Get a GLIMPSE of the real Milky Way with this 360-degree interactive map

A slice of the Milky Way in Scorpius and Sagittarius from the new zoomable Milky Way mosaic called GLIMPSE360. Two million images were used to create it. Click to zoom over to the interactive version. Credit: NASA/JPL-Caltech/GLIMPSE team

NASA’s in big picture mode this week. On Wednesday we traveled to the moon’s north pole with a fabulous, interactive gigapixel map. Now you can explore a similar interactive mosaic of the Milky Way called GLIMPSE360 or Galactic Legacy Infrared Mid-Plane Survey Extraordinaire. Some fierce creativity went into squeezing that into a word!

Two million images taken by NASA’s Spitzer Space Telescope over the past 10 years were stitched together to create the 20-gigapixel map. Spitzer shoots photos in infrared light, which lies to just beyond the red end of the rainbow spectrum. You and I can’t see infrared, but we can feel it as heat. When it comes to peering into our galaxy’s innards, infrared does a much better job than visual light because it’s able to penetrate the stellar smog – interstellar dust – that litters the Milky Way’s spiral arms.


A GLIMPSE of the Milky Way

Here’s the crazy thing about the mosaic. It only captures about 3% of the sky, but it’s centered on the thin plane of our galaxy where most of the stars are concentrated.

So what can we see? Well over half of the Milky Way’s 300 billion suns for starters, plus stellar nurseries swathed in fluorescent pink clouds of hydrogen and giant expanding gas bubbles inflated by gusty winds from supergiant stars. Oh – there’s also the galactic center. It’s totally obscured by dust in normal telescopes but infrared waves reveal a glowing core.

The best current model of the Milky Way galaxy. We live in a flattered, pancake-like disk about 100,000 light years wide. The solar system is located about two-thirds from the center to the outer edge in a small spiral arm called the Orion Spur. Credit: NASA

You and I may simply enjoy taking in the sights like tourists, but astronomers are using these photos/montage to discover new things about our home galaxy. Spitzer has revealed the true extent of the chunky bar of stars bisecting the core and discovered that the Milky Way is larger than had previously been thought.

The map will also be used to target specific regions of star formation for closer examination with NASA’s upcoming James Webb Space Telescope.

There’s something for everyone with the new interactive panorama. Check it out.

For more information on the project, click HERE.

Gaia space telescope blasts off today on a 5-year Milky Way mission

Soyuz VS06, carrying the Gaia space observatory, lifted off from Europe’s Spaceport, French Guiana today Dec. 19. Shock waves surround the speeding rocket. Credit: ESA

Early this morning the European Space Agency (ESA) successfully launched the Gaia space telescope from the Kourou Spaceport in French Guiana. Its mission: to create a precision three-dimensional map of the Milky Way galaxy by studying a billion stars over five years time. Yes, that’ one billion stars – about 1% of the total population of stars in the galaxy.

Illustration of the L2 point showing the distance between the L2 and the Sun, compared to the distance between Earth and the Sun. Gaia will take up residence at this gravitationally stable point in space away from much of the heat and light from Earth and sun. Credit: ESA

Gaia is now cruising toward the gravitationally-stable L2 point located 932,000 miles (1.5 million km) on the opposite side of the Earth from the sun. It will arrive there in about 20 days. Four months later, during which instruments will be turned on, checked and calibrated, Gaia will begin its 5-year mission.

Like petals surrounding the heart of a sunflower, Gaia’s sun shield unfolded shortly after launch and will prevent heat and light from the sun and Earth from interfering with ultra-precise measurements of the stars’ positions and compositions.

“Repeatedly scanning the sky, Gaia will observe each of the billion stars an average of 70 times each over the five years. It will measure the position and key physical properties of each star, including its brightness, temperature and chemical composition,” writes the agency.

Its sun shield unfolded, Gaia maps the stars of the Milky Way in this artist’s illustration using a sophisticated billion-pixel camera. Credit: ESA/ATG medialab; background image: ESO/S. Brunier

Gaia will take advantage of the changing perspective on the stars it observes as it orbits the sun during the year, using parallax and basic math to measure precise distances to all one billion stars. Over the five years, it will be able to track the stars’ motions across the galaxy, helping us discover from where they originated in the Milky Way and where they’re headed.

Plotting stellar motion may even lead us to a grander synthesis about the origin and evolution of the galaxy itself –  how it was assembled from the merger of smaller galaxies and what fate holds for our big, beautiful home.

By comparing its repeated scans of the sky, Gaia will also discover tens of thousands of supernovas. Small periodic wobbles in the positions of some stars caused by tugging planets should reveal the presence of planets in orbit around them. Closer to home, the probe will discover new asteroids flitting around the solar system and test Einstein’s General Relativity Theory.


Animation showing Gaia’s journey to its operating orbit. Credit: ESA

Much of what we know about stars, nebulas, galaxies and all the rest is based upon having accurate distances to them. The earlier ESA Hipparcos mission cataloged positions of 120,000 stars; Gaia will survey almost 10,000 times as many at roughly 40 times higher precision.

Humanity is reaching out to the stars in a big way here. It gives me hope that our distant descendants will one day roam the galaxy.

For more information on Gaia, please refer to today’s ESA press release.

Nova Delphini 2013 – a white dwarf with a yearn to burn

The bright nova in Delphinus photographed last night in a 16-inch telescope. Credit: John Chumack

It’s official. The new nova has been christened Nova Delphini 2013. Even better, it’s brightened since discovery. Last night a group of stargazers and I saw the pale yellow star with ease through the telescope. Later, when the moon had set, I was even able to spot the nova faintly with the naked eye at magnitude 5.8.

It’s been years since we’ve had an exploding star of this variety reach naked eye brightness. About 6-10 novae are discovered each year, most of them needing at least a small telescope to see. This year novae have popped off in Cepheus, Scorpius and possibly one in Aquila. Amateur astronomers are the nova finders, training cameras on swaths of the Milky Way night after night hoping to catch one in outburst.

The brightest nova ever recorded blew its top in Aquila the Eagle in 1918. V603 Aquilae shot all the up to -1.4 magnitude or nearly as bright as Sirius, the brightest star. You can still see it today in a 6-inch or larger telescope biding its time around magnitude 12 patiently waiting for another chance at nova-hood. Click HERE to get a finder chart.

The Milky Way is the favorite hunting ground for nova hunters. The dense concentration of stars along its band offers the best chance of finding the occasional nova. The galaxy averages about three dozen novae a year of which about a half dozen are discovered. Credit: Bob King

The Milky Way is the most lucrative hunting ground for novae hunting because stars are greatly concentrated along its length; that’s what creates the familiar hazy ribbon of light. You’re much more likely to spot one pointing your camera at millions of stars than at sparsely-strewn star fields outside the Milky Way band. Favorite hunting grounds include the Milky Way-streaked constellations of Scorpius, Sagittarius and Cygnus. I’ve never heard of one being found in the Big Dipper which is located well away from the galactic plane.

Novae occur in close binary systems where one star is a tiny but extremely compact white dwarf star. The dwarf pulls material into a disk around itself, some of which is funneled to the surface and ignites in a nova explosion. Credit: NASA

Just as there’s more than one type of tea, there are different kinds of novae. All involve close binary stars with a compact white dwarf stealing gas from its companion. The gas ultimately funnels down to the surface of the dwarf where it’s compacted by gravity and heated to high temperature on the star’s surface until it ignites in an explosive fireball. This is what you see when you look at a nova – a gigantic bomb going off.

Just to be clear, a nova doesn’t involve the destruction of the star, only a “shock to the system”. A supernova is a different beast entirely, resulting in the complete annihilation of a white dwarf or supergiant star. If a white dwarf accumulates too much matter from a companion and crosses the Chandrasekhar Limit, it can sidestep the nova stage and go straight to supernova.

Looking more closely we discover that novae come in two basic types – fast and slow. Fast ones rise abruptly to maximum brightness, some of them vaulting 10 magnitudes a day. Their decline can be equally swift.

All-sky Milky Way mosaic photo compiled by the 2MASS survey in dust-penetrating infrared light shows the flat disk, home to younger stars and fast novae and the fat central bulge, where more slow novae and older stars are found. Click to full-size version. Credit: 2MASS, J. Carpenter, T.H. Jarrett and R. Hurt.

Slow novae behave as you might expect, sometimes taking several months to reach peak brightness and often lingering for months. Fast novae, which arise from more massive white dwarfs, are concentrated in our galaxy’s flat disk; slow ones from smaller dwarfs are found in the central bulge. I suspect this recent nova is the fast variety.

Nova Delphini is still in the fireball stage engulfed by incandescent hydrogen gas. Astronomers have spectroscopically measured the speed of the ejecta from the blast at 1,250 miles (2,000 km) per secondThat’s 4.5 million miles per hour. Think about that for a second. Now picture the scene in your mind’s eye when you see the nova for yourself.

This map shows Delphinus and Sagitta, both of which are near the bright star Altair at the bottom of the Summer Triangle. You can star hop from the top of Delphinus to the star 29 Vulpeculae and from there to the nova. Or you can point your binoculars midway between Eta Sagittae and 29 Vul. Numbers in gold are star magnitudes. Stellarium

I’ve included a fresh map above. The numbers in gold are star magnitudes to help you track the nova’s brightness as it brightens or fades in the coming nights. The larger the number, the fainter the star. Click HERE for a nice explanation of star magnitudes. For more maps, please see my earlier Universe Today post.

Update 8/16: Last night Aug. 15 I saw the nova at magnitude 4.8 and it was even brighter this morning. That means it’s nearly ten times brighter than at discovery a two days ago.

Munchkin Milky Way meets mega-monster galaxy IC 1101

The Milky Way slices across the summer sky reached Cassiopeia and Perseus in the northeast down to Sagittiarius in the south as viewed from mid-northern latitudes. The galaxy is comprised of billions of stars, star clusters, gas clouds and planets. Credit: Bob King

We have the barest inkling of how truly vast the Milky Way galaxy is, but looking up on a dark summer night is enough to convince you it must be REALLY big. After all, this garland of hazy light speckled with stars touches both ends of the sky, north and south.

Astronomers have measured the galaxy’s diameter at 100,000 light years which means little until you appreciate that one light year equals 6 trillion miles, the distance a beam of light travels in one year. The fastest spacecraft ever built, the Helios probes, reached 157,000 mph (253,000 km/hr) as they zipped around the sun studying the solar wind from the mid-1970s to 1985. While that’s nine times faster than the International Space Station, it would still take 4,383 years to travel one light year at that phenomenal pace.

The Milky Way is a spiral galaxy with a prominent dense bar of stars across its core. The sun and planets are located with a spiral arm some 27,000 light years from the center. Illustration: NASA/JPL-Caltech/R. Hurt (SSC/Caltech)

Even fleet light takes 100,000 years to cross from one side of the galaxy to the other. A light ray leaving Earth 100,000 years ago, when Neanderthals were the dominate human species in Europe, recently arrived there in our mobile-phone obsessed era. What will Earth look like 100,000 years from now?

Vast as the Milky Way is, it’s dwarfed by IC 1101, a faint galaxy residing in the center of the rich galaxy cluster Abell 2029 in the constellation Virgo. Located a billion light years from Earth, IC 1101 is the largest known galaxy with a diameter of 6 million light years or at least 60 times the size of the Milky Way.

Earth’s huge and tiny at the same time depending upon your perspective. Credit: Lsmpascal

You’ve probably all seen the illustration comparing the size of Earth to the sun. We sure do look tiny. Now multiply our one star by 200-400 billion – that’s the number of stars in the Milky Way – and consider that many of them likely harbor planets. Impressive place this Milky Way … until you park it alongside IC 1101 with its 100 trillion stars.

The Milky Way fares well in the neighborhood “Local Group” cluster of galaxies. It and Andromeda are the largest of its approximately 54 members. Credit: Andrew Colvin

Galaxies can be broken down into three basic types: spirals (like the Milky Way), ellipticals and irregulars. Spiral galaxies’ cores glow yellow from billions of older stars that formed in the galaxy’s youth that have since aged and evolved. Hot, new stars, which are generally bluer in color, coalesce from dust and gas within the spiral arms that wind around the central hub.

Ellipticals are spherical or flattened like a footballs and generally featureless. Most appear like foggy patches of amorphous star-haze. At a young age, they quickly converted their dust and gas into billions of stars that have since aged and yellowed like the ones in the Milky Way’s core. No spiral arms or fresh-faced hot stars here.

Giant ellipticals like IC 1101 usually start out small, beginning with the merger of a few modest galaxies within a cluster like Abell 2029. But if the process continues unchecked,   a monster is born. Over their lifetimes large ellipticals can rack up a lot of mass, and the bigger they get, the more gravitational pull they exercise over their environment, sucking in even more galaxies. Large elliptical galaxies are common features in large, rich galaxy clusters.

IC 1101, the largest known galaxy, dwarfs all the others including another large elliptical galaxy M87, also in Virgo, Andromeda and the Milky Way. Credit: NASA

If you could put IC 1101 in place of our Milky Way it would encompass a volume of space big enough to include our galaxy and its satellites the Large and Small Magellanic Clouds plus the neighboring Andromeda and Triangulum galaxies. That’s I what call supersized!

Every time we look at the sky, we can’t help but be taught a lesson in perspective. Earth’s an atom compared to the Milky Way, and the Milky Way’s a mouse at the feet of IC 1101. Our job is to find our place in this vastitude.

To assist you in your journey, a great place to start, besides the night sky of course, is Cary Huang’s wonderful Scale of the Universe 2.

 

Weekend “Black Hole” full Moon brightest and closest of the year

Watch for a bigger and brighter full moon than usual tomorrow and Sunday nights. Photo illustration: Bob King

Wishing you a grand first day of summer today and clear nights ahead. This weekend we’ll see the full moon dangling like heavy fruit low in the southern sky. If it looks a tad bigger than last month’s Full Flower Moon, it really is. The moon reaches perigee – closest point to Earth in its orbit – at 6:11 a.m. CDT Sunday morning June 23 just a half hour before the moment of full moon. At the same time it will hover in front of the Milky Way’s central supermassive black hole.

With all those superlatives, you might think I’m setting you up for the end of the world. Trust me, I’m not. The full moon is near the same spot every June and perigees are almost as common as dandelions.

Like the planets do around the sun, the moon moves in an elliptical orbit around the Earth. Once a month it’s closest to us at perigee and farthest away at apogee. Next apogee will be at new moon on July 7. The moon’s average distance from Earth is 238,856 miles (384403 km).

The moon follows an elliptical path around the Earth with one side of its orbit some 31,000 miles (50,000 km) closer (perigee) to our planet than the other side (apogee). Since the moon orbits the Earth every 27 days it reaches perigee once or sometimes twice a month.

So what makes this one special? Well, not all perigees are alike. Some are closer than others and occur at times other than full moon. The closest perigees, like this Sunday’s, occur when the moon is either full or new – times when Earth, moon and sun are all lined up in a row. The sun’s gravity tugs more strongly on the moon at these phases, stretching its orbit and leading to extreme values for perigee and apogee.

No one notices an unusually large first quarter or crescent moon, but we all sit up and pay attention to a bigger-than-normal full moon.

The difference between the the moon at its most distant apogee and closest perigee dramatically illustrated in this pair of photos taken in 2006. The full moon can be as much as 14% bigger and 30% brighter when closest. The weekend’s moon will be 12% bigger than January 2014′s apogee full moon. Credit: Anthony Ayiomamitis

The moon’s most distant perigee (230,000 miles) happened at last quarter phase on March 5 this year. Sunday’s will be the closest of the year at just 222,000 miles (357,000 km). Some keen-eyed skywatchers might notice the moon looking a little larger than it will at apogee on Jan 14, 2014. I say might. Without a reference, it’s terribly hard to compare sizes. The moon illusion, an apparent bloating of our satellite when seen low in the sky, further complicates the view. Still, facts are facts. The moon will be bigger and brighter this weekend than on any other night this year.

Saturday night’s full “Black Hole Moon” will lie about one fist held at arm’s length left and above the center of Milky Way galaxy.  Astronomers call the spot Sagittarius A* (Sagittarius A star). Blocked by intervening dust and invisible to optical telescopes, it marks the site of a supermassive black hole. Created with Stellarium

Not only does the closest perigee of the year coincide with Full Moon, but the moon will be in the “Teapot” constellation Sagittarius in approximately the same direction as our galaxy’s 4-million-mass black hole. Look toward the moon and you can imagine it there munching its way on gas clouds and stars that pass that pass too close for comfort. Given that the beast is 26,000 light years (156 quadrillion miles) from us, neither moon nor monster have any gravitational inkling of the other.

Since full phase happens early Sunday morning, the moon will appear full to the eye both Saturday and Sunday nights. I hope you’ll get to enjoy the show.

Galactic cannibals devour hapless neighbors, don’t pick up after themselves

NGC 5907, also known as the Splinter Galaxy, is surrounded by loop de loops of stars and dust either ripped from a companion galaxy in an act of galactic cannibalism or spewed when two galaxies merged. Click to supersize. Credit: Jay Gabany,  Blackbird Observatory

Four billion years ago and 40 million light years away, an act of galactic cannibalism was committed. No human eyes saw the smaller galaxy shredded and ripped apart by the gravitational might of the larger. No tears were shed when its remains were finally devoured, but clues of the catastrophe remain to this day.

The Splinter Galaxy, an 11th magnitude edge-on spiral, is located high in the June sky in the constellation Draco. You can star-hop to it with your telescope using the Big and Little Dippers and the detailed map below. Edasich is also known as Iota Draconis. Maps made with Stellarium

High in the northern sky in the constellation Draco the Dragon ghostly ribbons of stars and dust swirling about the edge-on spiral galaxy NGC 5907 are all that remains of its one-time companion. Don’t expect to see those ethereal streams in a typical telescope; only long time-exposures reveal the remaining clots of dust and streams of stars torn from the companion galaxy during the close encounter and likely merger. The gigantic loops extend for more than 150,000 light years from NGC 5907, nicknamed the Knife-Edge or Splinter Galaxy.

In this closeup view, NGC 5907 is just a short star-hop from Edasich. Field of view is about 3 degrees.

Astronomers call these rivers of stars tidal streams. They’re created by disruptive gravitational tides induced when two galaxies pass near or through one another. As the companion orbited through the Splinter’s disk, repeated encounters stripped it of most of its goodies – stars, dust clouds and even dark matter – and flung the material into multiple tidal streams. When nothing but the compact stellar core was left it presumably merged (was eaten) by NGC 5907 and lost its individuality forever.

This illustration shows a stage in the predicted merger between our galaxy and the neighboring Andromeda galaxy, as it will unfold over the next several billion years. The image represents Earth’s night sky in 3.75 billion years. Andromeda (left) fills the field of view and begins to distort the Milky Way with tidal pull. After some 6 billion years the two will merge into a single elliptical galaxy. Click for more details. Credit: NASA; ESA; Z. Levay and R. van der Marel, STScI; T. Hallas; and A. Mellinger

Or … it could have happened a different way when two equally mighty galaxies on a collision course yanked swirls of stellar debris from each other before their eventual merger into one serene spiral we see today. Here neither was the winner – two came together much as the Milky Way and Andromeda Galaxy will several billion years from now to meld into something altogether new.

Tidal streams of stars torn by gravitational tides exerted by the Milky Way on one of its small satellite galaxies the Sagittarius Dwarf. The dwarf’s core is shown to the right of  our galaxy’s disk. Credit: David R. Law, UCLA

As far as galactic cannibalism goes, we needn’t look any farther than our own Milky Way, which has been munching on the Sagittarius Dwarf Galaxy for at least the past billion years. Four separate whirls of stars peeling off above and below the plane of the Milky Way attest to our galaxy’s systematic preying on what was once a bright companion. Now half its contents are gone, dumped along the winding highway by an unrepentant galactic litter bug. Over time the dwarf and its contents will be fully absorbed by our galaxy with little left of its presence save a few stray globular clusters that once called it home.

Curiosity rover ramps up for road trip to Glenelg

A dry river spreads out to form an alluvial fan in southern Iran. Farms follow the curve of the fan. Credit: NASA

Hi-ho, hi-ho, it’s off to Glenelg we go! Scientists with the Mars mission have chosen Curiosity’s first exploration destination, a little place nicknamed Glenelg (after a village in Scotland) near the base of an  alluvial fan of sedimentary rocks, dirt and sand. Alluvial fans are common on Earth as streams flowing from mountains or canyons gradually spread out and deposit rocks and sand in great fans onto the flatter plains below.

Curiosity landed near the base of a similar fan-deposit on Mars; scientists will drive the rover further downhill to where the water might have collected. They’ll be looking for things like salts that are dissolved by water but later precipitate as solids when the water evaporates.

Curiosity’s first destination will be Glenelg, located at the intersection of three different types of terrain near the base of an alluvial fan. Later, it will pass through a natural opening in the dark dunes and wind its way to the foothills of Mt. Sharp. Click to enlarge. Credit: NASA/JPL

Glenelg. Notice anything peculiar about it? It’s a palindrome, a word or phrase that reads the same way in either direction. Fun examples include “kayak”, “evil olive”, “tangy gnat”, “radar” and “Oh, cameras are macho”. NASA folks selected Glenelg because the rover will be visiting the area twice – both coming and going – before it turns around and heads to the base of Mt. Sharp. Having a sense of humor makes any job more fun.

ChemCam Principal Investigator Roger Wiens, of Los Alamos National Laboratory, tests the rover’s ChemCam by observing the light from a plasma ball induced by the laser hitting a sample rock from a distance of about 10 feet. The laser beam itself is invisible. Credit: NASA/JPL-Caltech/LANL

The rover will travel 1,300 feet (400 meters) to the east-southeast of its landing spot to reach Glenelg; its first drilling target will be a section of layered bedrock (likely sedimentary rock deposited by or in water). Prior to departure, the team in charge of ChemCam will zap a 3-inch rock 10 feet away named N165 with a powerful laser. The resulting spark of vaporized rock will be examined with a spectroscope to determine the minerals that make up the rock. The rover will also exercise its wheels in the coming days before moving out.

The Milky Way courses from one end of the sky to the other in mid-August around 10 p.m. local time. The three brightest stars in the photo – Deneb, Vega (right) and Altair (bottom) form the Summer Triangle. Photo: Bob King

If one of your destinations is tonight’s sky, you’ll again be able to watch the International Space Station (ISS) fly by. I saw it unexpectedly last night making a brilliant pass across the northern sky. Most of the station’s passes continue to be in the north for the next few nights.

The times below are for the Duluth, Minn. region. For local times for your city, click over to either Heavens Above or Spaceweather’s Satellite Flybys.

I’d also like to point out that we’re now entering the best time of year for northern hemisphere sky watchers to enjoy the sight of the bright summertime Milky Way. This hazy band of light made of a multitude of stars crosses overhead from the W of Cassiopeia in the northeast all the way to the southern horizon. While the moon is still “missing” from the evening sky, take a drive out to the countryside to relish a view of the galaxy we call home.

Space station viewing time for Duluth, Minn. and region:
Tonight Aug. 18 starting at 9:36 p.m. across the northern sky
* Sunday Aug. 19  at 8:45 p.m. in the north and again at 10:21 p.m. During the second pass the ISS rises in the northwest and dramatically fades as it enters Earth’s shadow near the bright star Vega.
* Monday Aug. 20 at 9:30 p.m. Near-overhead pass
* Tuesday Aug. 21 at 8:38 p.m. in early twilight and again at 10:14 p.m.
for a brief pass in western sky

Hunting for treasure in the Summer Triangle

The Summer Triangle is right on schedule with the season. Watch for the trio of Vega, Deneb and Altair across the eastern sky at nightfall.

The Summer Triangle invites our eyes to explore the eastern sky at nightfall. At dusk you’ll see Vega first, shining highest and brightest of the three stars that form the apexes of the triangle.

The others are Deneb in Cygnus the Swan (better known as the Northern Cross) and Altair in Aquila the Eagle. Vega heads up the small constellation Lyra the Harp.

All three are first magnitude or brighter; connect them by imaginary lines and you’ll make a triangle spanning 3 1/2 fists held at arm’s length or about 35 degrees.

Like the proverbial “X marks the spot” on a pirate treasure map, the Summer Triangle points sky watchers to a celestial hoard of star clusters, double stars and dark and bright gas clouds of all shapes and sizes. Many of these require a telescope or binoculars to see best, but not the Milky Way. All you need are your eyes and a dark sky.

The Northern Cross is outlined in the photo above. A bright patch of Milky Way stars occupies the bottom half of the cross, while a dark lane of  interstellar dust clouds splits the Milky Way down the middle. The dust blocks the light from more distant stars giving the galaxy a patchy texture. Photo: Bob King

The triangle corrals a particularly bright portion of the galaxy. The section in the bottom or southern half of the Northern Cross can even be glimpsed from suburban areas. As a kid living near Chicago years ago, I used to get up before dawn during the spring and summer months to catch sight of the Milky Way from Cassiopeia to as far south as Aquila. Why get up early? I’d heard that unnecessary city lights were turned off after midnight.

Other galaxies are bisected by clouds of interstellar dust along the mid-section. This is ESO510-G13. Dust is silhouetted against the galaxy’s many billions of stars.  Click to see more Hubble galaxy photos. Credit: NASA/ESA/Hubble Space Telescope

Last night a few of us were out in the driveway Summer Triangle gazing around 11 o’clock.   The big patch in the Northern Cross was very easy to see as was the Great Rift or apparent splitting of the Milky into two broad forks. What appears as empty space between them are really dark clouds of interstellar dust shed by previous generations of exploding and evolving stars.

The rift’s true nature took centuries to fathom. Only by the early 20th century did astronomers come to understand they’d been looking at dust all along and not empty space between the stars. Modern telescopes operating in the infrared and radio regions of the spectrum can now “see” into the dust and detect multitudes of stars slowly forming within the cold, dense cores of the clouds through gravitational collapse. Dust that was shed by stars long gone will one day become a new generation of stars as gravity coaxes the ashes to burn once again.

Our Milky Way galaxy is shaped something like a pancake. Where the butter is there’s a bulge in the disk where the stars are more concentrated.

The sun and planets are situated in the plane of our pancake-shaped spiral galaxy about 2/3 of the way from the center to the edge. Put yourself inside a pancake for a moment and imagine the Earth 2/3 the way from the butter to the edge.

There’s a lot more pancake (dough) between us and the center compared to looking straight up or down through the thin cake. In the real Milky Way, there are lots more stars between us and the center compared to looking up or down through the galaxy. The stars stack up along our line of sight to create a thick band of hazy starlight in the eastern sky we called the Milky Way. In other directions, the stars aren’t nearly so concentrated and simply appear as scattered jewels across the sky. The reason the stars look hazy is because most of them are so faint and far away their light mushes together into cloudy masses.

Meteorite-dropping fireball named after Sutter’s Mill

Great view of the interior of a 17.7 gram piece of Sutter's Mill meteorite. Credit: Larry Atkins

It’s official. The meteorites that peeled off the California fireball last month peppering the towns of Coloma and Lotus are named Sutter’s Mill after the famous locale where the California Gold Rush began. As of May 22, 49 fragments had been recovered with a total weight of 437 grams or 17 grams shy of one full pound.

Here are a few details from the Meteoritical Database:

Pinpoint and pinhead-sized bits of olivine and other materials inside my tiny specimen of Sutter's Mill. Magnified about 20x. Photo: Bob King

“A bright daytime east-to-west moving fireball was seen on April 22, 2012, from locations over California and Nevada between 7:51:10 and 7:51:30 am local daylight time (UT-7).

The meteoroid fragmented towards the end of its trajectory. A loud sonic boom was heard in a wide region around Lake Tahoe. Wind gusts were felt and houses shook. At least a kiloton of kinetic energy was released, based on the infrasound signal detected at two stations.”

Eye witnesses in the townships of Coloma and Lotus, El Dorado County, reported hearing whistling sounds and some smelled a “welding” odor. U.S. National Climatic Data Center’s “NEXRAD” Doppler weather radar sweeps detected the falling meteorites.”

“In data analyzed by Marc Fries of the Planetary Science Institute and Robert Matson of S.A.I.C., the radar-defined strewn field is centered on the Sutter’s Mill historic site. On April 24, Robert Ward searched under the radar footprint and collected the first 5.5 g meteorite in Henningsen-Lotus Park.” More details HERE.

Closeup of bubbly crust on a 3 mm-wide fragment of Sutter's Mill meteorite. 30x magnification. Photo: Bob King

Word soon circulated among the meteorite community that Sutter’s Mill was an unusual type of carbonaceous chondrite (car-bon-AY-shuss KON-drite).  These meteorites get their name from the carbon, water and sometimes organic compounds like amino acids they contain. Many of us were on tiptoes waiting for the final classification. Looks like we’re going to have a wait a bit longer.

Scientists were only willing to give it a preliminary “C” (for carbonaceous chondrite) until detailed studies at half a dozen labs are completed.

A week ago a very tiny bit of the meteorite made a second earthly journey straight into my mailbox. Under the microscope at 30x the interior is black as coal with only a few white crystalline flecks. What caught my eye was the crust. Finely stippled to the eye, the scope transforms the little bumps into a landscape of black bubbles that looks like a burnt marshmallow. You can even see where escaping gases punched tiny holes in the bubble tops. This “fusion crust” forms when the outer millimeter or two of the meteorite melts on entering the atmosphere at tens of thousands of miles per hour.

If you stay up past midnight you may find it hard to tear yourself away from the sight of the Milky Way spanning the eastern sky. This picture was taken Monday morning when I should have been sleeping. Details: 15mm lens at f/2.8, ISO 1600, 30-second exposure. Photo: Bob King

Buckle up for the cosmic roller coaster ride of your life

Water creates a chaos of shapes as it splatters into the air after striking a rock in a nearby creek. Photo: Bob King

Last week I watched water racing down a creek slam up against a boulder and break into a frothy spray of droplets and blobs.  My eyes struggled  to make sense of it. The camera proved a far better instrument to dissect the spray into a series of moments, so I could better appreciate the water’s ephemeral shapes and patterns.

We can stop movement and hold time still for a moment, but that’s all. You and I and everything around us are in constant motion. Take the rotation of the Earth. As I type, my keyboard, home, and the entire city of Duluth, Minn. are all moving together at 708 miles per hour toward the east. Speed varies according to latitude, ranging from 0 mph at the poles to 1,041 at the equator. Folks in Nome, Alaska are traveling at 455 mph on the merry-go-round, while those in Los Angeles zip along at 860 mph.

Depending on your latitude, the speed with which your rotation speed varies. Close to the poles, it's slow because you turn through a very tiny circle in 24 hours. At the equator, you have travel the entire circumference of the Earth in the same time. Illustration: Bob King

The reason rockets are launched in Florida and not North Dakota is because Florida is closer to the equator, giving them a 250 mph edge compared to Fargo as they head into orbit.

To determine how fast you’re moving, multiply Earth’s circumference times the cosine of your latitude and divide by 24 hours like this: 24,902 mph x cos (latitude) / 24 hours. Cosines are easily found by heading over to the handy Cosine Calculator and keying in your latitude. With that number in hand, use your computer’s calculator to arrive at your personal velocity.

We travel nearly 67,000 miles per hour in our yearly orbit around the sun. Illustration: Bob King

Spinning is just one of Earth’s several motions. We’re also orbiting the sun at 18.5 miles per second or nearly 67,000 miles per hour. At that speed our planet traverses 600 million miles in one year. Since Earth’s about 8,000 miles in diameter, it moves about 202 times its own size in one day. Even sitting still we’re putting on miles at a fantastic rate. Live till you’re 80 years old and you’ll  have 48 billion frequent orbital-flyer miles to show for it.

Destination Vega! The sun and solar system are moving the general direction of the bright star Vega in the constellation Lyra. Photo: Bob King

So far we’ve only talked about Earth, but the sun isn’t standing still either. Our star is one of several hundred billion stars in the Milky Way galaxy, all of which are moving. Based on studies of the motions of stars in our neighborhood, astronomers have determined that the sun hauls it family of planets, comets and asteroids at 43,000 miles per hour in roughly the direction of the bright star Vega in Lyra.

In the course of a  lifetime we will have moved 40 billion miles closer to the star. Unfortunately that huge figure will hardly begin to close the gap between the two stars. Vega is not only 25 light years away (150 trillion miles), but it’s not standing still either. If you’d like to see where we’re headed, face northeast around 11 o’clock the next clear night. The bright, twinkling star low in the sky is Vega.

The sun circles the galactic center once about every 225 million years traveling at 483,000 mph. Illustration: ESO with additions

If you guessed that we’re not quite finished yet, you’re right. The Milky Way is a gigantic starry pinwheel, where the speeds of stars vary with distance from its center the same as the speed of a planet varies with its distance from the sun. The spinning of the galaxy carries the sun and neighboring stars around the galactic center at 483,000 mph or nearly 7 times faster than Earth orbits the sun.

Good thing the sun is holding onto us or we’d soon be lost among the stars like change dropped from a pocket. Our solar system is located about 2/3 the way from galaxy’s center to its edge and takes 225 million years to complete one orbit. Each year we celebrate our birthday after completing another cycle around the sun. Since the sun and planets first formed 4.6 billion years ago, the sun has orbited the galactic center 20 times, making it 20 galactic years old. Hey, that means in another 225 million years it will finally come of age!

Watch out for what the future brings - Andromeda and the Milky Way will one day be one galaxy sometimes referred to as "Milkomeda". Other members of the Local Group are labeled. Credit: Andrew Colvin

The Milky Way is one of more than 50 galaxies in a small cluster of galaxies called the Local Group. Ours and the Andromeda Galaxy, located 2.5 million light years away in the constellation Andromeda, are the group’s two biggest members. As if we weren’t moving in enough ways, these two galactic behemoths are hurtling toward one another at 50 miles per second or 270,000 mph.

2.5 billion years from now we’ll collide in a spectacular display of fireworks as merging gas clouds fire up brand new clusters of stars. Over time, the two spiral galaxies will evolve into one much larger elliptical galaxy some like to call “Milkomeda” (milk-AH-meh-duh).

The Local Group is one of many galaxy clusters belonging to one vast assemblage of clusters named the Virgo Supercluster centered in the constellation Virgo. Credit: Andrew Colvin

The Local Group is a small cluster on the outskirts of the much larger Virgo Supercluster of galaxies. Consider Virgo as downtown New York and our gang as a small town in the boondocks. Like my daughters, who are drawn to the dazzle and glitter of the big city, the Local Group is falling at more than half a million miles an hour toward the center of the Supercluster.

Still not dizzy yet? Let’s take one final step and put the pedal to the metal.

Relative to the cosmic background radiation – the ever-expanding , steadily cooling energy left over from the Big Bang that permeates all of space – the Milky Way galaxy is moving at the amazing rate of 1.3 million miles per hour roughly in the direction of Leo and Virgo. The reason for our great haste? New space created between the galaxies as the universe expands causes them to appear to rush apart from each other. The Local Group holds together through the combined gravitation attraction of its members, but when you take in the bigger scene, galaxies have been rushing away from each other at alarming speeds since the Big Bang 13.75 billion years ago.

OK, even I need a little help at this point, so let’s sum up:

* We’re rotating around 700-800 mph depending on latitude.
* Orbiting the sun at 67,000 mph
* Traveling among the nearby stars at 43,000 mph
* Orbiting the center of the Milky Way at 483,000 mph
* Moving toward Andromeda at 270,000 mph
* Diving into the core of the Virgo Supercluster at 540,000 mph
* Riding aboard the Milky Way in the expanding universe at 1,300,000 mph

And yet, in spite of all the whirl and flow, we can still find quiet moments under a dark sky to contemplate it all.

A portion of the Hubble Deep Field photograph showing a multitude of galaxies. The space between each galaxy grows larger with time as the universe continues its expansive ways since the Big Bang about 14 billion years ago. Credit: NASA/ESA