Looking Within

As images go, it’s not very exciting. But, it’s what it means that makes a difference to the scientists commanding the Phoenix Mars lander. The image above is a picture taken by the lander’s robotic arm camera looking into the robotic arm’s scoop. The spacecraft is still on its way to Mars, so this picture is equivalent of taking a picture of yourself onboard a jet while you’re traveling and sending it back home via email to let your loved ones know you’re still alive.

Why do this? The scientists routinely test instruments onboard spacecraft to make sure they’ll be working when they arrive at their destinations. Cruise mode is a great time to make such tests and to work on any fixes (if they’re needed). In Phoenix’s case, these are the only pictures to be taken and returned to Earth while the spacecraft is en route. The next images we see from these instruments won’t arrive until the spacecraft gets to Mars in May 2008.

Phoenix’s work on Mars will be the sort of geology that humans would love to do when WE get to Mars. It will dig trenches, scoop up soil and water-ice samples, and then test them onboard the lander in a series of chemical and geological analyses. The imagers will give us full-color images of the nearby surface in great detail

Of course, the big questions this mission is designed to answer have to do with life; whether it existed on Mars and what remains would be detectable in the Martian soil. It’s one of the main drivers for all our Mars missions as we seek to understand this bleak, cold, alien yet Earth-reminiscent planet. So, it’s good that our planetary scout mission has sent us back some pictures. We know the camera works. And sometime next year, we’ll use the other instruments to further our understanding of Mars’s intricate geological history.

Sometimes we find things in space with names that sound like they’re straight of out the realm of science fiction. Like magnetars. Just the word alone invokes visions of some alien empress on a faraway planet: Magnetar, the Magnificent, of Planet Epsilon Indii III. Legions of her loyal subjects gather in a jewel-studded room to pay homage to her intelligence, her beauty, her awesome power: Magnetar, the Magnificent!!!

Well, I have no doubt that Edgar Rice Burroughs could have made a real tale out of Magnetar and her many adventures. But, in truth, there’s no such beautiful empress ruling over a faraway realm.

There is, however, the real magnetar, which is an object so strange that astronomers are still figuring out how they can exist. Magnetars are what remain after a star many, many times more massive than the Sun explodes. What’s left of the star collapses down to an extremely dense object called a neutron star (a star made entirely of neutrons, oddly enough). One of these babies is not much larger than an Earth mountain, but it has the mass of the Sun. A magnetar is a neutron star with a magnetic field hundreds of trillions of times more powerful than Earth’s. As the magnetar’s magnetic field decays over time, it spurs emissions of x-rays and gamma-rays, the most energetic radiation in the universe.

Nobody’s actually SEEN a magnetar so much as we’ve seen the emissions they give off. From those emissions we can figure out the strength and extent of the magnetic field that powers them. The XMM-Newton satellite, which is run by the European Space Agency, has detected powerful explosions emanating from just beneath the surface of the magnetar (shown in the artist’s conception up top). For several years astronomers followed the explosive history of one magnetar, called XTE J1810-197, and recorded changes in the energetic x-rays being emitted by this object. The astronomers made some computer models and have figured out that the outbursts are coming from a tiny island of magnetic activity just below the surface of the star. This island’s own magnetic field is six hundred million million times that of Earth’s. With all due respect to our fictional Empress Magnetar, this little magnetic spot in a distant neutron star is ‘way more powerful than the mightiest ruler (real or fictional). You can read more details about the magnetar at ESA.