Stargazing, Martians, and Hugo Chavez

Musings on a Wednesday Night

There’s never a dull moment in astronomy. If you’re a skywatching addict, then there’s something for you every night to check out. Last Saturday it was the Full Moon, and it was gorgeous!  We didn’t get to see it rise here at the hacienda, but after it cleared the mountain in back of us, the Moon looked great.  Tonight is quite clear (and cold), and so maybe later on I’ll step out and check out the starry skies. Right now, Sirius is twinkling low in the southwest and the stars of the Winter Circle are setting soon.  Another sign that spring is here for those of us in the Northern Hemisphere, and autumn has arrived for the folks in the Southern Hemisphere.

Mars isn’t in our night-time sky right now. In fact, it appears so close to the Sun that it’s nearly impossible to see without help. But, even though it’s out of sight, Mars is not out of mind.  Even the leader of Venezuela has been talking about the Red Planet this week, tying capitalism to the loss of life on Mars.  I’m not precisely aware of when Mr. Chavez got his degrees in planetary science OR economics and political science, and I’ve not seen evidence of his research contributions to those fields, but I’m reasonably certain that the lack of life on Mars isn’t due to a plot against Marxist-Leninist paradises here on Earth. It’s amusing to read his rhetoric, even as you see it for what it is — getting in a dig at his neighbors to the north. It seemed like an unlikely topic for him to bring up, but then again, any world leader talking about anything to do with the sky (astronomy or planetary science-wise) catches my attention.

No, Martian life — if it existed — probably never got started down the long evolutionary path that we did here on Earth. Conditions on the Red Planet became untenable for that — not due to Adam Smith-style capitalism, which is a human construct that came long after life took root on Earth.  More likely physical conditions were to fault on Mars, entirely NATURAL conditions that existed long before life on Earth was able to do more than look up to the sky in wonder. Changing conditions (atmospheric loss, cooling, geological changes) may well have doomed anything more complex than a Martian microbe to a very uncertain future.

Courtesy MIT/Christine Daniloff.

As it turns out, if a group of scientists at MIT in Cambridge, Massachusetts are right,  there’s a tantalizing possibility that life on EARTH may have its seeds on Mars, descending from organisms that somehow made their way from Mars to our planet in the very distant past.

It’s not so far-fetched as it might sound at first.  There are some well-established ideas about Mars that lend themselves to this story and make it a plausible avenue of research into the origins of life on Earth.

First, early in solar system history, the climates on Mars and the Earth were much more similar than they are now. Life that arose and flourished on one planet could presumably have survived on the other — if it could get from one place to the other. Second, an estimated one billion tons of rock have traveled from Mars to Earth since the two planets formed. That material was blasted loose by asteroid impacts and sent on its way between planets. Eventually, the “stuff” from Mars hit EArth.  Third, microbes have been shown to be capable of surviving the initial shock of such an impact.  So, if there WAS life on Mars (in handy microbe form, which is an easy way to transport living material), and it somehow caught a ride on an outbound rock, then given a good set of orbital conditions, there would have been NOTHING stopping that rock and its life-load from getting here eventually. When you look at the orbital dynamics of our two planets, it turns out that the chances are a hundred times better for rocks to travel from Mars to Earth.

I know that sounds surprising, but life is amazingly resilient, and in fact, there is evidence such microbes could also survive the thousands of years of transit through space before arriving at another planet.

So if life got started on Mars first, and it got blasted off the planet in a meteorite impact, then some hardy microbes could have been carried here to Earth. And, if that’s true, then Ray Bradbury’s final scene in “Martian Chronicles” is more prophetic than he may have thought when he wrote it back in 1950.   But, instead of finding those humanoid Martians staring at their own faces in a canal on Mars, all we have to do is look in the mirror in our homes here on Earth.

Of course, there’s a lot of work to do to prove this hypothesis, but I find it kind of poetic and interesting.  We — you, me, Mr. Chavez — all the people on Earth — really COULD be Martians, and here all along we’ve been yearning to explore that RedPlanet so far away. And, we’re using technology that is the fruit of the capitalism that Mr. Chavez regularly decries on TV, radio, and the Internet — ironically enough, media methods that also depend more on capitalist investment than he might feel comfortable with.

But there you go. Astronomy and planetary science lead one down some interesting paths, and not always scientific ones.  I think it’s rather interesting that even though his politics aren’t the same as mine, Mr. Chavez has an awareness of Mars and its past and future.  I wonder if he stargazes, too?

The Full Moon Rising over the Carnival

Carnival of Space, That Is

This week’s Carnival of Space — that compendium of writing by various bloggers — is now up for your reading pleasure. Take a few moments to check out stories about everything from the Japan earthquake to cataclysmic variables, density waves in spiral galaxies, comet Halley, and movie reviews over at Steve’s Astro Corner.

This enhanced image of the Moon was taken with the NOAO Mosaic CCD camera using two of the National Science Foundation's telescopes located at Kitt Peak National Observatory near Tucson, AZ. The image of the Moon itself was taken through the U-band filter at the 0.9-meter telescope. It is superimposed on a deep R-band image of the background sky taken at the Mayall 4-meter telescope. This composite image demonstrates the large field of view of the 0.9-meter telescope when using Mosaic, a view that covers more than five times the area of the Moon. It furnishes this large field of view without sacrificing high resolution - details as small as a few kilometers across can be seen on the lunar surface. Credit: T. A. Rector, I. P. Dell'Antonio/NOAO/AURA/NSF

As you’ve probably read (in breathless prose on some media sites, I’m sure), there’s a Full Moon today (March 19th).  You’ve no doubt been treated to all this hype and anguish over how it’s the LARGEST FULL MOON EVAR!!! and the CLOSEST FULL MOON IN MODERN TIMES and all kinds of other hyperbolic fulminating.

Lots of people are crowing about something that isn’t all that rare… and didn’t cause the earthquakes, thank you very much.

Here’s a sanity check on the news behind the hype.

As it turns out, tonight’s Full Moon is going to be closer to us than usual, and for that reason, it’s being dubbed a “SuperMoon”. The last one THIS big was in 1993 (as you can read here at NASA’s Science News site).

But it’s not all that an unusual thing to happen. During parts of its orbit, the Moon does sometimes come closer to us than other times.  As it happens, this is the closest one in less than three years. Yep, that’s right, the last “close” full Moon was in late 2008.  In fact, the January 2010 Full Moon was only 20 kilometers farther away than tonight’s.

The point is, this big Full Moon that lots of mainstream media (and astrologers) are hyping isn’t so rare after all.

My fellow blogger Ian Musgrave in Adelaide, Australia, did a little nosing around to find out the truth behind the hype.  He takes on some popular mythology about the Moon and all kinds of coincidental occurrences here on Earth. He also has a nice chart you can check out that shows the distances of the “close” Full Moons since 1991. There have been 21 in 20 years.

Umm… not so rare there, folks.  But, that hasn’t stopped Yahoo.com, Accuweather, and other sites I used to think were credible from spouting nonsense that appears to be based on something an astrologer wrote.  Do I need to point out (again) that an astrologer is not a scientist — not a lunar geologist, not an earth sciences person, not an astroNomer, and certainly not a credible expert on lunar orbits?

Look, think of the Full Moon in its orbit like a car going around an oval-shaped race course.  If you stand at one end of the oval, the car is going to be close to you at least once each time it goes around.  That’s called “perigee” and it’s entirely normal and nothing to start casting horoscopes over.  When the car is farthest from you in the oval, it’s at apogee.  Now, due to various conditions, sometimes the car gets closer to you during perigee than at other times during perigee.  So, imagine that in one lap it was three meters away from you. In the next lap, it might be one centimeter closer to you.  It’s perfectly normal and nothing to start reading palms about.

The Moon’s orbit is the same way, in that sometimes it’s a few percent closer to us than other times. Occasionally, that perigee time coincides with Full Moon — the phase of the Moon that occurs when the Moon is on the opposite side of Earth from the Sun, thus allowing the side facing us to be bathed in sunlight. (Perigee and Full Moon are two different things, so don’t confuse them with each other.  For a more thorough discussion of Full Moon, go here. )  They are perfectly normal and nothing to start blaming the Japan earthquake on. That temblor  and all the earthquakes that occur in Japan and around the Pacific Basin are due to the so-called “Ring of Fire” are due to Earth’s plate tectonics. These are natural phenomena and nothing to start blaming the Moon for.

I’m not sure why this is such a big deal, this SuperMoon thing.  Is it because if an astrologer says so in flowery language that somehow looks impressive but means very little (the definition of amphigory, by the way)?  If so, see the last sentence of previous paragraph.  Is it because if you put the word “Super” in front of something, that makes it all magical somehow?  It’s like putting “mega” in front of words. You see it all the time, particularly when somebody wants to sell you something (whether product or whack idea).  “MEGA-SAVINGS ON BULK ADULT DIAPERS!”  or “MEGA-SALE AT XXX AUTO DEALERSHIP!!!!!  SAVE 1000′S OF $$$”  (Try saying that last one out loud and it comes out as “Save one thousands of dollars!”  Who talks like that? Who taught the copywriter how to punctuate?)

Now, you can take my word for it that there’s nothing magical or mysterious about the closeness of this particular Full Moon.  It will look beautiful, provided you aren’t under cloudy skies. I guarantee you will (or have done so already) walk outside, look at this gorgeous Full Moon and say to yourself, “It’s wonderful, but I don’t see much difference from the other Full Moons I’ve seen.” And, you would be correct.

And, that’s the point.   Last month’s Full Moon measured 33.4 arcseconds across.  Tonight’s Full Moon will measure 33.7 arcseconds. It’s NOT a difference that you or me or anybody who looks at it with the old Mark I eyeballs are going to SEE. I defy you to tell me your eyes can discern that small of a difference.  And furnish proof, if you do.

What I will CHALLENGE you to do is go out and look at the lovely Moon.  Enjoy it. Cherish it.  That’s what its’ all about in skygazing. Enjoy what you see.  Any time you can step outside and enjoy a lovely moon rise is a life experience worth having!

Standard Mercury Orbit, Mr. Sulu

Mercury Has a Long-Term Visitor

MESSENGER at Mercury (artist's conception). Courtesy MESSENGER Mission.

Last night I went down to the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado for a briefing and “wait-it-out” event for the MESSENGER spacecraft’s orbital insertion. The lab built one of the instruments onboard the spacecraft — the Mercury Atmospheric and Surface Composition Spectrometer (MASCS). As I was sitting there watching the folks in the control room at the Johns Hopkins Applied Physics Laboratory (by remote link), I thought about all the times we’ve seen “standard parking” orbit commands applied in shows like Star Trek. They make it sound so easy. The captain just says “Standard orbit” to the helm, the officer punches a few buttons or slides a fader or waves a hand over the console, and the ship slides into the correct spot.  What we don’t see are the ship’s thrusters firing to nudge the ship — a massive behemoth compared to a small planetary probe like MESSENGER –  from its previous course into the parking orbit around the world it’s visiting.

We didn’t actually see MESSENGER’s thruster fire either last night. What we heard was a stream of announcements that told us what the Doppler readings were from the spacecraft as its fuel tanks fed the thruster that nudged it into a parking orbit (highly elliptical at that!) around Mercury.  You can see an animation of how it might have looked here.

To see the kind of orbital trip MESSENGER has taken since its launch on August 3, 2004 , go here for an animation showing its long journey. As of today, the spacecraft has traveled 4,902,668,000 miles. That’s 7,890,000,000 kilometers, or 52.7 astronomical units. If Messenger had traveled in a straight line for that distance, it would be well beyond the most distant point of Pluto’s orbit!

MESSENGER's orbit around Mercury is very elliptical, meaning its lowest point is only about 124 miles (200 km) above the surface and gets as far asway as 9,300 miles (15,000 km) at its most distant. The closest approach of the orbit will take it high over the north pole, where there is some radar evidence of something -- possibly water ice -- hidden on crater walls. Courtesy NASA/JHUAPL.

MESSENGER is small, only about the size of a minivan, so it wouldn’t take nearly as much power to put it into “standard orbit” as a giant starship would need.  But, the principles are the same no matter what size of object you’re trying to put in orbit around another one.  The incoming object has a certain path it’s following, and it’s going at a certain speed. If you want the spacecraft to merely fly by, you wouldn’t need to deviate the probe from its path.  But, if you want it to go into orbit, you have to slow it down at the right place, the right time, and at the right rate. Once you do that, you’ve got your spacecraft (regardless of its size) at a point where the gravitational pull of the planet it’s orbiting is EXACTLY matched by the spacecraft’s speed around the planet. It’s a constant tug of war that must be balanced correctly.

Now that MESSENGER is safely orbiting Mercury, scientists are testing its systems to make sure they’re doing okay in the hot, harsh environment around the planet.  The spacecraft is subject to solar heating eleven times hotter than we experience here on Earth, and it is protected with a sunshade to protect the delicate instruments inside. As soon as they’re satisfied that all systems are working on the nominal, they’ll turn the instruments on and commence the next phase of mission science.  The first images should start streaming to Earth in the first part of April, so stay tuned!