In 2007, the European Space Agency probe passed by Mars on its way to visit a comet. It used Mars for a gravity assist to help it on its way, and got close enough to take some very detailed pictures (it also passed by the asteroid Lutetia and returned amazing shots; see the gallery at the bottom of this post). That data wasn’t initially released by the mission leader (that’s fairly common in some missions), but they were finally made available late last year. My pal Emily Lakdawalla from the Planetary Society Blog grabbed a bunch of them and put together some simply amazing pictures from them, including this jaw-dropper:

Yeah. You really want to click that to Barsoomenate it. Holy dry ice polar caps!

In fact, you should go over to her blog where she gives all the details and has more incredibly cool pictures of the Red Planet as well. I don’t want to spoil her fun by giving it all away here. Go!

Credit: ESA / MPS / UPD / LAM / IAA / RSSD / INTA / UPM / DASP / IDA / processed by Emily Lakdawalla

- Rosetta’s cometary goal now in sight
- Lutetia may have witnessed the birth of the Earth
- Curiosity on its way to Mars!

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Yesterday morning, NASA successfully launched the Mars Science Laboratory — named Curiosity — toward the fourth planet. If, like me, you missed the launch itself (^%$#@&! sinuses) why then, here’s some pretty dramatic video of the liftoff:

[Make sure to set it to 720p resolution!]

The cool parts to watch are: about 2 minutes in when the booster rockets fall by the wayside; 3:42 when the payload fairing is jettisoned, exposing the Curiosity spacecraft — as seen by the camera onboard the rocket, which is way cool; 4:38 when the entire rocket starts to slowly spin up, providing stabilization and allowing the Sun to heat the assembly evenly; then a few seconds later when the upper stage Centaur rocket ignites, leaving the booster behind (also extremely cool).

But wait! There’s more!

(more…)

[UPDATE: SUCCESS! The launch was just about perfect, and Curiosity is now on its way to Mars, scheduled to land in August 2012. Congrats to everyone on the mission!]

Tomorrow, Saturday, November 26 at 10:02 Eastern (US) time (15:02 UTC), an Atlas V rocket carrying the Curiosity Mars rover will blast off from Florida, sending the sophisticated rolling lab to the Red Planet.

You can watch the launch live at NASA TV, or I recommend on the NASA/JPL UStream channel. I imagine I’ll be up and tweeting about it, as will my pal Emily Lakdawalla.

It is no exaggeration to say that Curiosity is a huge leap forward for Mars exploration. Designed to last for nearly two years, it’s 3 meters long — the size of a hefty golf cart — and its scientific payload is ten times more massive than its predecessors. It has instruments (PDF) that can sample and taste the air and surface, imagers to provide high resolution stereo pictures, a laser to zap rocks and get their spectra (which yields their composition), and even a camera that will take video of the last two minutes of its descent to the surface to provide aerial context for its cameras once it lands.

If you thought Spirit and Opportunity were cool — and you’d be right — Curiosity will up the ante considerably. I’m very excited by the prospect of the science this rover will do, and the exploration it’s capable of as a precursor, eventually, to a human being stepping foot on this odd, dry, and cold neighboring world.

[Update (20:30 UT): The mission launched on time, and everything looks good so far! As I write this, the probe's orbiting the Earth. In a few hours (a little after 01:00 UT) it will make its burn to send it on its way to the Red Planet. Congrats to everyone involved in this mission!]

[UPDATE 2 (05:00 UT): There are problems, potentially serious ones, with the mission. As I write this what happened is not clear, but Emily is keeping up with the news.]

[UPDATE 3 (Nov 9, 16:00 UT): It looks like the spacecraft is in safe mode, meaning it shut itself off to prevent damage due to an unforeseen problem. The burn to move it out of Earth orbit and no to Mars did not occur, which means it still has all its fuel. This is very bad, but perhaps not catastrophic. Emily has the details.]

The Russian Mars probe Phobos-Grunt — which will land on the Martian moon Phobos and return a sample to Earth! — is scheduled to launch today at 20:16 UT (15:16 Eastern US time). As usual with planetary missions, Emily Lakdawalla has the details. The launch will be streamed live on SpaceflightNow.

Grunt means "soil" in Russian; the name is a little misleading since soil technically is rock and other material broken down in part by bacterial processes. A better term is regolith, but I’m just being pedantic. The important thing to note is that if all goes well this probe will return a sample of the surface of another planet’s moon back to Earth!

That’s awesome.

We still don’t understand Phobos all that well; it may be a captured asteroid orbiting Mars, and its surface is weird, as you can see in the picture above. It’s lined with grooves, which may have formed when asteroid impacts on Mars below blasted up material, which the tiny rock then plowed through. That’s still being argued about. A sample return might help resolve issues like that (for example, finding clear evidence of Martian minerals in Phobos samples). I’m not a geologist, or an asteroid expert, so I’m just excited that a) this probe is going to get intense images of Phobos, 2) we’re going to expand the boundaries of science once again, and γ) there will be even more new mysteries to solve once the material is studied, too.

And it all starts today, in a few hours.

Credits: ESA/DLR/FU Berlin (G. Neukum)

Today, September 14, 2011, is the vernal equinox for the northern hemisphere of Mars!

If you want to be technical, it’s the time when the axis of Martian rotation is perpendicular to the direction of the Sun, and the northern hemisphere is headed into summer (making it the autumnal equinox for the southern hemisphere). When this happens here on Earth, it’s called the first day of spring (here in the US at least, in other countries it’s considered the middle of the season — a tradition with which I agree).

Mars, like Earth, is tilted with respect to its orbit around the Sun; Earth is canted at an angle of roughly 23°, while Mars is at 25°. That’s why we (and Mars) have seasons! Over the course of the year, the angle of sunlight hitting the surface of the planet changes, heating it more efficiently in the summer and less in the winter. Boom! Seasons.

On Earth, that’s most dramatically seen as polar ice shrinks and grows over the year. Same with Mars! The picture above is from the European Space Agency’s Mars Express orbiter, and shows the northern polar cap in May 2010, during the last summer. The north pole of Mars is icy, but it’s actually two kinds of ice: water, and frozen carbon dioxide. CO₂ turns directly from a solid into a gas (a process called sublimation), and does so at much lower temperature than water ice melts. This means the CO₂ goes away first as temperatures rise in the northern hemisphere, leaving the water ice behind. In that picture, the ice is essentially all water.

In other words: the north pole of Mars is sublime^*.

Where does the CO₂ go? Into the atmosphere! So much of it adds to the air there that the atmospheric pressure on the planet increases measurably, by about 30%. That much extra carbon dioxide adds a small but significant greenhouse effect to the planet as well, warming the surface. Estimates vary, but I’ve seen quotes of a few degrees Celsius for the effect.

The change of seasons also kicks up winds on Mars, and that can cause everything from dust devils which leave incredibly beautiful scrollwork on the surface to planet-wide dust storms.

I’ll note that the year on Mars is about twice the length of an Earth year, so all the seasons are about twice as long as well. May 2010 is when summer started on Mars (in the northern hemisphere), and here we are 17 months later with the start of spring. The Planetary Society has a page listing the next few seasonal dates on Mars if you’re curious.

So anyway, happy first day of spring, Martians! Don’t forget to try to stand up malagor eggs today.

Image credits: Earth/Mars tilts: from Calvin J. Hamilton’s fantastic Solar views website; Mars polar cap: ESA/DLR/FU Berlin (G. Neukum.)

^* Hahahahahaha! Man, that’s funny. Also, <McBain>ice to see you.</McBain>

Check. This. Out: a perfectly-formed collapse pit on Mars that leads to an underground cavern!

Amazing! [Click to barsoomenate.]

This was taken by the Mars Reconnaissance Orbiter in July 2011. See the hole in the bottom? You can tell from the lighting that this is an underground opening to a cavern — a skylight. Quite a few of these have been found on Mars, actually. We see them on Earth and even on the Moon. Given the angle of the shadows, the vertical distance from the bottom of the pit to the floor of the cavern is about 20 meters (65 feet). Watch your step!

Here’s how we think skylights like this form. In the distant past, Mars was geologically active. Rivers of lava ran across the surface. If the surface of the lava hardens it can form a roof, allowing the lava underneath to continue flowing; these are called lava tubes and there are bazillions of them in Hawaii, for example. Eventually, the source of the lava chokes off and the lava flows away, leaving the empty tube underground. If the roof is thin in one spot it can collapse. Sometimes that just leaves a hole, but apparently in this case it was under a sand field. Some of the sand must have fallen into the chamber below and eventually blown away, leaving the pit and the hole. The pit is located not too far from Pavonis Mons, a known (long-dead) Martian volcano.

The hole is about 35 meters (115 feet) across, so the pit is about 175 meters (nearly 600 feet) across the rim. I love how it sits in an otherwise nearly featureless sand field; the contrast is beautiful. In the high-res image you can see boulders perched on the pit wall, having rolled part of the way down as well. The inside of the pit has lines and furrows that are instantly recognizable to anyone who has tried to dig a hole at the beach and had sand continually flow down from the rim.

It would be incredible to see something like this up close. It’s possible eventually someone will: such lava tubes would make good homes for future Mars explorers; they’d be protected from sand storms, temperature swings, and solar radiation (which is worse than for us on Earth because Mars doesn’t have a strong magnetic field to protect it).

… but you couldn’t pay me enough to go inside one of those. I have no desire to be slowly digested over ten thousand years.

Image credit: NASA/JPL/University of Arizona. Tip o’ the light saber to reddit.

- More Mars caves found
- There’s a hole in the Moon!
- Spelunking the lunar landscape
- Martian dunes under the microscope