Sunday 1 February 2009

ANSMET

Although their search has just ended the ANSMET (ANtartic Search for METeorites) blog makes fascinating reading, especially how their search has given them insights into the trilas of the first antartic exploreers like Shackleton and Scott. This season they've netted over five hundred metoerites for study and collectors. I'll quote the post about being a tent slug here. I belong to the related familly of bed slugs some mornings:

The fine art of being a tent slug
January 23, 2009
Last night John got the disappointing news that we had been bumped from the primary to the alternate mission for today. It turned out not to matter. In the morning we were in white-out conditions, and a plane could not have landed anyway. The temperature was -21 C (-5 F) and John estimated the wind speed at 65-70 kph (40-45 mph), putting the wind chill temperature at roughly -50 C (-60 F). Not a pleasant day. Quite a contrast from earlier in the week when we had no wind and a warm day.
We have absolutely nothing to do except wait for our ride to McMurdo. We have become tent slugs. Herewith, a day in the life of a tent slug.
06:50: Wake up when John's alarm goes off. Go back to sleep.
08:00: Wake up when my alarm goes off.Go back to sleep.
09:45: Wake up for good.
09:45-11:30: Stay in the sleeping bag hoping the winds will die down.
11:30: Get out of the sack and go outside for necessary "business." Hard to stand in the wind while taking care of "business."
11:35: Vow never to do that again.
11:45: Listen to Pole-bound plane go overhead. Fantasize about being on that plane.12:00; Make breakfast, lunch, whatever it is. Yum. Lunch meat on Rye Krisps. The breakfast of champions.
12:15-14:00 Have coffee. Work on cryptograms and update daily journal.
14:00: Have more coffee. Continue working on cryptograms:14:45: Get back into the sleeping bag.14:45-16:15:
Stare at the tent walls. Consider desperate measures to get plane to come pick us up. Who might be willing to take one for the team?
16:15: Go outside again to take care of "business" and chip ice for water. Man, I've really got to stop doing that! Consider bringing a two-months supply of "astronaut diapers" the next time I come down.
16:30-18:00: Have Hot Cocoa and work on cryptograms.
18:00: Time to make supper. Yum, yum.
18:35: Go outside to take care of "business." Hey, not so bad this time. The winds have decreased. There is no more blowing snow. The sun is visible.
18:40-20:00: Have more hot cocoa. Work on blog.
20:00-21:10 The team mates gather for the daily reading of Shackleton's and Scott's expedition journals. Oh boy! Amy brought chocolate! Discuss our bleak future. General kibitzing.
21:10: go outside. More "business" to take care of. Not too bad; didn't put on the wind pants this time.
21:15-21:30: Post blog.
21:30-23:45: Get back in sleeping bag. Read.
23:45: Go outside to take care of "business" one last time for the day.
24:00: Turn in for the night. Prepare to do it all over again tomorrow.

ANSMET haiku
We are just tent slugs
We have nothing more to do
Take us Basler, please

100 years ago this date: Shackleton's daily entry was very short with little information. Shackleton must still have been suffering from his falls of a few days before.
Cheers,LYANduck

Saturday 31 January 2009

Over on the Planetary society there's an update on the Dawn Mission to the ice, and (maybe just maybe) ocean, bearing dwarf planet Ceres, and the giant volcanic asteroid Vesta. Ceres has very likely been host to liquid water at some point in its past, maybe even for billions of years. Vesta seems to have been a minature volcano world. That makes the Dawn mission one of the most exciting out there right now so I strongly reccomend you go see.

Another mission, one that I'm holding my breath for to launch, is the russian Phobos-Grunt mission. Literally translated it means 'Phobos soil' and it's a mission to one of mars tiny asteroid moons (called Phobos), designed to bring back a sample to earth. Phobos is a mysterious object, thought to be the origin point of one particulaly strange carbonaceous chondrite meteorite, the Kaidun meteorite, which contains minerals found nowhere else in nature. Being so close to Mars it may well preserve some of that planets history on its surface, in the form of materials blasted off Mars during asteroid impacts.

To cap it all of the probe will carry dormant micro-organisms to Phobos and back, to test the idea that some simple life might be able to travel to other planets on rocks thrown from Earth by aseroid impacts. One to watch closely!
Above: Comet Lulin, coutesy of Giovanni Sostero and Ernesto Guido, Remanzacco Observatory.
Comet Lulin is getting ready to come nearly as close to Earth as Mars, at which point it's tail will look eight times as long as the full moon is wide. Analysis of it's orbit shows it is a real nomad, either from interstellar space, or from the Oort cloud of frozen solar system building blocks nearly a light year from the sun. Either way it should be pretty spectacular through a pair of binoculars or small telescope! Watch this space....

More (nearly) moons than you'd expect....



One piece of news that I've been meaning to write about is that Earth has acquired yet another moon. Yet another? I hear you cry, but John, we've got only the one! It's that huge great grey silver thing lurking a light second or so away. Some American fella went there in the sixties and found he couldn't take small steps, only giant leaps.

Well if you were thinking that then you're only half right. Earth has one big, full time moon. It also has several small part time ones.
Here's how it works: these part timers are asteroids whose orbits happen to take roughly the same amount of time to orbit the sun as earth. Hence, they orbit at the same distance, follow earth closely, and earn the term co-orbital. They wander back and forth along their orbits relative to earth, and when they enter the region of earth gravitational influence the can become temporarily caught up with earth, and begin to follow it through space, along a spiral path. This isn't a true Earth orbit, but it looks a lot like one, so objects that do this are sometimes called quasi satellites.

Our newly found friend is called 2009BD. It's about ten meters wide and has come within 400,000 miles of earth. That’s a tribute to how well and sensitively the skies are watched these days, although I expect that its remarkably similar orbit to ours made detection easier.
For the record this one’s no threat to earth. It could pack a punch similar to the Hiroshima bomb, but even if at some point in the future it winds up on a collision course, the overwhelming odds are that it would explode to far above the ground (like this ten meter meteorite) to do any real damage; ten meters is not large enough to punch through our atmosphere very well.
Larger, although still not a danger for millions of years at least, is 3753 Cruithne, which is about five KM across.
We actually know little about these small companions, although they have histories and characters all their own. It has been speculated that one day they might be useful for in space manufacturing, but right now they hold the same interest as all asteroids: they are likely to be remnants from the solar systems formation, and could teach us more about how earth and its companion planets came to be.
Also, given their proximity to earth, they might be places to look for material blasted off of earth during big impacts, and so might tell us something about our planets history directly.

So hopefully someone will take the opportunity to do some science and earn some bragging rights, and be the first to send a probe or even an person to one of earths other moons.....

Sunday 11 January 2009

A couple of glaring omissions....

..to my list of useful websites below are:

The Planetary Society: All things space

The New Horizons mission to Pluto (Now officially a dwarf planet) and the Kuiper belt (A huge ring of ice asteroids and dwarf planets beyond the orbit of Pluto).

The Phobos - Grunt
mission to the Martian moon Phobos, a very mysterious little world that could be a source for one of the strangest carbonaceous meteorites...

Protoplanets and life...

Why start a blog on the small fry of the solar system? Well they have a lot teach us, and are in many ways a lot more accessible than many of the main planets (except earth obviously). Since the thing most people think about when they think of space is aliens I'm going to start with how the little guys of the solar system have advanced our understanding of life in the cosmos, and how they can teach us more.

First, a bit of background:
According to our best theories, and the evidence we've collected, the solar system formed about 4.5 billion years ago from a cloud of dust and gas. This cloud didn't build itself into the solar system we know overnight. For about 100 million years there were hundreds of small worlds in place of the nine big ones that we have today, called protoplanets. What we know about them comes mainly from meteorites. These, with a few exceptions, are believed to be fragments blasted off their surfaces by asteroid impacts, and collisions with each other. We also know a bit from observing the dwarf planets and asteroids, objects which are thought to be survivors from that time.

So what do we know about them (and what does this have to do with life)?
We know that many of them were big enough to have gravity that could pull them into a sphere, and warm enough, thanks to accretion heat (heat from stuff falling onto the surface) and radioactive elements, for their interiors to melt.
This led amongst other things to differentiation of their interiors, where the heavy elements sank towards the middle, and the lighter ones floated towards the surface. This has given us some of the different types of meteorites we find today, different types from different parts of the protoplanets. Recently meteorites were found that show some of these little worlds developed crusts similar to Earth. We know from observeing Ceres (a dwarf planet) and Vesta (about as big as rock can get without being a dwarf planet) that proto worlds could have very different characters: Certes is loaded with water ice, and might hold an ocean beneath its crust even today. Vesta shows signs of being a volcano world, a bit like asmaller version of Io, and seems to have been disfigured by a titanic smash with another space rock.

No really, what has this got to do with alien life?
What I'm leading up to with this; Some of these protoplanets had conditions that led to the creation of the building blocks of life. That basically means carbon chemistry, and liquid water. A fairly rare class of meteorite, calld carbanceous chondrites, have carbon buried in their interiors, and show signs of being in contact with liquid water. This has caused amino acids, the building blocks for protiens, and nucleobases, the building blocks of DNA to form inside them. Could any of this have got as far as simple life?
We don't know. It's quite likely that most of these worlds were destroyed, or froze solid before things could get that far, but at the very least some of the chemistry that eventually led to life on earth began out there. And when we've only begun to learn about these little worlds, and the conditions that have led to life, who can say for sure what was there?

If any of these ramblings have given you some curiosity aboutthe little worlds out there, here are some links you might find interesting:

Dawn: A space mission to Ceres and Vesta.

Hayabusa: A space mission to one of the solarsystems many asteroids.

Meteorite news:News all about meteorites.

Space weather: Follows the storms from the sun and general astronomical events.

I'd also recommend any of the following forums: BAUT forum, Unmannedspaceflight, habitable zone for anyone with a generall interest in space.

Thats all for now, I'm going to aim for one post a week, so have a good week one and all!

Welcome!

Welcome to Meteorites, rocks and dwarfs, hwer I hope to cover news and give my opinions on all things related to meteorites, asteroids and dwarf/protoplanets. I'm no expert on them, so opinions and constructive criticism is welcome, but please, keep it clean!