Canadian APXS Makes Mars Discovery
Tuesday, November 20th, 2012
by AJ Plunkett
It’s been almost three months since Curiosity landed on Mars. Found any life out there? Not yet. But what the Mars Science Laboratory has found has surprised researchers, including those at the University of Guelph who are in charge of operating one of the roving laboratory’s 10 science instruments — the Canadian-built Alpha Particle X-Ray Spectrometer, APXS for short.
Curiosity has spent the last few weeks poking and prodding the Red Planet; hitting rock samples with X-rays here, scooping a pinch of soil dust for testing there (results aren’t quite in yet), and sniffing the air looking for methane, but finding none.
Breathlessly waiting for every sniff, scoop, and zap are more than a million Earth-bound space-enthusiasts, who are following the little lab’s exploits daily on blogs, Twitter, Facebook, Tumblr, and various other social sites.
While it may appear like a venture into the future, the Mars rover’s endeavors are really more like a look back at history.
Since the rover landed in August, a lot of the landmarks along Curiosity’s Martian journey have had a decidedly Canadian sound to them. That’s because they are being named after sites in the Northwest Territories, where scientists believe that many of the rock formations may be as ancient as those on Mars.
The rover is just getting started in its work, and for the most part, NASA handlers are still putting it through its initial paces, testing various instruments and technologies to make sure everything is in good order. This has included a recent test using the APXS, which works by bombarding a target with alpha particles and X-rays, and then reading the energy thrown back to determine the sample’s properties.
While NASA and Canadian researchers note that this is not the first alpha particle X-ray spectrometer to work on Mars — others were on board robotic explorers Spirit and Opportunity — Curiosity’s APXS is producing much better information because it is both smaller and faster than previous versions.
Canada’s recent innovations in building robotics and other space instruments helped shrink Curiosity’s APXS down from the size of a refrigerator to that of a shoebox, with a sensor the size of a soda can.
Not only can Curiosity’s APXS get closer to specimens, it can take better readings and process the information faster: hat used to take eight to ten hours, now might take only two to three hours, researchers say.
Recently, researchers targeted a rock for testing, to calibrate readings against those of sample minerals Curiosity brought with it from Earth. Scientists know what the readings from the Earth rock should show and can then tell if the sensors are performing correctly when testing the real Mars deal. But there was a bit of surprise when the targeted rock (nicknamed Jake Matijevic after a recently deceased rover engineer) came back with a chemistry not unlike that found in volcanic rocks such as those in Hawaii.
“Jake is kind of an odd Martian rock,” said principal APXS investigator Ralf Gellert, with the University of Guelph in Ontario, according to information released by NASA. “It’s high in elements consistent with mineral feldspar, and low in magnesium and iron. While not uncommon on Earth, it hasn’t been widely found in other Mars explorations. Understanding how such rocks were made on Earth may help scientists further understand the history of Mars.
One thing the science laboratory hasn’t discovered yet that previous explorations detected is the presence of methane. Yes, we’re talking about that gaseous substance given off in certain organic decompositions that’s often fodder for comedians but serious stuff for scientists.
The presence of methane might be an indicator of life, either past or present. But Curiosity hasn’t sniffed any out yet. So far.
We’re barely three months into this adventure. There’s still the better part of a Martian year to go on this mission, which is 687 Earth days to me and you.
Stay tuned, Mars fans.
AJ Plunkett is a freelance writer in Virginia with experience in covering defense and aerospace industries, as well as health care issues. AJ blogs via Contently.com.