What’s in store for sunspot cycle 24

At least seven sunspot groups dot the sun this morning at 10 a.m. (CDT) as photographed by NASA’s Solar Dynamics Observatory (SDO). Sunspots are cooler regions where magnetic energy is concentrated. Sometimes that energy is released as a solar flare, propelling solar particles and radiation toward the Earth. Credit: NASA

Like you and I the sun has cycles. None of us escapes the day-night rhythm of sleep and wakefulness. The most visible of the sun’s rhythms is the 11 year solar cycle also called the sunspot cycle. These vary from 9 to 14 years but the average is 11.

In a typical cycle, the number of sunspots and solar storms begins at a minimum, rises to a maximum and then returns to minimum. During solar maximum the sun is peppered with sunspots and powerful, aurora-producing flares are common; at minimum the sun’s face can be blank for days or even weeks. Minimums and maximums also vary. Some peaks are longer and more sunspot-rich than others, while “valleys” can be short or long with variable spot numbers.

The peaks and valleys of the past 110 years of solar cycles. Sunspot numbers (shown at left) wax and wane in an approximately 11-year cycle.

The solar cycle was discovered by German astronomer Samuel Heinrich Schwabe in 1843 after he noticed sunspot numbers wax and wane in a regular pattern after 17 years of observation. Swiss astronomer Rudolf Wolf went back through previous sunspot records and reconstructed the sun’s ups and downs as far back as the mid-1700s.

Samuel Heinrich Schwabe

Each cycle gets a number. Solar Cycle 1 spanned the years 1755 to 1766. The last, Cycle 23, peaked in April 2000 with an average of 120 sunspots per day around the time of maximum. This was followed by a deep quiet period or minimum between cycles 23 and the current 24th with a record number of 801 spotless days between October 2005 and May 2010. This past solar minimum, which bottomed out in December 2008, was the longest and quietest in over a century. Since then, but especially over the past year, activity has been steadily on the rise.

The graph shows the last sunspot maximum in 2000 up through June this year. The current Cycle 24 is predicted to reach maximum next spring with an average of 60 spots a day. This would make it the smallest maximum in over 100 years. Credit: NASA

2012 has been a good year for sunspots, solar flares and auroras as we dig our way out of minimum and sail toward the next predicted peak in spring 2013. To date, the sun has kicked off about a half-dozen X-class flares. These are the most powerful variety with potential effects on Earth ranging from aurora creation to wreaking havoc with satellites and power grids. From late 2008 through early 2010 I recorded almost no auroras here in Duluth, Minn. In the past year however, we’ve been treated to several brilliant displays and at least 10 minor ones.

The brilliant flash is a  powerful solar flare that erupted in March 2012. Flares can affect the upper atmosphere (auroras), airplane communications, satellites, power grids and oil pipelines. Click image to see a spectacular video of a solar eruption that happened yesterday. Credit: NASA

NASA solar scientists predict a very weak maximum in 2013 with an average of 60 sunspots daily. If this holds true, Cycle 24 would be the least active since Cycle 14 which peaked in February 1906 at 64. While this sounds like bad news for aurora watchers, don’t put on your long face just yet. Every cycle max, even the wimpier ones, feature powerful flares and crazy space weather.

“Even a below-average cycle is capable of producing severe space weather,” says Doug Biesecker of the NOAA Space Weather Prediction Center. “The great geomagnetic storm of 1859, for instance, occurred during a solar cycle of about the same size we’re predicting for 2013.”

That storm, called the Carrington Event, is named after astronomer Richard Carrington who spotted a brilliant flare through his telescope on September 1, 1859.  Shortly before dawn the next day, the sky blew up in a brilliant display of northern lights visible as far south as Jamaica. Aurora-induced electric currents in telegraph lines shocked telegraph operators and set telegraph paper on fire.

“A report by the National Academy of Sciences found that if a similar storm occurred today, it could cause $1 to 2 trillion in damages to society’s high-tech infrastructure and require four to ten years for complete recovery,” according to a recent NASA press release.

We’ll soon see what Cycle 24 has in store. At the very least, more brilliant auroras are on the menu.

The star Capella returns with a message

No matter how bright the moonlight, if you’re out in late summer, the star Capella still catches the eye. This picture was taken last night. Photo: Bob King

The eye of winter is upon us these late summer nights. I was out last night with my dog Sammy enjoying a walk in the almost-Blue Moon moonlight. Since my dog has mostly black fur, the extra light helps me keep track of where she’s sniffing around. Without the moon, she’s a phantom. Finding a black dog under a dark sky is similar to spotting a snowman in a blizzard.

Looking up in the bright moonlight, I noticed how few stars there were in the sky. With the moon nearly full and high in the south, its overpowering light simply washed out most of the them. Especially at first glance. Looking more closely I could see Cassiopeia, the Great Square of Pegasus and a few others, but the one star undiminished by the moon’s reflective power was Capella. It caught my attention more than Vega and the luminaries of the Summer Triangle simply because it lay straight ahead in my field of vision. I didn’t have to toss back my neck and crane upward to catch sight of it.

In bright “Blue Moon” moonlight the Big Dipper, riding low in the northwestern sky, is faint and take a little effort to find. Capella in the constellation Auriga the Charioteer is easy to see in the northeastern sky around 11 p.m. Created with Stellarium

Capella’s the brightest star in Auriga, a constellation more closely associated with mid-winter than late summer, but every season contains the seeds of the next. The star begins its ascent in the northeastern sky in late July when no one’s paying attention. By the end of August, you’ll see it twinkling around 20 degrees high (two fists held at arm’s length) around 11 p.m.

If Capella seems to be winking at you slyly, you’re right. It’s as if the star knows it cannot be denied. Come January, Capella shines from nearly overhead on the coldest nights of the year. When the mid-winter full moon glares down from above, I’ll probably be looking to the northeast once again, watching for Capella’s counterpart Vega to give me hope that spring will come.

Stars do that for you. They’re messengers with news of what’s to be, which is why it’s good to get to know them.

Let the Blue Moon shine your blues away

Tomorrow night August 31 we’ll have a Blue Moon – the second full moon this month. Photo ilustration: Bob King

Tomorrow night’s the Blue Moon. It won’t actually be blue unless you happen to be near a volcano. Volcanic ash and forest fires can turn the moon blue. The secret? It’s the ash. If all the ash particles are about 1 micron in size (the period at the end of this sentence is 600 microns across), they efficiently scatter away all the warm colors in moonlight, leaving a pale blue orb. I’ve never seen the phenomenon, but much of the planet saw blue moons for months after the eruption of the Indonesian volcano Krakatoa in 1883. Ditto for Mt. St. Helens in 1980 and Mt. Pinatubo in 1991. If you live in western U.S. where forest fires have been rife this summer, perhaps you’ve seen one too many blue moons.

Farmers burning brush caused the sun to appear blue in the photo taken of the pyramids in Egypt on December 14, 2006. Credit: pyramidCam.com

Most of us will never get to see a real blue moon, but the calender version will shine in Pisces Friday night. According to modern folklore, a Blue Moon is the second full moon in a month. We normally get one full moon a month, but every 2 1/2 years there’s room for another to squeeze in.

That’s because the time between full moons is 29.5 days while most months are 30 or 31 days. Since the first full moon of August was on the 1st, there’s enough time left in the month to make room for a second one on the 31st. If the moon were always full at the beginning of each 30 or 31-day month, we’d get 11 Blue Moons a year. Now wouldn’t that be nice. That doesn’t happen because the moon’s not in sync with the calendar – it marches to its own 29.5 day rhythm.

Full moons have acquired a variety of names handed down from past generations. We get our moon names from the various American Indian tribes as well as the early colonists. Two common monikers for the August full moon are the Sturgeon and Red Moons. The first refers to August being a great time to catch sturgeon and the second to the color of the moon when it rises during the hazy summer months. According to the Old Farmer’s Almanac, the first full moon of August was the Sturgeon and the second, the Red Moon. It’s a fun coincidence that this month’s Red Moon is also Blue.

Full Moon, 1919 by Swiss painter Paul Klee

The term Blue Moon goes back hundreds of years, but it had a different meaning then of “impossible” or “absurd”. The term later morphed into a reference for something uncommon or that rarely occurred.

There are normally 3 full moons in each of the four seasons for a total of 12 per year. In the early 1930s, the Maine Farmers’ Almanac (unrelated to the Old Farmer’s) named the 3rd full moon in a season that had an extra 4th full moon a blue moon.  It’s unclear where the term ‘blue’ came from, but it’s possible it refers to that earlier meaning – an event that rarely happens.

Then in the March 1946 issue of Sky & Telescope magazine, American amateur astronomer James Hugh Pruett wrote an article titled “Once in a Blue Moon”. He either misread the Maine almanac’s definition or interpreted the meaning of “blue moon” differently, calling it the second full moon in a month. Sky and Telescope later adopted Pruett’s definition.

The Blue Moon snowballed into popular culture when Deborah Byrd, host of National Public Radio’s Star Date program,  used Pruett’s definition during a broadcast on January 31, 1980. Word got around and now you know the rest of the story. Fascinating, isn’t it, that the current Blue Moon definition is based on one person’s (mis) interpretation of an earlier definition. Makes you wonder what other accepted “facts” are based on odd turns of events and errors in interpretation.

Last night’s moon lit up the southern sky around midnight. Photo: Bob King

I personally like the modern definition. It still catches the gist of the old almanac sense in a way that’s easy to remember.  The next Blue Moon for North America will be in July 2015. Even better, there will be two blue moons in 2018 – one in January and one in March with no full moon at all in February! The last time that happened was in 1999. For more details on how the current view of blue moons came to be, click HERE to read a complete account of the story by the writers at Sky and Telescope.

I’m looking forward to a  fine moonlit walk Friday night and wish you the same.

How sweet it is! Sugar discovered around a sun-like star

Grains of refined sugar sucrose commonly used in baking and sweetening. Credit: Lauri Andler / Wiki

A sweet tooth. I love that little euphemism used by people who like to eat candy. Yes, I have a sweet tooth with a weakness for intensely sweet (and sour) stuff like gummy worms and sugar-coated bears. I also use sugar to sweeten my tea.

Sugar on Earth is found in sugar cane, maple syrup, honey, sugar beets, milk numerous fruits, trees and some vegetables. We often consume it in the form of high fructose corn syrup manufactured from corn.

Alien sugar was first found in this giant molecular cloud called Sagittarius B2 (North) in the central hub of the Milky Way in 2000. The cloud is 3 light years across. Credit: R. Gaume, M. Claussen, C. De Pree, W.M. Goss, D. Mehringer, NRAO/AUI/NSF

If we ever run out, there’s plenty more. In outer space that is. Harvesting won’t be easy since it’s spread across light-years-wide clouds of stellar gas and dust called molecular clouds.

Space sugar was first spotted near the center of the Milky Way galaxy back in 2000. Rotating sugar molecules give off a faint whiff of radio energy detectable in a large radio telescope. To date about 172 interstellar molecules have been found through the energy they emit in radio, microwave and infrared (heat).

Scientists used the 12 Meter Telescope, a radio telescope on Kitt Peak, Arizona to pick up that first faint signal and identified it as the simple sugar glycoaldehyde, an 8-atom molecule composed of carbon, oxygen and hydrogen. It’s a simple sugar similar to what you’d put in your coffee or tea. Glycoaldehyde can combine with other molecules to form more complicated sugars like glucose and the sugar ribose found in RNA, which is related to DNA. I smell gummy bears.

Artist’s impression of the simple sugar glycolaldehyde molecules, showing its molecular structure (C2H4O2). Carbon atoms are shown as grey, oxygen atoms as red, and hydrogen atoms as white. Credit: ALMA (ESO/NAOJ/NRAO)/L. Calcada (ESO)

Finding sugar in the Milky Way shows yet again that life-related organic molecules can form in even the most rarefied and hostile places. Getting all the bits and pieces together under the right conditions for the spark to set the works in motion seems to be the trick. To date, Earth’s the only place we know of where life forms stand out in the bitter cold waiting for a bus.

The universe got even sweeter today with another sugar sighting from a team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) of 66 radio telescopes in Chile.  Sugar molecules (glycoaldehyde again) were detected for the first time in the disk of gas and dust surrounding a sun-like star in a double star system in the constellation Ophiuchus.

Astronomers have found simple sugar molecules (inset) around a sun-like star IRAS 16293-2422 located about 400 light years away in the Rho Ophiuchi star forming region, here shown in infrared light. Click photo for more information on the discovery. Credit: ALMA (ESO/NAOJ/NRAO)/L. Calcada (ESO) & NASA/JPL-Caltech/WISE Team

“What is really exciting about our findings is that the ALMA observations reveal that the sugar molecules are falling in towards one of the stars of the system,” says team member Cécile Favre. “The sugar molecules are not only in the right place to find their way onto a planet, but they are also going in the right direction.”

Sugar-sweetened planets get my nod of approval. Kidding aside, astronomers are very interested in just how complicated molecules can become before they’re incorporated into planets. If sufficiently complex molecules around stars are common, including them in newly formed planets might increase the chances for life to arise by providing plenty of the right ingredients.

There’s something about the mindlessness of nature that I relish almost as much as candy. That under the right conditions, complexity and even life are inevitable, given time and the propensity for stuff to collect and connect. I find this simple “is-ness” of nature to be both beautiful and mysterious. Definitely something to sink your sweet tooth into.

Curiosity photographs layer cake hills on Mars

Wow, look at that layering! The base of Mt. Sharp taken with Curiosity’s 100 mm telephoto lens. These mounds and knobs are the rover’s main destination. They’re about 10 miles away. Click for larger version. Credit: NASA/JPL-Caltech/MSSS

Curiosity hasn’t been idle. NASA released several exciting new images beamed back from the surface of Mars by the happy rover. They’re high resolution, full-color photos taken with the wide angle 34mm and telephoto 100mm Mastcam cameras. Those are the ones perched on the 7 foot-high mast that sticks out of Curiosity like the head of one of those mean Mars saucers in the original 1953 “War of the Worlds” movie.

Curiosity’s Mastcams focus on a next scene ahead in this NASA illustration.

Some of the wonderful layering at the base of Mt. Sharp was almost certainly deposited by lakes, rivers or flood plains that once sloshed around inside the crater. Orbiting satellites have detected signs of clays and other water-fashioned rocks within these very foothills.

I can’t help but recall the South Dakota Badlands, where sediment deposition by water happened over a period of more than 40 million years beginning 69 million years ago.

Bands of red sandstone in these Badlands hills mark the course of ancient rivers. Credit: NPS photo by Larry McAfee

During the last half million years, water and wind erosion carved the Badlands, revealing layer upon layer of sediments stacked high like an uber-Viennese torte cake. Years ago, while hiking there with my wife, we came across the fossil teeth and jaws of extinct oreodonts eroding out of the mudstone mounds. What might be hidden in the Mars hills?

Volcanic ash, lava flows and windblown sands can also accumulate in beds, so Mt. Sharp’s layers likely have multiple origins just as the hills of the Badlands do.

While the hills look relatively close in the photo, it will take the rover many months to reach them as the team of rover drivers figure out a safe way through swales and sand dunes along the way. For additional new Mars pix, check out the Curiosity gallery.

New panorama made with Curiosity’s wide-angle Mastcam showing Mt. Sharp in the distance. Click to see the hi-res view. Credit: NASA/JPL-Caltech/MSSS

The moon looks pregnant lately. Tonight it will be only a few days from full and very close to a pair of bright binocular double stars in Capricornus the Sea Goat.

The view through binoculars tonight when the gibbous moon will hover only 1 degree from Beta Cap and 3 degrees from Alpha Cap. All three will fit in the same binocular field of view. Map created with Stellarium

All you have to do is point your glass at the moon and look one degree (two moon diameters) to its upper right to find 3rd magnitude Beta Capricorni.  Beta is a true double star with a 6th magnitude companion orbiting close by to the west.

Don’t expect to see either star move anytime soon – they’re so far apart they require nearly a million years to orbit about their common center of gravity.

Above Beta you’ll see the even wider pair Alpha 1 and Alpha 2. While this duo looks like a convincing double star, it’s really a fake. It only appears double because we see the two stars along the same line of sight. Alpha 2, the brighter star, is 109 light years away; Alpha 1 is over 6 times farther at 690 light years. Fake sure, but still pretty.

While the two Alphas should be easy to see even with the bright moon so close, Beta’s fainter companion will be harder. Holding the binoculars as steady as possible will help.

See Neil Armstrong’s crater on the moon

A closeup view from orbit shows the pair of 18.5 mile-diameter craters Ritter and Sabine which are easily visible in a small telescope. They’ll help to guide you to the three smaller craters named after the Apollo 11 astronauts. North is up in the photo. Click to scout around an interactive moon map. Credit: NASA

Neil Armstrong will always have a place on the moon alongside his fellow Apollo astronauts Michael Collins and Buzz Aldrin. Each has a crater in their name not far from the Apollo 11 landing site in the Sea of Tranquillity. These three craters and three on the lunar farside for the crew of Apollo 8 are the only ones to my knowledge named for living  astronauts. Frank Borman, James Lovell and William Anders of Apollo 8 were the first the leave Earth orbit and travel around the moon.

14 other astronauts and cosmonauts who died while involved in their respective space programs have also been memorialized with craters. The most recent were seven craters named for the Space Shuttle Challenger astronauts who perished during while ascending to orbit after launch on January 28, 1986.

The astronauts who died in the Space Shuttle Columbia explosion while returning from orbit on February 1, 2003 are remembered in a cluster of craters in the Apollo Basin on the lunar farside and in seven named peaks in the Columbia Hills on the planet Mars. This range is located in Gusev Crater where the Spirit Rover landed in 2004.

You can start with this photo to first identify one of the man in the moon’s eyes – the Sea of Tranquillity. The photo map below will help you hone in on the trio of Armstrong, Aldrin and Collins. Photo: Bob King

Several years back on a clear night with little air turbulence, I trained my 10-inch telescope on the Apollo 11 landing site near the pair of medium-sized craters Ritter and Sabine. The site itself appears smooth and featureless to the eye, but Armstrong’s crater, along with his pals Buzz Aldrin and Michael Collins, who remained in orbit while the other two gathered rocks and set up experiments on the lunar surface, came into view at a magnification of around 200x.

All three form a neat little row with Armstrong the largest and Collins the smallest, but they’re all quite small really. Armstrong’s crater is just 2.9 miles across, Aldrin 2.1 miles and Collins 1.5 miles. The trio is located a short distance due north of the bright crater Moltke. With a 6-inch scope and steady air, you should be able to pick out all three out at high magnification starting about the time the moon is 6 days old or just before 1st quarter phase. Neil’s is the easiest to see.

Be patient. Unsteady air may cause them to waver and dissolve. If you keep your eye glued to the eyepiece, you’ll catch a few ideal moments when the trio will be tack sharp. I enjoyed the experience of seeing these “buddies for all of time” and picturing the nearby landing site.

In this tighter view, I’ve labeled Sabine, Ritter and the bright little crater Moltke along the eastern edge of the Sea of Tranquillity.  Once you’ve found your way to these craters, switch to high magnification and use the photo at the top of this blog to navigate to Armstrong and the others. Credit: Frank Barrett

Here are some photos to help you find them, too. The best time to look would be around the 6-8 day-old moon when shading and shadows will help reveal the craters’ contours, but feel free to try at any phase. Good luck in your explorations. Should you succeed, you will have taken one impressive leap for an amateur sky watcher.

How about this perspective? A view out the window of the lunar lander module looking back toward the command service module and the site where Armstrong and Aldrin would soon land. Credit: NASA

Want to learn more about Apollo 11? Read an excellent re-telling of the first lunar landing and what it was like to be there in the NASA Science News article Wide Awake in the Sea of Tranquillity.

What color is the sun?

The sun usually appears yellow to our eyes when it’s high in a clear blue sky. Photo: Bob King

Think of the sun. What color is it in your mind’s eye? Most of us would say yellow without hesitation. That’s how appears in a clear blue sky. I looked at it this morning and thought pale gold was also a good fit. We’ve also seen red and orange suns around sunrise and sunset, but we know that’s not the intrinsic color of our star but soupy air and dust at work.

White light or sunlight is composed of every color in the rainbow from violet to green to yellow to red. When the sun is high in the sky, all these colors reach our eye with equal intensity and the sun appears pure white. But wait – the sun doesn’t look white. It’s yellow, right?

In truth, colors aren’t created equal when it comes to Earth’s atmosphere. Each is affected differently by everything ranging from air molecules to suspended dust to volcanic aerosols.

White sunlight composed of all the rainbow colors streams through
space. When it hits Earth’s atmosphere, the oxygen and nitrogen
molecules scatter the blue and violet part of sunlight across the sky to color it blue. Credit: www.pingry.org

Air molecules scatter blue and violet rays away from the hidden rainbow of colors in white light and send them bouncing around the sky. That’s why the sky is blue. When you look up to admire a blue sky, you’re seeing the blue part of sunlight set free. Come to think of it, we’re literally inhaling blue sky every time we take a breath. And to go one step further, we spend most of our time with our heads in the sky, since our feet are the only part of us touching the ground.

This loss of blue and violet to the sky causes the sun to look look yellow or “warmer” than it should. If we could peer out the cupola windows of the space station at a sun unfiltered by the atmosphere it would appear its natural color – glaring white.

Around noon, sunlight takes a short, direct path through the atmosphere and appears pale yellow. When near the horizon around sunset and sunrise, it passes through the lower, ”dirtier” part of our atmosphere the entire distance. All that extra dust, smoke, etc. effectively scatter much of the sun’s light, leaving only oranges and reds. Illustration: Bob King

The size and concentration of particles in the atmosphere like smoke, dust, pollen and pollution affect what colors we see from the sun. When the sun’s high overhead, its light takes the short path through mostly rarefied air and then through the bottom 10 miles of atmosphere where the air is thickest. No great loss of light. But at sunset and sunrise, the sun is near the horizon and has to shine horizontally through hundreds of miles of the lowest, thickest layer of Earth’s atmosphere.

A red sunrise over Lake Superior. Dust, pollen, smoke, salt and
other particulates, collectively called “aerosols”, scatter violet,
blue, green and even yellow from sunlight leaving only orange and red. Credit: Lyle Anderson

Air molecules and aerosols across that great distance scatter away not only the shorter wavelength violet and blue parts of sunlight but also the longer wavelength yellows, leaving the familiar rich oranges and reds of a beautiful sunset.

This is a weird analogy but imagine tossing a handful of rocks, some very tiny pebbles and others the size of golf balls, at a beaded curtain. The teeny-tiny rocks will be scattered back by the curtain but the big ones will sail right through. Blue light (tiny pebbles) consists of very short wavelengths easily scattered by air molecules; red light rays (big rocks) have longer wavelengths and move through the air unimpeded.

When particles are few, sunsets are a bright yellow, but when the air is laden with dust or salt (near the oceans) the sun looks like a big red ball of fire. What color will it be tonight?

A white sun in airless, black outer space seen from the International Space Station. Credit: NASA

Neil Armstrong, first man to walk on the moon, dies at 82

A tight crop of a photo Neil Armstrong took of Buzz Aldrin. You can see Armstrong and the lunar lander in the foreground. The lovely Earth is the small dot near the top. Click for full image. Credit: NASA

If you haven’t heard the news yet, Neil Armstrong, the first man to walk on the moon, died Saturday from complications resulting from cardiovascular procedures. He was 82. I’ll never forget the night he and lunar module pilot Buzz Aldrin walked out onto the surface of the moon on July 20, 1969. Who could forget those first words from the moon after their harrowing landing:

“Houston, Tranquility Base here. The Eagle has landed.”

Neil on the moon July 20, 1969

I was 15 at the time and had a camera and tripod ready to go in front of the black-and-white TV set in the basement. Watching the quiet drama unfold, I squeezed the shutter button to record one of mankind’s greatest achievements. Armstrong’s left foot touched the lunar surface at exactly 9:56:15 p.m. (CDT). I got it! Tonight I dug around my current basement for those photos, but in the blizzard of life since 1969, I’ve lost or misplaced them.  Luckily, memory serves well.

Part of a panoramic shot showing Neil Armstrong working with equipment stored on the lander. Credit: NASA

There aren’t many pictures of Armstrong on the moon because he had the camera during most of the time he and Aldrin were outside the module. That’s why you see Aldrin in most of the first moon landing images. There’s only one high-quality still image of Armstrong (above); the rest is low-res TV and film.

The grainy TV image of Armstrong’s first step on the moon. Click to see the original “One Small Step” video. Credit: NASA

No matter. He did the deed and returned home to tell the tale. He and Buzz inspired lots of us kids and teens to think about space and space travel. And yes, I wanted to be an astronaut. We pointed our little scopes at the moon at every opportunity. I remember memorizing the vague area in the Sea of Tranquillity where Aldrin and Armstrong walked so I’d be ready to point it out to parents or friends when they inevitably asked. People still ask to this day.

Neil Armstrong’s boot print on the moon. Credit: NASA

While Armstrong brought the moon closer to us, it’s what he said about the Earth that sticks in my mind:

“It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn’t feel like a giant. I felt very, very small.”

Thanks Neil for making the first tracks in the long and winding path to the asteroids, planets and beyond.

Feed your head with photons from Andromeda

The Andromeda Galaxy as it appears in binoculars with a bright center set in a fainter, saucer-shaped disk. Photo: Bob King

Two nights ago I was out with a group under the sky at 11 o’clock. We were a good distance from city lights with dark sky all around. The W-shape of Cassiopeia stood high in the northeastern sky.

I love the W not just for its easy-to-recognize outline but because it can take you places. The farthest place it points is the most remote object typically visible with the naked eye – the Andromeda Galaxy.

Subtle spiral structure is visible in this photo of the Andromeda Galaxy taken with a 200mm lens. One of its companion galaxies, M32, is visible at upper left. The view approximates what you’d see in an 8-inch or larger telescope. Photo: Bob King

The galaxy looks like an unassuming small, fuzzy patch of light, but don’t let it fool you. Andromeda is at least half again as large as the Milky Way galaxy and contains 1 trillion stars or more than twice as many as our galaxy. When you take all those riches and stash them 2.5 million light years away, only a hint of their grandeur remains. We can bring some of the galaxy’s spectacle back through photography. Our imagination does the rest, transforming fuzz into glory.

Before the moon is too bright, go out the next clear, haze-free night, face east around 11 p.m. and use the Cassiopeia “W” or the Great Square to find the Andromeda Galaxy (M31). Our second featured galaxy, M33, is shown in the nearby constellation Triangulum. Created with Stellarium

Like you, I enjoy looking at pictures of nebulas, galaxies, planets – you name it – taken with big scopes like the Hubble. But I’m never satisfied until I get a look at the real thing. The thought of tiny photons of light traveling all the way from a particular deep sky object straight into my own eyeballs gives my spine a sizzle. Who cares if it looks like nothing more than a pinpoint of light. If you know you’re staring at a supernova or Earth-approaching asteroid, reality wins.

Andromeda in all its glory photographed by Adam Evans. Click for the sumptuous version.

That’s why you should go out the next clear night to find the Andromeda Galaxy. It’s not too hard to find. If you can see the hazy band of the Milky Way across Cassiopeia even faintly, Andromeda’s within your reach. Use the right side of the W as an arrow to point you to the galaxy. It’s a little more than one fist held at arm’s length away from the “pointing star”. I’ve picked out the galaxy from suburban areas here in Duluth, Minn.; it’s even easier from the countryside.

If you have any trouble at all, take along your binoculars. Heck, take them anyway. With just a little extra glass and magnification, Andromeda expands into a disk several times the size of the full moon. You’ll also be able to distinguish the galaxy’s central bulge, where most of its stars are concentrated, from the flat disk. Both Andromeda and the Milky Way are spiral galaxies with arms that wind around their centers. Other types of galaxies include ellipticals which are spherical to oblong but lack arms, and the ragtag “irregulars” that lack symmetry.

A photograph shows Triangulum and the Triangulum Galaxy. Even if you can’t spot this one with your naked eye, it’s visible as a smoky smudge in 7×35 and 7×50 binoculars. NGC 752 is a nearby star cluster in the Milky Way. Photo: Bob King

Since light takes 2.5 million years to reach your eye from Andromeda, I’ve often been asked whether we’re even sure it’s still there right now in 2012. The answer is yes! Compared to a galaxy’s lifetime of billions of years, a few million is just a drop in the bucket.

Care to see even farther? Not far from Andromeda in the constellation Triangulum the Triangle sharp-eyed sky watchers under very dark skies can spot M33, the Pinwheel or Triangulum Galaxy.

M33 is also a spiral galaxy like Andromeda and the Milky Way but its arms are flocculent and loosely wound. Credit: Hunter Wilson

Catch it and you’re peering out another 200,000 clicks to 2.7 million light years. It’s faint but even my aging eyes can spot it under great skies. I’ve heard of some amateur astronomers pushing back the naked eye limit even further with sightings of the galaxy M81 in the Great Bear Ursa Major. That one’s nearly 12 million light years away!

Rocks on Earth that fell from Mars

The beach in Duluth’s Canal Park is a mix of different kinds of volcanic rocks. The grey ones in the foreground are the commonly-found basalt. Photo: Bob King

When Curiosity used its powerful laser to zap the fist-sized “Coronation Rock” last Sunday, the resulting spark of vaporized minerals revealed the rock was made of basalt (ba-SALT). Basalt is a common volcanic rock found both on Mars and Earth. Just this morning I tromped around on grey, fine-grained basalt pebbles along the beach in Duluth’s downtown.

The fist-sized rock Coronation, the first rock ever to get zapped by a laser on another planet. The background is the wide-angle Navcam image; the closeup was made with ChemCam’s Micro-Imager. Coronation appears to be a basaltic rock. Credit: NASA/ JPL-CalTech

Basalt is formed by rapid cooling of lavas on the surface of a moon or planet. Fast-cooling lavas are made of tiny crystals, which is why basalt pebbles are a flat, uniform gray and pleasingly smooth to the touch.

Molten rock beneath the surface of the Earth is called magma. Magmas take a longer time to cool and grow bigger crystals, forming rocks like granite and gabbro. Both magma and lava cool and solidify to produce igneous rocks. I apologize for the Geology 101 lesson, but it will be helpful when we look at the makeup of Mars rocks.

As of July 2012, 63 Martian meteorites have been found on Earth. All are igneous rocks similar to the one Curiosity sampled. Some have been altered by water flowing over them, creating patches of minerals called carbonates, but most are a Martian version of basalt similar to Earth’s igneous rocks.

The Viking 1 lander touched down on Mars on July 20, 1976. Credit: NASA

How do we know they’re from Mars? Thanks to the two Viking spacecraft that landed on Mars in 1976, scientists were able to precisely measure the composition of the Mars’ atmosphere. Those same gases in the same proportions were found trapped within a meteorite called Elephant Moraine 79001 recovered in Antarctica in the early 80′s and in other meteorites since. Elephant Moraine has other elemental and mineral peculiarities shared by a small group of space rocks called “Snick” or SNC meteorites that scientists have positively linked to Mars.

Getting here took a lot of energy. Meteorite and asteroid impacts on Mars millions of years ago sent chunks of Mars’ crust flying into space. Over time, Earth intercepted some of this material which landed as meteorites. The most recent meteorite to land on Earth from the Red Planet fell in the early morning hours of July 18, 2011 in a rugged desert near Tissint(TEE-sint), Morocco. Based on a detailed study of its composition, the Tissint meteorite is believed to have formed in a lava flow on Mars 460 million years ago and likely launched by impact 1.1 million years ago along with 11 other similar meteorites.

A small endcut of the Tissint meteorite, a recent arrival from Mars in Morocco. It’s similar in composition to basalt rocks on Earth. The round, pale green dots are made of olivine, also known as peridot and used in jewelry. The small black spots and black vein (at right) are shocked and melted rock from impact. Photo: Bob King

We know the impact that excavated the rocks was powerful in the extreme because a number of Mars meteorites, including Tissint, contain dark “melt pockets” and shock veins where heat and pressure melted the minerals into a black glass. It’s in those dark glasses that scientists find precious samples of Mars atmosphere sealed up waiting to be released and analyzed by re-heating.

Going to Mars to study rocks as Curiosity is doing will help us understand the context for the “free delivery” samples we already have here on Earth. We may even be able to nail down just where our earthly Martians originated. Scientists think the currently known 63 were launched from a half dozen different sites rather than 63 separate ones. Enough are similar to one another it’s believed they’re different parts of a single large lava flow.

Bounce Rock after being drilled by the Opportunity Rover. Bounce is the closest in composition to Mars meteorites found on Earth. Credit: NASA

The various Mars rover missions have uncovered lots of Mars rocks that are different from the samples bequeathed to us by chance encounter. Only one is a good match, a rock called “Bounce” examined by the Opportunity Rover and found to have a composition very similar to some of the Mars meteorites. No doubt we’re missing many Mars rocks from our collection. Think of the diversity of types on Earth.

Another Mars meteorite discovered in 2011 in the Sahara Desert – NWA (Northwest Africa) 6963. It still has fresh black crust from its fiery fall through the atmosphere. It’s also a type of basaltic rock. Click to learn more. Photo: Bob King

If we had only 63 rocks from our planet we’d hardly get a complete picture of Earth’s garden of rocky delights. Scientists would love to stumble across a Martian sedimentary meteorite blasted from an ancient river bed. A better sampling of extremely ancient rocks would also be appreciated. Most of the samples we have are relatively young with formation ages measured in millions rather than billions of years.

That’s why we keep returning again and again the Red Planet – to wrest the secrets the rocks hold onto so tightly. To learn more about Mars meteorites, click HERE or check out a current list of Martians HERE.