Saturday, October 29, 2011

Jupiter, King of Planets

Last night I moved the DOB (with a little help) out to the South Porch and waited for this bright star to move above the Tree Line. Around 10 pm, I was able to center it in my FOV, an unusually good view of the planet's belts, storms, and moons.

The largest planet in the solar system, Jupiter, reaches maximum brightness the night of October 28. On this date, the planet lies opposite the Sun from Earth in our sky — this is called opposition. Jupiter will rise at sunset, appear highest around local midnight, and set as the Sun rises. The king of planets will glow at magnitude −2.9, far brighter than any other point of light in the sky. The gas giant currently lies in Aries the Ram and is about 100 times more brilliant than the brightest star in that constellation. You’ll be able to spot its dark equatorial cloud belts and even its four major moons, which align with Jupiter’s equator. The planet’s South Equatorial Belt returned in November 2010 after it mysteriously faded away for about six months.At opposition, the planet’s disk will span 49.7" across its equator but 46.5" through the poles. This difference is because the planet is gaseous and spins rapidly, thus squashing its shape.

Fast facts about Jupiter
Jupiter is the largest planet in the solar system. More than 1,300 Earths could fit inside it, and all the other planets together make up only about 70 percent of Jupiter’s volume.
It takes Jupiter about 12 years to orbit the Sun once, but only about 10 hours to rotate completely, making it the fastest-spinning of all the solar system’s planets.
Jupiter rotates so rapidly that its polar diameter, 83,082 miles (133,708 kilometers), is only 93 percent of its equatorial diameter, 88,846 miles (142,984 km).
Jupiter reflects 52 percent of the sunlight falling on it, more than any other planet except Venus (65 percent).

Jupiter’s four large moons — Io, Europa, Ganymede, and Callisto — are easily visible through small telescopes. Io takes less than two days to orbit its plamet, so its relative position visibly changes in an hour or so — less when it appears close to Jupiter.
Our line of sight lies in the plane of the jovian moons’ orbits, so we see occultations (when a moon moves behind Jupiter), eclipses (when Jupiter’s shadow falls on a moon), and transits (when a moon passes in front of Jupiter) at various times. Jupiter’s moon Ganymede is the solar system’s largest satellite, with a diameter of nearly 3,300 miles (5,300 km), which is greater than that of Mercury


StarLog ^1028Y2K+11

Jupiter is at opposition tonight, opposite the Sun as seen from Earth. This an unusually close opposition of Jupiter, one of the closest in its 12-year cycle.

I counted 3 moons visible and the bands were bright and clear on the surface. There was a black shadow, mid way on the second band. This was from the Io, just completing transit.
G------------(J)---E-------C

After 11pm I put the bright planet and 4 moons in the FOV.
G-----------I-(J)----E------C

I swung the scope over to Andromeda and spotted the Galaxy, floating where I left it the last time I captured it in my FOV. Left the scope idle, did not make it back out, this crisp, cold night.

November, week one highlights:
Look for Saturn and Spica low in the dawn sky
Saturday night the crescent Moon is higher and easier to spot now after sunset. Its round side points to the lower right, toward very low Venus and Mercury.
Sunday the waxing crescent Moon is 4 days old. It's a great time to explore the Moon with binoculars or a small telescope
Monday night, Halloween evening finds the crescent Moon lowering in the southwest and bright Jupiter rising higher in the east. Perfect for setting up your telescope in the driveway and giving looks to visiting trick-or-treaters!
The First-quarter Moon is Wednesday, (exact at 12:38 p.m.). The half-lit Moon stands high in the south at sunset. As the stars come out, the Moon reveals itself to be above the dim star-pattern of Capricornus.
Look lower left of the Moon Thursday evening, by two or three fist-widths at arm's length, for Fomalhaut, the Autumn Star.
Next week end, Daylight-saving time ends (for most of North America) at 2 a.m. Sunday morning. Clocks "fall back" an hour.

News from the Net:
Asteroid Lutetia May Have A Molten Core
Astrophoto: Comet Garradd by Bob Christmas
Russia Fuels Phobos-Grunt and sets Mars Launch for November 9
NASA Issues Report On Commercial Crew as SpaceX’s CEO Testifies About SpaceX’s Progress
Science Fiction No More: Humans and Robots to Explore Space Together
Observing Alert: Bright Spot On Uranus Reported
Astrophoto: Mu Cephei by Jan Inge Berentsen Anvik
Astronomy Without A Telescope – Dark Matter Science

Monday, October 24, 2011

Earthshine and a Meteor

Early morning visual astronomy in a crisp, clear sky just before sunrise. Heading out for an early breakfast , we saw the last quarter crescent moon high in the night sky with the glow of the earth shining visible on the surface. Always an awsome sight to behold. Yesterday morning a report from the wife on her early morning walk : a meteor hit the atmosphere with an obvious explosion (bright color, light) about 40 degrees in the North. After the bright colorful light, it streaked downward to the west, then disappeared. Space junk? Most likely a meteor! These are great events and seen often, but I suspect they happen a lot more than reported. Always feel special when we can catch them streaking across the sky.

It should be clear and crisp again, after this cold front blows in Thursday...
Jupiter and Mars still provide the planetary show. At opposition to the Sun next Friday the 28th, Jupiter rises just after sunset, is nicely up in the east by the time the sky is dark, and is with us all night, crossing the meridian to the south around local midnight (1 AM Daylight Time). The planet is so bright (minus-third magnitude) that it is drawing considerable public attention. About half an hour after Jupiter moves into the sky's western half, Mars, now scurrying toward the Sickle of Leo, rises, the orangy-red color of the planet making a nice contrast with blue-white Regulus.

News from the Net:
Stunning New Cassini Image: A Quartet of Moons
Astrophoto: Moon And Saturn by Jeff Swick
ROSAT’s Crash Site Determined

Sunday, October 23, 2011

My Sky in October's Last Week

Last Thursday at the Group meeting, seven of us discussed the cloudy forecast for the Saturday Night Stargazing event at the TPL. By noon Friday the forecast had changed some and the Event went to GO! The clouds did move in and out all day Saturday. A note from Larry Sunday, indicated that the Event was a Big Success!

Five Planets in the Night Sky this week:

In their outward order from the sun, the visible planets are Mercury, Venus, Mars, Jupiter and Saturn. These planets are easy to see without an optical aid, so they were known to our distant forebears since time immemorial.
Tonight, Mercury is 2.6 degrees to the lower right of Venus. Look for Venus and Mercury with binoculars very low in the WSW 30 minutes after sunset.
Saturn is emerging from behind the Sun. Look very Low in the east 35 minutes before sunrise. The red planet Mars lights up the wee morning hours, not far from Regulus, the constellation Leo’s brightest star. Jupiter (magnitude –2.9, in southern Aries) shines low in the east-northeast in twilight, then blazes higher in the east to southeast all evening. Look above it for the stars of Aries and below it for the head of Cetus, rather dim. Jupiter is nearly at its highest in the south by midnight. It's a big 49 arcseconds wide, as big as it will appear at its October 28th opposition.

We are expecting cloudy skies Wednesday and Thursday nights with a real Cold front due here. There is a New Moon in the sky Wednesday (exact at 3:56 p.m. EDT). This is a period for a high tide alert!

By Friday, with a clear cold night, after the front moves through, look in bright twilight for the thin waxing crescent Moon very low in the southwest. Venus is to its lower right.

By 9 or 10 p.m. this week, the Autumn Star, Fomalhaut, shines at its highest in the south (not all that high). Fomalhaut is 25 light-years away — exactly the same distance as Vega, shining brighter high in the west. So, the difference in brightness that you see is the two stars' actual difference in true luminosity. Vega looks 1 magnitude brighter than Fomalhaut (in other words, 2.5 times brighter), and so it really is.

News from the Net:
Bringing Satellites Out Of Retirement – The DARPA Phoenix Program
Astrophoto: Cassiopeia by Matt W. Childs
What Happened On the International Space Station this Week?
Astrophoto: The Prawn Nebula
Curiosity Buttoned Up for Martian Voyage in Search of Life’s Ingredients
ROSAT Satellite has Re-Entered; No Reports of Debris
Stunning Loops and Filaments on the Sun Today
Astrophoto: Close-up Image of the Moon by Andrei Juravle
Astrophoto: The Pleiades by Eduardo Marino

Tuesday, October 18, 2011

Mid October Skies

Now that it's mid-October, Deneb has replaced Vega as the zenith star after nightfall (for skywatchers at mid-northern latitudes). Accordingly, Capricornus has replaced Sagittarius as the most notable constellation low in the south. Jupiter shines brightly in the east during evening. Capella shines a little less brightly in the northeast, somewhat lower (depending on your latitude). These are the two brightest lights in the whole eastern side of the sky. Now find the midpoint between them. A little below that point are the Pleiades.

Our Last-quarter Moon is Wednesday evening (exact at 11:30 p.m. Eastern Daylight Time). The Moon rises around midnight local time, below Gemini and left of Procyon. Later this week, before and during dawn Friday morning, look for Mars to the left of the Moon.

Friday Evening This year’s Orionids will peak on the evening of October 21/22. These meteor fragments radiate from the top of Orion’s upraised club, near the Gemini border. Meteor specialists have meteor counts for this pass averaging a modest 20 per hour under dark skies. The moonlit glare of the waning crescent Moon, however will probably reduce the numbers somewhat this year. The best time to view these meteors is usually in the wee hours before dawn. That time holds true no matter what time zone you’re in.

Next Saturday, the first Stargazing Event will be held up at the TPL. The Group will have several folks at the event with Scopes set up with great items in the FOV. Fomalhaut, the Autumn Star, shines low in the south-southeast after dusk next Saturday. It's due south later in the evening. The western (right-hand) side of the Great Square of Pegasus, very high in the sky, points down nearly to Fomalhaut.

The ROSAT X-ray observatory, launched in 1990 by NASA and managed for years by the German Aerospace Center (DLR), will return to Earth within soon. The massive ROSAT X-ray space telescope continues to descend toward Earth. Latest estimates place the re-entry around noon Universal Time on Oct. 23rd. Uncertainties exceed 10 hours, which makes it impossible to say exactly where ROSAT will re-enter. Many sky watchers are seeing ROSAT in the night sky shining about as brightly as a 1st magnitude star. Check Spaceweather's Satellite Tracker for local flyby times. (There's an app for that, too.)According to a DLR study, as many as 30 individual pieces could survive the fires of re-entry. The largest single fragment would likely be the telescope's mirror, which is very heat resistant and may weigh as much as 1.7 tons.

More News from the Net:
A Tale of Three Moons: Is There Life in the Outer Solar System?
Astrophoto: Flame Nebula and Horsehead Nebula by Fabricio Siqueira
Dawn Discovers Surprise 2nd Giant South Pole Impact Basin at Strikingly Dichotomous Vesta
Coming in 2012: Our Last Transit of Venus
Wake Up! The Orionid Meteor Shower Peaks On October 20…
Digging Deeper For Dark Matter
NASA to Test New Atomic Clock
All-Sky Camera Captures Mysterious Flashes

Tuesday, October 11, 2011

Sky-Watching in the Second week of October

The forecast is not the best until mid week when we get a partly cloudy sky in the evening. We did have some “good rain” here over the past few days! The Night Sky is expected to clear by the weekend for the Alignment and first light at the TPL Dome Telescope.

Our Full Moon is Tuesday evening, (exact at 10:06 p.m. Eastern Daylight Time). The Moon is in dim Pisces, below the Great Square of Pegasus. There's a full Moon tonight and according to folklore it has a special name--the Hunter's Moon. It gets its name from Native American hunters who tracked and killed their prey by autumn moonlight, stockpiling food for the winter ahead. This year's Hunter's Moon is beautifully close to the planet Jupiter. [sky maps: Oct. 11, 12, 13]

Try and catch bright Jupiter in my FOV Wednesday night and Thursday night, which is nearing its opposition, shines close to the Moon, which is just past its own opposition (full Moon).

At the end of the week, Friday, Binoculars show the Pleiades left of the waning Moon this evening. Saturday night, the moon will be above the Seven Sisters. Next Saturday, a few folks from the Group plan to place the 11” scope in the Dome at the TPL and align the Telescope for first light there.

News from the Net:
Amazing New View of the Mt. Everest of Vesta
Video: A Rover’s 3-Year Drive Across Mars
A Meteorite Visits the Comettes
Suitable For Framing: Latest Eye Candy from Cassini
Welcome To The Heart Of The Milky Way…
Did The Draconids Perform?
Astrophoto: The Distant Worlds of Uranus and Neptune by Rolf Wahl Olsen

Monday, October 3, 2011

October Night Skies

This October started with a Star Party at the TPL new site, last Saturday night. Larry and a few others from the Group set up their scopes in the parking lot ( I did not make it). The Dome has been moved, but not completely set up with a scope yet. The Pier for the scope has to set up a week first. Several folks from the Library were there and viewed the sights from the eyepiece at the scopes. Larry mentioned that there was some city lights that interfered a bit in East and there was moonlight from an early crescent moon!

The winds of change from the NE have brought us cooler nights...finally! By the end of the week, a Pacific front will bring back the clouds! Bad news for the IOMN Event set up at the NB Library at the end of the week, next Saturday! Also we wll miss the meteor shower set to pass over us next weekend. This week I hope to catch Jupiter, and try and view that Comet again in Hercules this week.

It is the time of year, if you’re in the northern hemisphere, try looking northeast this evening for two prominent constellations, Cassiopeia and Perseus. The easier to see will be Cassiopeia, which has a distinctive M or W shape, depending on what time of night you see it. This constellation represents a Queen in ancient mythology. Cassiopeia is easy to identify and so it is one of the most famous constellations in the sky. You’ll see it in the northeast this evening, and higher up in the evening sky in late fall and winter. Perseus (the Hero) follows Cassiopeia across the night sky. As night passes, you’ll see them both ascending in the northeast — then arcing high in the north — then descending in the northwest — with Perseus following Cassiopeia all the while.

Our First-quarter Moon is Monday(exact at 11:15 p.m. Eastern Daylight Time). The Moon hangs above the Sagittarius Teapot after dark. I am already seeing moon beams across the drive!

Look a little above or upper right of the Moon Wednesday evening for Alpha and Beta Capricorni. Binoculars easily reveal Alpha as a wide, yellow double star. Beta (nearer to the Moon) is also a double, but its closer, unequal components are harder to resolve.

The weekend forecast has Rain! Too many clouds will hide the stars above my backyard. But here is what I will miss should the clouds remain over my portal:

Look high in the east Friday evening, if it is not cloudy, far left of the Moon, for the Great Square of Pegasus. It's balancing on one corner. Your fist at arm's length probably just fits inside it.

Forecasters say Earth is heading for a stream of dust from Comet 21P/Giacobini-Zinner. A close encounter with the comet's fragile debris could spark a meteor outburst over parts of our planet on October 8th. [full story] [meteor radar] The Draconid (Giacobinid) meteor shower may put on an intense burst of activity during good observing hours for Europe or possibly elsewhere. Various predictions put one or more outbursts between about 17:00 and 20:30 Universal Time (GMT). The shower's radiant is near the head of Draco, but the meteors themselves can flash into view anywhere in the sky. Unfortunately, the light of the waxing gibbous Moon will obscure all but the brightest of them.