QUEST Community Science Blog

Mockup of Phoenix (top) and ‘Robinson Crusoe on Mars’
(bottom)—both set in Death Valley National Park…
Credit: NASA (top), Paramount Pictures (bottom)It’s that time of the Martian year again: when a flying saucer from Earth appears in the skies of Mars. Imagine if there actually were Martians up there: what’s science fiction here on Earth would pass for reality on the Red Planet—and a routine occurrence at that!

This time the flavor of the day is the Phoenix Lander, courtesy of NASA, scheduled to land on May 25th at about 4:38 PM PDT. We’ll be watching live NASA coverage of the landing at Chabot Space & Science Center that afternoon, if you’d care to join us…

Following somewhat in the footsteps of the Viking landers of the 1970s, Phoenix’s primary mission is to look for evidence of life, or at least the chemical conditions that might be suitable for life to exist. The two Viking landers carried small chemical laboratories that analyzed soil samples scooped up from the surface, as does Phoenix.

While its mission parallels that of Viking, one big difference from Phoenix is its destination: the Northern Polar Ice Cap of Mars. The Vikings landed much farther south in the mid latitudes. Phoenix is targeting the ices of Mars’ arctic region.

Growing up, one of my favorite sci-fi films was Robinson Crusoe on Mars. Made in 1964, the same year that Mariner 4, the first space probe to Mars, was launched, RCOM made a descent stab at imagining what it was like. So what if the main character walked around in apparent t-shirt weather and with sufficient atmospheric pressure to keep his blood from boilin–he still wore a respirator that doled out oxygen from an ever-dwindling supply tank, a nod to Mars’ thin atmosphere.

A couple of other things our astronaut Robinson Crusoe found on that fictional Mars that we are now looking for on the real one: liquid water and life…Our hero found small caches of water (with the help of a monkey) in grottos between the rocks, and, lo and behold, living in that water was a vine-like life form with edible fruit or tubers. He even took a foot-trek, along with his guy Friday, to the polar ice cap…

(I also loved the film because some of its “Martian terrain” scenes were shot in my favorite spot on Earth, Death Valley…)

Though evidence of past liquid water action seems to be all about the planet, Phoenix certainly won’t find any brooks or pools or grottos of spring water, owing at least in part to the frigid arctic region it will set feet on–an arctic zone on a world where the warmest temperatures in the tropics might reach levels of the coldest climates on Earth. What’s important about landing on Mars’ ice cap is that Phoenix is almost certain to dig up some water–albeit frozen.

And it is the chemical compounds either locked up in that ice or preserved by its proximity that Phoenix is interested in. (Similarly, climatologists on Earth study ice cores from Antarctica to analyze the trapped and preserved gases of Earth’s atmosphere of past millennia.)

We wish Phoenix a happy landing, and look forward to the first images and discoveries from the Martian North Pole. And I’m fairly confident the epic polar adventure ahead won’t resemble in the least another “great” film of 1964: Santa Claus Conquers the Martians….

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.

This has been a month of dashed hopes for astronomers around the world. Last month it seemed possible that an asteroid the size of a Boeing 737 jet was due to collide with Mars on January 30. Today that seems far less likely, but, as Amy Standen reports, astronomers consider it a wake up call.
You may listen to the “An Asteroid’s Close Call” radio report online, as well as find additional links and resources.

Amy Standen is a Reporter for QUEST and Radio News at KQED-FM.

latitude: 37.8768, longitude: -122.251

Victoria Crater on Mars, similar in size to the crater the
near-Mars asteroid 2007 WD 5 would have produced.
Credit: NASA/Mars Reconnaissance Orbiter

The possibility that a sizable asteroid would strike the planet Mars on January 30th temporarily raised the excitement level in the astronomical community to a pretty high level in the last couple of months. We were even toying with the idea of having a 3:00 AM Mars Bashing Party at Chabot that morning.

At one point astronomers had given odds of 1 in 25 that asteroid 2007 WD 5, newly discovered in November, would collide with Mars–which are astronomically great odds for this sort of thing. Alas, further observations refined our knowledge of the big rock’s trajectory, and the probability declined, hitting rock bottom (0.0%) by January 9th.

Why blog about a non-event? I see it as an opportunity to talk about big rocks bashing planets in general–specifically, the Earth.

While we haven’t witnessed an event like this one (a big impact on a solid, Earth-like planet), we have examined the remains of past events, on Earth as well as other planets and moons—such as the hole in the Arizona desert called “Meteor Crater,” an impact basin roughly the size of what might have been gouged out on Mars by 2007 WD 5. And compared to the asteroid that is believed to have caused the extinction of the dinosaurs, the Meteor Crater impact was a pipsqueak!

Smaller objects hit the Earth, or its atmosphere, all the time: meteors and meteorites. Fortunately we haven’t experienced a larger impact for a very long time. There was a significant impact of some kind in 1908, over Siberia–but luckily that wasn’t a major catastrophe.

Nevertheless, the possibility of a big impact on Earth is something to take seriously. NASA certainly does. They even have a program for it: the Near Earth Object Program, whose goal is to detect and track Near Earth Objects (NEOs) in order to warn of those that might eventually collide with the Earth. A NEO is defined as an asteroid or comet whose orbit carries it close to Earth. The program searches for NEOs that are 1 kilometer in size or larger–objects that would cause catastrophic local devastation and “severe global consequences.”

Thus far, over 5,000 NEOs have been found, almost 800 of them 1 kilometer across or larger–and it is expected that there are plenty more out there that we haven’t found.

So, is this a good idea? Do we really want to know that the end of the world is going to occur on such and such a date in the near future–or would it be better not to know, living our daily lives in blissful ignorance right up to the last, Earth-shattering day?

Well, whatever your philosophical approach to that question might be, there is a practical side to the NEO Program. If we can predict a NEO collision with enough advance warning, there may be something we can do to avert disaster. For example, we could send Bruce Willis out to destroy it… .

Seriously, though, NASA is working on methods of diverting the course of a NEO, possibly with a spaceship that acts as a sort of tug boat, gently nudging the NEO off course far enough in advance of the impact to make it eventually miss the Earth.

This month, however, Mars 1, asteroid 0. The Martians are quite relieved…

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.

latitude: 37.8768, longitude: -122.251

Picture of the edge of Victoria Crater superimposed with
image of the rover Opportunity.
Credit: NASA/JPLMars is not only on the horizon, it’s become a sky-high creature of the night…and so, it’s time to blog about the Red Planet once again, and to showcase a few favorite pictures from the veteran robots presently exploring that world.

Mars reaches “opposition” on December 24th. This is the time when Earth crosses directly between the Sun and Mars–in other words, when Mars is at the opposite end of the sky from the Sun and at its closest distance from Earth–this time about 55 million miles. You can see Mars yourself in the evening hours if you face east and look high: it’s that steady, bright, orange dot right between Gemini and Taurus.

So what’s been happening on Mars, exploration-wise? Here’s a quick summary on that score:

NASA’s Mars Exploration Rovers, Spirit and Opportunity, have had their tours of duty extended a fifth time, which should keep the rovers going–their health willing–possibly through 2009. Having landed on Mars in January of 2004 for a nominal 90 day mission, the robot pair has now lasted almost four years.

Spirit, which landed in the huge Gusev Crater, has traveled four and a half miles from its landing point and is now exploring a range of hills on a volcanic plateau. Probably topping the list of scientific evidence it has turned up is that water, in some form, has altered the chemistry in the environment, sometime in the past.

Opportunity, on the opposite side of the planet from Spirit, is currently exploring the half-mile-wide Victoria Crater. Exposed rock layers in the walls of the crater are expected to be an excellent “book” of Mars’ geologic history for Opportunity’s various instruments to read.

In its more than seven mile journey, Opportunity has revealed even stronger evidence that Mars’ distant past may have been warmer and wetter, and that, at least in Opportunity’s neck of the woods (Meridiani Planum), there may have been extended periods with liquid surface water.

The Mars Reconnaissance Orbiter spacecraft, with its array of instruments and super-powerful camera, has produced the most discerning orbital imagery of Mars’ surface to date, giving us aerial views of the Martian deserts, canyons, ice caps, plateaus, volcanoes, craters, drainage channels, sand dunes, and so on, that look like they could have been taken from the window of a small airplane flying at very low altitude.

Even as Spirit and Opportunity send back postcard after postcard from the ground, like a pair of camera-happy tourists, that tantalize us with evidence of possible lakes, seas, and oceans in Mars’ past, Mars Reconnaissance Orbiter with its more global viewpoint has revealed evidence that suggest another possibility: that the apparently periodic “bursts” of water activity might have been the work of large meteoroid impacts blasting through layers of ice and creating temporary episodes of water melt…

To round out the role-call, NASA’s 2001 Mars Odyssey and Europe’s Mars Express orbiters are also still in business and contributing to our already huge–but nowhere near complete–body of knowledge of that wandering orange dot in the sky…

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.

latitude: 37.8148, longitude: -122.178