pluto, the previous planet: a song

a couple years ago i was walking to the bus stop with the song "rudolph the red nosed reindeer" stuck in my head, much to my frustration! in order to maintain my sanity, i started singing alternative lyrics based on the phrase that popped into my head: pluto the previous planet! i've been wanting to record this song and post it for the public ever since, but had never really been inspired.

so yesterday during the hack day portion of dotAstronomy meeting, i gathered a few fellow conference participants: astronomers, a great pianist, and an enthusiastic director.... and off we went!

so without futher ado... pluto, the previous planet!!

Pluto, the previous planet from carolune on Vimeo.

as much as i like the song as it is, the last verse might lead one to believe that i would like to reinstate pluto as a planet. i want to state for the record that this is NOT the case! i'm pleased that astronomers have decided on a definition of a planet that is based on some actual physics! the song is just fun and i hope people enjoy it.

with all this in mind, we also developed an accompanying website with a special message from pluto:

"First of all, thank you everyone for your concern, but really, I’m happy in my new role as the original dwarf planet! And there’s no need to worry, nothing physically happened to me to cause my reclassification. In fact, Charon’s been jealous for years that I was considered a planet, while we’ve been dancing around each other in our joint orbit around the sun. And don’t forget about our other two small satellites: Nix and Hydra! They may be small, but they’re important to me. And your Earth only has one Moon, so I feel special..."

here's the website: http://youpiter.org/pluto/

hope you enjoy!

messenger's orbit around mercury

in honor of the MESSENGER space craft successfully maneuvering into orbit around mercury this week, i thought i'd share a blast from the past from sixty symbols. if i remember right, this one one of first videos i recorded with brady :)

mercury - sixty symbols

here's my latest contribution to the sixty symbols of physics and astronomy project: the closest planet to the sun... mercury!

kepler launches tonight!

as i mentioned before, the kepler space craft is prepped and ready for launch tonight at precisely 10:49:57 p.m. EST (on March 6, 2009)!! you can watch the launch online from nasa tv!! one day, i really hope to witness a night launch in person....

kepler's mission is to detect earth-size planets around distant stars. this is the first telescope with the capabilities to find such small planets using the transit method. if a planet happens to pass in front of its star, it blocks a tiny amount of light output from the star. sensitive telescopes can detect this dip in the light from the star and then we can attempt to model how big the planet must be!


the graph above slightly exaggerates the dip in signal, but you can see that it does exist. after the planet passes in front of the star, the signal from the star remains constant while the planet continues on its orbit all the way around the other side of the star and back.

here's an image of mercury transiting in front of our sun - you can see how tiny it looks even from our close view from the earth!!


such a tiny planet is still impossible for us to detect around distant stars. but you can imagine that we will be able to find bigger planets more easily!!

good luck with the launch tonight!! hopefully we'll be hearing news about new earth-like planets being detected quite regularly when kepler starts taking data!

"The Kepler spacecraft will watch a patch of space for 3.5 years or more for signs of Earth-sized planets moving around stars similar to the sun. The patch that Kepler will watch contains about 100,000 stars like the sun. Using special detectors similar to those used in digital cameras, Kepler will look for slight dimming in the stars as planets pass between the star and Kepler. The Kepler's place in space will allow it to watch the same stars constantly throughout its mission, something observatories like Hubble cannot do."

the moon, mercury, jupiter, and mars over australia

mike salway gorgeously captured the early morning planetary line up of the moon, mercury, jupiter, and mars over australia!


unfortunately, he was also clouded over last night, so didnt image comet lulin or saturn :(

night sky august 2008

this month provides many nice planetary alignments and the perseids meteor shower: usually the best of the year!

five planets will be visible with the naked eye this month: mercury, venus, mars, jupiter, and saturn!! starting on august 11th, we'll be able to see mercury, venus, and saturn approaching each other low on the western horizon. they'll be challenging to see since they are settling early with the sun, but all the planets are bright so they should be spottable... venus will be the brightest at magnitude -3.9, the mercury at -0.6 and saturn will be the faintest of the three at 0.8. mars hangs above the trio and jupiter shines brightly in the southern sky (see full night sky maps here).

august 13th provides a closeness between venus and saturn of less than a degree in the sky. if you hold out your arm at full length, your pointing index finger (one degree across) will easily block both planets! also on this night, the bright planet jupiter in the south will be 3 degrees north of the moon!

on august 16th, there will be a partial lunar eclipse visible from much of the world, best in africa and europe. since we just saw such a brilliant total solar eclipse due to the tight alignment of the sun, the moon, and the earth as the moon passed between the larger orbs, it's not surprising that the three are still aligned so tightly as the moon swings around the opposite side of the earth and passes thru our shadow!


after mid-august, saturn sinks in the sky each night, while mercury and venus rise higher. venus will shine brightly after sunset for the rest of the year, returning to its status as the "evening star." on august 20th, mercury and venus will be less than a degree apart, and both very bright!

the perseids meteor shower occurs between august 11-13th this year, peaking before dawn on august 12th for north american viewers. look below the sideways "W" of cassiopeia in the northeast to find the direction from which all the meteors will be shooting across the sky: the radiant. in reality, if you stand outside under the dark sky for a little while, you'll most likely see one bright streak or more overhead per minute after the gibbous moon sets at 1:30 am EDT.


enjoy!!

mercury's caloris basin

another cool image of mercury taken in january from the messenger space craft. this enhanced color image shows the caloris basin.


found at APOD.

moon covers venus this wednesday!

early-risers have quite a few interesting solar system alignments to entertain them for the next several mornings!

before the sun rises to outshine everything in the sky, three planets glow brightly toward the southeast: jupiter, venus, and mars. monday morning, march 3rd, the moon rises above the horizon just after jupiter, showing off its waning crescent to jupiter's lower left. the next morning, the sliver moon will shine between jupiter and the planet pair, venus and mercury! wednesday morning, the moon passes very close to mercury and venus... so close that the moon will pass in front of venus during the day!!


the lunar occultation of venus will be visible from many parts of north america (see map below). in austin, texas, we will be able to see the moon cover venus at 12:12pm (here's a table to determine times of occult for other locations - note that times are given in Universal Time so i subtracted 6 hours to get CST).


there are many times when venus is bright enough to be seen during the day, but it's a difficult (nearly impossible) task to see it when you don't know exactly where to look! this occultation will allow more of us to see venus during the day, because the much bigger target, the moon, will be so close! from texas, the crescent moon will be about 30 degrees up in the sky from the horizon, but still difficult to spot since only a tiny portion will be lit up by reflected sunlight. try to find the moon by looking southeast around noon, then look for venus just to the left of the moon.

i really enjoy seeing distant objects other than the sun in the sky during the day, so i'll be eating my lunch outside this wednesday!!

mercury and venus - together!

tomorrow morning about 45 minutes before sunrise, look to the east to see a very bright venus about 1.2 degrees below the usually-difficult-to-find planet mercury!

our moon and mercury

congratulations! everyone fared very well on this week's mercury or the moon game! without further hesitation... the bottom image in the game was mercury and the top was the moon! now its time to take a closer look at their similarities and differences between these two neighbors of ours.

take another guess....




could you tell the difference between them in the new images above? this time i think it's a bit easier because only the second image... the moon... reveals the sharp-edged darker regions called maria. the low-laying maria are flat planes that appear smooth in the image because they have fewer crater impacts.

there are a few maria visible on mercury, but they are small and not so defined. the striking brightness variations on mercury's surface might be caused by different things.


some people identify familiar objects on the surface of the moon based on the patterns resulting from the strong contrast between the dark maria, and the bright hilly highlands. i've never been able to find the man in the moon on my own. i think this phenomenon is somewhat subjective since people tend to find faces among patterns easily, but also because i'm always so distracted by the realization that the moon is a big huge rock flying around us in gigantic, predictable circles... that my eyes tend to not seek familiarity!

an obvious similarity between our two neighbors is their dense covering of impact craters. they both have large craters that are covered with smaller, younger craters. the fact that we can still see these craters tells us that neither object experiences strong storms caused by thick atmospheres, or lingering geologic activity. it appears to me from closer inspection of their surfaces, that mercury has more little tiny craters than the moon.


there are a couple very large impact sites seen on the moon. two of these seem much bigger than the largest impacts on the surface of mercury. the moon's largest impact craters also have large radial white lines shooting from them, caused by debris material thrown out at impact. i see some of these lines on mercury, but they are much fainter. i think this can be explained by mercury's higher surface gravity.

the planet mercury is larger than our moon. i can apply newton's law of universal gravitation to determine the relative strengths the gravitational forces one would feel on the surface of each orb...


if i'm sitting on mercury, then i say my mass is m1 in the equation above, mercury is m2 and the radius of mercury is d. I do the same thing for the moon and take the ratio of their F_grav. i discover that i weigh a little over 2 times more on mercury than i would on the moon! higher surface gravity means that the impacts on mercury did not throw debris as far as they did on our moon, and we see weaker white streaks coming out from each crater! it's interesting though that the brightest lines on mercury seem to radiate from very small impact craters.

what other differences do you see?

mercury or the moon?

take a guess... which image below is the moon and which is mercury?

deceiving first glance from MESSENGER

look at this image.... what do you see?


at first glance, it looks like our moon! there are craters, straight lines of stuff thrown out from the meteorite impacts that caused the craters, light spots, darker patches, etc...

but this is not our moon, its the closest planet to our sun... mercury! this is one of the first images from the MESSENGER spacecraft as it orbits our inner solar system (of course MESSENGER is an acronymn: MErcury Surface, Space ENvironment, GEochemistry, and Ranging). this is also the first detailed image humans have seen of the surface of mercury since the Mariner 10 spacecraft flew by 35 years ago!

the image was taken two days ago on monday, january 14, 2008 at a distance from the planet of 27,000 kilometers (about 17,000 miles) and can resolve things as small as 10 kilometers (6 miles) in size!

some major questions the MESSENGER spacecraft hopes to help us answer include why mercury is so dense, what mercury's magnetic fields are like, and what are the unusual materials at mercury's poles? mercury's poles are never fully in or out of sunlight. the light grazes the tops of the craters, but the deep insides remain dark..... expect at radar wavelengths. the fact that these inner crater regions of the poles reflect radar wavelengths, could be indicative of the presence of water ice! why and how could water ice survive so close to the sun?!

more exciting insights from the MESSENGER spacecraft soon!