Rays of aurora punctuate a green arc near the northern horizon last night. They were spawned by particles streaming from a coronal hole in the sun’s outer atmosphere aimed at Earth. Chances for minor activity continues through tonight and tomorrw. Details: 35mm lens at f/2.8, ISO 800 and 25-second exposure. Photo: Bob King

During a twilight walk yesterday with the dog I thought I saw a patch of those night-loving noctilucent clouds in the direction of sunset. Upon returning home, I drove out to an wide-open field hoping to catch a glimpse of them but encountered a modest show of northern lights instead. The time was about 10:45 p.m. Lots of stars were out but twilight still lingered along the northern horizon. Several auroral rays, faint as distant smoke, materialized in the northeast before melting away five minutes later. Hoping for the display to strengthen, I drove further north to even darker skies, but sadly, the show was already over by 11:15. Curious how fickle the aurora is — such is the nature of subatomic particles and our moody magnetosphere.

As Earth blazes at 18 1/2 miles per second in its orbit around the sun, constellations slowly drift westward over the weeks and months. You’ve probably noticed Orion’s gone, and he’ll soon by followed by Gemini. Remember how Leo the Lion once dominated the southern sky at nightfall? Even he’s padding off in search of new prey. Virgo is now due south during late evening twilight and accompanied by the brilliant pink-orange Arcturus. Once darkness takes hold, another constellation pipes up in the south-southeast hoping to catch our attention, Libra the Scales or Balance.

To find Libra, go out between about 10:15 and midnight and face south. First get oriented with the huge triangle composed of the bright stars Arcturus and Spica and the planet Saturn. Alpha Librae is two outstretched fists to the left of Spica. Maps created with Stellarium

Back in 2000+B.C. the Sumerians saw this unassuming group of stars as a balance (right) because the sun crossed into Libra during the autumnal equinox when the hours of day "balanced" those of night. The Greeks didn’t see a separate constellation here at all. To them Libra’s stars comprised the claws of the nearby Scorpius the Scorpion. We owe it to the Romans who restored the balance to the night sky giving us today’s Libra, the newest constellation of the zodiac. Libra is also the only zodiac constellation that doesn’t represent an animal.

Don’t expect to be wowed by this diamond-shaped pattern. It has neither 1st nor 2nd magnitude stars. The brightest are Alpha and Beta Librae which outline the right side (western half) of the constellation. They’re 3rd magnitude or one level below the Big Dipper stars’ brightness. You’ll find them easily enough two outstretched fists to the left of Spica in Virgo. The other stars in the diamond are fainter yet and require some persistence and fairly dark skies.

The westernmost star in Libra is a double star called Alpha-1 and Alpha-2. Oddly, Alpha-2 is the brighter star, the one you see with your naked eye. The 5th magnitude companion sits just to its upper right (northwest). If you’re vision is extremely good, you may be able to split this pair with nothing more than your eyes. Give it a try, and if that doesn’t work, binoculars will easily cleave the two Alphas. Alpha Librae’s proper name is Zubenelgenubi (zu-BEN-el-ge-NEW-bee), Arabic for "southern claw" and named back in the day when Libra’s stars belonged to Scorpius. Beta Libra has an equally mellifluous moniker: Zubeneschamali (zu-BEN-ess-sha-MAH-lee) or "northern claw". Say them outloud when you’re out tonight in search of Libra and you’ll feel like a stargazer of old.

A cutaway diagram of the sun peels away its different layers to expose the blazing core where nuclear fusion reactions occur that set it ablaze and make for a cozy Earth. Credit: NASA/CXC/M.Weiss

Sunshine. Sure felt good yesterday except when I had to mow the grass. We usually don’t think about the particulars of sunlight’s origin but vaguely recall it has something to do with nuclear fusion. The sun is a titanic ball of highly-compressed incandescent gas 865,000 miles in diameter composed of 71% hydrogen and 27% helium gases; the other 2% comprises all the other natural elements like carbon, oxygen and aluminum. Deep within the sun’s core, the temperature is in the neighborhood of 30 million degrees Fahrenheit, hot enough to strip off the electrons whirling around the nucleus of hydrogen atoms. The bare nuclei are called protons, and they slam into one another at a ferocious rate, something like 90 followed by 37 zeros per second. I don’t know if that number even has a name.

Protons, which are positively charged, naturally resist coming together just like trying to force two magnets together with facing positive poles. But in the fury of the sun’s center, these forces are overcome and the two protons fuse to form a different form of hydrogen called deuterium. During the fusion process, one of the protons becomes a neutron which is similar to a proton but like Switzerland is neutral. This conversion also releases two tinier particles — a positron and a lightweight, evanescent neutrino. With me so far?

The nuclear fusion process inside the sun called the proton-proton chain is responsible for most of the sun’s energy output. Hydrogen is converted into helium in a step-by-step process that liberates energy. Illustration: Bob King, adapted from A Question and Answer Guide to Astronomy

The positron immediately meets an electron and the two self-annihilate in a POOF! of energy, while the neutrino passes through the sun and into space. In the next step, our freshly-made deuterium combines with another proton to form Helium-3 and releases a jolt of energy in the form of gamma rays. In the third and final step, two Helium-3s combine to form a helium atom and two free protons which go their way to begin the cycle anew.

Hydrogen fusion is alchemy at its finest. The sun takes four hydrogen atoms and forges the element helium liberating energy in the process. Helium, which is heavier than hydrogen, settles into the sun’s center while the gamma rays slowly work their way outward from the core. Ten thousand to 100,000 years later, they finally reach the sun’s blindingly-bright outer surface called the photosphere. Due to many collisions with particles along the way, the lethal gamma rays have been "watered down" over the eons to the visible light and heat we call sunshine.

Hydrogen fusion inside the sun converts four million tons of matter into energy every second. Our lives depend on it. Credit: Halfdan

Perhaps the most amazing fact about the hydrogen fusion process is the sheer volume of material transformed. 600 million tons of hydrogen are converted to 596 million tons of helium each second. Hey wait — what happens to that other four million tons of matter? Turns out that the mass of a helium atom is 0.7% less than the mass of the original four hydrogen atoms. That tiny percentage is transformed into pure energy — gamma rays and positron annihilations — during the fusion process at the rate of four million tons per second. We’ve now accounted for both matter and energy.

Matter is a strange thing. According to Einstein’s famous E=mc² equation — energy equals mass times the speed of light (abbreviated "c") squared — matter and energy are equivalent. We know the speed of light is a large number to begin with, but square it and you get 34.6 billion. That’s what I call giganti-normous! Multiply that number times "m", and you can appreciate that even a minute amount of matter can be converted into prodigious amounts of "E". One might look at matter as nothing more than highly-compressed energy. Stars have unlocked the key to its liberation and people on Earth are still trying to make it happen with experimental fusion reactors.

And now I know why I got so sweaty mowing the lawn.

Two pairs of twins draw our attention in the west over the next few nights. In this picture taken last night around 10:45, Mars is on the right in the upper left pair. Keep an eye on Mars and Regulus because their separation changes nightly. Photo: Bob King

Looks like the Gemini Twins are forming a gang. Last night I looked in the west as the sky cleared and saw not one but two sets of twins. The Gemini brothers Castor and Pollux took up their usual place low in the northwestern sky, but joining them was an equally bright, identically-spaced pair of lookalikes: Mars and Regulus. Take a look at the photo and I think you’ll agree we’ve got a pair of impersonators up there. What’s fun about this extra set of twins is that they won’t mimic their brothers for very long. Even tonight you’ll notice that Mars and Regulus are a little closer than Castor and Pollux. Regulus stays in the same place in the sky, but Mars is on the move eastward. Watch over the coming week as the planet draws closer and closer to Regulus; by June 6 and 7 they’ll be less than a degree apart.

Green grass, green aurora and blue sky. Moonlight provided both the sky and ground illumination while high speed electrons and protons from the sun were responsible for the aurora. More northern lights are possible through Monday night for the northern U.S. and higher latitudes. Details: 35mm lens at f/2.8, ISO 800 and 25-second exposure. Photo: Bob King

The northern lights stopped by for a visit last night. A band of pale green reached from the northwest to the northeast below the W of Cassiopeia low in the northern sky. No rays or other activity were seen from my location, but it was plainly visible despite moonlight and served as a pretty backdrop for the silhouetted clouds. This aurora stems from CMEs or coronal mass ejections from the sun flung our way on May 23-24. According to the Space Weather Prediction Center, our chances of seeing the northern lights continues in the nights ahead as more high-speed particles stream from an open hole in the sun’s outer atmosphere called a coronal hole. To see if the aurora is headed in your direction, check out the NASA POES satellite photos showing both northern and southern hemispheres. If you see the deep yellow or orange part of the color-coded auroral oval hovering near your location, it’s time to take a look outside. The plot at right was made at 11:05 p.m. last night and clearly shows the oval reaching across southern Canada to just north of Minnesota and Michigan. That was close enough for us to see its edge very low in the northern sky.

Several days ago we talked about the U.S. Air Force’s somewhat super-secret X-37B military surveillance satellite (at left). In appearance it resembles a miniature version of the space shuttle. I’d written that because of its orbit, the X-37B would only be visible from the southern U.S. and other areas of the globe between the latitudes of 40 South and 40 North. I was wrong. While the satellite won’t ever get very high for points further north, it is visible across the northern states in places like my homebase of Duluth, Minn. The spybird’s combination of altitude and orbit are just enough to provide views of low passes across the southern sky. You’ll be looking for a moving light much fainter than the shuttle or space station. X-37B is only 4th magnitude at brightest meaning it’s two levels of brightness below the stars of the Big Dipper. That’s the naked eye limit if you live in the suburbs. If you’re further out on the fringe or live in the country, X-37B should be relatively easy to see. The fact that it’s moving will make it more apparent, too. 

Here are some opportune times to watch in the coming week. For times and charts for your location, click HERE and type in your zipcode. Let us know if you make a sighting.

* Tonight starting at 11 p.m. across the southwest. Just before fading into Earth’s shadow it will reach its highest elevation of 17 degrees or a little less two outstretched fists above the horizon. Total visibility of 3 minutes — this pass will be more challenging than tomorrow’s.
* Sunday May 30 at 10:08 p.m. Highest and brightest pass of the week at 25 degrees (2 1/2 fists) and magnitude 4.2. X-37B will swing across the south below the bright star Spica in Virgo. Visibility of 4 minutes. See map below.
* Monday May 31 at 10:53 p.m. across the southwest. Maximum height of 24 degrees
* Tuesday June 1 at 10:01 p.m. across the south. Max. height 25 degrees
* Wednesday June 2 at 10:46 p.m. across the southwest. Max. height 18 degrees — dim and challenging.

If you live in the Duluth, Minn. region you can use this chart to help you find X-37B tomorrow (Sunday) night when the satellite makes its brightest, highest pass of the week. The blue line shows its path and spans about 3 minutes of visibility. Created with Stellarium

Val Germann of Columbia, Missouri took this time exposure photo of X-37B yesterday evening streaking through the constellation Bootes. Details: 50mm lens at f/2.8, 10 second exposure at ISO 1250. Credit: Val Germann

This is small area in a much larger photograph of a phytoplankton bloom off the coast of Ireland taken by NASA’s Terra satellite. The green coloration is due to chlorophyll inside the bodies of the organisms. Phytoplankton form the basis of the oceanic food chain and help produce much of the oxygen in our atmosphere. Credit: Jeff Schmaltz, MODIS Rapid Response Team

We’ve featured many photos looking down on planets and moons taken by orbiting satellites. Lunar boulders, Jupiter’s swirling cloud belts and crater-pocked Mercury come to mind. Now and then we see the Earth as a planet, too, either through the eyes of astronauts aboard the space station or taken by one of the many Earth observing satellites. Most recently, you’ve seen pictures of the Gulf oil spill from NASA’s Terra satellite. Today I thought it might be more uplifting to share this image of phytoplankton blooms off the west coast of Ireland captured last Saturday May 22.

Diatoms are one of the most common forms of phytoplankton. They live in the ocean, fresh water and even in soil. A simple microscope easily reveals their jewel-like forms. Credit: NOAA

Phytoplankton are microscopic plants that live in the upper layers of the ocean. During their spectacular seasonal "blooms" the tiny creatures cover hundreds of miles of open water and are easily visible from orbit. Just look at those vividly-colored swirls and vortices and think for a moment how many billions of individuals it must take to create this iridescent emblem of earthly life. When we one day resolve distant exoplanets as disks, will we see similar patches of blue and green staining their globes?

The International Space Station (ISS) and Atlantis (on left side between the two sets of solar panels) passes in front the sun on May 22. The ISS took only 1/2-second to cross the sun’s face. Credit and copyright: Thierry Legault

Let’s turn around now and direct our gaze back up into space. I thought you’d like to see Thierry Legault’s incredible photographs of the International Space Station with space shuttle Atlantis in tow transiting the face of the sun. He took the photos through a 6-inch refracting telescope with a Canon 5D Mark II and 1/8000-second exposure on May 22, the same date as Terra aimed its camera at the plankton bloom. Thierry’s photos are nothing short of spectacular and show fine details of the space station — check out those eight big solar arrays — as well as the granulated texture of the sun. Each of the small granules is about the size of the state of Texas and represents a column of hot gas rising from beneath the sun’s surface. The dark gaps between the granules are the gaps where cooled gas descends back below the surface again. The sun churns like an enormous pot of oatmeal on the stove.

This is the full frame of the ISS crossing the sun. A sunspot group is also visible. More photos. Credit and copyright: Thierry Legault

One of the season’s most distinctive flowers, bleeding hearts bloom in my wife’s flower garden this week. Photo: Bob King

One of the joys of my life are wildflowers. I’ve been identifying them, getting to know their habits, smells and time of first appearance since I was in high school. You can divide the spring, summmer and fall into "mini seasons" by flower types beginning with April’s hepaticas and ending with tansies and lion’s teeth. Whenever I see daisies glowing brightly in twilight, I know we’re approaching the beginning of summer’s heat.

This map shows the sky as you look moonward around 10:30 p.m. tonight. Created with Stellarium

Tonight the full moon becomes a flower of sorts, a blossom of brilliance along the southeastern horizon after sunset. May’s full moon is called the flower moon in recognition of the all-out flowering frenzy the month brings. For most locations in the western hemisphere, the moon will rise shortly after sunset in the constellation Scorpius the Scorpion. As a bonus, once it’s up high enough to clear the trees and buildings in your neighborhood, look just below it and to the right for the star Antares, the heart of the scorpion. The two will be separated by a little more than a degree or two full moon diameters. With binoculars, you’ll be able to better see the three stars that precede the moon known as the scorpion’s head.

SOFIA with its door open and telescope pointing to the sky during a test run. Credit: NASA

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA), a 100-inch telescope mounted in the rear fuselage of a modified 747SP aircraft, successfully completed its "First Light" mission yesterday. Scientists are still studying the images gathered by the telescope and will provide pictures in a few days. SOFIA flys 39,000 to 45,000 feet high above 99% of the water vapor in the atmosphere. Water vapor absorbs infrared (heat) light, preventing observatories on the ground from studying the universe in that spectral range. SOFIA solves the problem by literally flying above it all. 

The difference between seeing the sky in ordinary or visual light and infrared (right) is dramatically illustrated in these two pictures of the constellation Orion. Infrared light reveals dust clouds and sites of star formation brilliantly. SOFIA can observe in visual light but is optimized for infrared. Credit: Akira Fujii (left); Infrared Astronomical Satellite (right)

The crew boarded the plane Tuesday night and spent almost 8 hours in the air gathering data. According to NASA, SOFIA will be used to "observe occultations of stars by solar system objects to help determine the objects’ sizes, compositions and atmospheric structures." It will also study how stars and planets are formed, how organic materials necessary for life form and evolve, and the nature of the black hole at the center of our Milky Way. 

Grab a bag of peanuts and come along for the ride. You’ll find more information about SOFIA HERE or check out the informative video below.

May is filled with sunbeams. My daughters take advantage of them by spreading a blanket on beach or deck and working on the ultimate tan. Unless it’s the middle of winter and I’ve found a comfortable rock to lie on, sitting in the sun is not my cup of tea. We’re all familiar with the potential damage sunlight can do to our skin like causing premature aging and cancerous melanomas, but there’s a bright side too. Sunlight generates the production of vitamin D in our bodies. A half hour a week to face, arms, back and legs will do the trick. The best advice for sun exposure is the one you’re most familiar with: moderation.

The light to which our eyes are sensitive comprises the familiar colors of the rainbow. Invisible ultraviolet light that’s also present in sunlight lies just beyond the violet end of the spectrum. Illustration: Bob King

Most of us prefer to avoid painful sunburns which are caused by ultraviolet light from the sun. Ultraviolet or UV is a form of light hiding out just beyond the violet end of the rainbow spectrum. Certain birds and insects like bees can see UV, but we cannot. Like infrared light, which is begins just beyond the red end of the spectrum, our eyes are not tuned to the ultraviolet world. That doesn’t mean we can’t feel its effects.

Three varieties of ultraviolet light or UV bath the Earth: UV-A, UV-B and UV-C. UV-A, which is closest to the violet end of the spectrum, streams through our atmosphere effortlessly. Even in large quantities it causes little if any sunburn. UV-A is the same type of UV emitted by a “black light”. The sunburn culprit is UV-B, a shorter-wavelength, more energetic form of ultraviolet light. Individual photons of UV-B striking your skin are energetic enough to damage the DNA in your cells. Damaged cells are the root of sunburn pain. Sunblock lotions are an effective way to prevent damage because they contain chemicals that reflect or absorb ultraviolet light before it can reach your skin.

The ozone layer makes life as we know it possible on Earth by shielding us from the most damaging forms of ultraviolet light emitted by the sun. Credit: Center for Global Environmental Research, National Institute for Environmental Studies, Japan

The ozone layer contains a high concentration of ozone or O_3. It’s located in the lower stratosphere some 12-35 miles high and allows UV-A to pass through to the ground but absorbs 98% of the UV-B light. Amazing to think that the small amount that does eke its way through is responsible for all those sunburns! Thankfully, the atmosphere absorbs all of the even more dangerous UV-C. The C-version has a shorter wavelength and is far more energetic than UV-B or A. If it weren’t for the ozone layer, no one would dare venture out unprotected in the sun. UV-C light is used as a germicidal agent to kill bacteria by deactivating their DNA. Nasty stuff.

Below 30 degrees altitude, almost all sunburn-variety UV light is filtered out by the thickess of the air in the lower atmosphere. That’s why you can’t get a tan in the early morning or late afternoon. Created with Stellarium

Our atmosphere is helpful in yet another way. As the sun goes down, it shines through ever thicker amounts of air. At 30 degrees high — three outstretched fists stacked one above the other — the density of the air is twice as thick compared to where the sun is at noon.  At a height of 10 degrees, sunlight travels through six times as much atmosphere. We’ve all noticed that the sun’s intensity lessens as it drops lower in the sky. So does the amount of UV-B coming through. As the sun drops from its high elevation of around 65 dgrees (for mid-northern latitudes) on a typical summer afternoon to 30 degrees, its UV-B intensity drops by a factor of 100. Below 30 degrees, almost all the sunburn-causing UV-B is absorbed by the air and tanning is impossible.

For Duluth and region in late May, the sun is below 30 degrees altitude from sunrise until 8:30 a.m. and again from 5:30 p.m. until sunset. Go ahead and enjoy the heat and light, which are much less affected by the air, but you needn’t worry about getting a burn during these hours. Come winter, the sun never gets higher than about 20 degrees. No matter how bright it may look and feel, you can’t get burned because of the filtering effects of the atmosphere. That makes me breathe easier.

The lineup of stars and planets at approximately evenly-spaced internvals has to be some kind of record. My "walking stick" stretches from southwest to southeast across a third of the sky tonight. Created with Stellarium

Some of you enjoy making your own celestial figures in the night sky using the stars and planets at hand like I do. With the moon nearing full phase and its light bright enough to erase most of the fainter stars, one is left with only the sky’s brighter lights this week. Tonight you can use the moon to connect the brightest stars and planets arrayed across the southern sky into a what we’ll call "the walking stick". While this may seem a simple exercise, it has a deeper purpose. We find our way across the sky by first learning the brightest stars. Then with the aid of constellation maps, available for free online at Skymaps.com, these easy-to-spot stars help us find the fainter ones that form the complete constellation figures. Get to know the walking stick and with a little effort, you’ll stride with confidence through the spring and early summer stars. 

The bright gibbous moon is between Antares in Scorpius and Spica in Virgo. Saturn is midway between Regulus and Spica. Interestingly, Mars and Antares, which are both orange-red in color and nearly the same brightness, top off either end of the stick.

A boulder left a trail in the lunar soil, called regolith, as it bounced down a slope in this photo taken by the Lunar Reconnaissance Orbiter (LRO). The boulder’s about 12 feet across while the frame is a little more than 1/3 mile side to side. Credit: NASA/GSFC/Arizona State University

There’s been some chatter online the past couple days about rocks rolling down slopes on the moon. Not that it’s unusual. You’d expect an occasional rock to dislodge itself under the right conditions (moonquake, nearby meteorite impact) and start tumbling along a gradient until it reached a resting place. We see it all the time on Earth; it’s one of the many forces of natural erosion that shapes local landforms. But to see them on the moon, you’ve got to have a high resolution camera aboard a satellite in orbit. That would be the LRO, which has been mapping our only natural satellite in exquisite detail. The picture above is a small section of a much larger picture strip (15 x 2.5 km) that you’ll enjoy exploring on your own. Click the link and be patient as the detailed, zoomable areas load. How many bouncing boulders can you find?

The sun shot off a drapery of hot hydrogen gas called a filament into space yesterday. Some of the electrons and protons it’s composed of may reach Earth and spark auroras on May 27 for high latitudes. This will most likely be for Arctic observers only, but there’s always a chance for "spillage" further south. Keep a watch to the north the next few nights just in case.

The X-37B as seen in this artist’s depiction. The craft is visible in mid-latitudes in both northern and southern hemispheres and orbits some 250 miles overhead. Credit: NASA/Boeing Phantom Works

If you live in the central and southern U.S. from about latitude 40 degrees southward, you have an opportunity to see the X-37B Orbital Test Vehicle 1, a pilotless, mini-space shuttle launched under the auspices of the U.S. Air Force on April 22. Although its mission is hush-hush, it’s widely believed to be involved in military reconnaissance because its orbit is similar to other surveillance satellites. Despite the secrecy, amateur satellite trackers have kept a close watch on X-37B, which is about as bright as the stars of the Big Dipper, and have calculated an orbit. To see if it’s flying over your location go the Spaceweather’s Satellite Tracker, key in your zipcode and select X-37B in the objects to display box.

The U.S. Air Force’s X-37B during its encapsulation before the April launch. Credit: USAF

Like the Hubble Space Telescope, which is also only visible in mid and lower latitudes, the X-37B won’t be making any appearances across the northern U.S. Its orbit is not tipped at a steep enough angle to the equator to swing it up over my neighborhood. If you’re fortunate enough to see it from where you live, please let us know in the comments link below. Photos are appreciated, too. Thanks!

An intriguing whirlpool in Lake Onalaska in LaCrosse, my imaginary "black hole", swirls day and night. Photo: Bob King

I’ve been in LaCrosse, Wisconsin with family the past couple days and saw a most curious phenomenon near my brother’s home. Along the shore of the lake there’s a permanent whirlpool that was the spittin’ image of an accretion disk around a black hole. In a real accretion disk, gravity from the black hole causes nearby matter — perhaps material pulled off a companion star — to spiral inward toward the hole where it’s compacted and heated through friction. Before the material disappears forever into its maw, the gas reaches extremely high temperatures and radiates brilliantly across the spectrum. Astronomers study the radiation and the speed of the material in the swirling disk to determine how much the black hole weighs. No black hole has yet been imaged but accretion disks spewing powerful X-rays into tell us black holes are there. Dozens have been identified to this day based on how they affect matter and stars in their neighborhood. It’s like hearing the rumble of a distant plane — we may not be able to see the plane, but we know what it is by the characteristic sound it produces.

An artist’s depiction of a black hole surrounded by an accretion disk (left) around a star like our sun. Material is drawn off the companion by the hole’s powerful gravity and spirals down to its infinitely dense core called a singularity. Jets of radiation are also given off in the process. Credit: NASA/ESA

The Lake Onalaska black hole is formed by suction rather than gravity, but there’s a good similiarity with a real black hole, because the two forces essentially do the same thing, that is, they draw material toward them into a spiral and take it down to a new level. The black hole pulls dust and gas toward the infinitely dense, microscopic singularity at its center ripping it into subatomic particles along the way, while the whirlpool in the lake is the outward sign of a pipe below the surface that conducts water beneath an earthen berm to pools and wetlands on the other side.

Einstein’s theory of relativity predicts that the opposite of a black hole, called a white hole, is theoretically possible. A white hole is a region of space that spits everything out instead of sucking everything in. While these probably don’t exist in nature, if you combine a white and a black hole you get a wormhole. A wormhole forms a shortcut or tunnel through space connecting a black hole to an entirely different place in the universe. If you could jump into a black hole, somehow make it past the singularity without being turned into shredded wheat, you’d get spat out the other end at say, the Andromeda Galaxy. Lovely idea to think about on a hot May day while sipping an ice tea.

Diagram of a hypothetical wormhole connecting where you are (top) to another region of space (bottom). The hard part is keeping the hole open and stable. You mere presence inside could cause it to collapse and then where would you be? Credit: Wikipedia

As we walked along the berm, it was fun to imagine the whirlpool as a black hole, the pipe as the wormhole and the placid waters on the other side of the lake as another part of the universe. Whether real wormholes exist is still open to debate. Black holes that form through the collapse of matter during events like supernovas don’t produce wormholes. Once you fall in, you’re going to be crushed to a point at the singularity. Even if you could fashion a homemade wormhole using exotic matter and negative energy, it would likely be unstable and collapse. Let’s say you succeeded in making one anyway and were able to keep it open long enough to travel to a different time and space. Wormholes unfortunately have one more nasty property: light passing through them from nearby stars and the universe’s background radiation get shifted to much higher energies, ie. X-rays and gamma rays. Sorry to say, you’d soon be toast.

If you’re curious like me about black holes and all that good stuff, be sure to stop by Ted Bunn’s Black Holes FAQ. He’s got answers.

Students hold their school’s banner with a portrait of Nicolaus Copernicus in front of the astronomer’s remains in the catherdral in Frombork, northern Poland. Credit: AP

Copernicus, the 16th century Polish astronomer who proved that the planets revolved around the sun at the center of the solar system and not the Earth, was finally given a hero’s burial yesterday by Polish priests 500 years after he was laid to rest in an unmarked grave. At the time, the church considered Copernicus a heretic because his new theory removed Earth and mankind from the center of things. We’ve been moving farther and farther away ever since. The Earth became a planet around a star, the star one of 400 billion in a galaxy and the galaxy just one of a trillion. Simple facts have forced considerable changes in the definition of heretic since those times.

The heliocentric idea had been around before Copernicus, most notably touted by the 3rd century B.C. astronomer Aristarchus of Samos, but Copernicus was the first to prove it using rigorous mathematics. While his central idea was correct, the sun-centered solar system still had its problems in its ability to accurately predict the planets’ movements. That had to wait for the early 1600s when Johannes Kepler discovered that planets’ orbits are elliptical (oval) rather than circular, a long-held assumption.

The ancient model of the solar system was called geocentric because it placed the Earth at center with all the planets, sun and moon in orbit about it. This was a commonsense if false view. Copernicus championed the correct heliocentric (sun-centered) solar system to better explain his observations of the planets. Notice that the planets were believed to describe circles within circles in the geocentric model in order to explain their movements better. Credit: Niko Lang

The Catholic church made their peace and buried Copernicus’ remains in the cathedral where he once served as a cleric. His black granite tombstone is decorated with a model of the solar system with the planets known at the time of his life — Mercury, Venus, Earth, Mars, Jupiter and Saturn — circling a central sun.

No doubt Copernicus watched and studied the motions of the planet Jupiter, which has figured prominently in the news of late after losing one of its stripes. Jim Schaff of Florida sent along a photo today of the planet (above) that shows its appearance in a typical small telescope. One big, old stripe — the North Equatorial Belt — and the Cyclopean eye of the Great Red Spot stand out clearly.

A screen grab from Meridian shows Jupiter looked like this morning at dawn for my location. It includes a simple map of the moons’ positions and information about size, brightness and more. Photos: Bob King

I imagine many of you use software programs like Stellarium, CyberSky and the like to see what’s doing in the sky tonight. There are tons of great tools like these on the Web, many of them free, for determing the moon’s phases, the nightly positions of Jupiter’s brightest moons and even when the sun kicks off a big flare. One of my favorites is Meridian by Claude Duplessis. It’s small, free, simple and loads fast on my infernally slow machine. The program shows you particulars about each bright planet and the moon showing what face is visible, the positions of Jupiter’s and Saturn’s moons, where the Red Spot is, ring inclination and more.

Another frame grab, this one of Mars. Telescopic observers will find the information very useful. 

Once you’ve installed the program, select a planet and the information pops up instantly. I highly recommend it for anyone with a telescope (or without) who wants the most current information on planets at their fingertips. Copernicus would have given it two thumbs up. Interested? Click HERE.

We’ll finish today with the words of Copernicus himself: "Those who know that the consensus of many centuries has sanctioned the conception that the earth remains at rest in the middle of the heavens as its center, would, I reflected, regard it as an insane pronouncement if I made the opposite assertion that the earth moves."

A simple geometry lesson livens up the southern sky tonight when three bright celestial bodies form a right triangle — defined as a triangle where one of the angles (yellow) is 90 degrees. Created with Stellarium

Let’s see. How many different types of triangles are there? There are only six so I shouldn’t have too much trouble remembering them all. You’ve got your right triangle, equilateral, scalene, isosceles, acute and obtuse. I’ll leave it to you to click on the link above for their individual descriptions. For the moment, we’re interested in one of the most familiar — the right triangle. One will be put on display for us this evening at dusk when the moon, Saturn and Spica, Virgo’s brightest star, gather together in the southern sky. You could quibble that it’s not a perfect right triangle where the square of the hypotenuse is equal to the sum of the squares of the two sides but for a casual gathering with no forethought, it’s a solid effort.

The 9-day moon shows off hundreds of craters in a small telescope but even binoculars will show the craters Copernicus and Plato. Photo: Bob King

The moon is nine days old tonight and casts enough light to easily see your way about in the dark. I always look forward to the moon at this age because the crater Copernicus makes such a stunning presentation near the lunar terminator. Both Copernicus, which is 58 miles across, and nearby Plato, 68 miles, are easily viewable in a pair of steadily-held 7 or 8-power binoculars. The two are similar in size but of very different ages: Plato was carved out by a small asteroid 3.8 billion years ago while Copernicus is only 800 million years old. You can see its relative youth in the crater’s more rugged walls and central mountain peaks. Erosion occurs on the moon over the eons as micrometeorites "sandpaper" its surface. Moonquakes, temperature extremes, the solar wind and the slumping of crater walls through gravity and settling contribute as well.

Copernicus (left) shows many terraces due to slumping of its walls. The crater is 2.3 miles deep and the central peaks rise 1300 feet above its floor. Plato’s floor (right) has been filled with lava that welled up from below and is only 3300 feet deep. No doubt it too had central mountains, now submerged beneath dark, smooth lava flows. Credit: Damian Peach