landed the Curiosity rover on Mars last August. To make sure the car-sized explorer survived the interplanetary trip and dramatic landing intact, the above image and others was taken peering at, under, and around Curiosity. Pictured above in this unusual vista are three of Curiosity's six wheels, each measuring about half a meter across. In recent months, Curiosity has been exploring the surroundings of an area dubbed Yellowknife Bay. Analyses of data taken by Curiosity's cameras and onboard laboratories has provided strong new evidence that Mars could once have supported life. In the distance is part of the slope to the central peak inside Gale Crater that Curiosity is scheduled to attempt to climb - Mt. Sharp.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Above the Big Dipper's high handle is north-central Bootes, home to double stars, three spindle galaxies, and the Kangaroo asterism.

-By June 5th the line of Venus, Mercury and Jupiter is 13° long with Jupiter falling far away.

News Posted Today:
June 3, 2013
Chance to Catch Closest Planet?
Source:


Astro Picture of the Day:
June 4, 2013

Source:
Few astronomical sights excite the imagination like the nearby stellar nursery known as the Orion Nebula. The Nebula's glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud. Many of the filamentary structures visible in the above image are actually shock waves - fronts where fast moving material encounters slow moving gas. The Orion Nebula spans about 40 light years and is located about 1500 light years away in the same spiral arm of our Galaxy as the Sun. The Great Nebula in Orion can be found with the unaided eye just below and to the left of the easily identifiable belt of three stars in the popular constellation Orion. The above image shows the nebula in three colors specifically emitted by hydrogen, oxygen, and sulfur gas. The whole Orion Nebula cloud complex, which includes the Horsehead Nebula, will slowly disperse over the next 100,000 years.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Vega is the brightest star in the east these evenings. The main part of its little constellation, Lyra, dangles from it to its lower right.

-Jupiter is now all but out of view and only Venus and Mercury remain in the evening planet dance. However, Pollux and Castor will soon be joining them.

Astro Picture of the Day:
June 5, 2013

Source:
Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial band. Its classic appearance is understood to be due to our own perspective, though. The recent mapping of the expanding nebula's 3-D structure, based in part on this clear Hubble image, indicates that the nebula is a relatively dense, donut-like ring wrapped around the middle of a football-shaped cloud of glowing gas. The view from planet Earth looks down the long axis of the football, face-on to the ring. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from the dying, once sun-like star, now a tiny pinprick of light seen at the nebula's center. Intense ultraviolet light from the hot central star ionizes atoms in the gas. In the picture, the blue color in the center is ionized helium, the cyan color of the inner ring is the glow of hydrogen and oxygen, and the reddish color of the outer ring is from nitrogen and sulfur. The Ring Nebula is about one light-year across and 2,000 light-years away.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-With June well under way, the Big Dipper has swung around to hang down by its handle high in the northwest after dark. The middle star of its handle is Mizar, with tiny little Alcor right next to it. On which side of Mizar should you look for Alcor? As always, on the side exactly toward Vega! Which is now shining in the east.

News Posted Today:
June 4, 2013
Radiation Risks for Future Marsonauts
Source:


Astro Picture of the Day:
June 6, 2013

Source:
Although you've surely seen it, you might not have noticed it. During a cloudless twilight, just before sunrise or after sunset, part of the atmosphere above the horizon appears slightly off-color, slightly pink. Called the Belt of Venus, this off-color band between the dark eclipsed sky and the blue sky can be seen in nearly every direction including that opposite the Sun. Straight above, blue sky is normal sunlight reflecting off the atmosphere. In the Belt of Venus, however, the atmosphere reflects light from the setting (or rising) Sun which appears more red. The Belt of Venus can be seen from any location with a clear horizon. Pictured above, the Belt of Venus was photographed above morning fog in the Valley of the Moon, a famous wine-producing region in northern California, USA. The belt is frequently caught by accident in other photographs.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-This week, Earth is passing through a stream of debris from asteroid Icarus, source of the annual Arietid meteor shower. The strange thing about this shower is that it occurs mainly during daylight hours. At its peak on June 7-8, as many as 60 Arietids per hour will streak invisibly across the blue sky after sunrise. The best way to observe the Arietids is via radar. Listen to their echoes on Space Weather Radio. http://spaceweatherradio.com/

-Mercury in the twilight has reached its farthest distance above Venus, 5°. See the scene below. They're as far apart as fainter Pollux and Castor above them, which come into view as twilight dims. 5° is about three finger-widths at arm's length.

Astro Picture of the Day:
June 7, 2013

Source:
The bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects. Though its wingspan covers over 3 light-years, NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees C, the dying central star of this particular planetary nebula has become exceptionally hot, shining brightly in ultraviolet light but hidden from direct view by a dense torus of dust. This sharp and colorful close-up of the dying star's nebula was recorded in 2009 by the Hubble Space Telescope's Wide Field Camera 3, installed during the final shuttle servicing mission. Cutting across a bright cavity of ionized gas, the dust torus surrounding the central star is near the center of this view, almost edge-on to the line-of-sight. Molecular hydrogen has been detected in the hot star's dusty cosmic shroud. NGC 6302 lies about 4,000 light-years away in the arachnologically correct constellation of the Scorpion (Scorpius).

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-After dark, look southeast for orange-red Antares. It's one of the two great red supergiants of the naked-eye sky; the other is Betelgeuse in winter. Around and to the upper right of Antares are other, white stars of upper Scorpius.

-This morning marks day 2 of the peak of the Arietids. The best way to observe the Arietids is via radar. Listen to their echoes on Space Weather Radio. http://spaceweatherradio.com/

-New Moon (exact at 3:14 a.m. on this date EDT).

Astro Picture of the Day:
June 8, 2013

Source:
Many bright nebulae and star clusters in planet Earth's sky are associated with the name of astronomer Charles Messier, from his famous 18th century catalog. His name is also given to these two large and remarkable craters on the Moon. Standouts in the dark, smooth lunar Sea of Fertility or Mare Fecunditatis, Messier (left) and Messier A have dimensions of 15 by 8 and 16 by 11 kilometers respectively. Their elongated shapes are explained by an extremely shallow-angle trajectory followed by the impactor, moving left to right, that gouged out the craters. The shallow impact also resulted in two bright rays of material extending along the surface to the right, beyond the picture. Intended to be viewed with red/blue glasses (red for the left eye), this striking stereo picture of the crater pair was recently created from high resolution scans of two images (AS11-42-6304, AS11-42-6305) taken during the Apollo 11 mission to the moon.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-After sunset, look for the young crescent Moon about 6° to 8° below Venus very low in the west-northwest (at the times of twilight in North America). Binoculars will help.

-NOAA estimates a 60% chance of polar geomagnetic storms on June 9th when a CME is expected to deliver a glancing blow to Earth's magnetic field. High-latitude sky watchers should be alert for auroras.

-High latitude sky watchers should be alert for NLCs in the evenings ahead. In recent years they have been sighted as far south as Utah, Colorado, and Nebraska. Observing tips: Look west 30 to 60 minutes after sunset when the sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you've probably spotted a noctilucent cloud.

Astro Picture of the Day:
June 9, 2013

Source:
On the afternoon of June 5th, the European Space Agency launched a robotic spaceship named "Albert Einstein" into Earth orbit. Also known as "ATV-4" (Automated Transfer Vehicle 4), the Albert Einstein is a cargo carrier laden with supplies for the International Space Station. Marco Langbroek saw it flying over Leiden, the Netherlands, just two hours after launch:

"The ATV-4 was very bright (mag +1 to +0.5) and easily visible to the naked eye, even from Leiden center," Langbroek. "Still in a low orbit, it was very fast."

To resupply the space station, the Albert Einstein is carrying the most dry cargo ever launched by a European spacecraft - 2,480 kilograms, and the most diverse cargo mix - 1400 different items. It will catch up to and dock with the ISS on June 15th. As that date approaches, the ATV-4 and the ISS will become visible in the night sky at the same time.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-The thin crescent Moon low in twilight now forms a triangle with Venus and Mercury, as shown at right. Look above the triangle for the Pollux-and-Castor pair.

-NOAA forecasters have downgraded the chance of polar geomagnetic storms today to 25%. A CME expected to deliver a glancing blow to Earth's magnetic field on June 9th did not arrive on time and might have missed our planet altogether.

-Sky watchers in North America might see an outburst of meteors during the early hours of June 11th when Earth passes through a stream of cometary debris last seen in 1930. Forecasters Peter Jenniskens (SETI Institute) and Esko Lyytinen (Helsinki, Finland) predict the return of the gamma Delphinid meteor shower this Tuesday morning around 08:30 UT (04:30 am EDT). The shower is expected to last no more than about 30 minutes with an unknown number of bright, fast meteors. Bill Cooke of NASA's Meteoroid Environment Office will chat about the shower starting tonight at 11 PM EDT. Link: http://www.nasa.gov/connect/chat/gamma_chat.html

Astro Picture of the Day:
June 10, 2013

Source:
Where are the hottest stars in the nearest galaxies? To help find out, NASA commissioned its Earth-orbiting Swift satellite to compile a multi-image mosaic of the neighboring Large Magellanic Cloud (LMC) galaxy in ultraviolet light. The above image shows where recently formed stars occur in the LMC, as the most massive of these young stars shine brightly in blue and ultraviolet. In contrast, a more familiar view of the LMC in visible light better highlights older stars. On the upper left is one of the largest star forming regions known in the entire Local Group of galaxies: the Tarantula Nebula. The Large Magellanic Cloud and its smaller companion the Small Magellanic Cloud are easily visible with the unaided eye to sky enthusiasts with a view of the southern sky. Detailed inspection of the above image is allowing a better galaxy-comprehensive picture for how star formation occurs.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-The waxing Moon after sunset now forms a wide arc with Castor, Pollux, and low Procyon, as shown at right. Venus and Mercury are not far from the center of the arc's curve.

-Early Wednesday morning, the faint asteroid 332 Siri will will occult (hide) a 6.4-magnitude star east of Antares for up to 4 seconds as seen along a track from Oklahoma across northwest Texas, southern New Mexico, and southern Arizona. The star is an unusually bright one to be occulted by an asteroid, but the event happens low in the southwestern sky. Details: http://www.asteroidoccultation.com/2..._332_29849.htm

Astro Picture of the Day:
June 11, 2013

Source:
What's happening in the NGC 3582 nebula? Bright stars and interesting molecules are forming. The complex nebula resides in the star forming region called RCW 57. Visible in this image are dense knots of dark interstellar dust, bright stars that have formed in the past few million years, fields of glowing hydrogen gas ionized by these stars, and great loops of gas expelled by dying stars. A detailed study of NGC 3582, also known as NGC 3584 and NGC 3576, uncovered at least 33 massive stars in the end stages of formation, and the clear presence of the complex carbon molecules known as polycyclic aromatic hydrocarbons (PAHs). PAHs are thought to be created in the cooling gas of star forming regions, and their development in the Sun's formation nebula five billion years ago may have been an important step in the development of life on Earth. The above image was taken at the Desert Hollow Observatory north of Phoenix, Arizona, USA.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-The interesting binocular field around Antares holds the dim glow of the globular cluster M4, as many skywatchers well know. But do you also know about Rho Ophiuchi, the fine binocular triple star in the same field? It's the top of a loop of five stars including Antares.

-Mercury and Venus remain in twilight view low in the west-northwest, but Mercury is fading: from magnitude +0.2 to +0.8 from June 7th to 14th. Mercury is upper left of much brighter Venus, magnitude –3.8. Their separation closes from 5° to 3.6° during this time. Above them shine fainter Castor and Pollux.

Astro Picture of the Day:
June 12, 2013

Source:
For the first time, the entire surface of planet Mercury has been mapped. Detailed observations of the innermost planet's surprising crust have been ongoing since the robotic MESSENGER spacecraft first passed Mercury in 2008 and began orbiting in 2011. Previously, much of the Mercury's surface was unknown as it is too far for Earth-bound telescopes to see clearly, while the Mariner 10 flybys in the 1970s observed only about half. The above video is a compilation of thousands of images of Mercury rendered in exaggerated colors to better contrast different surface features. Visible on the rotating world are rays emanating from a northern impact that stretch across much of the planet, while about half-way through the video the light colored Caloris Basin rotates into view, a northern ancient impact feature that filled with lava. MESSENGER has now successfully completed its primary and first extended missions.

[ninjaKIWI]

Re: Terry's Astronomy Thread.

hi terry

[Bluearrowll]

Re: Terry's Astronomy Thread.

Hi Chocille, hi ninjaKIWI.

What's in the sky tonight?
June 13, 2013

-Look above the Moon after nightfall to spot Regulus and the Sickle of Leo.

-Saturn (magnitude +0.4, in Libra) glows in the south during evening, with Spica 12° to its right. Look almost as far to Saturn's left or lower left for Alpha Librae.

-In a telescope, Saturn's rings are tilted 17° from our line of sight.

-The sunspot number may be low, but the sun is far from blank. Amateur astronomers monitoring the sun report a large number of magnetic filaments snaking across the solar disk. Sergio Castillo captured more than half a dozen in this picture he sends from his backyard observatory in Inglewood, California:

Astro Picture of the Day:
June 13, 2013

Source:
You can see four planets in this serene sunset image, created from a series of stacked digital exposures captured near dusk on May 25. The composite picture follows the trail of three of them, Jupiter, Venus, and Mercury (left to right) dropping toward the western horizon, gathered close in last month's remarkable triple planetary conjunction. Similar in brightness to planet Mercury, the star Elnath (Beta Tauri) is also tracked across the scene, leaving its dotted trail still farther to the right. Of course, in the foreground are the still, shallow waters of Alikes salt lake, reflecting the striking colors of sunset over Kos Island, Greece, planet Earth. For now, Jupiter has wandered into the glare of the setting Sun, but Mercury and Venus remain low in the west at twilight.

[ninjaKIWI]

Re: Terry's Astronomy Thread.

wow so impersonal ...

i still read this thread all the time Terry (we lov u)

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
June 14, 2013

-The waxing crescent Moon hangs to the lower left of Regulus and the Sickle of Leo this evening.

-If you've been looking for Jupiter, stop. The glare could hurt your eyes. Jupiter is approaching the sun for an extremely tight conjunction. Today they are only 3.5 degrees apart. On June 19th, Jupiter will pass directly behind the solar disk, less than a quarter of a degree from disk center. It's a rare total eclipse of Jupiter by the sun. Because of the glare, the event is invisible to human eyes. Coronagraphs, however, block the glare and monitor Jupiter's approach.

Astro Picture of the Day:
June 14, 2013

Source:
Sharpless 115 stands just north and west of Deneb, the alpha star of Cygnus the Swan in planet Earth's skies. Noted in the 1959 catalog by astronomer Stewart Sharpless (as Sh2-115) the faint but lovely emission nebula lies along the edge one of the outer Milky Way's giant molecular clouds, about 7,500 light-years away. Shining with the light of ionized atoms of hydrogen, sulfur, and oxygen in this Hubble palette color composite image, the nebular glow is powered by hot stars in star cluster Berkeley 90. The cluster stars are likely only 100 million years old or so and are still embedded in Sharpless 115. But the stars' strong winds and radiation have cleared away much of their dusty, natal cloud. At the emission nebula's estimated distance, this cosmic close-up spans just under 100 light-years.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
June 15, 2013

-Mercury is drawing closer to Venus as it fades in the twilight, as shown below. They're 3.3° apart now and will be 2° from each other at their closest on the 19th.

Astro Picture of the Day:
June 15, 2013

Source:
Over a five hour period last Tuesday morning, exposures captured this tantalizing view of meteor streaks and the Milky Way in dark skies above Las Campanas Observatory in Chile. During that time, astronomers had hoped to see an outburst from the gamma Delphinid meteor shower as Earth swept through the dust trail left by an unknown comet. Named for the shower's radiant point in the constellation Delphinus, a brief but strong outburst was reported in bright, moonlit skies on June 10, 1930. While no strong Delphinid meteor activity was reported since, an outburst was tentatively predicted to occur again in 2013. But even though Tuesday's skies were dark, the overall rate of meteors in this field is low, and only the three lower meteor streaks seem to point back to the shower's estimated radiant.