Planets Before Dawn

Get up early later this week and enjoy a look at the moon plus our sun’s five innermost planets. Later in the year Mars and Jupiter will be easier to spot. But the end of April will be prime time for viewing the planet Mercury. At least from Planet Earth. Did you know that the Messenger spacecraft is currently in orbit and sending back images? At first glance, these images are reminiscent of the moon, but there are subtle differences.

Above image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington. Note the “smile” in the crater. I’m sure somebody somewhere has or will consider this evidence of ET’s trying to get our attention.

Speaking of Dawn, there is a spacecraft by that name closing in on minor planet Vesta. Worth monitoring, that.

 

Fifty Years Ago, Or Less

Fifty years ago today Yuri Gagarin rocketed into a new frontier. This BBC piece muses on the what-if: the Soviets were the first to land on the moon.

Both space programs were really pushing in 1968. The Americans got Apollo 8 in orbit, mainly because the first lunar module wasn’t ready for a mission. Partly also that American intelligence was thinking the USSR was pulling out all stops for a flight around the moon.

Had the Soviets got to the Moon first it is unlikely that they would have abandoned it as swiftly as the Americans.

Not being a democracy may have enabled the USSR to spend money and marshal the talents of their population in a way that America could not.

Space historian Dr Christopher Riley believes that not only would the Soviet Union have continued with Moon missions, but they might also have built lunar bases.

And he believes that the Americans would have been compelled to do the same and even try to continue to outdo their communist rivals.

“The history that followed in the decades afterwards would have been completely different,” he says.

The Russians had sturdy hardware, and a tenacious approach to their space program. They were willing to push, sometimes beyond the capabilities of their personnel and/or equipment.

 

For the Ninth Orbited Object: Add Mercury

The Messenger team is thrilled: after five years, their probe has achieved Mercury orbit. The spacecraft now settles in for a year of ceramic-shielded study of the solar system’s innermost planet.

For the record, the years and first human-made orbiters of the various celestial bodies:

1. Earth, 1957, Sputnik 1
2. Sun, 1959, Luna 1
3. Moon, 1966, Luna 10
4. Mars, 1971, Mariner 9
5. Venus, 1975, Venera 9
6. Jupiter, 1995, Galileo
7. Eros 433 (asteroid), 2000, NEAR-Shoemaker
8. Saturn, 2004, Cassini
9. Mercury, 2011, Messenger

This decade we will see the Dawn probe orbit asteroids Vesta and Ceres. Rosetta will orbit a comet, 67P/Churyumov-Gerasimenko in 2014, if all goes according to plan. I don’t think anything else is on the horizon as far as a “first” orbiter goes. It would be nice to see orbiters at Uranus and Neptune.

Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

 

Satellite Imagination: Before Kuiper’s Belt

As we read in the last edition of this series, Seth Nicholson’s satellite discoveries spanned nearly four decades. Let’s dial the clock back a bit from the discovery of his last, Jupiter XII, and take stock of the situation just after WWII.

Jupiter had eleven known satellites–the most number for the largest planet. And that seemed fitting. Saturn had nine. Uranus four. Mars two. Earth one. And distant Neptune one. Total of twenty-nine. Until 1900, these satellites had been discovered by telescopic observation. Jupiter’s latest six had been detected using photography–comparing film negatives and noting the movement of a small black dot in the vicinity of the planet.

Pluto was found in the same way in 1930. Clyde Tombaugh, country-boy astronomer from Kansas, not even a college degree in his resume, caught slight movement almost four billion miles away in Arizona.

By mid-20th century detecting a planet’s satellite was fraught with one or two major problems. A closer orbiter would be washed out in the glare of nearby planet. More commonly, the threshhold of size was shrinking. The moons of Mars and the smaller moons of Jupiter were the size of large cities. The smallest moon detected in the 17th century, by contrast, is Tethys, about 700 miles across. (Tethys, by the way, masses more than all of the solar system’s known smaller moons combined.)

Enter Dutch-born astronomer Gerard Kuiper. Before he had a whole belt of icy bodies named after him, he made two significant satellite discoveries.

After his schooling in the Netherlands, he came to California’s Lick Observatory in 1933. After a two-year sojourn in Cambridge at the Harvard College Observatory, he settled in at the University of Chicago in 1937, where he was noted for his early work in planetary astronomy.

He turned his attention to atmospheres, detecting carbon dioxide on Mars in 1944.

You may recall the other famous Dutch satellite astronomer, Christiaan Huygens. Professor Kuiper followed in three-century-old footsteps and detected methane on Saturn’s moon Titan, the first definitive non-planet atmosphere detected in the solar system.

Did I mention Dr Kuiper was gifted with extraordinarily sharp eyesight? Perhaps it inspired his imagination to look at the night sky and see objects four times fainter than the average skywatcher. His vision, however above average, was of no help for his satellite discoveries. While Seth Nicholson was finding small moons of Jupiter, Kuiper found previously unknown objects in orbit around the sun’s distant ice giants, billions of miles away, and far too faint to be found by a sharp-eyed observer.

Meet Miranda, his 1948 find:

Kuiper, of course, didn’t see it this way. The image above is from NASA’s Voyager 2, taken from 90,000 miles away. The earthbound astronomer is well over a billion miles distant. Far enough away that the planet Uranus washes out the view–at least for the average amateur telescope.

Meet Nereid, his 1949 discovery:

Again, Kuiper didn’t see it so close. This was also imaged by Voyager 2 during its Neptune encounter, but from a distance of a few million miles. The astronomer of the 1940′s was more accustomed to this family portrait:

Arrows mark the two moons of Neptune in this photograph: Triton near the planet, and Nereid the very faint dot.

Two very different satellites discovered in consecutive years. One orbits her planet in a circular way, just outside a ring system. The other orbits in a long loop that takes her from one to six million miles.

Humans will return to Miranda, if only by means of a future Uranus orbiter. Miranda’s irregular landscape begs many questions. Was it blown apart in a collision and reassembled in a random way? Does it harbor ice geysers and volcanoes like another small moon? Curious and imaginative minds will want to know.

Nereid, sorry to say, will likely be forgotten. Future exploration of the Neptune region will focus on the planet, it’s large moon Triton, and its clumpy ring system. Nereid is a bit out of the way, and will be left to future imaginations pondering the dark, lonely bodies of the outer solar system.

This website’s survey of solar system natural satellites now covers everything up to the Space Age. As future posts will show, the dispatching of robot explorers will put a familiar face on most of the natural satellites discovered before the first artificial ones were sent aloft. Stay with us for those journeys of imagination.

 

Satellite Imagination: Nicholson’s Quartet

Detecting natural satellites of Jupiter is darned difficult. The planet is bright. The satellites are small and dim. Most of Jupiter’s moons orbit in irregular paths, nudged by the sun. Some even orbit backwards. If you blinked, you might lose one. In fact, one moon was detected in 1975, only to be lost, then rediscovered in 2000.

One early twentieth century astronomer was up to the task, though. With big telescopes gathering a few reflected photons on photographic plates, Jupiter’s family of satellites grew and surpassed Saturn’s nine, thanks to the efforts of an Illinois-born astronomer working in California.

In 1914, a grad student found the ninth moon of Jupiter. While observing the newly discovered Jupiter VIII from Lick Observatory, Seth Barnes Nicholson found his PhD thesis topic: Jupiter IX, now known as Sinope. Over the course four decades, he added three to his tally, tying Galileo, Cassini, and Herschel for the most discoveries up to that time–four. Here are the others, all found at the Mount Wilson Observatory (image above and left), where Dr Nicholson spent his entire career:

Jupiter X, or Lysithea, in July 1938

Jupiter XI, or Carme, also in July 1938.

Jupiter XII, or Ananke, in September 1951.

Nicholson was more than an observer of dim, irregular satellites. He developed tools for assessing surface temperatures of solar system bodies (his moons as well as planets and the sun) and distant stars.

These seven outer satellites of Jupiter–Nicholson’s four, plus the three found from the first decade of the 1900′s are all thought to be captured from the nearby asteroid belt. Or they could be comets. Or they could be fragments from a few larger bodies that broke up. Since Jupiter’s outer moons move in similar orbits this last theory seems to fit observations pretty well. Don’t think clumps of moons, though. These bodies orbit millions of miles from Jupiter. A close association is more like them sharing a fairly wide pathway far out from the planet. Imagine Jupiter sitting on the thirty-yard line of a high school football stadium, its north pole pointed up, but at an angle, perhaps toward a near bank of lights. The satellite Carme and associated moons (discovered in the last ten years) would be at different places circling the field mainly on the surrounding track. Don’t imagine a handful of closely-bunched runners.

Nobody really knows for sure about any of this. No human-made spacecraft has ever flown anywhere near them. They aren’t big priorities for NASA or other nations’ space programs. It might be that the first robots or humans visiting these satellites will be lonely wanderers themselves.

In my imagination, I see a twenty-third or twenty-fourth century ship pushed by the pulse of ions. Looking around, Jupiter would be far away, only about the size of our moon as seen from Earth. Light from the sun would be only about four percent Earth levels. An unenhanced view would find us moving up next to a dark gray body with just a hint of red. Much of it might be water ice mixed in with rock. But don’t think of icebergs sticking out from soil–from Earth it seems these bodies are fairly homogeneous in surface. The ice will be dirty, laced with carbon dioxide and maybe ammonia, and studded with boulders and dust and particles of sizes in between.

As the explorer gets closer, the body–let’s say it’s Ananke–will loom large, dwarfing the living compartment and the ion engine. But even compared to asteroids, it would be small–only twenty miles across. Centuries after Seth Nicholson noted moving specks in the Jupiter neighborhood and plotted orbits, someone would finally see the moon, and not just in her or his imagination. It’s not likely there would be a landing. Maybe grappling hooks if the ship were sturdy. More likely a few small robots would tumble down to the surface. Dig around a bit. Send an optical feed back to the main ship. Taste the dust of the surface and clarify the makeup of the impurities.

It might be that the same mix of trace compounds and elements was detected at last month’s stop–ratios of cyanide, carbon monoxide, or silicate crystals. So it will be confirmed that Ananke and about one or two dozen mile-sized satellites were once a single asteroid captured by Jupiter. Then pulverized into fragments. If space explorers of the 2300′s feel the need to put down roots, Ananke would be an interesting place. There’s likely enough ice to turn into water for drinking and other industrial uses–more than on the moon, that’s for sure. Splitting water molecules into hydrogen for fuel and oxygen for breathing will be child’s play in future centuries. The sun being so far away, is only four percent as efficient as a power source as it would be near the Earth. On second thought, these intrepid explorers may have other places in their imagination, closer to the life-giving energy of our central star. After a few days, the ship will pull out its stakes, leave behind the robot probes, and move on to the next target.

It’s a lonely existence ten to twenty million miles out from Jupiter. No gazing back at Earth either–our home world will be lost in the glare of the sun–not unlike the way Jupiter’s reflected light washes out viewing some of its moons.

 

Satellite Imagination: Unnamed Moons

Galileo discovered the first satellites (except for our Moon) in the solar system. In the opener of the “satellite imagination” series, you get a piece of the story connected with that. You might think that moons half a billion miles away have little effect on the Earth. Speaking astrologically and gravitationally, you would be right. Yet those moons orbiting Jupiter shook the relationship between science and religion. It has remained in a sort of tension ever since. Occasionally it explodes like volcanoes on Io. Other times, one beholds a certain serenity, but who knows what scientist or religious person is really thinking under that crust of ice.

You might think there was a rush to name the satellites of other planets. But professional astronomy was, for the most part, apathetic. Roman numerals were enough for Jupiter’s satellites. American astronomers making discoveries didn’t really push the issue. In fact, some of them had more important things to consider: comets, star clusters, and galaxies. VI, VII, and VIII weren’t the most imaginative designations, but they were sufficient until the Space Age.

By the final decades of the nineteenth century, the baton of planetary astronomy had passed to American shores, at least as far as the discovery of natural satellites was concerned. Americans built big telescopes, and they started putting them on mountains. The Lick Observatory began operations in 1888, and six years later they scored a big find: Jupiter’s first moon in almost three centuries.

California’s Lick Observatory, above in 1900.

 

Glory To Space

NASA’s Glory satellite lifts off tomorrow from California to find any connections between solar radiation output, human-made or natural aerosols in the upper atmosphere, and climate change on the ground.

Universe Today has coverage here, too.

It will be interesting to see how the climate change deniers handle Glory results.

 

Apollo 20′s Cave?

The Lunar Reconnaissance Orbiter has captured the image of a lava cave in the Marius Hills region on the moon. Some curious questions: is it a cave, or just the lit end of a long lava tube? That would be a ready-made shelter for a lunar base. No ice like at the lunar poles, but  deep underground protection from solar radiation, meteor fall, and temperature extremes of the lunar surface.

Interesting side note is that American astronauts might have landed there. Before the mission was cancelled, this area slated was a possible landing site for Apollo 20. They didn’t know about this cave at that time, but it sure would have been exciting to end the Apollo program with spelunking astronauts, wouldn’t it?

 

Tracking the Storm

The movement of clouds is so beautiful from above. What’s underneath them, much less so, from the view on the ground.

 

1235!

1235: the number of new candidate planets uncovered by the Kepler Observatory which has a bead on over a hundred thousand stars between the constellations Lyra and Cygnus. A nice summary on the Universe Today blog, with two cautions:

The first planets discovered outside our solar system were pulsar planets. And these irradiated burned-out cinders never get their due. It’s almost as if astronomers are p***ed off they didn’t find the first planets orbiting a cute little yellow star like our own. This quote:

The first planets beyond our solar system were discovered in 1995.

Wrong. The first planets were found orbiting the pulsar PSR B1257+12 in 1992. Three years before planet hunters started finding hot Jupiters circling stars far far away.

Another oops:

In January 2011, Kepler confirmed the discovery of its first rocky planet, named Kepler-10b. The molten world measures just 1.4 times the size of Earth and is the smallest planet ever discovered outside our solar system.

Wrong again. The smallest known planet outside the solar system is orbiting that star PSR B1257+12. It masses about twice as much as the moon.

Pulsar planets are dismissed out of hand as having zero chance for life, but I think they teach an important lesson nonetheless. Planets are resilient, as indeed PSR B1257+12 went supernova and didn’t obliterate it’s whole system. At least the cores of these planets were left behind. An alternate view is that these planets were formed after the supernova stage. And that might be even more good news–that planets form in all sorts of circumstances, around both infant stars as well as dying ones. 

Now that I’ve gotten that out of the way, the Kepler findings, though expected, are really quite exciting. Astronomers will soon have several hundred planets from Earth-size all the way up to “super-Jupiters” to broaden the statistical survey of planets in the universe. After Kepler identifies candidates, other telescopes will be brought to bear to confirm these findings and bring out more detail.

Last snipe today: as much as I love biology, I do not expect that we will ever find life on other planets. I still think the search is worthwhile, but I think the wonder of interstellar exploration will be for the geology, chemistry, meteorology, and physics of these planetary systems. Of course, I’d be happy to be wrong. It’s my suspicion that the universe is empty of intelligent life, and probably other forms of life. I don’t have a real rational basis for this. And I know that finding would be deeply disappointing to many scientists, who entertain an obvious bias in favor of finding life. William Borucki, principal science investigator for the Kepler mission:

If we find that Earth’s are common in the habitable zones of stars, very likely that means life is common around these stars.

Nice optimism, but there is no scientific basis for this statement. Until we can see it, we have no idea about life beyond the Earth.

 

Young Discoverer

We have news that a ten-year-old has, with her dad, co-discovered a supernova in galaxy UBG 3378. Not only is astronomy a science still alive with significant amateur input, the door is wide open for young people.

 

The Fish Enthrone a King

King of the planets, that is. If you are looking up in the night sky these days at that bright object high in the sky, behold Jupiter. It’s well placed for viewing, being on the opposite side of the sun from Earth. There are no other bright stars nearby, so there’s no mistaking what you’re seeing. Tonight the moon is nearby.

You non-astro people out there should know that the sky is divided into 88 groupings of stars known as constellations. I’ve blogged about thirteen of them in the past–just check the sidebar under “categories.” Each of these groupings represents a person, living thing, or an object. It’s a fanciful way of sorting out the two-thousand points of light we see in our skies. The groupings along the orbits of the planets make up the thirteen (not twelve!) constellations of the zodiac. As Jupiter orbits the sun (once every twelve years) it traces a leisurely path through the background stars. The dignity of a king who spends about a year in each of the twelve “signs.”

At present Jupiter is in Pisces, the constellation of the fish pair. And there’s an interesting theological connection for this group of two fish.

Is it a happy accident that the constellation of Pisces receives the sun each year as winter turns to spring? You know that the fish is connected symbolically with Christ and the Eucharist. You also know that Lent into Easter is a time for Eucharistic renewal in Christ. It’s a bit more palatable to some Christians than the astrological significance of Pisces.

Over the next few months, the sun will trace its own path through the constellations. Jupiter will still be visible until Spring. If you look up in the sky each night as winter sails by, Jupiter will appear closer and closer to the western horizon as the weeks and months pass. What is actually happening is the Earth is progressing in its orbit around the sun. So from the Earth’s perspective, the starry background behind the sun changes.

Pisces, unfortunately, blends into its own background of stars, as you can see below …

… the two fish connected at the tail don’t stand out really well. And God doesn’t provide the telltale lines between the stars to help you. You’ll need a telescope to ferret out a few details. Even so, there not a whole lot in the constellation of great interest to astronomers. The third-closest white dwarf to the sun is in Pisces, Van Maanen’s star, only eighty-four trillion miles away.

There’s also one really beautiful galaxy. Image credit: NASA, ESA and the GMOS Commissioning Team (Gemini Observatory):

 

So if it’s not too cold out, look high above the horizon. Find that bright planet. For the next few months, you may be able to make out that large and faint “V” behind the king of planets. There are unseen riches deep in these stars. Waiting for explorers. And for the King of the Eucharist, more riches for those who seek him in the sign of the fish.

 

Gee, It Might Not Be There

That “new Earth” discovered orbiting Gliese 581? Maybe it’s not there after all. Astronomers have confirmed this red dwarf star has four planets. But the two newest ones–including planet “g” that’s getting all this attention–cannot be discerned apart from the background “noise” of the data.

When you’re dealing with a star 120 trillion miles away, there will be some uncertainty in the data. In astronomy, it’s traditional for other scientists to confirm discoveries. If two or more people working from different observatories can independently ratify a find, then the IAU (International Astronomical Union) will endorse. Until other astronomers get Steven Vogt’s back on this, I’d say the whole thing is now in doubt. Somebody might still avoid egg on face over this, but it represents the best of the scientific process. Results must be verified. And even something as dear as finding extraterrestrial life won’t distract the tenacious rationalism of science.

There have been many false starts on the planet hunt in the past. The most famous case occurred when I was a boy–and boy, did I want there to be Barnard’s Star planets! Some astronomers were dismayed when the first extra-solar planets were discovered orbiting a pulsar. That was no fun.

I think scientists desperately want to find an earth-like planet. I think it’s more than just being the “first.” There’s a certain kind of mania about it–I don’t understand it. Personally, I like thinking about carbon planets or other unusual bodies we will find near stars and out among them. It’s also my contention that we will find that life is unique in the universe. Ask me about it sometime. But I have this feeling (I’ll admit it’s a hunch) that Earth is unique and the universe is our personal egg.

That’s not to say the search for Earth-like planets is useless. Far from it. We might be living on them in a few dozen millennia.

 

Toward a Common East-West Easter

The North American Orthodox-Catholic Theological Consultation endorses a common date for Easter:

In 2010, Eastern and Western Church Calendars coincided so that all Christians celebrated the Feast of the Resurrection on the same day.  The dates for the Holy Day will coincide again in 2011, but will vary again after that.  As we remember the joys of a common date this year, we look forward to the entire Christian world proclaiming the joy of the Resurrection together again next year.  We are convinced that the time is at hand for a permanent resolution of this issue.

This would be a profoundly easy step to take. And to take it within the next few months, that would certainly be a welcome sign, especially to those discouraged by Roman footdragging under the last two pontificates.

The consultation suggests this scientific approach:

The key today to resolving the issue in accordance with the mandate of Nicaea is to determine the Equinox from the meridian of Jerusalem (Longitude 35° 13’47.1) using the most accurate scientific instruments and astronomical data available.  This will resolve the conflict in our liturgical observance by aligning existing Church calendars to the Nicene formula– not just the calendar from one set of Churches, but from both Eastern and Western traditions.

The full document is up on the USCCB site.

 

 

2013 a Solar Stormy Year?

Will our cell phones and computers be safe? Vatican astronomer Guy Consolmagno on the solar maximum and a potential threat to wireless technology. Nice seven-minute feature from Vatican Radio–worth a listen, despite a cutoff before the end of the piece.