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Peas in a pod

ESP_042697_2055_0.5x A Piece of Mars: These “peas-in-a-pod” are dunes covered in long ripples (the scene is 960×480 m, or 0.6×0.3 mi). They’re a bit odd, surrounded by a rippled apron. It reminds me of melted-looking dunes that are common in high southern latitudes, but these are at 21.5ºN. Yet more Mars mysteries to solve… (HiRISE ESP_042697_2055 NASA/JPL/Univ. of Arizona).

Is it windblown or not?

A Piece of Mars: This scene is 0.96×0.54 km (0.60×0.34 mi) across. There’s an old river valley running across it. The walls of the valley have been eroded and there’s a washboard pattern with a wavelength of ~6m (20 ft). When I first saw this image I thought it was exposed, tilted layers, but a closer look reveals a much smaller (and younger) set of ripples that are similarly oriented and almost certainly formed by the wind. What do you think? (HiRISE ESP_041982_1535, NASA/JPL/Univ. of Arizona)

Parental organizational states

There are three states of parental organization. I’ve done all three on occasion, but I do have my tendencies. We all have our way of getting things done. Here they are:

1. Super organized parent: These are the folks who know where every thing is, and everything has its place (you can tell where the place is, because the things are there, in their place). Appointments are made ahead of time, marked on a calendar, all people who should know about said appointments are informed (possibly more than once), and all required attendants show up at said appointments on time. My mother in law is one of these people. Sometimes she’ll find a stray kid’s sock that we left behind at her house, and she’ll keep it and tell us about it, because to her this is a Problem. She’s actually surprised at stray socks, because in her world they are an oddity. They are worth discussion, and they are even pondered. I’m rarely this organized, but it does happen on occasion, and then everybody is surprised (more discussion and pondering usually ensues).

2. Sporadically-organized parent: This is the parent who remembers to register for summer camp the day before it begins, hoping it’s not too late. The parent who once bought a package of wipes for the car, and who might even know if it’s getting close to empty, but might forget to buy more on their next shopping trip. The parent who usually does the kids’ laundry on time, but every once in a while forgets and the next morning has to go digging through the drawers to find clothes for the kids that aren’t too torn or too small, all while urging sleepy children to wake up and get their teeth brushed. I usually fall into this camp. Hey, this time I registered the kids for gymnastics a whole week ahead of time. Go me!

3. Disorganized parent: You know what this is, I don’t have to tell you. We all have our fuzzy moments. (OK, maybe my mother in law doesn’t. She has skillz.) I sometimes slip in this direction. But here’s thing thing about being in a disorganized parental state, which is why I don’t worry about it too much: sometimes it works for me. Take what happened to me tonight (which prompted me to write this whole thing). My oldest is 5, and he’s got some sort of stomach bug. On the way home from my in-laws’ this evening, he announced that he had to throw up. I’m surprised by this, because he hasn’t thrown up all day, so I haven’t thought about this ahead of time (I’m not the super-organized type, remember). But. On the floor of my (messy) car, among other oddities, is a plastic bag with a bunch of party favors that I got for my kid’s birthday party. Not the birthday party we threw a week ago, but the one last year, because I guess I forgot about those party favors and they didn’t make it into the party favor bags for the guests. So yes, there’s been a plastic bag with about 20 little plastic rings with big googly eyes on them sitting on the front passenger floor of my car for about a year. So I pull over, dump the googly-eyed rings on the car floor, and get the bag to him, in time to get most of the throwup in it. I’m very grateful the bag didn’t have holes.

See, if I’d been super organized, I’d have had a box of Ziploc bags or something at all times, plus some wipes. That would have been nice, but that’s also a lot of spare cycles my tired brain doesn’t want to have to worry about, along with all the other spare cycles that being super organized requires.

If I’d been sporadically-organized, I’d have eventually found that bag of googly-eyed rings sometime over the last year (perhaps while cleaning my car – don’t laugh, I actually cleaned out my car once) and put it somewhere sensible (wherever one stores such things, to be found in time for the next year’s birthday party – because they didn’t make it in this year either), and thrown away the bag. So then I would have had nothing to hand my kid. I’d have been screwed. (On the other hand, I might have had some wipes on hand, which would have been nice.)

But no, in this case I was simply disorganized. So I had the bag, and the evening was not a complete parental failure. Disorganized parenting FTW!

Dune trails

A Piece of Mars: The dark dunes in this 0.96×0.54 km (0.60×0.34 mi) scene are slowly migrating towards the lower left. Look closer and you’ll see brighter ripples between the dunes – the biggest ones are ~8m (26 ft) apart. They form trains in the wake of the dunes. Why? This is where the dunes previously marched on by, obliterating the ripples as they went. Ripples form again after the dunes pass by, growing in size and regularity with time. (HiRISE ESP_01746_2570, NASA/JPL/Univ. of Arizona)

NASA Mars acronym fun


Today I’ve got something different. Today NASA announced the discovery of hydrated salts in some dark slope features that form during the spring on Mars. These “recurring slope lineae”, or RSLs, were discovered a few years back, and they form on steep slopes every spring in a few places on Mars. There’s been a big debate over whether these things are formed by flowing water (which would be big news: flowing water on Mars today, right now, where we can witness and study it, not just billions of years ago in the distant past – these RSLs could be an environment where life could exist) or whether they’re just boring dry flows of sand or dust that only turn dark because for some weird reason the bright dust gets kicked off the surface (things like that also happen on Mars in other places).

But now they’ve found hydrated salts, which only form in the presence of water. So that means these RSLs are associated with water. They’re not just dry sandy avalanches. So now they’re places we need to pay more attention to, partly because we might find life there (yay!) and also because we need to be careful not to kill it or infect it with our biological cooties (boo!).

So in honor of this new discovery, I’m giving you a list of some of the words we’ve used to describe landforms on Mars. It’s true, we planetary scientists have a penchant for acronyms and names that don’t roll off the tongue. It may be partly because we lack imagination, but it’s also partly to cover ourselves (CYA, there’s another 3 letter acronym), so that we don’t pick a name that makes us assume something about what process forms that feature. Thus we have the mighty “recurring slope lineae” instead of something more catchy like “springtime slush”, because what if that name stuck and they turned out to be something much less exciting? Then we’d have to call them by the wrong name, and it would be the Pluto demotion fiasco all over again. Nobody wants that.

With some luck these RSLs will be renamed something more catchy. Most likely the IAU (another acronym!) will give them names relating to water features on Earth, like naming them after famous springs or fountains or something. That won’t happen for years to come. In the meantime, you can make your very own 3 letter acronym from the list above and play at martian geology. Have fun!

A wind-levelled surface

ESP_041864_1745_0.71x A Piece of Mars: In this 676×380 m (0.42×0.24 mi) scene, the high-standing hills here were all carved by sandblasting, by a wind that probably blew from right to left. Ripples in the valleys show that this erosion is still occurring today. (HiRISE ESP_041864_1745, NASA/JPL/Uni. of Arizona)

What do we know about planet formation?

Understanding how planets form in the Universe is one of the main motivations for GPI. Thanks to its advanced design, GPI specializes in finding and studying giant planets that are similar to Jupiter in our solar system. These are the kind of planets whose origin we hope to understand much better after our survey is complete.


This artist’s impression shows the formation of a gas giant planet around a young star. Credit: ESO/L. Calçada


Sand sheets and ripples

ESP_041977_1515_1.0xA piece of Mars: Not all sand piles up into big dunes. If the grains are the wrong grain size (too fine or too coarse), then it might just form sand sheets with ripples on top, like it does here, slowly migrating from top left to bottom right. There are two different kinds of sand here: the ripples seem more grayish and the underlying sand sheet seems more brownish. Grains of different sizes and densities respond to the wind in varying ways, so that they form different features on the surface. (HiRISE ESP_041977_1515, NASA/JPL/Univ. of Arizona)

The Slumbering Dwarf Awakens: Pluto is about to come back into the limelight


The best images so far of Nix and Hydra. Much better images will be sent down from the New Horizons spacecraft in early September

After the busiest July of our lives, the New Horizons team members have finally caught up on sleep. A few of us have even had a chance to take vacations. It’s good that we’re rested up, because an onslaught of new data from Pluto is about to begin.

Right now, 95% of the data obtained during the July 14 flyby is still stored on the spacecraft. After a quiet August, new images will start flowing down to Earth again on Saturday, We will get a few images almost every day. Why just a few? Well, Pluto is very far away, and the New Horizons transmitter is not very powerful. The downlink data rate is 125 bytes per second. For those who are old enough to remember dialup modems, this is slow even by that standard. It takes more than an hour for a single image to come down from the spacecraft. It will take almost a year before we have seen every image. That seems like a long time, but compared to the decade it took to plan, build and launch the spacecraft, and the second decade that it took to travel three billion miles to Pluto, waiting another year doesn’t seem so bad.

I am particularly looking forward to seeing some of our first closeup images of Hydra and Nix, two of Pluto’s small outer moons. Expect them to have weirdly irregular shapes, pockmarked by craters. The small moons of Pluto a particularly odd bunch. Whereas most of the moons in the Solar System rotate in a simple way, keeping one face toward the central planet at all times, we believe that Pluto’s moons might be tumbling chaotically. In a few days, maybe we will finally know for sure. Stay tuned.

By the way, every Friday the latest New Horizons images will be released to the public here:

What Self-Luminous Planets are Like

The planets that we are familiar with in our own solar system have evolved, aged, and cooled, for over 4.5 billion years since the Sun and planets formed. What do planets look like at younger ages? Can we use the light that a planet emits to understand its past history?