—Image courtesy NASA/JPL/University of Arizona

Those of you who think it's cool to drill into Google Maps and find, for example, your car sitting in your driveway, probably know that it's all about coming to a resolution.

The higher a camera's resolution, the more details you can capture in a single image, and the deeper you can zoom in.

Google gets many of its images from Earth-orbiting probes that have eyes sharp enough to see 19.7 inches (50 centimeters) per pixel.

Such satellites have a counterpart orbiting Mars: the High Resolution Imaging Science Experiment, or HiRISE, camera aboard the Mars Reconnaissance Orbiter.

HiRISE can see in resolutions of 9.8 to 19.7 inches (25 to 50 centimeters) per pixel, enough to take snapshots of features as small as an office desk from about 186 miles (300 kilometers) above the planet's surface.

And like Earthlings scanning web maps for their tricked-out Hondas, Mars mission managers can peer into the more detailed shots of the Martian terrain to pick out their vehicles in action.

Case in point: Last week HiRISE treated us to a glorious new shot of Victoria Crater, which the Mars rover Opportunity had risked life and limb to explore in 2007.

Now peer closely at those scalloped edges, and you can just see where it looks like someone was playing connect the dots up near the crater's left-hand rim.

Those are Opportunity's tacks, preserved in the Martian dust after all this time!

—Image courtesy NASA/JPL/University of Arizona

After about a year in the crater, the rover clambered back out and headed south, and NASA's been using its orbiters to follow the rover's path since then.

Using such "traverse maps," like the one featured above, Emily Lakdawalla over at the Planetary Society did some heavy lifting and tracked down the rover itself in the full version of the new crater picture.

She's zoomed in so you can clearly see Opportunity ambling across the red planet's dunes after it had stopped to investigate a Martian meteorite.

—Image courtesy NASA/JPL/University of Arizona

Now is that freakin' sweet or what?

Any allergy sufferer will tell you that dust can be a killer. But those dust bunnies under the couch have nothing on the planet-wide storms that periodically engulf Mars in late spring and early summer.

—Image courtesy NASA, J. Ball (Cornell), M. Wolff (SSI), and the Hubble Heritage Team (STScI/AURA)

Such storms are kind of a big deal to the twin Mars rovers Spirit and Opportunity, which rely on well-lit solar panels to keep themselves running.

A couple summers ago, dust blocked more than 99 percent of direct sunlight reaching the rovers and nearly spelled doom for the plucky robots, which have been toiling away on Mars since 2001.

To try and stay ahead of the curve, the rovers each point a camera toward the sun every day to check for atmospheric clarity, allowing researchers on Earth to adjust the bots' power needs.

Spirit goes into stealth mode?
—Image courtesy NASA/JPL-Caltech/ Cornell

The rovers get some extra help from the Mars Reconnaissance Orbiter, which—among its many talents—can act like a weather satellite and track dust storms from the sky.

"We can identify where dust is rising into the atmosphere and where it is moving from day to day," Michael Malin of Malin Space Science Systems, which operates one of the orbiter's cameras, said in a NASA statement.

Such knowledge is key, as science missions can get interrupted or delayed if there's even a hint that an oncoming storm will drain power reserves.

The orbiter's "weather reports" in recent weeks "have let us be more aggressive about using the rovers," Mark Lemmon, a rover-team atmospheric scientist, said in the statement.

"There have been fewer false alarms. Earlier in the mission, we backed off a lot on operations whenever we saw a small increase in dust. Now, we have enough information to know whether there's really a significant dust storm headed our way."

—Image courtesy NASA/JPL-Caltech/MSSS

The latest composite image shows almost the whole globe, with billowing clouds of dust being lifted into the air by a storm near the south polar ice cap. (The blurry bits running vertical in the image aren't dust, fyi, but an effect of the camera's viewing geometry.)

Luckily the same wild winds that churn up the occasional dust storm also help clean particles that accumulate on the rover's solar panels. According to NASA, the rovers would have died years ago from dusty buildup if it wasn't for these regular wipe-downs.

Bill Nelson, the rovers' engineering chief, said that this spring "we're all hoping we'll get another good cleaning."

In the animal world, the fight-or-flight instinct is a pretty common response to danger. But when you're a multimillion-dollar spacecraft, caution is usually the only response you get preprogrammed with.

Adding to poor beleaguered NASA's spate of recent glitches, the Mars Reconnaissance Orbiter went into safe mode on Monday after suffering what appears to have been an unexpected power surge.

Initial analysis of the flight data shows that the batteries are charged and the solar panels are doing their thing. The orbiter is also "talking" normally to mission control.

"We are going to bring the spacecraft back to normal operations, but we are going to do so in a cautious way, treating this national treasure carefully," MRO project manager Jim Erickson said in a NASA statement. "The process will take at least a few days."

That means, for the time being, science operations are stalled until NASA can be sure the craft is healthy enough to get turned back on.

Aside from returning what could be some of the most artful images of Mars, since 2006 the craft has been a steady source of pretty cool science.

For example, just yesterday a joint NASA-USGS team announced MRO's high-resolution camera caught what appear to be the first evidence for columnar joints on any planet other than Earth.

—Image courtesy NASA/JPL-Caltech/University of Arizona

Columnar joints are fractures that form as lava cools and contracts. These particular joints, found inside an unnamed crater on Mars, resemble features seen on Earth when water gushes over and cools down basalt flows.

Study author Moses Milazzo, of the USGS, notes in the press release that his favorite place to see columnar joints up close is Grand Falls, east of Flagstaff, Arizona.

"If you hike down to the bottom during the dry season, you'll cross some perfect examples of columnar joints, which formed when enormous amounts of water flooded the cooling lava," he said.

Here's hoping the MRO can safely get back to work soon!

Those sneaky folks at Google. Even as waves of coverage come pouring forth about the newly launched oceans layer in Google Earth, a short NASA press release and no more than a few lines in a couple news articles note that, oh, yeah, and by the way, there's a new 3-D Mars layer too.

Wha?!?!?

Sure enough, it's in the new Google Earth version 5.0, and It's beautimous. Just launch Earth, click the top tab with the Saturn-looking icon on it, and toggle between Earth, Sky, and Mars.

—Google Earth, Mars layer screenshot

[Google Sky, btw, was launched in 2007 and features a ridonkulous amount of astronomy data, from pretty pictures to current and historical sky charts. Fun.]

For a planet at the center of so many discussions about life, Mars can seem like a really dead world.

It's cold, dry, and dusty with a thin atmosphere that doesn't block out much solar radiation. There's minerals and gullies that suggest water flowed there more than three billion years ago, but aside from a few wandering robots, a big landslide, and the occasional planet-wide dust storm, modern Mars doesn't seem to see a lot of action.

Or maybe we just haven't been looking in the right places.

Today a group of university and NASA scientists announced they've found plumes of methane that could be coming from some mysterious underground source on Mars's northern hemisphere.

—Image courtesy NASA

Over a three-year span starting in 2003, ground-based observatories saw that the plumes appeared and disappeared, varying with the seasons. At one point Mars spewed out about 19,000 metric tons of methane at nearly 0.6 kilograms a second. Take that, Aussie sheep.

And so comes the big question: Does active methane mean life in motion?

After shaking off the daze induced by family, bubbly, and the vast amounts of tamales that accompany my winter holidays, I have washed up on the shores of Long Beach, California, where almost 2,500 astronomers are gathered for the 213th meeting of the American Astronomical Society.

The biggest astro-nerd fest of the year is even bigger for 2009, because the meeting is playing host to the U.S. kick-off of the International Year of Astronomy, tied to the 400th anniversary of Galileo's telescope. Woot!

Having peeked at the press conference sked and session lists, I can tell there's some fun things in the works, including the imminent arrival of Galileo's *actual* original telescope to the U.S. But that comes later.

In a neat little cosmic alignment, the start of the meeting also coincides with the five-year anniversary of the twin Mars rovers Spirit and Opportunity, those plucky little workhorses that have been roaming the Martian landscape since 2004.

Opportunity snaps dunes in Endurance Crater tinted blue in false color due to the presence of hematite-rich spherules known as blueberries
—Image courtesy NASA/JPL

The holiday season has officially descended upon us, and many a child is eagerly waiting for that jolly red roundness with a snowy white cap to appear in the sky.

Meanwhile, anyone whose day job requires listening for and deciphering radio signals from Mars is probably only too glad that white-capped red ball has hidden itself behind the sun, and will stay that way through the end of 2008.

Peek-a-boo!
—Image courtesy ESA

Last Friday Mars slipped into place behind the sun directly opposite to Earth observers, and over the next few weeks the red planet will drift through a line of sight very close to our stormy star.

This means that solar noise effectively blocks radio communications with the five craft now orbiting or actively exploring the face of Mars—and that means Mars mission engineers can take a bit of a breather.

Earth isn't the only planet that puts on a flashy light show.

Last week Saturn was the exhibitionist, showing off a vibrant blue aurora around its northern polar hexagon. And Jupiter made the crowds cheer in 2007 with a shot of its "hyper-auroras" lighting up both poles.

—Photo by Bruce Dale/NGS

Not to be outdone, Mars is the headliner this week. A team using ESA's Mars Express orbiter used a combination of onboard instruments to track nine auroral emissions on the red planet.

Their data allowed the team to draw the first map of auroras on Mars, showing that the events coincide with regions on Mars that have the strongest magnetic fields.

An artist's impression of auroras on Mars's night side
—Image courtesy M. Holmström (IRF)/ESA

Auroras on Mars are pretty unusual cases, because unlike Earth and the gas giants, Mars no longer has an internal dynamo generating a planet-wide magnetic field.

On Earth it's the magnetic field lines that channel streams of charged particles from the sun through the atmosphere, getting molecules all excited and causing them to emit light in the form of breathtaking auroral displays.

What Mars has are sections of the crust that were somehow magnetized, and the teams thinks it could be these regions that are attracting streams of particles, allowing auroras to occur.

The trick is that Mars's thin atmosphere is low in oxygen and molecular nitrogen, which are the elements that create visible light in Earthly auroras.

The Mars Express team's instruments see only in ultraviolet and so can't tell if any future human missions to Mars would be in for a show.

"There's now a large domain of physics that we have to explore in order to understand the aurorae on Mars," noted team member Francois Leblanc of France's Service d'Aéronomie.

Late last night the Mars Phoenix Lander put itself to sleep after experiencing a malfunction brought on by its deteriorating power supply.

The craft also unexpectedly switched over to its backup electronics and shut off one of its batteries.

The news was surely a disappointment, but not entirely a surprise, for NASA engineers, who had been expecting problems with the rugged lander right about now.

That's because the Martian arctic is moving into fall, and as the days get shorter, poor Phoenix has been losing its fire [in the form of sunlight to power its instruments].

An image from the Mars Reconnaissance Orbiter shows the Martian north pole, with the Phoenix lander at about the 10 o'clock position
—Image courtesy NASA/JPL-Caltech/Malin Space Science Systems

It's not just the scientific equipment that needs power.

Mars is pretty frigid even in summer, and right now it doesn't get much warmer than -50 degrees Fahrenheit (-45 degrees Celsius) during the day, with overnight temperatures plummeting to -141 degrees Fahrenheit (-96 degrees Celsius).

NASA's Phoenix Mars Lander has seen snow falling on the red planet!

One of the probe's atmospheric instruments detected ice crystals coming from clouds about 2.5 miles (4 kilometers ) above, although the flakes seem to have vaporized before they reached the ground.

—Image courtesy NASA/JPL-Caltech/University of Arizona/Canadian Space Agency

This probably isn't a huge surprise, as we already knew Mars has glaciers and ice caps that grow and retreat with the seasons, so it was a good bet it still has a hydrological cycle of some sort. Still, way cool to be potentially seeing it in action.

NatGeo News reporter Anne Minard has the full scoop, including other data from Phoenix that bolster Mars's likely history as a wet and wild world.

The news got me to thinking: Which other bodies in our solar system have snowfall?

After a quick roll around teh Internets, it seems the answer depends on how one defines "snow."