Waning moon moons Saturn at dawn tomorrow

Saturn lies just a degree from Beta Scorpii, a fine double star for small telescopes. Tomorrow morning a waning lunar crescent will join the pair in a fairly close conjunction. This photo shows the sky facing southeast at the start of morning twilight. Credit: Bob King

Have you seen Saturn at dawn yet? No? Here’s a great excuse to go out. The waning crescent moon squeaks just 1° north of the planet tomorrow morning in a close conjunction. It all happens not far from Antares, the fiery heart of the summertime constellation Scorpius the Scorpion.

Look low in the southeast tomorrow morning (Friday) Jan. 16th just when the sky starts to brighten at dawn. First you’ll notice the moon. Right below it will be Saturn, and one degree below Saturn, the sweet double star Beta Scorpii. Source: Stellarium

I know that getting up at 6 or 6:30′s not much fun, but I’m convinced that if you act boldly and wisely (dress well for the cold), you’ll return to the warmth of your home a half-hour later with a smile on your face.

Seeing the conjunction requires no optical aid whatsoever, though a pair of binoculars will show nice details on the moon as well the smoky glow of earthshine on the portion not illuminated by the Sun. Saturn requires only a telescope magnifying 30x or higher for a good view.

Saturn, its fab rings and brightness moons depicted for Friday morning. Source: Stellarium

While we’ve been sleeping, Saturn’s rings have been tilting ever more in our direction. Now at mid-month, they’re tipped nearly 25° – almost to their 27° max – and really look showy.

Saturn never travels alone, preferring instead to sally about with its grand family of moons. The diagram above shows the positions of the brightest ones tomorrow morning around 6:30 a.m. (CST).

Saturn in late August 2014. We currently view the north face of the rings. Credit: Paul Maxson

Finally, you’ll notice a modestly bright star just south of Saturn. That’s Beta Scorpii or Graffias, one of the sky’s best and brightest double stars. The 2.6 and 4.5 magnitude stars nestle together like chicks in a nest. Even a 3-inch telescope will show them.

So get out there and say “hi!” to the ringed planet tomorrow.

12 new telescopes to beam in on Earth-sized exoplanets

Artistic representations of all the potentially habitable exoplanets ranked from best to worst by the Earth Similarity Index (ESI), a measure of Earth-likeness based on the host star’s energy output and planet size. Planets with high ESI values are not necessarily more habitable as habitability depends of other unknown factors such as surface and atmospheric composition. Earth, Mars, Jupiter, and Neptune are shown for scale on the right. Click to enlarge. Credit: Phil@UPR Arecibo

The tally grows like digits ticking up on the take-a-number display in a New York deli. 1,876 extrasolar planets as of Jan. 9th this year. 475 of them are multiple planetary systems or true solar systems around other stars. Most are huge, gaseous, beefier than Jupiter and searingly close to their host stars to be happy places for life.

Locations of stars with potentially habitable extrasolar planets. The cluster at upper right is along the border of Lyra and the Northern Cross where NASA’s Kepler spacecraft continually measured the brightness of over 145,000 stars for almost 5 years, finding many planets in the process. Click to enlarge. Credit: PHL @ UPR Arecibo / Jim Cornmell

Of the 1,876, just 28 lie within their stars’ habitable zones where liquid water can pool and remain on the surface long enough to offer the potential habitat for life as we know it. Drilling down further, only 10 of the 28 are similar in size to Earth. Yet based on data returned by NASA’s Kepler exoplanet mission, scientists estimate there could be more than 40 billion Earth-sized planets in the Milky Way alone.

The Next-Generation Transit Survey (NGTS) is located at  Paranal Observatory in northern Chile. This time exposure view shows the telescopes during testing. The bright moon appears in the center of the picture and the VISTA (right) and VLT (left) domes can also be seen on the horizon. Credit: ESO/G. Lambert

Astronomers constantly refine and build new equipment to track down ever-smaller planets with the hopes of finding more clement Earth-like worlds. Enter the Next-Generation Transit Survey (NGTS), a system of dozen wide-field 8-inch (20 cm) telescopes, designed to discover transiting exoplanets of Neptune-size and smaller around stars as faint as magnitude 13. Hosted by the European Southern Observatory (ESO), the project is based at Paranal Observatory in southern  Chile, where the skies are exceptionally dry and clear.

NGTS is fully robotic and optimized to detect bright but relatively small and cool orange and red host stars. These stellar dwarfs are not only the most numerous stars in the universe, but they burn their nuclear fuel frugally, giving them very long lives. Those factors in turn increase the potential for habitability.

Animation showing an extrasolar planet passing in front of a star, causing its light to dim. By studying the light curve astronomers can determine planets sizes and other details. Credit: Transits of Extrasolar Planets Network

As a planet passes in front of its parent star it produces a slight dimming of its light that sensitive equipment attached to the telescopes will record. By studying the periodic brightening and fading of a star’s light, astronomers can determine the size, mass and other characteristics of an orbiting alien planet.

NGTS will continuously monitor the brightness of hundreds of thousands of comparatively bright stars in the southern skies with an accuracy of one part in a thousand, a level never attained before with a ground-based survey.

It may also be possible to probe the atmospheres of the exoplanets. During the transit some of the star’s light passes through the planet’s atmosphere, if it has one, and leaves a tiny but detectable signature. To date we’ve uncovered basic atmosphere compositions of a few planets, but NGTS should provide many more potential targets.

Once-in-6-year-alignment makes Jupiter’s moons dance in shadows

Jupiter and his Great Red Spot photographed on January 3rd through a 14-inch telescope. Credit: Paul Maxson

Now that Jupiter’s up in the east by 9 o’clock local time, we have lots of opportunities to observe it before bedtime. That’s good because the Jupiter system is currently edge-on to the Earth and Sun, allowing us to see the planet’s brightest moons eclipse and occult one another now through August.

Io, Europa, Ganymede and Callisto all orbit very close to the plane of Jupiter’s equator. From our perspective on Earth, the moons usually pass a little above or below one another and escape each other’s shadows. But every six years or so, Earth and Sun cross the plane of the satellites’ orbits putting us “level” with Jupiter’s equator.

Instead of missing one another, the moons appear to merge into one during occultations and cast their shadows on one another during eclipses. This cyclic but relatively rare planetary alignment last happened in 2009 and won’t again until 2020.

The six varieties of eclipses and occultations possible among Jupiter’s four brightest moons now through August. Credit: Dave Dickinson

While you may not be able to resolve the four brightest moons in your telescope, you’ll have no difficulty watching them approach one another and meld into either an extremely close “double moon” or a single object during an occultation. Minutes later, the pair breaks apart as each moon follows its own track around the mothership.

Io eclipses Ganymede back on August 16, 2009. Credit: Christopher Go

During an eclipse, one moons will cast a shadow on another, causing it to fade the same way our moon dims when entering Earth’s shadow during a lunar eclipse. Assuming a fairly deep eclipse, you’ll be able to watch a Jovian moon fade and then re-brighten in a matter of minutes.

Again, you won’t see the shadow itself because the moons are so tiny, but the drop in brightness is clearly visible especially during deep eclipses.

With Jupiter coming to opposition on February 6th you’ll have lots of opportunities to catch at least one of each type of phenomenon. Not to mention, that all the moons cross over the Jupiter’s bright equatorial zone as they orbit the planet, making shadows they cast on the cloudtops easier than ever to see. Those are called shadow transits, and we’ll feature those soon, too.

Io eclipses Ganymede on Christmas night 2014. Credit: Paul Maxson

Below is a list of the best upcoming mutual events of the four brightest satellites for locations across North America. To view them, you’ll need at 3-inch or larger telescope.

A drop of 0.5 magnitude or larger during an eclipse or occultation should be apparent to the eye by carefully comparing before and after views. For occultations, you can also have the pleasure of seeing the moons in close embrace

Two for the price of one. Io occults and then eclipses Europa in this animation of still photographs taken on September 28, 2009. Credit: Brian Combs

For a customized table of events when Jupiter’s easily visible in a dark sky from your location, click over to this list of observatories, do a Control-F (Command-F on Mac) and type in the name of a larger city within a few hundred miles of your location. Next, copy the 3-digit code number and then paste it into the window on the IMCCE table creation page. Click enter and you’ll get a handy list of every event visible from your location through August.

To help you pick which eclipse events are worth your time, make sure the “Δm” (change in magnitude) is 0.5 or greater. Times listed in the table are Universal Time. Subtract 5 hours for EST, 6 for CDT, 7 for MST and 8 for PST. Also, each moon is listed by number rather than name. Io=1, Europa=2, Ganymede=3 and Callisto=4, so “2e4″ means Europa eclipses Callisto.

More event information and some great animations are available at SAF Planetary Observation Commission’s page.

Events – Times are CST:

Jan. 15 – Io eclipses Callisto starting 6:13 a.m., ending 6:39 a.m. Magnitude drop: 0.5
Jan. 18 – Ganymede occults Europa starting 8:31 p.m., ending 8:37 p.m. Mag. drop: 0.5
Jan. 23 – Callisto eclipses Ganymede starting 3:06 a.m., ending 3:20 a.m. Mag. drop 1.4!
Jan. 25 – Ganymede occults Europa starting 11:13 p.m., ending 11:19 p.m. Mag. drop 0.5
Jan. 28 – Europa eclipses Io starting starting 12:18 a.m., ending 12:27 a.m. Mag. drop 0.5
Jan. 29 – Io occults Europa starting  8:31 a.m., ending 8:35 a.m. Mag. drop 0.6

Nice sequence showing Io occulting Ganymede on December 21, 2014. The moons meet and part over 22 minutes. Credit: Paulo Casquinha

Bear in mind, these are the most easily observed events. There are many more! I’ll post a new list at the beginning of every month through the summer. Let us know if you get to see one of these. Good luck!

Dragon captured, Christmas finally comes to the space station

Frame grab from video of the spectacular burn of Falcon 9′s nine first-stage engines during Saturday’s morning’s launch of the Dragon cargo ship to the ISS. Credit: NASA

SpaceX has successfully delivered it fifth cargo mission to the International Space Station. Astronauts Barry “Butch” Wilmore and Samantha Cristoforetti captured the Dragon, the named of the free-flying space ship, at 7:54 a.m. today January 12th. The ship will remain attached for the next four weeks.

The Falcon booster (right) and possibly the cargo ship (left) in a photo taken this past Saturday morning January 10th near Pike Lake, Minn. Credit: Stephanie Francis

Over the weekend two readers contacted me about seeing an amazing sight Saturday morning around 7 a.m. (CST). They described a hazy, glowing, mushroom-shaped object trailed by three fairly bright stars that first appeared near the moon traveling east. In case you saw it too, you were a lucky viewer of the Falcon 9 S2 booster, two ejected solar panels and the Dragon ship.

The SpaceX Dragon (with solar panels) is attached to the Harmony module. Credit: NASA TV

Dragon is crammed with a record breaking 5,108 pounds (2317 kg) of cargo to make up for some of the cargo lost on the Antares failure back in October. Its primary payload is NASA’s Cloud Aerosol Transport System (CATS) that will spend between 6 months and 3 years studying the location, composition and distribution of dust, smoke, pollution and aerosols (things like sea salt, dust and volcanic ash) from 250 miles up. CATS will gather data by shooting pulses of laser light into the air using Light Detection and Ranging (LIDAR) technology.

On a more personal note, the ship will deliver belated Christmas presents to the 6-person crew plus essential food, water, clothing and spare parts. Besides the CATS system, 17 student experiments called the “Yankee Clipper” mission as well as science experiments to be conducted by the astronauts are included in the delivery.


Liftoff of Falcon 9 with the Dragon cargo ship

Among the student experiments, one will analyze the effect of microgravity on the attachment rate of E. coli bacteria to lettuce cells. Another will study whether teeth decay more quickly in microgravity. The list goes on. Smart kids.

All the goodies will be unpacked starting tomorrow when the crew will open the hatch of the Harmony module of the space station, where Dragon is docked. Merry Christmas!

Mars gets a new crater, smiles for the camera

This new crater excavated by an impacting meteorite on Mars shows a striking pattern of ejecta – rocks and other debris blasted off the surface during the impact. The shape of the ejecta indicate that the incoming space rock likely struck from the west (left). Credit: NASA/JPL/Univ. of Arizona

Close your eyes. OK, now open them again. In a cosmic blink of the eye, this brand new crater appeared on the Martian plain called Elysium. It formed sometime between February 2012 and June 2014 as revealed by NASA’s Mars Reconnaissance Orbiter (MRO). A previous image showed only ancient cratered terrain.

Before (left) and after photos show relatively smooth plain with numerous older crater and the fresh impact (right). Credit: NASA/JPL/Univ. of Arizona

The impact exposed removed the ubiquitous orange-hued dust to reveal darker materials beneath the surface. The crater’s rim has a sharp outline showing virtually zero erosion. Some of the smaller, irregular divots near the strike were formed when huge chunks of rock from the impact fell back to the surface creating secondary craters.

A closer-in view shows how sharp and fresh the crater’s rim is. One way astronomers estimate relative ages of craters by examining how sharp or soft their rims appear. Click for hi-res image. Credit: NASA/JPL/Univ. of Arizona

This is far from the first fresh crater recorded at Mars by orbiting spacecraft. More than 400 have been found over the years as researchers pour over the hundreds of thousands of images returned by probes like MRO. Although I have no indication how large our featured crater is, the largest new crater ever discovered on the planet measures 161 feet (49-meters) or half the length of a U.S. football field.

How Mars’ largest new crater was discovered

We wrap up today with a big smile from the Red Planet’s south polar cap. MRO takes images throughout the Martian year (687 Earth days) of the polar regions to document changes in carbon dioxide ice coverage. Mars’ polar regions contain both water and CO2 ices which vaporize in the spring and summer heat, causing the caps to shrink back toward their respective poles.

The residual polar cap at Mars south pole in the summer season is rich in carbon dioxide or dry ice. Ice vaporizing in sunlight created as series of low mounds that resemble a smiling face. Click to enlarge. Credit: NASA/JPL/Univ. of Arizona

This fun photo was taken last November 30th and depicts an area about 1/3-mile across (500 meters) that resembles a smiley face. Just as sunlight and wind sculpts wild patterns in snow and ice on Earth, so too on Mars.

Look! Up in the sky! It’s a bird. It’s a plane. Wait, it’s Mercury and Venus at their closest!

Mercury and Venus 45 minutes after sunset last night in the southwestern sky. The planets will be even closer tonight and remain near each other for about another week. Credit: Bob King

I was amazed at how close and easy to see Mercury and Venus were last night so I took a picture to prove it. But the picture only hints at how cool these two planets looked together. And how easy they were to see.

If it’s clear tonight, I encourage you to go out to see them yourself. They’ll be even closer – just a tad more than the width of a full moon. Start looking about 30 minutes after sundown about 10° (one fist held at arm’s length) above the southwestern horizon well to the left of the sunset point.

Venus blazes but Mercury’s a little fainter and will lie to the right and below the brighter planet. At 45-50 minutes after sunset Mercury will be plain to see. This is one of the best apparitions of the year for the solar system’s smallest and swiftest planet, so I encourage you to seize the moment.

Comet Lovejoy last night January 9th photographed with a 200mm telephoto on a tracking mount. The big, full-moon-size coma glow a subtle blue-green; the gas tail, made mostly of carbon monoxide, fluoresces blue in sunlight. Details: f/2/8, ISO 800, 2-minute exposure. Credit: Bob King

Seen Comet Lovejoy yet? I froze a few fingers getting some pictures of it last night. The comet’s still 4th magnitude and easily visible from a dark sky. It looks like a faint, fuzzy star with the naked eye but shows big and bright in 10×50 binoculars with a faint 1° tail pointing to the north-northeast. For a more in-depth article on viewing and finding the comet, please take a look at How to Find and Make the Most of Comet Lovejoy.

Hard to resist the three stars in the Belt of Orion and his sword that holds the Orion Nebula (bottom), one of the best sights in the sky. At upper left, next to the easternmost belt star, is the fainter Flame Nebula, another nice target for amateur telescopes. Credit: Bob King

 

Comet Lovejoy’s tail gets pinched / Let there be (refracted) light!

Lovejoy gets kinky. In this photo taken January 8th, the comet’s tail is caught in the act of separated from the head or coma. Magnetic fields embedded in the stream of particles from the Sun occasionally reconnect on the rear side of a comet and pinch off its tail. Credit: Rolando Ligustri

Looks like Comet Lovejoy got its locks trimmed again. A flutter of solar wind swung round the comet and pinched off its tail, an event captured in the dramatic photo above. You can already see a new tail growing in place.

The solar wind, a dilute stream of electrons and protons blown free of the Sun, wafts across the solar system and touches everything from the biggest planet to the smallest comet.

An ion or gas tail like the one in the photo forms when cometary gases, primarily carbon monoxide, are ionized by solar radiation and lose an electron to become positively charged. Once “electrified”, they can be twisted, kinked and even snapped off by magnetic fields embedded in the Sun’s particle wind.

Having passed closest to the Earth on January 7th, Comet Lovejoy is now high in the southeastern sky at nightfall and near its maximum brightness of 4th magnitude. It’s a little dim with the naked eye, but once you know where to look, I think you’ll be surprised how easy it stands out. At least from the less light-polluted outer suburban and rural areas.

If you can find Orion, you can find the comet. Use Betelgeuse and Rigel (above and below the constellation’s 3-star belt) to form a right triangle with Comet Lovejoy. Once you fix the spot with your eyes, you may see the comet directly. If not, just point your binoculars there and sweep around a bit. Source: Stellarium

I’ve been using bright stars in Orion and Taurus to first guide my binoculars – and then my eye – to the comet. It’s easy to use two bright stars, like Aldebaran and Betelgeuse, and extend a line from each to form a triangle with Lovejoy at one of the corners. If you then point binoculars at that spot in the sky, the comet should pop out. You can then lower the binoculars to see if you can spot it with your naked eye.

The map above is drawn just for tonight. Click HERE for a map showing the comet’s changing position through January 23rd.

A halo rings the bright moon and planet Jupiter (upper left of moon) Wednesday night. Ice crystals in high cirrostratus clouds bends or refracts moonlight into a circle of light. Credit: Bob King

Two nights ago, when I last looked at the comet, a bank of icy cirrostratus clouds moved in around moonrise and created a lovely halo around the moon and Jupiter. These familiar high, wispy clouds are composed of myriad six-sided ice crystals resembling the cells in a honeycomb. Light entering one side of the crystal is refracted or bent out another side. Add up billions of these tiny bits of bent light and they to form a circle around the Sun or moon called a 22-degree halo. The number indicates the radius of the halo or distance from the moon to the edge.

The Sun rises over a “steamy” Lake Superior in Duluth this morning as seen through the window of a local hospital. Credit: Bob King

At the moment, a large swath of the U.S. is steeped in bitter cold air. That often means clear skies at night. Allow yourself at least 5-10 minutes to get your eyes used to the darkness and then another 5 hunting for the comet. If you plan it right, you can be in and out in 20 minutes!

Patches of iridescent colors glow near the Sun an hour after sunrise this morning. Light scattered or diffracted by the extremely small ice crystals in the clouds creates a full range of vivid colors. A single sundog glows at left from light refracted by ice crystals in lower clouds or perhaps within a frozen wisp of vapor rising from the lake. Credit: Bob King

In Duluth, Minn. this morning the temperature dipped to around -10F°. Whenever we go below zero, water vapor above warmer Lake Superior condenses in the chill air into curly wisps of fog locally known as “steam fog”. This made for a very pretty sunrise. If that wasn’t enough, high altocumulus clouds passed near the Sun shortly after sunup, creating a palette of delicious greens, reds and purples. We even had a solitary sundog appear for a few minutes in a different set of lower clouds composed of ice crystals.

A closer view of the Sun and the strikingly beautiful iridescence. Click to learn more about diffraction and iridescence. Credit: Bob King

What a treat for the eyes! My wife and I saw all this unfold from the window of one of the local hospitals where we’d gone for a routine procedure. Whenever light puts on a show like it did this morning, I always tell myself I really need to get up earlier to catch more sunrises. And pack something a bit higher-end than a mobile phone!

Milky Way’s black hole freaks out, has record flare

The main portion of this photo shows the area around Sagittarius A* where low, medium, and high-energy X-rays are red, green, and blue respectively. The inset box contains an X-ray movie of the region close to Sgr A* and shows the giant flare. Credit: NASA

26,000 light years from your front door in the heart of the Milky Way galaxy lurks a black hole 4.5 million times more massive than the Sun. Every so often something strays too close to the massive abyss and gets sucked in – a star, rogue planet, asteroid or clots of interstellar gas and dust. As they swirl toward the center of the hole, called a singularity, the material gets heated to millions of degrees and radiates vast amounts of radiation – mostly as powerful x-rays – before disappearing forever.

In this illustration, a supermassive black hole is surrounded by matter flowing onto the black hole from a swirling disk of dust and gas attracted from the hole’s surroundings by its gravity. Also shown is an outflowing jet of energetic particles, believed to be powered by the black hole’s spin. High-energy x-rays from infalling matter lights up the disk. Credit: NASA/JPL-Caltech

Astronomers call the location of the supermassive black hole Sagittarius A* (pronounced Sagittarius A-star), a very bright and very compact object about the size of the solar system in the constellation Sagittarius.  Sgr A* normally sputters with x-rays from incoming material, but on September 14, 2013, astronomers saw the largest X-ray flare ever detected. Captured by NASA’s Chandra X-ray Observatory, this firecracker event was 400 times brighter than the usual X-ray output from Sgr A*. Another flare 200 times brighter than normal happened a little more than a year later last October.

X-rays occupy the high-energy end of the electromagnetic spectrum. What we see as the rainbow of colors comprises just a small slice of light’s extensive range of wavelengths. Credit: Univ. of Oregon

There are two theories as to what might cause these sudden x-ray outbursts. The black hole could have torn apart an asteroid in its vicinity, heating the debris to high enough temperatures to produce x-rays before devouring the remains. Their other proposed explanation involves the strong magnetic fields.

Magnetic forces around black holes can nearly equal their gravitational prowess. If the magnetic field lines around the hole reconfigured themselves and reconnected, this could also create a large burst of X-rays. Such events are seen regularly on the Sun – think of the coronal mass ejections that can spawn auroras –  and the events around Sgr A* appear to have a similar pattern in intensity levels to those.

This simulation of a gas cloud passing close to the supermassive black hole at the center of the galaxy shows the situation in mid-2013. The cloud is now so stretched that the front part of it has passed the closest point and is travelling away from the black hole at more than 6 million mph, while the tail may still be falling towards it. Credit: ESO/S. Gillessen/MPE/Marc Schartmann

Astronomers have been closely watching Sgr A* in the past few years to see if the black hole would devour a nearby cloud of gas known as G2. G2 was discovered zooming toward the hole in 2011 possibly on a collision course. The most recent observations however reveal that it narrowly missed a fateful plunge – for now. Had it been involved in the recent outbursts, its end was expected to spawn a flurry of x-rays. But due to G2′s distance from Sgr A* at the time of the September 2013 flare, researchers don’t think the gas cloud was responsible for the spike.

It’s a pity we can’t see Sgr A* and the busy environment of smaller black holes, dust clouds and star clusters that surround it with normal light telescopes. So much dust lies between us and the galactic center, it’s dimmed by 25 magnitudes. That’s like turning the blazing disk of the Sun into an object only as bright as Jupiter at night. Astronomers use Chandra and other dust-penetrating wavelengths of light like infrared and radio to “see” Sgr A*.

Surprise auroral storm / Comet Lovejoy update / Jupiter,moon tight tonight

Aurora and the Full Wolf Moon photographed on January 5th from Abisko National Park in Sweden. A surprise auroral storm early this morning produced auroras visible across Canada and the northern U.S. even in moonlight. Click to see more aurora photos. Credit: Oliver Wright / oliverwrightphotography.com

No one suspected it was coming, but this morning from about 3 a.m. till dawn (Central time) Earth’s magnetic bubble went bananas and busted out with auroras. At peak, the Kp index hit “7″ for a G3 or strong geomagnetic storm. If only we’d known.

The auroral oval around 3:30 a.m. (CST) January 7th. Credit: NOAA

The storm appears to have been sparked by a large coronal mass ejection that may have occurred on January 3rd. The blast was originally thought to have happened on the far side of the Sun.  As the rogue solar winds passed Earth, its embedded magnetic field happened to “point south”. South-pointing magnetism find easy linkage with Earth’s north-pointing field, opening a portal for solar electrons and protons to stream in and incite polar auroral displays.

A G3 event expands the ever-present auroral oval far enough south that even folks in Illinois and other mid-western states as far south as Illinois will see the northern lights. While the activity has dropped off this afternoon, minor storming is still expected early this evening. Look to the north before moonrise for signs of a bright greenish arc.

Comet Lovejoy through a 200mm telephoto lens yesterday January 6th around 7 p.m. (CST). The comet was fainly visible with the naked eye. You can just see the tail pointing to the left of the blue-green coma. Details: 2.5 seconds, ISO 16,000. Credit: Bob King

Earlier last night before moonrise, we had clear skies here in Duluth, Minn., presenting us with a brief but nice showing of Comet Q2 Lovejoy in the constellation Eridanus. With only about 20 minutes of dark sky and the comet relatively low in the southeast it was still faintly visible with the naked eye. My 10×50 binoculars offered up the best view of the comet’s big, condensed coma; it was surprisingly easy to see about 1.5° (three full moon diameters) of faint tail streaking off to the northeast.

Watch for the waning gibbous moon to rise in conjunction with the planet Jupiter this evening. This map shows the sky facing east around 9 p.m. local time. Source: Stellarium

The moon rises later tonight leaving us even more dark sky for comet viewing. It also joins the company of the planet Jupiter this evening. Yes! The two orbs will be in conjunction tonight and really grab your eye when you face east for a view.

Hubble takes sharpest view ever of Andromeda Galaxy

This image, captured with the NASA/ESA Hubble Space Telescope, is the largest and sharpest image ever taken of the Andromeda galaxy. Click to enlarge. Click for a beefier version. Credit: NASA/ESA

The photo doesn’t look like much in this scrunched-up view, but I dare you to click it. When you do, you’ll get a good taste of the biggest Hubble Space Telescope image ever released. You’re looking at just one-third of the Andromeda Galaxy, the closest, large galaxy to the Milky Way. It shows over 100 million stars and thousands of star clusters embedded in a section of the galaxy’s pancake-shaped disc stretching across over 40 000 light-years.

Here’s the 4.3GB original, but if you don’t care to wait an hour, try the zoomable version. It’s a manageable file size and cool way to get around the galaxy at your own pace. Just scroll to zoom in and drag to navigate.

Sandy with stars, this is a section of the Andromeda Galaxy, also known as M31, photographed with the Hubble Space Telescope. Dust lanes, star clusters, Milky Way stars, and even background galaxies visible through the stellar haze. Click to enlarge. Credit: NASA, ESA/Hubble, and Z. Levay (STScI/AURA)

The panoramic image contains an amazing 1.5 billion pixels. To display it at full resolution would require more than 600 HD television screens.

Along the left side of the photo is the dense, star-filled core of the galaxy called the galactic bulge. The yellow color tells us we’re looking at older generation, evolved stars that have expanded and reddened with age. Tangly webs of interstellar dust are silhouetted against the rich starry backdrop beyond, particularly at right where they thread among crowds of blue stars that indicate the locations of star clusters and star-forming regions in one of Andromeda’s spiral arms.

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Zooming in on Andromeda

Our Milky Way has a similar structure with a denser bulge of older stars and spiral arms where new stars continue to be born from collapsing clouds of cosmic dust released into the galaxy by generations of stars that have come and gone.

This photo shows the entire Andromeda galaxy along with its satellite galaxies NGC 205 (below center left) and M32 (above center left).  The system is located 2.5 million light years from Earth. Credit: Adam Evans

The Andromeda Galaxy is plenty large to begin with a diameter of about 220,000 light years or about twice that of the Milky Way but appears huge in the night sky because it’s closer to us than most galaxies. At nearly 3° across, it’s six times the diameter of the full moon you saw rise the other night. To capture the just a third of it, Hubble took 411 images which were later assembled into a single mosaic photograph.

This map shows the sky facing west around 8 o’clock local time. You can use the lower half of the W of Cassiopeia to point you to Andromeda. Source: Stellarium

Now that the moon is departing the evening sky, you can find the Andromeda galaxy in binoculars, telescope and even with the naked eye high in the southwestern sky at nightfall. Through any pair of binoculars it’s a hazy, elongated disk with a bright center where the galactic bulge resides.

Andromeda contains more than twice the number of stars in the Milky Way, a trillion in all, but we needn’t be enviou. The two galaxies are approaching one another and expected to collide in 3.8 billion years. After the usual awkward silence and few lumps and bumps, we’ll all be one big, happy family.