Astronomy

SOFIA and Pluto occultation

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) just completed a very cool assignment: watch how the light from a distant star is blocked by Pluto. As you might imagine, getting directly into Pluto’s star-shadow here on Earth is a pretty tricky task, especially since the Earth is moving pretty rapidly with respect to Pluto, and spinning on its axis to boot. But SOFIA is mounted in a 747, and can move to whatever location is necessary to do the job. SOFIA in flight. The opening in the back of the 747 is where the telescope is located. Because SOFIA can measure light very accurately, seeing how the star dims and brightens as it disappears and reappears behind Pluto tells scientists about its atmosphere. These results will provide data that supplements our scant knowledge of Pluto, the only solar system planet not yet visited by any of our robots (well, I…

Astronomy

Northern Lights

It’s been quite a while, but growing up in New Hampshire, I had the good fortune to watch the northern lights play across the sky a few times. One of the most memorable was an evening spent with friends above the tree-line in the Presidential Range of the White Mountains. Below us the clouds formed a blanket around the foothills of the peaks, lit dimly by a crescent moon, while above us the lights shimmered and flickered for hours. It was quite an experience. The science associated with the northern lights is pretty interesting as well: charged particles from the sun spiraling down the earth’s magnetic field lines where they interact with the upper atmosphere to create the show. There are a number of references to it across the web, of course, and NASA offers some good background. Check out the Themis satellite space weather link. If you’ve never been…

Analytics

Worlds like our own

It’s incredible that in our lifetime we will know how many earth-like planets there are in the galaxy. The NASA Kepler mission has been staring at one patch of sky for more than a year now, looking for winking stars. These are the kind that dim ever-so-slightly when a planet passes between them and us. Finding Jupiters is relatively easy; finding Earths … not so much. But Kepler has shown that it is up to the task. A few weeks ago, the first results were published, and it turns out that out of about 150,000 stars, 54 of them have planets in the habitable zone – the distance from the star that might support liquid water on the surface. Is that incredible, or what? — 54! — It may not sound like much, but for all the centuries of people looking up into the sky and wondering if there were…